Updated docs.

.gitignore

@@ -3,3 +3,6 @@ __pycache__/
 *.pyc
 /dist/
 
+
+/wormhole/bin/
+/battery-status/bin/

CONTRIBUTING.md

@@ -9,7 +9,7 @@ directly from a Tentacle.
 
 Before publishing catalog entries, validate metadata and source, review grants,
 and test the actual command through the host. Run `make check` for this repository.
-For reader changes, also run relevant existing Cthulhu-Go tests. Xorg regressions
+For reader changes, also run relevant existing Cthulhu tests. Xorg regressions
 block a contribution. Verify keyboard bindings, learn mode, remapping, ordinary
 reading, speech interruption, speech modes, lock/handoff and connected Braille
 where affected. Automated results alone cannot prove accessibility acceptance.

Makefile

@@ -1,13 +1,16 @@
-GOCACHE ?= /tmp/cthulhu-go-cache
+GOCACHE ?= /tmp/cthulhu-cache
 export GOCACHE
 
 .PHONY: build check package
 
 build:
 	go build -buildvcs=false -mod=readonly -o hello-world/bin/hello-world ./hello-world/src
+	go build -buildvcs=false -mod=readonly -o wormhole/bin/wormhole-tentacle ./wormhole/src
+	go build -buildvcs=false -mod=readonly -o battery-status/bin/battery-status ./battery-status/src
 
 check: build
 	go vet ./...
+	go test ./...
 	python3 -B tools/check.py
 
 package:

README.md

@@ -1,20 +1,38 @@
 # Cthulhu Tentacles
 
-A repository of experimental Tentacles for Cthulhu-Go, maintained by Storm
-Dragon. It currently contains one Tentacle: [Hello World](hello-world/README.md).
-Repository material and Hello World are licensed under GPL-3.0-or-later; see
+A repository of experimental Tentacles for Cthulhu, maintained by Storm
+Dragon. It contains [Hello World](hello-world/README.md), the development
+[Wormhole tentacle](wormhole/README.md), and
+[Battery Status](battery-status/README.md).
+Repository material and these Tentacles are licensed under GPL-3.0-or-later; see
 [LICENSE](LICENSE) and [CONTRIBUTING.md](CONTRIBUTING.md).
 
 `repository.toml` identifies this source. `catalog.toml` explicitly lists its
 Tentacles, each in a direct top-level folder with its own `tentacle.toml`.
-The catalog lists verified native packages for Linux amd64 and arm64. Prepared
-release artifacts live in `dist/`; they become downloadable only after publication.
+The catalog lists native packages for Linux amd64 and arm64. Hello World 0.1.0 is
+available from the [release page](https://git.stormux.org/storm/cthulhu-tentacles/releases/tag/hello-world-v0.1.0).
+Wormhole 0.1.2 requires the matching reader with interactive Tentacle settings support.
+Native packages are available from the
+[Wormhole release page](https://git.stormux.org/storm/cthulhu-tentacles/releases/tag/wormhole-v0.1.2).
+Battery Status 0.1.0 packages are available from the
+[Battery Status release page](https://git.stormux.org/storm/cthulhu-tentacles/releases/tag/battery-status-v0.1.0).
+It uses Cthulhu+Shift+B and requires the UPower system service.
+Local build artifacts live in the ignored `dist/` directory.
 The discovery source URL is
 `https://git.stormux.org/storm/cthulhu-tentacles`.
 
+Tentacles are independent of the Git hosting service. Discovery reads TOML files
+from an HTTPS Git repository; installation downloads the HTTPS URLs explicitly
+listed in its catalog. Packages can live in pretty much any git provider,
+on an HTTPS web server, or in object storage with stable public HTTPS
+links. The reader does not call a hosting service's release API. Keeping packages
+in separate downloads avoids putting binaries into Git history.
+
+To write your own, follow the [creation and release tutorial](#create-and-release-your-own-tentacle).
+
 ## Build and check
 
-Keep the matching experimental `cthulhu-go` checkout beside this directory.
+Keep the matching experimental `cthulhu` checkout beside this directory.
 The `go.mod` local replacement uses its Go SDK, including the new
 uninterruptible presentation option. Building requires Go 1.24 or newer;
 checks also require Python 3.11 or newer and Make.
@@ -24,24 +42,32 @@ make build
 make check
 ```
 
-The executable is `hello-world/bin/hello-world`, which is ignored by Git.
+The executables are `hello-world/bin/hello-world`,
+`wormhole/bin/wormhole-tentacle`, and `battery-status/bin/battery-status`;
+all are ignored by Git.
 Checks validate the TOML metadata, registration and suggested bindings, and
-invoke Hello World through the actual Cthulhu-Go host. They produce no speech
+invoke all three Tentacles through the actual Cthulhu host. They produce no speech
 or Braille and leave the running reader alone.
 
 ## Repository installation
 
 With the updated reader, open global Cthulhu Preferences → Tentacles → Add
 repository and enter the HTTPS Git URL above. Refresh an already added source.
-Select Hello World and press Space to review its source/version and requested
-speech/Braille access, then **Install and enable**. **Install** instead downloads
+Select Hello World or Wormhole and press Space to review its source/version and
+requested access, then **Install and enable**. Wormhole requests internal forms
+and focused-item/clipboard access as well as speech/Braille. **Install** instead downloads
 and saves the package disabled. The reader verifies the catalog's SHA-256 digest,
 package identity and native architecture before saving a launch entry. Catalogs
 without a published compatible release show a clear message and remain unchecked.
 No source builds or install scripts run during this workflow. Resource limits
 do not make untrusted same-user programs safe.
 
-After installation, refresh status until Active and use Cthulhu+Alt+Shift+H.
+Install and enable reports success after the Tentacle becomes Active. A failed
+start returns an error and leaves the installed package disabled. Enable it again
+to retry. Activation needs no administrator setup or particular init system;
+configured cgroup resource limits are optional.
+
+For Hello World, use Cthulhu+Alt+Shift+H after activation.
 Disable retains the package; re-enabling and reader startup use installed files
 without network access. Removing the source retains installed Tentacles. Removing
 a managed Tentacle stops it and deletes its package files after shutdown.
@@ -65,12 +91,12 @@ module metadata, trim paths and omit VCS stamping. To build one architecture:
 python3 -B tools/package.py --architecture amd64
 ```
 
-Validate the actual host-architecture package through Cthulhu-Go's installer
+Validate the actual host-architecture package through Cthulhu's installer
 and command host, without changing the running reader:
 
 ```sh
-cd ../cthulhu-go
-CTHULHU_TENTACLE_RELEASE_ROOT=../cthulhu-tentacles GOCACHE=/tmp/cthulhu-go-cache go test ./internal/tentacle -run '^TestBuiltHelloWorldPackageThroughHost$' -count=1 -v
+cd ../cthulhu
+CTHULHU_TENTACLE_RELEASE_ROOT=../cthulhu-tentacles GOCACHE=/tmp/cthulhu-cache go test ./internal/tentacle -run '^TestBuiltHelloWorldPackageThroughHost$' -count=1 -v
 ```
 
 Before publication, review both repositories' changes and contributing guides.
@@ -86,6 +112,346 @@ changed content; bump the version before preparing a later release.
 The package command creates local artifacts only. It does not create commits,
 releases, tags, uploads or pushes. Prepared catalog changes are not evidence that
 the corresponding release is already available. Live shortcut, speech, Braille,
-lock/handoff and interruption checks remain necessary after publication and an
-explicit reader restart. For source-only local testing, the development launch
-procedure remains in [Hello World](hello-world/README.md#local-launch).
+lock/handoff and interruption checks remain necessary after installation. An
+explicit restart is needed when changing the reader itself. For source-only local
+testing, the development launch procedure remains in
+[Hello World](hello-world/README.md#local-launch).
+
+## Create and release your own Tentacle
+
+This tutorial creates a native Go Tentacle named **Greeting**, then makes it
+installable from a repository. The SDK and package format are experimental;
+use a matching Cthulhu checkout. Currently the installer supports native Linux
+executables, protocol 1.0, command registration and optional presentation access.
+Python SDK development is separate from this native package workflow. Broader
+APIs and automatic package updates are still pending.
+
+### 1. Set up the source repository
+
+You need Go 1.24 or newer, Git, Python 3.11 or newer for this repository's checks,
+GNU tar and gzip. Keep your new repository beside `cthulhu`. From their parent
+directory:
+
+```sh
+mkdir -p greeting-tentacles/greeting/src
+cd greeting-tentacles
+git init -b main
+```
+
+Create these files:
+
+```text
+greeting-tentacles/
+  repository.toml
+  catalog.toml
+  go.mod
+  .gitignore
+  greeting/
+    tentacle.toml
+    README.md
+    LICENSE
+    src/main.go
+```
+
+Use this `go.mod`:
+
+```go
+module example.org/greeting-tentacles
+
+go 1.24.0
+
+require git.stormux.org/storm/cthulhu v0.0.0
+
+replace git.stormux.org/storm/cthulhu => ../cthulhu
+```
+
+The SDK import path names its source project; it does not constrain where you
+host your own repository or downloads. Record the tested reader/SDK revision in
+release notes, since this local replacement does not pin it. Add `/dist/` and
+`/greeting/bin/` to `.gitignore`.
+
+Give `greeting/README.md` a description, shortcut, requirements and test procedure.
+Put the full license text in `greeting/LICENSE`; choose terms you have permission
+to distribute. For an example derived from Hello World, preserve its notices and
+GPL-3.0-or-later license. Include source corresponding to your executable.
+
+Create `repository.toml`:
+
+```toml
+format-version = 1
+id = "example.greeting-tentacles"
+name = "Greeting Tentacles"
+description = "A small example Tentacle repository."
+```
+
+Create the initial `catalog.toml`:
+
+```toml
+format-version = 1
+
+[[tentacles]]
+id = "greeting"
+manifest = "greeting/tentacle.toml"
+```
+
+Manifests belong in direct top-level folders. Repository and Tentacle IDs start
+with a lowercase letter and contain only lowercase letters, digits, dots and
+hyphens, up to 128 characters. Keep IDs stable: the reader uses the source URL,
+repository ID and Tentacle ID to identify an installation. A catalog can list
+several Tentacles, each with its own manifest and releases. Entries without
+releases can be discovered, but cannot yet be installed.
+
+### 2. Describe the package and permissions
+
+Create `greeting/tentacle.toml`, replacing the example source URL with your own
+HTTPS Git URL before publication:
+
+```toml
+format-version = 1
+id = "greeting"
+name = "Greeting"
+description = "Speak and braille a short greeting."
+version = "0.1.0"
+authors = ["Contributor"]
+license = "GPL-3.0-or-later"
+source = "https://example.org/projects/greeting-tentacles.git"
+help = "README.md"
+runtime = "native"
+platforms = ["linux"]
+entry-point = ["bin/greeting"]
+apis = ["commands", "presentation"]
+capabilities = ["presentation"]
+
+[protocol]
+major = 1
+minor = 0
+```
+
+Paths refer to the archive's root, not the source repository's root. The entry
+point is an executable followed by optional literal arguments, not a shell
+command. Presentation access allows speech and Braille results through the
+reader. A command-only package uses `apis = ["commands"]` and
+`capabilities = []`, without requesting presentation in command registration.
+Other package API or capability combinations are currently unsupported.
+
+### 3. Implement a command
+
+Create `greeting/src/main.go`:
+
+```go
+package main
+
+import (
+    "context"
+    "encoding/json"
+    "os"
+
+    "git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+)
+
+func say_greeting(ctx context.Context, _ json.RawMessage) (any, error) {
+    if err := ctx.Err(); err != nil {
+        return nil, err
+    }
+    return tentacle.Presentation{
+        Speech: "Hello from Greeting!",
+        Braille: "Hello from Greeting!",
+    }, nil
+}
+
+func main() {
+    command := tentacle.Command{
+        ID: "greet", Title: "Greeting",
+        Description: "Speak and braille a greeting", Presentation: true,
+        Bindings: []tentacle.Binding{
+            {Layout: "desktop", Scope: "global", Key: "Cthulhu+Ctrl+Alt+F10"},
+            {Layout: "laptop", Scope: "global", Key: "Cthulhu+Ctrl+Alt+F10"},
+        },
+        Handle: say_greeting,
+    }
+    if tentacle.Serve(os.Stdin, os.Stdout, []tentacle.Command{command}) != nil {
+        os.Exit(1)
+    }
+}
+```
+
+The SDK handles the JSON-RPC session and registration. Stdout belongs exclusively
+to that protocol; send limited diagnostics to stderr. Respect the supplied
+context when doing work, including network requests. The reader owns input,
+speech, Braille, user settings and lifecycle safeguards. Use its public SDK
+instead of reader internals or output backends. Core and user bindings take
+precedence over suggested shortcuts; users can remap Tentacle commands.
+
+Greeting uses ordinary interruptible presentation. Hello World demonstrates
+`Uninterruptible: true`; use that deliberately, rather than for every message.
+See its [output behavior](hello-world/README.md) for cancellation, the 30-second
+protection bound and speech backend limitations.
+
+### 4. Build and test before packaging
+
+From `greeting-tentacles`:
+
+```sh
+gofmt -w greeting/src/main.go
+mkdir -p greeting/bin
+CGO_ENABLED=0 GOCACHE=/tmp/cthulhu-cache go build -buildvcs=false -mod=readonly -trimpath -o greeting/bin/greeting ./greeting/src
+GOCACHE=/tmp/cthulhu-cache go test ./...
+```
+
+Invoke the compiled command through the development host. From `cthulhu`:
+
+```sh
+GOCACHE=/tmp/cthulhu-cache go run ./cmd/tentacle-host -presentation -command greet "$PWD/../greeting-tentacles/greeting/bin/greeting"
+```
+
+Expect JSON containing `speech` and `braille`, both `Hello from Greeting!`.
+This runs the executable through the actual command host, but produces no speech
+or Braille. The harness's default mode has no resource containment; use it only
+with development code you trust. Protocol tests do not establish live behavior.
+
+For a live test, follow [Hello World's development launch procedure](hello-world/README.md#local-launch),
+substituting your absolute executable path and launch ID `greeting`, with
+`Presentation: true` in the launch JSON. `--replace --tentacles` replaces the
+current Go reader and selects the development list instead of the saved registry;
+run it explicitly when ready. Rebuild the reader first if its implementation
+changed. Production activation uses init-independent process supervision and
+needs no administrator setup. Kernel resource limits are optional: configure a
+delegated cgroup v2 parent with `--tentacle-cgroup-parent` or
+`CTHULHU_TENTACLE_CGROUP_PARENT`. An invalid explicit parent fails startup.
+
+Test the shortcut, learn mode, remapping, ordinary reading and web navigation on
+Xorg. Verify speech modes, interruption, screen lock, terminal handoff, disable
+and connected Braille where affected. See [CONTRIBUTING.md](CONTRIBUTING.md) for
+review and regression requirements; contributors remain responsible for reviewing
+and testing AI-assisted changes.
+
+### 5. Create architecture-specific archives
+
+The `make build`, `make check` and `tools/package.py` commands in **this**
+repository build/check Hello World, Wormhole, and Battery Status. `tools/package.py --tentacle wormhole`
+packages Wormhole; `--tentacle battery-status` packages Battery Status.
+The default still packages Hello World. The checker pins the
+current versions and expected Tentacles. Adapt those tools and checks when
+extending this repository, or use
+this standalone procedure for Greeting.
+
+From `greeting-tentacles`, stage the root manifest, documentation and license:
+
+```sh
+mkdir -p dist/greeting-package/bin
+cp greeting/tentacle.toml greeting/README.md greeting/LICENSE dist/greeting-package/
+```
+
+Run the following in Bash for version `0.1.0`. Change the version together with
+the manifest on later releases. `set -euo pipefail` stops on build/archive failures.
+
+```bash
+set -euo pipefail
+version=0.1.0
+for architecture in amd64 arm64; do
+    CGO_ENABLED=0 GOOS=linux GOARCH="$architecture" GOCACHE=/tmp/cthulhu-cache \
+        go build -buildvcs=false -mod=readonly -trimpath -ldflags='-s -w' \
+        -o dist/greeting-package/bin/greeting ./greeting/src
+    tar --sort=name --mtime=@0 --owner=0 --group=0 --numeric-owner \
+        -C dist/greeting-package -cf - tentacle.toml README.md LICENSE bin \
+        | gzip -n > "dist/greeting-$version-linux-$architecture.tar.gz"
+done
+sha256sum "dist/greeting-$version-linux-amd64.tar.gz" \
+    "dist/greeting-$version-linux-arm64.tar.gz" \
+    | sed 's@  dist/@  @' > dist/SHA256SUMS
+```
+
+Each archive must have this layout, without an enclosing `greeting/` folder:
+
+```text
+tentacle.toml
+README.md
+LICENSE
+bin/greeting
+```
+
+The executable must be a regular, executable Linux ELF file for the advertised
+architecture. Static Go builds avoid undeclared shared-library dependencies.
+The reader rejects unsafe paths, symbolic/hard links and special files. Current
+limits are 32 MiB per compressed download, 64 MiB expanded file data and 1,024
+archive entries. Installation runs no install scripts or source builds. Package
+ID, name, version and capabilities must match the repository manifest.
+
+Inspect each archive with `tar -tzf`; from `dist`, run `sha256sum -c SHA256SUMS`.
+Run each extracted executable through the host on its matching architecture;
+a cross-build alone is not an execution test. The staging executable above ends
+with the last architecture built, so use the appropriate extracted archive for
+your local test. Keep the exact archives for publication. Normalized tar/gzip
+metadata supports repeatable packaging; compare hashes when rebuilding with the
+same source and toolchain.
+
+### 6. Publish downloads, then advertise them
+
+Review the source diff and tests before committing. Push reviewed source to your
+chosen Git host. For later versions, use a release branch while preparing assets
+so the default branch's existing manifest and catalog remain consistent. Create
+a release/tag such as `greeting-v0.1.0` targeting that source commit. If using a
+separate download server, record that source revision alongside the files.
+Upload both `.tar.gz` files and `SHA256SUMS`, and make the release public when the
+assets are ready. Keep `dist/` and executables out of Git.
+
+Use stable direct HTTPS download URLs. Release attachments are convenient but
+optional; an ordinary HTTPS file server works too. URLs cannot embed credentials
+or fragments, and redirects must remain HTTPS. The reader has no authenticated
+private-download workflow; expiring signed URLs are unsuitable for a durable
+catalog.
+
+Download the published files again and check `sha256sum -c SHA256SUMS` against
+those downloads. Check the archive manifest and executable. Only then append
+these tables after Greeting's entry in `catalog.toml`:
+
+```toml
+[[tentacles.releases]]
+platform = "linux"
+architecture = "amd64"
+url = "https://downloads.example.org/greeting/0.1.0/greeting-0.1.0-linux-amd64.tar.gz"
+sha256 = "REPLACE_WITH_THE_AMD64_ARCHIVE_SHA256"
+
+[[tentacles.releases]]
+platform = "linux"
+architecture = "arm64"
+url = "https://downloads.example.org/greeting/0.1.0/greeting-0.1.0-linux-arm64.tar.gz"
+sha256 = "REPLACE_WITH_THE_ARM64_ARCHIVE_SHA256"
+```
+
+Replace the URLs and placeholders with published URLs and their actual
+64-character lowercase hexadecimal hashes. These tables belong to the preceding
+`[[tentacles]]`; each platform/architecture pair may appear once. Keep the
+manifest version equal to the version inside the packages. Include only
+architectures you actually publish. For several Tentacles, preserve the existing
+entries: this repository's generated `dist/catalog.toml` preserves catalog entries and prepares
+release metadata for the selected Tentacles. Review it before publication.
+
+Review and push the matching catalog and manifest together to the repository's
+default branch, which discovery fetches. Never replace a release file with changed
+content: increase the version, create new archives and URLs, then publish a new
+catalog revision. Refresh updates available metadata, not installed packages.
+To test a newer version with the current reader, remove that managed Tentacle
+and install it again after refreshing the source.
+
+### 7. Verify the published installation
+
+Open global Preferences → Tentacles → Add repository in the matching reader and
+enter your HTTPS Git URL, or refresh an existing source. Select Greeting and
+press Space. Check source, version and presentation access in the first-use
+dialog, then choose **Install and enable**. Confirm status becomes Active and
+test Cthulhu+Ctrl+Alt+F10 and the live checks from step 4.
+
+Also check **Install** without enabling, enable/disable, offline reader restart
+and removal. Disabled packages retain their files; installed packages launch
+offline. Removing a source retains installed packages; removing a managed
+Tentacle stops it and deletes its package files. Keep ordinary reader commands,
+keyboard navigation and speech/Braille preferences working.
+
+For no compatible release, check architecture and refresh the source. For
+download/checksum errors, verify the exact public URL and digest. For package
+metadata errors, compare the archive manifest with the repository manifest. For
+activation failures, check the reader log for protocol, executable or cgroup
+errors. Resource limits constrain consumption; they do not sandbox access to
+account files or network. Install publishers you trust and state any remaining
+unverified live behavior in release notes.

battery-status/LICENSE

@@ -0,0 +1,232 @@
+GNU GENERAL PUBLIC LICENSE
+Version 3, 29 June 2007
+
+Copyright © 2007 Free Software Foundation, Inc. <https://fsf.org/>
+
+Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
+
+Preamble
+
+The GNU General Public License is a free, copyleft license for software and other kinds of works.
+
+The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.
+
+When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.
+
+To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.
+
+For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
+
+Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.
+
+For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions.
+
+Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.
+
+Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.
+
+The precise terms and conditions for copying, distribution and modification follow.
+
+TERMS AND CONDITIONS
+
+0. Definitions.
+
+“This License” refers to version 3 of the GNU General Public License.
+
+“Copyright” also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.
+
+“The Program” refers to any copyrightable work licensed under this License. Each licensee is addressed as “you”. “Licensees” and “recipients” may be individuals or organizations.
+
+To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a “modified version” of the earlier work or a work “based on” the earlier work.
+
+A “covered work” means either the unmodified Program or a work based on the Program.
+
+To “propagate” a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well.
+
+To “convey” a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying.
+
+An interactive user interface displays “Appropriate Legal Notices” to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion.
+
+1. Source Code.
+The “source code” for a work means the preferred form of the work for making modifications to it. “Object code” means any non-source form of a work.
+
+A “Standard Interface” means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language.
+
+The “System Libraries” of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A “Major Component”, in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it.
+
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+
+7. Additional Terms.
+“Additional permissions” are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions.
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+Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms:
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+All other non-permissive additional terms are considered “further restrictions” within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying.
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+
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+
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+9. Acceptance Not Required for Having Copies.
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+
+10. Automatic Licensing of Downstream Recipients.
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+
+11. Patents.
+A “contributor” is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's “contributor version”.
+
+A contributor's “essential patent claims” are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, “control” includes the right to grant patent sublicenses in a manner consistent with the requirements of this License.
+
+Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.
+
+In the following three paragraphs, a “patent license” is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party.
+
+If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. “Knowingly relying” means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid.
+
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+
+A patent license is “discriminatory” if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007.
+
+Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.
+
+12. No Surrender of Others' Freedom.
+If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.
+
+13. Use with the GNU Affero General Public License.
+Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.
+
+14. Revised Versions of this License.
+The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.
+
+Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.
+
+If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program.
+
+Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.
+
+15. Disclaimer of Warranty.
+THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+16. Limitation of Liability.
+IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+
+17. Interpretation of Sections 15 and 16.
+If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.
+
+END OF TERMS AND CONDITIONS
+
+How to Apply These Terms to Your New Programs
+
+If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
+
+To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.
+
+     <one line to give the program's name and a brief idea of what it does.>
+     Copyright (C) <year>  <name of author>
+
+     This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
+     This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+     You should have received a copy of the GNU General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:
+
+     <program>  Copyright (C) <year>  <name of author>
+     This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+     This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.
+
+You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see <https://www.gnu.org/licenses/>.
+
+The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read <https://www.gnu.org/philosophy/why-not-lgpl.html>.

battery-status/README.md

@@ -0,0 +1,64 @@
+# Battery Status
+
+Press **Cthulhu+Shift+B** in either keyboard layout to report battery status.
+With one battery, hear and read a short message such as
+“Laptop battery, discharging, 90 percent.” With several batteries, an internal
+**Battery Menu** lists each device with its status and charge. Use Up and Down
+to browse; Enter and Escape both close without additional output. The shortcut
+is a suggestion and can be remapped in Cthulhu.
+
+Battery Status reads the UPower service over the system D-Bus. It does not run
+the `upower` command, require root, or change power settings. Install and enable
+your distribution's UPower service if it is missing. An unavailable service
+produces “Battery information unavailable.” A successful read with no batteries
+produces “No batteries detected.” If some devices cannot be read, readable
+results are accompanied by “Some battery information is unavailable.”
+
+The kernel, drivers, and hardware determine which laptop, controller, headset,
+mouse, UPS, and other batteries UPower can expose. Device model names may be
+generic. Unknown charge is reported explicitly; unknown charging state is
+omitted. Devices with only coarse levels use words such as “low” or “normal”
+rather than an artificial percentage. Precise percentages are rounded to whole
+numbers. System batteries appear first; duplicate names have numbered suffixes.
+UPower's combined DisplayDevice and AC adapters are excluded.
+
+Each invocation reads UPower's latest reported values, with a one-second read
+limit to fit Cthulhu's two-second command deadline. An open menu is a snapshot:
+close and invoke again to refresh. There are
+no background notifications, time estimates, hardware-statistics views, or
+sysfs fallbacks. UPower may itself cache values between device updates.
+See the [UPower device API](https://upower.freedesktop.org/docs/Device.html).
+
+## Build and verify
+
+From the repository root, run `make check`. Build release artifacts with
+`python3 -B tools/package.py --tentacle battery-status`. This prepares amd64 and
+arm64 packages and a proposed catalog under `dist/`; it publishes nothing.
+The source catalog intentionally advertises no release downloads yet.
+
+For an actual-host diagnostic without speech or changes to the running reader,
+run from the adjacent `cthulhu` checkout:
+
+```sh
+GOCACHE=/tmp/cthulhu-cache go run ./cmd/tentacle-host -presentation -interaction -command battery-status "$PWD/../cthulhu-tentacles/battery-status/bin/battery-status"
+```
+
+Use the development launch procedure in Hello World's README for live testing,
+with launch ID `battery-status`, the matching executable, and both Presentation
+and Interaction grants. Review and test before submission, as required by
+CONTRIBUTING.md. Verify:
+
+- The shortcut, learn-mode description, and remapping in both layouts.
+- A single battery speaks and brailles its status without a menu.
+- With another battery-bearing device connected, the Battery Menu opens,
+  Up/Down reads each row, and Enter and Escape dismiss it silently.
+- Reopening reflects updated devices and charge; no combined duplicate appears.
+- Speech preferences and interruption, connected Braille, screen lock/handoff,
+  disable/re-enable, and normal reading after closing the menu still work.
+
+Automated tests use injected device sources for absent/unavailable services,
+partial failures, and battery combinations, without altering the system service.
+Cross-building arm64 does not establish execution on arm64; test that package
+on matching hardware before publication.
+
+Licensed GPL-3.0-or-later; see LICENSE.

battery-status/src/battery.go

@@ -0,0 +1,126 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"fmt"
+	"math"
+	"sort"
+	"strings"
+	"unicode"
+
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+	"github.com/godbus/dbus/v5"
+)
+
+type battery struct {
+	id, name, state, charge string
+	system                  bool
+}
+
+// UPower device kinds, indexed by their public D-Bus enum values.
+var deviceNames = []string{
+	"Device", "AC adapter", "Battery", "UPS", "Monitor", "Mouse", "Keyboard",
+	"PDA", "Phone", "Media player", "Tablet", "Computer", "Game controller",
+	"Pen", "Touchpad", "Modem", "Network device", "Headset", "Speakers",
+	"Headphones", "Video device", "Audio device", "Remote control", "Printer",
+	"Scanner", "Camera", "Wearable", "Toy", "Bluetooth device",
+}
+
+func cleanName(name string) string {
+	name = strings.Map(func(r rune) rune {
+		if unicode.IsControl(r) {
+			return ' '
+		}
+		return r
+	}, strings.ToValidUTF8(name, ""))
+	name = strings.Join(strings.Fields(name), " ")
+	// Device-provided names must fit the host's form and output limits.
+	chars := []rune(name)
+	if len(chars) > 160 {
+		name = string(chars[:160])
+	}
+	return name
+}
+
+func decodeBattery(id string, properties map[string]dbus.Variant) (battery, bool) {
+	kind, _ := properties["Type"].Value().(uint32)
+	present, _ := properties["IsPresent"].Value().(bool)
+	if !present || kind == 1 || id == "/org/freedesktop/UPower/devices/DisplayDevice" {
+		return battery{}, false
+	}
+	powerSupply, _ := properties["PowerSupply"].Value().(bool)
+	model, _ := properties["Model"].Value().(string)
+	name := cleanName(model)
+	system := kind == 2 && powerSupply
+	if system {
+		name = "Laptop battery"
+	} else {
+		if name == "" {
+			name = "Device"
+			if int(kind) < len(deviceNames) {
+				name = deviceNames[kind]
+			}
+		}
+		if !strings.HasSuffix(strings.ToLower(name), "battery") {
+			name += " battery"
+		}
+	}
+	state, _ := properties["State"].Value().(uint32)
+	states := []string{"", "charging", "discharging", "empty", "fully charged", "pending charge", "pending discharge"}
+	stateText := ""
+	if int(state) < len(states) {
+		stateText = states[state]
+	}
+	charge := "charge unknown"
+	level, hasLevel := properties["BatteryLevel"].Value().(uint32)
+	if text, ok := map[uint32]string{3: "low", 4: "critical", 6: "normal", 7: "high", 8: "full"}[level]; ok {
+		charge = text
+	} else if !hasLevel || level == 1 {
+		percentage, ok := properties["Percentage"].Value().(float64)
+		if ok && !math.IsNaN(percentage) && !math.IsInf(percentage, 0) && percentage >= 0 && percentage <= 100 {
+			charge = fmt.Sprintf("%.0f percent", math.Round(percentage))
+		}
+	}
+	return battery{id: id, name: name, state: stateText, charge: charge, system: system}, true
+}
+
+func batteryItems(batteries []battery) []tentacle.ListItem {
+	// Own the slice so concurrent invocations cannot reorder shared source data.
+	batteries = append([]battery(nil), batteries...)
+	sort.Slice(batteries, func(i, j int) bool {
+		a, b := batteries[i], batteries[j]
+		if a.system != b.system {
+			return a.system
+		}
+		if strings.ToLower(a.name) != strings.ToLower(b.name) {
+			return strings.ToLower(a.name) < strings.ToLower(b.name)
+		}
+		return a.id < b.id
+	})
+	totals, counts := map[string]int{}, map[string]int{}
+	for _, b := range batteries {
+		totals[strings.ToLower(b.name)]++
+	}
+	items := make([]tentacle.ListItem, 0, len(batteries))
+	seen := map[string]bool{}
+	for _, b := range batteries {
+		if seen[b.id] {
+			continue
+		}
+		seen[b.id] = true
+		key := strings.ToLower(b.name)
+		counts[key]++
+		name := b.name
+		if totals[key] > 1 {
+			name += fmt.Sprintf(" %d", counts[key])
+		}
+		parts := []string{name}
+		if b.state != "" {
+			parts = append(parts, b.state)
+		}
+		parts = append(parts, b.charge)
+		items = append(items, tentacle.ListItem{ID: b.id, Label: strings.Join(parts, ", ")})
+	}
+	return items
+}

battery-status/src/battery_test.go

@@ -0,0 +1,243 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"math"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+	"github.com/godbus/dbus/v5"
+)
+
+func properties(kind uint32, model string) map[string]dbus.Variant {
+	return map[string]dbus.Variant{
+		"Type": dbus.MakeVariant(kind), "IsPresent": dbus.MakeVariant(true),
+		"PowerSupply": dbus.MakeVariant(kind == 2), "Model": dbus.MakeVariant(model),
+		"State": dbus.MakeVariant(uint32(2)), "BatteryLevel": dbus.MakeVariant(uint32(1)),
+		"Percentage": dbus.MakeVariant(float64(90)),
+	}
+}
+
+func TestChargeReporting(t *testing.T) {
+	for _, test := range []struct {
+		name       string
+		level      any
+		percentage any
+		want       string
+	}{
+		{"precise", uint32(1), 85.5, "86 percent"},
+		{"zero", uint32(1), float64(0), "0 percent"},
+		{"full", uint32(1), float64(100), "100 percent"},
+		{"older service", nil, float64(90), "90 percent"},
+		{"unknown level", uint32(0), float64(50), "charge unknown"},
+		{"low", uint32(3), float64(10), "low"},
+		{"critical", uint32(4), float64(5), "critical"},
+		{"normal", uint32(6), float64(55), "normal"},
+		{"high", uint32(7), float64(70), "high"},
+		{"coarse full", uint32(8), float64(100), "full"},
+		{"future level", uint32(99), float64(50), "charge unknown"},
+		{"missing", uint32(1), nil, "charge unknown"},
+		{"wrong type", uint32(1), "90", "charge unknown"},
+		{"negative", uint32(1), float64(-1), "charge unknown"},
+		{"over full", uint32(1), 100.1, "charge unknown"},
+		{"nan", uint32(1), math.NaN(), "charge unknown"},
+		{"infinity", uint32(1), math.Inf(1), "charge unknown"},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			p := properties(2, "Primary")
+			delete(p, "BatteryLevel")
+			delete(p, "Percentage")
+			if test.level != nil {
+				p["BatteryLevel"] = dbus.MakeVariant(test.level)
+			}
+			if test.percentage != nil {
+				p["Percentage"] = dbus.MakeVariant(test.percentage)
+			}
+			b, ok := decodeBattery("/battery", p)
+			if !ok || b.charge != test.want {
+				t.Fatalf("got %+v, included %v; want %s", b, ok, test.want)
+			}
+		})
+	}
+}
+
+func TestNamesStatesAndFiltering(t *testing.T) {
+	for _, test := range []struct {
+		kind        uint32
+		model, want string
+	}{
+		{2, "Primary", "Laptop battery"}, {12, "Playstation 4 controller", "Playstation 4 controller battery"},
+		{12, "", "Game controller battery"}, {3, "", "UPS battery"}, {17, "", "Headset battery"},
+		{99, "", "Device battery"}, {5, "Mouse Battery", "Mouse Battery"}, {6, " A\nB\x00 ", "A B battery"},
+	} {
+		b, ok := decodeBattery("/device", properties(test.kind, test.model))
+		if !ok || b.name != test.want {
+			t.Fatalf("got %+v; want %s", b, test.want)
+		}
+	}
+	for state, want := range []string{"", "charging", "discharging", "empty", "fully charged", "pending charge", "pending discharge", ""} {
+		p := properties(2, "")
+		p["State"] = dbus.MakeVariant(uint32(state))
+		b, _ := decodeBattery("/battery", p)
+		if b.state != want {
+			t.Fatalf("state %d: got %s, want %s", state, b.state, want)
+		}
+	}
+	p := properties(2, "")
+	p["PowerSupply"] = dbus.MakeVariant(false)
+	b, _ := decodeBattery("/battery", p)
+	if b.name != "Battery" || b.system {
+		t.Fatalf("peripheral classified as laptop: %+v", b)
+	}
+	p["IsPresent"] = dbus.MakeVariant(false)
+	if _, ok := decodeBattery("/battery", p); ok {
+		t.Fatal("absent battery included")
+	}
+	if _, ok := decodeBattery("/adapter", properties(1, "")); ok {
+		t.Fatal("AC adapter included")
+	}
+	if _, ok := decodeBattery("/org/freedesktop/UPower/devices/DisplayDevice", properties(2, "")); ok {
+		t.Fatal("synthetic device included")
+	}
+	if name := cleanName(strings.Repeat("猫", 200)); len([]rune(name)) != 160 {
+		t.Fatal("long name not bounded")
+	}
+}
+
+func TestOrderingAndDuplicateNames(t *testing.T) {
+	batteries := []battery{
+		{id: "/z", name: "Mouse battery", charge: "low"},
+		{id: "/bat1", name: "Laptop battery", system: true, charge: "90 percent"},
+		{id: "/a", name: "Mouse battery", charge: "normal"},
+		{id: "/bat0", name: "Laptop battery", system: true, charge: "80 percent"},
+	}
+	want := []tentacle.ListItem{
+		{ID: "/bat0", Label: "Laptop battery 1, 80 percent"},
+		{ID: "/bat1", Label: "Laptop battery 2, 90 percent"},
+		{ID: "/a", Label: "Mouse battery 1, normal"},
+		{ID: "/z", Label: "Mouse battery 2, low"},
+	}
+	if got := batteryItems(batteries); !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %+v", got)
+	}
+	if batteries[0].id != "/z" {
+		t.Fatal("modified source data")
+	}
+}
+
+type fakeDevices struct {
+	paths  []dbus.ObjectPath
+	values map[dbus.ObjectPath]map[string]dbus.Variant
+	err    error
+	reads  int
+}
+
+func (f *fakeDevices) devices(ctx context.Context) ([]dbus.ObjectPath, error) { return f.paths, f.err }
+func (f *fakeDevices) properties(ctx context.Context, p dbus.ObjectPath) (map[string]dbus.Variant, error) {
+	f.reads++
+	v, ok := f.values[p]
+	if !ok {
+		return nil, errors.New("disconnected")
+	}
+	return v, nil
+}
+
+func TestEnumeration(t *testing.T) {
+	f := &fakeDevices{paths: []dbus.ObjectPath{"/bat", "/bat", "/ac", "/absent", "/org/freedesktop/UPower/devices/DisplayDevice"}, values: map[dbus.ObjectPath]map[string]dbus.Variant{
+		"/bat": properties(2, ""), "/ac": properties(1, ""), "/absent": properties(2, ""),
+	}}
+	f.values["/absent"]["IsPresent"] = dbus.MakeVariant(false)
+	b, partial, err := readDevices(context.Background(), f)
+	if err != nil || partial || len(b) != 1 || f.reads != 3 {
+		t.Fatalf("got %+v, %v, %v; reads %d", b, partial, err, f.reads)
+	}
+	f.paths = append(f.paths, "/gone", "/malformed")
+	f.values["/malformed"] = map[string]dbus.Variant{}
+	b, partial, err = readDevices(context.Background(), f)
+	if err != nil || !partial || len(b) != 1 {
+		t.Fatalf("partial read: %+v, %v, %v", b, partial, err)
+	}
+	f.err = errors.New("service unavailable")
+	if _, _, err := readDevices(context.Background(), f); err == nil {
+		t.Fatal("lost service failure")
+	}
+	f.err = nil
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	f.reads = 0
+	_, partial, _ = readDevices(ctx, f)
+	if !partial || f.reads != 0 {
+		t.Fatal("read after cancellation")
+	}
+}
+
+func TestInvocationAndCompletion(t *testing.T) {
+	laptop, _ := decodeBattery("/bat", properties(2, ""))
+	controller, _ := decodeBattery("/controller", properties(12, "Playstation 4 controller"))
+	for _, test := range []struct {
+		name      string
+		batteries []battery
+		partial   bool
+		err       error
+		speech    string
+		menu      bool
+	}{
+		{name: "none", speech: "No batteries detected."},
+		{name: "single", batteries: []battery{laptop}, speech: "Laptop battery, discharging, 90 percent."},
+		{name: "multiple", batteries: []battery{controller, laptop}, menu: true},
+		{name: "service missing", err: errors.New("missing"), speech: "Battery information unavailable."},
+		{name: "all unreadable", partial: true, speech: "Battery information unavailable."},
+		{name: "partial single", batteries: []battery{laptop}, partial: true, speech: "Laptop battery, discharging, 90 percent. Some battery information is unavailable."},
+		{name: "partial menu", batteries: []battery{controller, laptop}, partial: true, menu: true, speech: "Some battery information is unavailable."},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			h := openBatteries(func(ctx context.Context) ([]battery, bool, error) {
+				deadline, ok := ctx.Deadline()
+				if !ok || time.Until(deadline) > readTimeout {
+					t.Fatal("missing read deadline")
+				}
+				return test.batteries, test.partial, test.err
+			})
+			value, err := h(context.Background(), nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			v := value.(tentacle.Interaction)
+			if v.Speech != test.speech || v.Braille != test.speech || (v.Form != nil) != test.menu {
+				t.Fatalf("got %+v", v)
+			}
+			if test.menu {
+				if v.Form.Title != "Battery Menu" || v.Next != "close-menu" || len(v.Form.Elements[0].Items) != 2 || v.Done {
+					t.Fatalf("bad menu: %+v", v)
+				}
+			} else if !v.Done {
+				t.Fatal("message did not complete")
+			}
+		})
+	}
+	for _, submission := range []string{`{"activated":"/bat"}`, `{"cancelled":true}`} {
+		value, err := closeMenu(context.Background(), json.RawMessage(submission))
+		if err != nil || value != (tentacle.Interaction{Done: true}) {
+			t.Fatalf("completion: %+v, %v", value, err)
+		}
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	called := false
+	h := openBatteries(func(context.Context) ([]battery, bool, error) { called = true; return nil, false, nil })
+	if _, err := h(ctx, nil); !errors.Is(err, context.Canceled) || called {
+		t.Fatal("ignored cancellation")
+	}
+	ctx, cancel = context.WithCancel(context.Background())
+	h = openBatteries(func(context.Context) ([]battery, bool, error) { cancel(); return []battery{laptop}, false, nil })
+	if _, err := h(ctx, nil); !errors.Is(err, context.Canceled) {
+		t.Fatal("presented after cancellation")
+	}
+}

battery-status/src/host_test.go

@@ -0,0 +1,111 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+)
+
+// Only the test executable accepts fixture arguments; production has no test mode.
+func TestBatteryHostChild(t *testing.T) {
+	if len(os.Args) < 3 || os.Args[len(os.Args)-2] != "battery-host-child" {
+		return
+	}
+	fixture := os.Args[len(os.Args)-1]
+	source := func(ctx context.Context) ([]battery, bool, error) {
+		laptop, _ := decodeBattery("/bat", properties(2, ""))
+		controller, _ := decodeBattery("/controller", properties(12, "Playstation 4 controller"))
+		switch fixture {
+		case "none":
+			return nil, false, nil
+		case "single":
+			return []battery{laptop}, false, nil
+		case "multiple":
+			return []battery{controller, laptop}, false, nil
+		case "partial":
+			return []battery{controller, laptop}, true, nil
+		case "slow":
+			<-ctx.Done()
+			return nil, false, ctx.Err()
+		default:
+			return nil, false, errors.New("UPower unavailable")
+		}
+	}
+	if tentacle.Serve(os.Stdin, os.Stdout, commands(source)) != nil {
+		os.Exit(1)
+	}
+	os.Exit(0)
+}
+
+func TestBatteryThroughActualHost(t *testing.T) {
+	reader, err := filepath.Abs("../../../cthulhu")
+	if err != nil {
+		t.Fatal(err)
+	}
+	host := filepath.Join(t.TempDir(), "tentacle-host")
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	build := exec.CommandContext(ctx, "go", "build", "-buildvcs=false", "-mod=readonly", "-o", host, "./cmd/tentacle-host")
+	build.Dir = reader
+	if output, err := build.CombinedOutput(); err != nil {
+		t.Fatalf("build actual host: %v\n%s", err, output)
+	}
+	child, err := os.Executable()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, fixture := range []string{"none", "single", "multiple", "partial", "missing", "slow", "close"} {
+		t.Run(fixture, func(t *testing.T) {
+			command := "battery-status"
+			if fixture == "close" {
+				command = "close-menu"
+			}
+			invoke := exec.CommandContext(ctx, host, "-presentation", "-interaction", "-command", command,
+				child, "-test.run=^TestBatteryHostChild$", "--", "battery-host-child", fixture)
+			output, err := invoke.CombinedOutput()
+			if err != nil {
+				t.Fatalf("actual host: %v\n%s", err, output)
+			}
+			var value tentacle.Interaction
+			if err := json.Unmarshal(output, &value); err != nil {
+				t.Fatalf("invalid output: %v\n%s", err, output)
+			}
+			switch fixture {
+			case "multiple", "partial":
+				if value.Form == nil || value.Form.Title != "Battery Menu" || value.Next != "close-menu" {
+					t.Fatalf("unexpected menu: %+v", value)
+				}
+				items := value.Form.Elements[0].Items
+				if len(items) != 2 || items[0].Label != "Laptop battery, discharging, 90 percent" || items[1].Label != "Playstation 4 controller battery, discharging, 90 percent" {
+					t.Fatalf("unexpected items: %+v", items)
+				}
+				if fixture == "partial" && value.Speech != "Some battery information is unavailable." {
+					t.Fatal("missing partial warning")
+				}
+			case "close":
+				if value != (tentacle.Interaction{Done: true}) {
+					t.Fatalf("completion was not silent: %+v", value)
+				}
+			default:
+				want := "Battery information unavailable."
+				if fixture == "none" {
+					want = "No batteries detected."
+				} else if fixture == "single" {
+					want = "Laptop battery, discharging, 90 percent."
+				}
+				if value.Form != nil || !value.Done || value.Speech != want || value.Braille != want {
+					t.Fatalf("unexpected announcement: %+v", value)
+				}
+			}
+		})
+	}
+}

battery-status/src/main.go

@@ -0,0 +1,86 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"time"
+
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+)
+
+type batterySource func(context.Context) ([]battery, bool, error)
+
+// Leave room for presentation within the host's two-second RPC deadline.
+const readTimeout = time.Second
+
+func message(text string) tentacle.Interaction {
+	return tentacle.Interaction{Presentation: tentacle.Presentation{Speech: text, Braille: text}, Done: true}
+}
+
+func openBatteries(source batterySource) tentacle.Handler {
+	return func(ctx context.Context, _ json.RawMessage) (any, error) {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		readCtx, cancel := context.WithTimeout(ctx, readTimeout)
+		defer cancel()
+		batteries, partial, err := source(readCtx)
+		if ctx.Err() != nil {
+			return nil, ctx.Err()
+		}
+		if err != nil || len(batteries) == 0 && partial {
+			return message("Battery information unavailable."), nil
+		}
+		if len(batteries) == 0 {
+			return message("No batteries detected."), nil
+		}
+		items := batteryItems(batteries)
+		warning := ""
+		if partial {
+			warning = "Some battery information is unavailable."
+		}
+		if len(items) == 1 {
+			text := items[0].Label + "."
+			if warning != "" {
+				text += " " + warning
+			}
+			return message(text), nil
+		}
+		return tentacle.Interaction{
+			Presentation: tentacle.Presentation{Speech: warning, Braille: warning},
+			Form: &tentacle.Form{Title: "Battery Menu", Elements: []tentacle.Element{
+				{ID: "batteries", Label: "Batteries", Kind: tentacle.List, Items: items},
+			}}, Next: "close-menu",
+		}, nil
+	}
+}
+
+func closeMenu(ctx context.Context, _ json.RawMessage) (any, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	// Both activation and cancellation complete without additional output.
+	return tentacle.Interaction{Done: true}, nil
+}
+
+func commands(source batterySource) []tentacle.Command {
+	return []tentacle.Command{
+		{ID: "battery-status", Title: "Battery Status", Description: "Report battery status or browse multiple batteries",
+			Presentation: true, Interaction: true, Handle: openBatteries(source),
+			Bindings: []tentacle.Binding{
+				{Layout: "desktop", Scope: "global", Key: "Cthulhu+Shift+B"},
+				{Layout: "laptop", Scope: "global", Key: "Cthulhu+Shift+B"},
+			}},
+		{ID: "close-menu", Title: "Close Battery Menu", Description: "Close the battery menu",
+			Presentation: true, Interaction: true, Handle: closeMenu},
+	}
+}
+
+func main() {
+	if tentacle.Serve(os.Stdin, os.Stdout, commands(readUPower)) != nil {
+		os.Exit(1)
+	}
+}

battery-status/src/upower.go

@@ -0,0 +1,74 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"context"
+
+	"github.com/godbus/dbus/v5"
+)
+
+const upower = "org.freedesktop.UPower"
+
+type deviceSource interface {
+	devices(context.Context) ([]dbus.ObjectPath, error)
+	properties(context.Context, dbus.ObjectPath) (map[string]dbus.Variant, error)
+}
+
+type upowerSource struct{ conn *dbus.Conn }
+
+func (s upowerSource) devices(ctx context.Context) ([]dbus.ObjectPath, error) {
+	var paths []dbus.ObjectPath
+	err := s.conn.Object(upower, "/org/freedesktop/UPower").CallWithContext(ctx, upower+".EnumerateDevices", 0).Store(&paths)
+	return paths, err
+}
+
+func (s upowerSource) properties(ctx context.Context, path dbus.ObjectPath) (map[string]dbus.Variant, error) {
+	var properties map[string]dbus.Variant
+	err := s.conn.Object(upower, path).CallWithContext(ctx, "org.freedesktop.DBus.Properties.GetAll", 0, upower+".Device").Store(&properties)
+	return properties, err
+}
+
+func readDevices(ctx context.Context, source deviceSource) ([]battery, bool, error) {
+	paths, err := source.devices(ctx)
+	if err != nil {
+		return nil, false, err
+	}
+	var batteries []battery
+	partial := false
+	seen := map[dbus.ObjectPath]bool{}
+	for _, path := range paths {
+		if err := ctx.Err(); err != nil {
+			return batteries, true, nil
+		}
+		if seen[path] || path == "/org/freedesktop/UPower/devices/DisplayDevice" {
+			continue
+		}
+		seen[path] = true
+		properties, err := source.properties(ctx, path)
+		if err != nil {
+			partial = true
+			continue
+		}
+		// These properties are needed to classify a device reliably.
+		_, kindOK := properties["Type"].Value().(uint32)
+		_, presentOK := properties["IsPresent"].Value().(bool)
+		if !kindOK || !presentOK {
+			partial = true
+			continue
+		}
+		if b, ok := decodeBattery(string(path), properties); ok {
+			batteries = append(batteries, b)
+		}
+	}
+	return batteries, partial, nil
+}
+
+func readUPower(ctx context.Context) ([]battery, bool, error) {
+	conn, err := dbus.ConnectSystemBus(dbus.WithContext(ctx))
+	if err != nil {
+		return nil, false, err
+	}
+	defer conn.Close()
+	return readDevices(ctx, upowerSource{conn})
+}

battery-status/tentacle.toml

@@ -0,0 +1,23 @@
+format-version = 1
+id = "battery-status"
+name = "Battery Status"
+description = "Report battery status or browse multiple batteries in an internal menu."
+version = "0.1.0"
+authors = ["Storm Dragon"]
+license = "GPL-3.0-or-later"
+source = "https://git.stormux.org/storm/cthulhu-tentacles"
+help = "README.md"
+runtime = "native"
+platforms = ["linux"]
+entry-point = ["bin/battery-status"]
+apis = ["commands", "presentation", "interaction"]
+capabilities = ["presentation", "interaction"]
+
+[protocol]
+major = 1
+minor = 0
+
+[requirements]
+reader = "Cthulhu with interactive Tentacle support"
+runtime = "UPower service on the system D-Bus; no upower CLI required"
+build = "Go 1.24 or newer and the adjacent cthulhu source checkout"

catalog.toml

@@ -15,3 +15,35 @@ platform = "linux"
 architecture = "arm64"
 url = "https://git.stormux.org/storm/cthulhu-tentacles/releases/download/hello-world-v0.1.0/hello-world-0.1.0-linux-arm64.tar.gz"
 sha256 = "9ef956a04fb1fa98ac01b04fadc122f92b77d708440e0438a7451da62078a9d4"
+
+[[tentacles]]
+id = "wormhole"
+manifest = "wormhole/tentacle.toml"
+
+[[tentacles.releases]]
+platform = "linux"
+architecture = "amd64"
+url = "https://git.stormux.org/storm/cthulhu-tentacles/releases/download/wormhole-v0.1.2/wormhole-0.1.2-linux-amd64.tar.gz"
+sha256 = "537480f85effde8097afd2201dbd815c4093abc05da80feace5577bd777b2ed9"
+
+[[tentacles.releases]]
+platform = "linux"
+architecture = "arm64"
+url = "https://git.stormux.org/storm/cthulhu-tentacles/releases/download/wormhole-v0.1.2/wormhole-0.1.2-linux-arm64.tar.gz"
+sha256 = "0c6254bd96dc9921884e81a58db3385cf0433073129e8ce64d86407992ce4134"
+
+[[tentacles]]
+id = "battery-status"
+manifest = "battery-status/tentacle.toml"
+
+[[tentacles.releases]]
+platform = "linux"
+architecture = "amd64"
+url = "https://git.stormux.org/storm/cthulhu-tentacles/releases/download/battery-status-v0.1.0/battery-status-0.1.0-linux-amd64.tar.gz"
+sha256 = "53939e7674c1f8ba4193a71a69c3e917b51439fa29884bebb7c622bdcef2c3d9"
+
+[[tentacles.releases]]
+platform = "linux"
+architecture = "arm64"
+url = "https://git.stormux.org/storm/cthulhu-tentacles/releases/download/battery-status-v0.1.0/battery-status-0.1.0-linux-arm64.tar.gz"
+sha256 = "d75e40fd76280ecba228f3d3132d846f4e8f79a3e2bdd6dafd515c39a191cca0"

go.mod

@@ -2,8 +2,10 @@ module git.stormux.org/storm/cthulhu-tentacles
 
 go 1.24.0
 
-require git.stormux.org/storm/cthulhu-go v0.0.0
+require git.stormux.org/storm/cthulhu v0.0.0
+
+require github.com/godbus/dbus/v5 v5.1.0
 
 // The experimental SDK is developed alongside this repository.
-replace git.stormux.org/storm/cthulhu-go => ../cthulhu-go
+replace git.stormux.org/storm/cthulhu => ../cthulhu
 

go.sum

@@ -0,0 +1,2 @@
+github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
+github.com/godbus/dbus/v5 v5.1.0/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=

hello-world/README.md

@@ -30,12 +30,12 @@ status until Active before trying the shortcut.
 
 ## Local launch
 
-Run `make build` from the repository root. Rebuild Cthulhu-Go with the matching
+Run `make build` from the repository root. Rebuild Cthulhu with the matching
 SDK/output implementation before a live test:
 
 ```sh
-cd ../cthulhu-go
-GOCACHE=/tmp/cthulhu-go-cache go build -o /tmp/cthulhu-with-hello-world ./cmd/cthulhu
+cd ../cthulhu
+GOCACHE=/tmp/cthulhu-cache go build -o /tmp/cthulhu-with-hello-world ./cmd/cthulhu
 ```
 
 Create a development launch list with an absolute executable path. From this
@@ -60,9 +60,10 @@ When ready to test, launch the rebuilt reader explicitly:
 ```
 
 That command replaces the running Go reader and selects the development launch
-list instead of saved Tentacles. The reader automatically requests systemd user
-cgroup delegation. A delegation failure leaves the Tentacle unavailable.
-Resource limits do not make untrusted same-user programs safe.
+list instead of saved Tentacles. The reader supervises each Tentacle directly;
+no administrator setup or particular init system is required. Kernel CPU, memory
+and task limits are optional and require an explicitly configured delegated
+cgroup v2 parent. Tentacles run with your account's access; install trusted code.
 
 ## Live verification
 

hello-world/src/main.go

@@ -8,7 +8,7 @@ import (
 	"encoding/json"
 	"os"
 
-	"git.stormux.org/storm/cthulhu-go/sdk/go/tentacle"
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
 )
 
 func say_hello(ctx context.Context, _ json.RawMessage) (any, error) {

hello-world/tentacle.toml

@@ -18,6 +18,6 @@ major = 1
 minor = 0
 
 [requirements]
-reader = "Cthulhu-Go with uninterruptible presentation support"
-build = "Go 1.24 or newer and the adjacent cthulhu-go source checkout"
+reader = "Cthulhu with uninterruptible presentation support"
+build = "Go 1.24 or newer and the adjacent cthulhu source checkout"
 

tools/check.py

@@ -29,45 +29,50 @@ def check_metadata(repoRoot):
             "Unsupported metadata format")
     require(repository["id"] == "storm.cthulhu-tentacles" and repository["name"],
             "Repository identity is missing")
-    require(len(catalog["tentacles"]) == 1 and catalog["tentacles"][0]["id"] == "hello-world"
-            and catalog["tentacles"][0]["manifest"] == "hello-world/tentacle.toml",
-            "Catalog must list exactly Hello World")
-    manifest = read_toml(repoRoot / catalog["tentacles"][0]["manifest"])
-    require(manifest["format-version"] == 1 and manifest["id"] == "hello-world"
-            and manifest["name"] and manifest["version"] == "0.1.0",
-            "Invalid Hello World metadata")
-    require(manifest["entry-point"] == ["bin/hello-world"]
-            and manifest["capabilities"] == ["presentation"], "Unexpected launch or grants")
-    require((repoRoot / "LICENSE").is_file() and (repoRoot / "hello-world/LICENSE").is_file(),
-            "Repository and Tentacle licenses are required")
-
-    seen = set()
-    for release in catalog["tentacles"][0].get("releases", []):
-        key = (release["platform"], release["architecture"])
-        require(key not in seen and key[0] == "linux" and key[1] in ("amd64", "arm64"),
-                "Invalid or duplicate release target")
-        seen.add(key)
-        parsed = urlparse(release["url"])
-        require(parsed.scheme == "https" and parsed.hostname and not parsed.username
-                and not parsed.fragment, "Release URL must be HTTPS without credentials")
-        digest = release["sha256"]
-        require(len(digest) == 64 and all(character in "0123456789abcdef" for character in digest),
-                "Invalid SHA-256 digest")
-        artifactPath = repoRoot / "dist" / parsed.path.rsplit("/", 1)[-1]
-        if artifactPath.exists():
-            require(hashlib.sha256(artifactPath.read_bytes()).hexdigest() == digest,
-                    "Prepared package does not match its catalog digest")
+    require([item["id"] for item in catalog["tentacles"]] == ["hello-world", "wormhole", "battery-status"],
+            "Catalog must list Hello World, Wormhole, and Battery Status")
+    for item in catalog["tentacles"]:
+        name = item["id"]
+        require(item["manifest"] == f"{name}/tentacle.toml", "Manifest path must match ID")
+        manifest = read_toml(repoRoot / item["manifest"])
+        require(manifest["format-version"] == 1 and manifest["id"] == name
+                and manifest["name"] and manifest["version"] == ("0.1.2" if name == "wormhole" else "0.1.0"), "Invalid Tentacle metadata")
+        expectedGrants = ["presentation"] + (["interaction"] if name in ("wormhole", "battery-status") else [])
+        expectedProgram = "wormhole-tentacle" if name == "wormhole" else name
+        require(manifest["entry-point"] == [f"bin/{expectedProgram}"]
+                and manifest["capabilities"] == expectedGrants
+                and manifest["apis"] == ["commands"] + expectedGrants,
+                "Unexpected launch or grants")
+        require((repoRoot / "LICENSE").is_file() and (repoRoot / name / "LICENSE").is_file()
+                and (repoRoot / name / "README.md").is_file(), "License and help are required")
+        seen = set()
+        for release in item.get("releases", []):
+            key = (release["platform"], release["architecture"])
+            require(key not in seen and key[0] == "linux" and key[1] in ("amd64", "arm64"),
+                    "Invalid or duplicate release target")
+            seen.add(key)
+            parsed = urlparse(release["url"])
+            require(parsed.scheme == "https" and parsed.hostname and not parsed.username
+                    and not parsed.fragment, "Release URL must be HTTPS without credentials")
+            digest = release["sha256"]
+            require(len(digest) == 64 and all(character in "0123456789abcdef" for character in digest),
+                    "Invalid SHA-256 digest")
+            artifactPath = repoRoot / "dist" / parsed.path.rsplit("/", 1)[-1]
+            if artifactPath.exists():
+                require(hashlib.sha256(artifactPath.read_bytes()).hexdigest() == digest,
+                        "Prepared package does not match its catalog digest")
 
 
-def check_registration(programPath):
+def check_registration(programPath, name):
+    apis = ["commands", "presentation"] + (["interaction"] if name in ("wormhole", "battery-status") else [])
     with subprocess.Popen([str(programPath)], stdin=subprocess.PIPE,
                           stdout=subprocess.PIPE, stderr=subprocess.PIPE) as process:
         try:
             initialization = {
                 "jsonrpc": "2.0", "id": "1", "method": "initialize",
                 "params": {"protocol": {"major": 1, "minor": 0}, "session": "check",
-                           "apis": ["commands", "presentation"],
-                           "capabilities": ["commands", "presentation"]},
+                           "apis": apis,
+                           "capabilities": apis},
             }
             process.stdin.write((json.dumps(initialization) + "\n").encode())
             process.stdin.flush()
@@ -76,11 +81,21 @@ def check_registration(programPath):
             require(registration["id"] == "1" and registration["result"]["session"] == "check",
                     "Invalid registration response")
             commands = registration["result"]["commands"]
-            require(len(commands) == 1 and commands[0]["id"] == "hello-world"
+            require(len(commands) == (9 if name == "wormhole" else 2 if name == "battery-status" else 1) and commands[0]["id"] == name
                     and commands[0]["presentation"] is True, "Unexpected commands or grant")
             require(commands[0]["bindings"] == [
-                {"layout": layout, "scope": "global", "key": "Cthulhu+Alt+Shift+H"}
+                {"layout": layout, "scope": "global", "key": ("Cthulhu+Ctrl+Shift+W" if name == "wormhole" else "Cthulhu+Shift+B" if name == "battery-status" else "Cthulhu+Alt+Shift+H")}
                 for layout in ("desktop", "laptop")], "Wrong suggested shortcut")
+            if name == "battery-status":
+                require(commands[0].get("interaction") is True
+                        and commands[1]["id"] == "close-menu"
+                        and commands[1].get("interaction") is True
+                        and not commands[1].get("bindings")
+                        and not any(command.get("settings") for command in commands),
+                        "Battery Status must have one bound entry point and an unbound continuation")
+            if name == "wormhole":
+                require([command["id"] for command in commands if command.get("settings")]
+                        == ["settings"], "Wrong registered settings entry point")
             process.stdin.close()
             require(process.wait(timeout=5) == 0, "Tentacle did not stop cleanly on EOF")
         finally:
@@ -89,14 +104,50 @@ def check_registration(programPath):
                 process.wait(timeout=5)
 
 
-def check_host(repoRoot, programPath):
-    readerRoot = repoRoot.parent / "cthulhu-go"
+def check_host(repoRoot, programPath, name):
+    readerRoot = repoRoot.parent / "cthulhu"
     environment = os.environ.copy()
-    environment.setdefault("GOCACHE", "/tmp/cthulhu-go-cache")
+    environment.setdefault("GOCACHE", "/tmp/cthulhu-cache")
+    flags = ["-interaction"] if name in ("wormhole", "battery-status") else []
     result = subprocess.run([
-        "go", "run", "./examples/tentacles/host", "-presentation",
-        "-command", "hello-world", str(programPath),
+        "go", "run", "./cmd/tentacle-host", "-presentation",
+        *flags, "-command", name, str(programPath),
     ], cwd=readerRoot, env=environment, capture_output=True, text=True, timeout=60, check=True)
+    if name == "battery-status":
+        value = json.loads(result.stdout)
+        form = value.get("form")
+        if form:
+            require(form.get("title") == "Battery Menu" and value.get("next") == "close-menu"
+                    and len(form["elements"][0]["items"]) > 1,
+                    "Host returned an unexpected Battery Menu")
+        else:
+            require(value.get("done") is True and value.get("speech")
+                    and value.get("speech") == value.get("braille"),
+                    "Host returned an unexpected battery announcement")
+        result = subprocess.run([
+            "go", "run", "./cmd/tentacle-host", "-presentation", "-interaction",
+            "-command", "close-menu", str(programPath),
+        ], cwd=readerRoot, env=environment, capture_output=True, text=True,
+            timeout=60, check=True)
+        require(json.loads(result.stdout) == {"done": True},
+                "Battery menu completion must be silent")
+        return
+    if name == "wormhole":
+        value = json.loads(result.stdout)
+        require(value.get("form", {}).get("title") == "Wormhole menu"
+                or value == {"speech": "Magic wormhole is not installed",
+                             "braille": "Magic wormhole is not installed", "uninterruptible": True},
+                "Host returned an unexpected Wormhole menu")
+        result = subprocess.run([
+            "go", "run", "./cmd/tentacle-host", "-presentation", "-interaction",
+            "-command", "settings", str(programPath),
+        ], cwd=readerRoot, env=environment, capture_output=True, text=True,
+            timeout=60, check=True)
+        value = json.loads(result.stdout)
+        require(value.get("form", {}).get("title") == "Wormhole preferences"
+                and value.get("next") == "save-settings",
+                "Host returned an unexpected Wormhole settings form")
+        return
     require(json.loads(result.stdout) == {
         "speech": "Hello world!", "braille": "Hello world!", "uninterruptible": True,
     }, "The actual host returned an unexpected greeting")
@@ -106,9 +157,12 @@ def main():
     repoRoot = Path(__file__).resolve().parents[1]
     programPath = repoRoot / "hello-world/bin/hello-world"
     check_metadata(repoRoot)
-    check_registration(programPath)
-    check_host(repoRoot, programPath)
-    print("Repository metadata, shortcut registration and actual-host greeting passed.")
+    for name, binary in (("hello-world", "hello-world"), ("wormhole", "wormhole-tentacle"),
+                         ("battery-status", "battery-status")):
+        programPath = repoRoot / name / "bin" / binary
+        check_registration(programPath, name)
+        check_host(repoRoot, programPath, name)
+    print("Repository metadata, shortcut/settings registration and actual-host greeting/menu/settings/battery checks passed.")
 
 
 if __name__ == "__main__":

tools/package.py

@@ -1,6 +1,6 @@
 # Copyright (c) 2026 Storm Dragon
 # SPDX-License-Identifier: GPL-3.0-or-later
-"""Build reproducible Hello World release artifacts and a catalog for review."""
+"""Build reproducible Tentacle release artifacts and a catalog for review."""
 
 import argparse
 import gzip
@@ -12,26 +12,30 @@ from pathlib import Path
 import subprocess
 import tarfile
 import tomllib
+from urllib.parse import urlparse
 
 
-def build_package(repoRoot, architecture, version):
+def build_package(repoRoot, architecture, version, name):
+    sourceRoot = repoRoot / name
+    manifest = tomllib.loads((sourceRoot / "tentacle.toml").read_text())
+    binaryName = manifest["entry-point"][0]
     distRoot = repoRoot / "dist"
     distRoot.mkdir(exist_ok=True)
-    programPath = distRoot / f"hello-world-linux-{architecture}"
+    programPath = distRoot / f"{name}-linux-{architecture}"
     environment = dict(os.environ, CGO_ENABLED="0", GOOS="linux", GOARCH=architecture)
-    environment.setdefault("GOCACHE", "/tmp/cthulhu-go-cache")
+    environment.setdefault("GOCACHE", "/tmp/cthulhu-cache")
     subprocess.run(["go", "build", "-buildvcs=false", "-mod=readonly", "-trimpath",
-                    "-ldflags=-s -w", "-o", str(programPath), "./hello-world/src"],
+                    "-ldflags=-s -w", "-o", str(programPath), f"./{name}/src"],
                    cwd=repoRoot, env=environment, check=True)
-    artifactPath = distRoot / f"hello-world-{version}-linux-{architecture}.tar.gz"
+    artifactPath = distRoot / f"{name}-{version}-linux-{architecture}.tar.gz"
     with artifactPath.open("wb") as output:
         with gzip.GzipFile(filename="", mode="wb", fileobj=output, mtime=0) as compressed:
             with tarfile.open(fileobj=compressed, mode="w", format=tarfile.USTAR_FORMAT) as archive:
                 for name, data, mode in [
-                    ("tentacle.toml", (repoRoot / "hello-world/tentacle.toml").read_bytes(), 0o644),
-                    ("README.md", (repoRoot / "hello-world/README.md").read_bytes(), 0o644),
-                    ("LICENSE", (repoRoot / "hello-world/LICENSE").read_bytes(), 0o644),
-                    ("bin/hello-world", programPath.read_bytes(), 0o755),
+                    ("tentacle.toml", (sourceRoot / "tentacle.toml").read_bytes(), 0o644),
+                    ("README.md", (sourceRoot / "README.md").read_bytes(), 0o644),
+                    ("LICENSE", (sourceRoot / "LICENSE").read_bytes(), 0o644),
+                    (binaryName, programPath.read_bytes(), 0o755),
                 ]:
                     member = tarfile.TarInfo(name)
                     member.size, member.mode, member.mtime = len(data), mode, 0
@@ -43,25 +47,43 @@ def build_package(repoRoot, architecture, version):
 def main():
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument("--architecture", nargs="+", choices=["amd64", "arm64"], default=["amd64", "arm64"])
+    parser.add_argument("--tentacle", nargs="+", help="Catalog IDs to package (default: hello-world)")
+    parser.add_argument("--download-base", help="Immutable HTTPS directory containing the archives")
     args = parser.parse_args()
+    if args.download_base:
+        parsed = urlparse(args.download_base)
+        if parsed.scheme != "https" or not parsed.hostname or parsed.username or parsed.fragment or parsed.query:
+            parser.error("Download base must be an HTTPS directory without credentials, query or fragment")
     if len(set(args.architecture)) != len(args.architecture):
         parser.error("Architectures must not be repeated")
     repoRoot = Path(__file__).resolve().parents[1]
-    manifest = tomllib.loads((repoRoot / "hello-world/tentacle.toml").read_text())
-    version = manifest["version"]
-    if not version or any(character not in "0123456789abcdefghijklmnopqrstuvwxyz.-" for character in version):
-        raise ValueError("Version must be safe for release filenames")
-    lines = ["format-version = 1", "", "[[tentacles]]", 'id = "hello-world"',
-             'manifest = "hello-world/tentacle.toml"']
+    catalog = tomllib.loads((repoRoot / "catalog.toml").read_text())
+    names = [item["id"] for item in catalog["tentacles"]]
+    selected = args.tentacle or ["hello-world"]
+    if len(set(selected)) != len(selected) or any(name not in names for name in selected):
+        parser.error("Select distinct Tentacle IDs from catalog.toml")
+    lines = ["format-version = 1"]
     checksums = []
-    for architecture in args.architecture:
-        artifactPath, digest = build_package(repoRoot, architecture, version)
-        releaseURL = f"https://git.stormux.org/storm/cthulhu-tentacles/releases/download/hello-world-v{version}/{artifactPath.name}"
-        lines += ["", "[[tentacles.releases]]", 'platform = "linux"',
-                  f"architecture = {json.dumps(architecture)}", f"url = {json.dumps(releaseURL)}",
-                  f"sha256 = {json.dumps(digest)}"]
-        checksums.append(f"{digest}  {artifactPath.name}")
-        print(f"Prepared {artifactPath.name}: {digest}")
+    for item in catalog["tentacles"]:
+        name = item["id"]
+        lines += ["", "[[tentacles]]", f"id = {json.dumps(name)}",
+                  f"manifest = {json.dumps(item['manifest'])}"]
+        releases = item.get("releases", [])
+        if name in selected:
+            manifest = tomllib.loads((repoRoot / item["manifest"]).read_text())
+            version = manifest["version"]
+            if not version or any(character not in "0123456789abcdefghijklmnopqrstuvwxyz.-" for character in version):
+                raise ValueError("Version must be safe for release filenames")
+            releases = []
+            for architecture in args.architecture:
+                artifactPath, digest = build_package(repoRoot, architecture, version, name)
+                releaseURL = (args.download_base.rstrip("/") + "/" + artifactPath.name) if args.download_base else f"https://git.stormux.org/storm/cthulhu-tentacles/releases/download/{name}-v{version}/{artifactPath.name}"
+                releases.append(dict(platform="linux", architecture=architecture, url=releaseURL, sha256=digest))
+                checksums.append(f"{digest}  {artifactPath.name}")
+                print(f"Prepared {artifactPath.name}: {digest}")
+        for release in releases:
+            lines += ["", "[[tentacles.releases]]"]
+            lines += [f"{key} = {json.dumps(release[key])}" for key in ("platform", "architecture", "url", "sha256")]
     (repoRoot / "dist/catalog.toml").write_text("\n".join(lines) + "\n")
     (repoRoot / "dist/SHA256SUMS").write_text("\n".join(checksums) + "\n")
     print("Prepared dist/catalog.toml and dist/SHA256SUMS for review. Nothing was published.")

wormhole/LICENSE

@@ -0,0 +1,232 @@
+GNU GENERAL PUBLIC LICENSE
+Version 3, 29 June 2007
+
+Copyright © 2007 Free Software Foundation, Inc. <https://fsf.org/>
+
+Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
+
+Preamble
+
+The GNU General Public License is a free, copyleft license for software and other kinds of works.
+
+The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.
+
+When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.
+
+To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.
+
+For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
+
+Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.
+
+For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions.
+
+Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.
+
+Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.
+
+The precise terms and conditions for copying, distribution and modification follow.
+
+TERMS AND CONDITIONS
+
+0. Definitions.
+
+“This License” refers to version 3 of the GNU General Public License.
+
+“Copyright” also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.
+
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+
+12. No Surrender of Others' Freedom.
+If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.
+
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+THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
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+
+END OF TERMS AND CONDITIONS
+
+How to Apply These Terms to Your New Programs
+
+If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
+
+To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.
+
+     <one line to give the program's name and a brief idea of what it does.>
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+
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+
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+
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+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:
+
+     <program>  Copyright (C) <year>  <name of author>
+     This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+     This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.
+
+You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see <https://www.gnu.org/licenses/>.
+
+The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read <https://www.gnu.org/philosophy/why-not-lgpl.html>.

wormhole/README.md

@@ -0,0 +1,159 @@
+# Wormhole
+
+An experimental Magic Wormhole Tentacle for Cthulhu. Suggested shortcut:
+**Cthulhu+Ctrl+Shift+W**, on desktop and laptop layouts. It opens the reader's
+internal **Wormhole menu**, preserving the underlying application's focus.
+
+With a reader supporting Tentacle settings registration, global Preferences →
+Tentacles → select Wormhole → Settings opens **Wormhole preferences** directly.
+Save persists the two checkboxes and returns to reader preferences; Escape
+discards the form's edits. This entry point works without the Wormhole CLI.
+Use Wormhole 0.1.2 and rebuild the reader to obtain settings registration and the
+Ctrl+Shift shortcut; the published 0.1.1 binary uses Alt+Shift and has no
+registered settings entry point.
+
+Install the `magic-wormhole` CLI using your distribution's package manager.
+Clipboard operations require `xclip` on Xorg. Missing `wormhole` does not stop
+reader startup: the shortcut speaks and brailles **Magic wormhole is not
+installed**, with speech protected from ordinary interruption. Lock, shutdown,
+disable and the reader's explicit stop policy still take precedence.
+
+Use Up/Down and Enter in lists. Tab/Shift+Tab move through forms, Space toggles
+checkboxes, and Escape closes the UI. Entries support editing, selection, Ctrl+C,
+Ctrl+X and Ctrl+V. A transfer's Escape or Cancel transfer stops its process.
+Changing native focus closes the UI and cancels the transfer. Only one transfer
+runs at a time; keep the transfer UI open until it completes.
+
+The menu offers:
+
+- **Send focused item**: send one current text line, preserving spacing and
+  replacing line breaks with spaces. Password fields are excluded. A reliably
+  exposed local file URI/path is sent as one file or folder. File icons/list
+  items/table rows without a path are rejected; a filename never silently
+  becomes a text message. Flat review without an exact text range is unavailable.
+- **Send from clipboard**: send text as a message, preserving its line breaks.
+  A local file URI from a file manager sends the file or folder. Exactly one
+  item is required; multiple files are rejected. Plain text that resembles a
+  path remains a text message. If the clipboard supplies PNG data, create a
+  private temporary `clipboard.png`, send it, and remove it after completion or
+  cancellation. A missing file path without any file data cannot be reconstructed.
+- **Receive**: type/paste a code in the internal Wormhole code entry, then press
+  Enter. Files and folders are saved in `~/Downloads`, which is created if
+  needed. Existing destinations are refused rather than overwritten. Text is
+  read automatically when the transfer completes.
+- **Preferences**: two independent checkboxes, both unchecked by default:
+  **Save received text messages to clipboard** and **Copy send code to clipboard**.
+  Checked means both speak and copy the respective text/code. Unchecked means
+  speak it and preserve the clipboard. Save persists both choices in
+  `$XDG_CONFIG_HOME/cthulhu-tentacles/wormhole.json` (normally `~/.config/...`).
+  Escape discards changes.
+
+Transfer controls offer **Read transfer status**, **Copy code**, and **Cancel
+transfer**. Generated codes are automatically spoken and shown on braille, and
+copied only when the preference is enabled. Copy code performs an explicit copy
+regardless of that preference. There is no per-packet progress chatter. Errors
+report failure, not success, and do not copy partial received messages.
+
+File managers such as Thunar, PCManFM, Caja and Nautilus do not have a common
+AT-SPI method that guarantees the selected file's full URI. The portable path
+is to select one file/folder, press Ctrl+C, open the menu and choose **Send from
+clipboard**. Direct selected-file sending without that copy remains unavailable
+when the application does not expose an exact path. No path is guessed from a
+window title, status bar, or filename.
+
+Text transfers currently have an 8 KiB input limit; received text has an 8,000
+byte limit so its complete announcement fits the reader's bounded output.
+Oversized data is rejected, not silently truncated. Clipboard PNG data has a
+32 MiB limit. Clipboard support currently uses Xorg; on Wayland a missing
+clipboard service reports an unavailable item. The Wormhole CLI manages the
+network protocol, directory archive and transport; the tentacle never executes
+received text or launches a shell for transfers. Consult the
+[Magic Wormhole documentation](https://magic-wormhole.readthedocs.io/en/latest/welcome.html).
+
+## Build and local launch
+
+Keep this repository beside the matching `cthulhu` checkout:
+
+```sh
+make build
+make check
+```
+
+The binary is `wormhole/bin/wormhole-tentacle`. The current reader must support
+`interaction` grants; an older presentation-only host will reject it.
+Use a local launch entry with both grants:
+
+```json
+[
+  {
+    "ID": "wormhole",
+    "Program": ["/home/angus/devel/cthulhu-tentacles/wormhole/bin/wormhole-tentacle"],
+    "Presentation": true,
+    "Interaction": true
+  }
+]
+```
+
+Development launches use `--tentacles /absolute/launch.json` and the existing
+contained launcher. Alternatively, add a local entry to the reader's version-1
+`tentacles.toml` beside its settings file (normally
+`~/.local/share/cthulhu/tentacles.toml`), preserving existing entries:
+
+```toml
+[[tentacles]]
+id = "wormhole"
+program = ["/home/angus/devel/cthulhu-tentacles/wormhole/bin/wormhole-tentacle"]
+enabled = true
+presentation = true
+interaction = true
+```
+
+The normal installation path is global Preferences → Tentacles → Add repository
+with `https://git.stormux.org/storm/cthulhu-tentacles`, followed by selecting
+Wormhole and Install and enable. Version 0.1.2 downloads use the normal
+[`wormhole-v0.1.2` release attachments](https://git.stormux.org/storm/cthulhu-tentacles/releases/tag/wormhole-v0.1.2). The manifest
+requests presentation and interaction permissions. Local metadata above is an
+optional development path.
+Prepare amd64/arm64 archives with
+`python3 -B tools/package.py --tentacle wormhole`. Generated `dist/catalog.toml`
+preserves other catalog entries. Nothing is published by that command.
+
+## Live verification
+
+After configuring the local entry:
+
+1. Quit Cthulhu with Cthulhu+Q. Press Ctrl+Escape, then Shift+G. These are
+   separate key presses. Shift+G rebuilds the reader and braille helper.
+2. Focus an ordinary multiline text field. Open Cthulhu+Ctrl+Shift+W. Expect
+   “Wormhole menu. Send focused item” in speech and the menu option on braille.
+   Native application focus must stay on the original field. Send it to a
+   second Wormhole endpoint; the recipient must get exactly the current line.
+3. Open Preferences. Tab and Shift+Tab across both checkboxes and Save; Space
+   toggles each. Enable Copy send code to clipboard and Save. Send text from
+   the clipboard; expect the generated code spoken and shown on braille.
+   The clipboard must contain that exact code. Cancel the transfer. Disable
+   the preference and repeat; the original clipboard text must remain.
+4. In a file manager, copy exactly one file with Ctrl+C. Choose Send from
+   clipboard. Receive it at another endpoint and compare the contents.
+   Repeat with one folder, then multiple selected files: multiple items must
+   be refused. Sending a file icon without a usable path must give the copy
+   instruction and must not send its filename as text.
+5. Receive a file with the code entry. Test typing, cursor movement and Ctrl+V.
+   After completion, expect “Wormhole transfer received in Downloads” and the
+   actual file in Downloads. Repeat with an existing filename: expect failure
+   and unchanged original contents. Test a folder too.
+6. Receive text containing line breaks, quotes, backslashes and Unicode. With
+   Save received text messages to clipboard off, expect the complete message
+   spoken/shown and the previous clipboard preserved. Enable it and repeat:
+   expect the exact original text in the clipboard. Restart and verify both
+   checkbox choices persist.
+7. Cancel a waiting transfer with Escape and with Cancel transfer. Ordinary
+   typing must return to the original application, with no remaining modal
+   key capture. Test focus change, reader quit, and tentacle disable during
+   a waiting transfer. Check ordinary actions, learn mode, reading, and braille
+   afterward.
+
+Report the exact speech and braille, the focused control, the clipboard contents,
+and any key that behaved differently. Unexpected results should be diagnosed
+from `~/devel/cthulhu.log`. Automated and private Xorg checks do not establish
+physical speech, keyboard or braille acceptance.

wormhole/src/main.go

@@ -0,0 +1,201 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+)
+
+type preferences struct {
+	SaveReceivedText bool `json:"save_received_text"`
+	CopySendCode     bool `json:"copy_send_code"`
+}
+type wormhole struct {
+	mutex        sync.Mutex
+	preferences  preferences
+	settingsPath string
+	downloads    string
+	program      string
+	job          *transfer
+	workers      sync.WaitGroup
+}
+
+func message(text string) tentacle.Interaction {
+	return tentacle.Interaction{Presentation: tentacle.Presentation{Speech: text, Braille: text}}
+}
+func menu() tentacle.Interaction {
+	return tentacle.Interaction{Form: &tentacle.Form{Title: "Wormhole menu", Elements: []tentacle.Element{{ID: "options", Label: "Options", Kind: tentacle.List, Items: []tentacle.ListItem{
+		{ID: "send-focus", Label: "Send focused item"}, {ID: "send-clipboard", Label: "Send from clipboard"}, {ID: "receive", Label: "Receive"}, {ID: "preferences", Label: "Preferences"},
+	}}}}, Next: "menu"}
+}
+func (w *wormhole) open(ctx context.Context, _ json.RawMessage) (any, error) {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	if _, err := lookPath(w.program); err != nil {
+		result := message("Magic wormhole is not installed")
+		result.Uninterruptible = true
+		return result, nil
+	}
+	if w.job != nil {
+		return w.transferForm(), nil
+	}
+	return menu(), nil
+}
+func submission(raw json.RawMessage) (tentacle.Submission, error) {
+	var value tentacle.Submission
+	err := json.Unmarshal(raw, &value)
+	return value, err
+}
+func (w *wormhole) choose(ctx context.Context, raw json.RawMessage) (any, error) {
+	value, err := submission(raw)
+	if err != nil {
+		return nil, err
+	}
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	if value.Cancelled {
+		return tentacle.Interaction{Done: true}, nil
+	}
+	switch value.Activated {
+	case "send-focus":
+		return tentacle.Interaction{Source: "focus", Next: "send"}, nil
+	case "send-clipboard":
+		return tentacle.Interaction{Source: "clipboard", Next: "send"}, nil
+	case "receive":
+		return tentacle.Interaction{Form: &tentacle.Form{Title: "Receive with Wormhole", Elements: []tentacle.Element{
+			{ID: "code", Label: "Wormhole code", Kind: tentacle.Entry, Required: true, MaxLength: 256},
+			{ID: "receive", Label: "Receive", Kind: tentacle.Button},
+		}}, Next: "receive"}, nil
+	case "preferences":
+		return w.preferencesForm(), nil
+	}
+	return menu(), nil
+}
+func (w *wormhole) preferencesForm() tentacle.Interaction {
+	return tentacle.Interaction{Form: &tentacle.Form{Title: "Wormhole preferences", Elements: []tentacle.Element{
+		{ID: "save-text", Label: "Save received text messages to clipboard", Kind: tentacle.CheckBox, Checked: w.preferences.SaveReceivedText},
+		{ID: "copy-code", Label: "Copy send code to clipboard", Kind: tentacle.CheckBox, Checked: w.preferences.CopySendCode},
+		{ID: "save", Label: "Save", Kind: tentacle.Button},
+	}}, Next: "preferences"}
+}
+func (w *wormhole) openPreferences(ctx context.Context, _ json.RawMessage) (any, error) {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	result := w.preferencesForm()
+	result.Next = "save-settings"
+	return result, nil
+}
+func (w *wormhole) saveSettings(ctx context.Context, raw json.RawMessage) (any, error) {
+	value, err := w.savePreferences(ctx, raw)
+	if err != nil {
+		return nil, err
+	}
+	result := value.(tentacle.Interaction)
+	result.Form, result.Next, result.Done = nil, "", true
+	return result, nil
+}
+func (w *wormhole) savePreferences(ctx context.Context, raw json.RawMessage) (any, error) {
+	value, err := submission(raw)
+	if err != nil {
+		return nil, err
+	}
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if value.Cancelled {
+		return tentacle.Interaction{Done: true}, nil
+	}
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	next := preferences{SaveReceivedText: value.Values["save-text"].Checked, CopySendCode: value.Values["copy-code"].Checked}
+	if err := writePreferences(w.settingsPath, next); err != nil {
+		return message("Wormhole preferences could not be saved"), nil
+	}
+	w.preferences = next
+	result := menu()
+	result.Presentation = message("Wormhole preferences saved").Presentation
+	return result, nil
+}
+func writePreferences(path string, value preferences) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
+		return err
+	}
+	data, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	file, err := os.CreateTemp(filepath.Dir(path), ".wormhole-*.json")
+	if err != nil {
+		return err
+	}
+	defer os.Remove(file.Name())
+	defer file.Close()
+	if _, err = file.Write(data); err != nil {
+		return err
+	}
+	if err = file.Sync(); err != nil {
+		return err
+	}
+	if err = file.Close(); err != nil {
+		return err
+	}
+	return os.Rename(file.Name(), path)
+}
+func (w *wormhole) commands() []tentacle.Command {
+	var commands []tentacle.Command
+	for _, entry := range []struct {
+		id, title string
+		handler   tentacle.Handler
+	}{
+		{"wormhole", "Wormhole menu", w.open}, {"menu", "Wormhole menu selection", w.choose},
+		{"send", "Send Wormhole item", w.send}, {"receive", "Receive Wormhole item", w.receive},
+		{"preferences", "Save Wormhole preferences", w.savePreferences}, {"control", "Wormhole transfer controls", w.control}, {"poll", "Wormhole transfer status", w.poll},
+		{"settings", "Wormhole preferences", w.openPreferences}, {"save-settings", "Save Wormhole settings", w.saveSettings},
+	} {
+		command := tentacle.Command{ID: entry.id, Title: entry.title, Description: entry.title, Presentation: true, Interaction: true, Handle: entry.handler}
+		if entry.id == "wormhole" {
+			command.Bindings = []tentacle.Binding{{Layout: "desktop", Scope: "global", Key: "Cthulhu+Ctrl+Shift+W"}, {Layout: "laptop", Scope: "global", Key: "Cthulhu+Ctrl+Shift+W"}}
+		}
+		command.Settings = entry.id == "settings"
+		commands = append(commands, command)
+	}
+	return commands
+}
+func main() {
+	config, err := os.UserConfigDir()
+	if err != nil {
+		os.Exit(1)
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		os.Exit(1)
+	}
+	w := &wormhole{program: "wormhole", settingsPath: filepath.Join(config, "cthulhu-tentacles", "wormhole.json"), downloads: filepath.Join(home, "Downloads")}
+	if data, err := os.ReadFile(w.settingsPath); err == nil {
+		if json.Unmarshal(data, &w.preferences) != nil {
+			os.Exit(1)
+		}
+	} else if !os.IsNotExist(err) {
+		os.Exit(1)
+	}
+	err = tentacle.Serve(os.Stdin, os.Stdout, w.commands())
+	w.workers.Wait()
+	if err != nil {
+		os.Exit(1)
+	}
+}

wormhole/src/transfer.go

@@ -0,0 +1,421 @@
+// Copyright (c) 2026 Storm Dragon
+// SPDX-License-Identifier: GPL-3.0-or-later
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+	"unicode"
+	"unicode/utf8"
+
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+)
+
+var lookPath = exec.LookPath
+
+type transfer struct {
+	cancel       context.CancelFunc
+	code         string
+	reportedCode bool
+	received     bool
+	done         bool
+	cancelled    bool
+	hasMessage   bool
+	output       string
+	diagnostic   string // Bounded CLI detail retained in memory; never logged or spoken.
+	status       string
+	copyCode     bool
+	saveText     bool
+}
+type boundedOutput struct {
+	mutex    sync.Mutex
+	data     []byte
+	overflow bool
+}
+
+func (output *boundedOutput) Write(data []byte) (int, error) {
+	output.mutex.Lock()
+	defer output.mutex.Unlock()
+	limit := 65536 - len(output.data)
+	if len(data) > limit {
+		output.overflow = true
+	}
+	output.data = append(output.data, data[:min(len(data), limit)]...)
+	return len(data), nil
+}
+func (output *boundedOutput) result() (string, bool) {
+	output.mutex.Lock()
+	defer output.mutex.Unlock()
+	return string(output.data), output.overflow
+}
+
+func localPath(raw string) (string, error) {
+	if strings.HasPrefix(raw, "file:") {
+		uri, err := url.Parse(raw)
+		if err != nil || uri.Host != "" && uri.Host != "localhost" || uri.RawQuery != "" || uri.Fragment != "" {
+			return "", errors.New("not a local file URI")
+		}
+		raw = uri.Path
+	}
+	if strings.HasPrefix(raw, "~/") {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "", err
+		}
+		raw = filepath.Join(home, raw[2:])
+	}
+	if !filepath.IsAbs(raw) {
+		return "", errors.New("not an absolute path")
+	}
+	info, err := os.Stat(raw)
+	if err != nil {
+		return "", err
+	}
+	if !info.IsDir() && !info.Mode().IsRegular() {
+		return "", errors.New("not a file or folder")
+	}
+	return filepath.Clean(raw), nil
+}
+func (w *wormhole) send(ctx context.Context, raw json.RawMessage) (any, error) {
+	value, err := submission(raw)
+	if err != nil {
+		return nil, err
+	}
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	if value.Error != "" || value.Item == nil {
+		return message("Cannot send this item. Copy one file or folder, then choose Send from clipboard"), nil
+	}
+	if w.job != nil {
+		return w.transferForm(), nil
+	}
+	args := []string{"send", "--hide-progress", "--no-qr"}
+	text := ""
+	if value.Item.Path != "" {
+		path, err := localPath(value.Item.Path)
+		if err != nil {
+			return message("The file or folder path is unavailable"), nil
+		}
+		args = append(args, "--", path)
+	} else {
+		text = value.Item.Text
+		if text == "" {
+			return message("There is no text to send"), nil
+		}
+		if !utf8.ValidString(text) || len(text) > 8192 {
+			return message("The text message is too large or invalid"), nil
+		}
+		args = append(args, "--text", "-")
+	}
+	if err = w.start(ctx, args, text, false); err != nil {
+		return message("Wormhole transfer could not start"), nil
+	}
+	return w.transferForm(), nil
+}
+func validCode(code string) bool {
+	if len(code) == 0 || len(code) > 256 {
+		return false
+	}
+	parts := strings.Split(code, "-")
+	if len(parts) < 2 {
+		return false
+	}
+	if _, err := strconv.ParseUint(parts[0], 10, 64); err != nil {
+		return false
+	}
+	for _, part := range parts[1:] {
+		if part == "" {
+			return false
+		}
+		for _, r := range part {
+			if !unicode.IsLetter(r) {
+				return false
+			}
+		}
+	}
+	return true
+}
+func (w *wormhole) receive(ctx context.Context, raw json.RawMessage) (any, error) {
+	value, err := submission(raw)
+	if err != nil {
+		return nil, err
+	}
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if value.Cancelled {
+		return tentacle.Interaction{Done: true}, nil
+	}
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	if w.job != nil {
+		return w.transferForm(), nil
+	}
+	code := strings.TrimSpace(value.Values["code"].Text)
+	if !validCode(code) {
+		return message("Invalid Wormhole code"), nil
+	}
+	if err = os.MkdirAll(w.downloads, 0700); err != nil {
+		return message("Downloads could not be opened"), nil
+	}
+	if err = w.start(ctx, []string{"receive", "--accept-file", "--hide-progress", "--", code}, "", true); err != nil {
+		return message("Wormhole transfer could not start"), nil
+	}
+	return w.transferForm(), nil
+}
+func (w *wormhole) start(ctx context.Context, args []string, text string, received bool) error {
+	path, err := lookPath(w.program)
+	if err != nil {
+		return err
+	}
+	jobCtx, cancel := context.WithCancel(ctx)
+	command := exec.CommandContext(jobCtx, path, args...)
+	command.Env = append(os.Environ(), "PYTHONUNBUFFERED=1", "WORMHOLE_QR=0")
+	command.WaitDelay = time.Second
+	if received {
+		command.Dir = w.downloads
+	}
+	command.Stdin = strings.NewReader(text)
+	output := &boundedOutput{}
+	command.Stdout = output
+	stderr, err := command.StderrPipe()
+	if err != nil {
+		cancel()
+		return err
+	}
+	if err = command.Start(); err != nil {
+		cancel()
+		return err
+	}
+	job := &transfer{cancel: cancel, received: received, status: "Waiting for receiver", copyCode: w.preferences.CopySendCode, saveText: w.preferences.SaveReceivedText}
+	if received {
+		job.status = "Waiting for sender"
+	}
+	w.job = job
+	w.workers.Add(1)
+	go func() {
+		defer w.workers.Done()
+		defer cancel()
+		diagnostic := &boundedOutput{}
+		scanner := bufio.NewScanner(stderr)
+		scanner.Buffer(make([]byte, 1024), 8192)
+		for scanner.Scan() {
+			line := scanner.Text()
+			diagnostic.Write(append(scanner.Bytes(), '\n'))
+			if strings.HasPrefix(line, "Wormhole code is:") {
+				code := strings.TrimSpace(strings.TrimPrefix(line, "Wormhole code is:"))
+				if validCode(code) {
+					w.mutex.Lock()
+					job.code = code
+					w.mutex.Unlock()
+				}
+			}
+		}
+		if scanner.Err() != nil {
+			command.Process.Kill()
+			io.Copy(io.Discard, stderr)
+		}
+		err := command.Wait()
+		data, overflow := output.result()
+		w.mutex.Lock()
+		defer w.mutex.Unlock()
+		job.diagnostic, _ = diagnostic.result()
+		job.done = true
+		if job.cancelled || jobCtx.Err() != nil {
+			job.status = "Wormhole transfer cancelled"
+			return
+		}
+		if err != nil {
+			job.status = "Wormhole transfer failed. Check the code, connection, and whether the destination already exists"
+			return
+		}
+		if overflow {
+			job.status = "The received text message is too large to read or copy"
+			return
+		}
+		if received && data != "" {
+			decoded, err := decodeMessage(strings.TrimSuffix(data, "\n"))
+			if err != nil || len(decoded) > 8000 {
+				job.status = "The received text message is too large or invalid"
+				return
+			}
+			job.hasMessage = true
+			job.output = decoded
+			job.status = "Received text message"
+		} else if received {
+			job.status = "Wormhole transfer received in Downloads"
+		} else {
+			job.status = "Wormhole transfer complete"
+		}
+	}()
+	return nil
+}
+func (w *wormhole) transferForm() tentacle.Interaction {
+	title := "Wormhole transfer. " + w.job.status
+	return tentacle.Interaction{Form: &tentacle.Form{Title: title, Elements: []tentacle.Element{{ID: "controls", Label: "Transfer controls", Kind: tentacle.List, Items: []tentacle.ListItem{
+		{ID: "status", Label: "Read transfer status"}, {ID: "copy-code", Label: "Copy code"}, {ID: "cancel", Label: "Cancel transfer"},
+	}}}}, Next: "control", Poll: "poll"}
+}
+func (w *wormhole) poll(ctx context.Context, _ json.RawMessage) (any, error) {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	if w.job == nil {
+		return tentacle.Interaction{Done: true}, nil
+	}
+	job := w.job
+	if job.code != "" && !job.reportedCode {
+		job.reportedCode = true
+		result := message("Wormhole code: " + job.code)
+		if job.copyCode {
+			code := job.code
+			result.Clipboard = &code
+		}
+		return result, nil
+	}
+	if job.done {
+		result := message(job.status)
+		if job.hasMessage {
+			result = message("Received text message: " + spokenText(job.output))
+			if job.output == "" {
+				result = message("Received empty text message")
+			}
+			if job.saveText {
+				result.Clipboard = &job.output
+			}
+		}
+		result.Done = true
+		w.job = nil
+		return result, nil
+	}
+
+	return tentacle.Interaction{}, nil
+}
+func (w *wormhole) control(ctx context.Context, raw json.RawMessage) (any, error) {
+	value, err := submission(raw)
+	if err != nil {
+		return nil, err
+	}
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	if w.job == nil {
+		return message("No Wormhole transfer is running"), nil
+	}
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	if value.Cancelled || value.Activated == "cancel" {
+		w.job.cancelled = true
+		w.job.cancel()
+		w.job = nil
+		result := message("Wormhole transfer cancelled")
+		result.Done = true
+		return result, nil
+	}
+	result := w.transferForm()
+	if value.Activated == "copy-code" {
+		if w.job.code == "" {
+			result.Presentation = message("The Wormhole code is not ready yet").Presentation
+		} else {
+			code := w.job.code
+			result.Clipboard = &code
+			result.Presentation = message("Wormhole code: " + w.job.code).Presentation
+		}
+	} else {
+		status := w.job.status
+		if w.job.code != "" {
+			status = fmt.Sprintf("Wormhole code: %s. %s", w.job.code, status)
+		}
+		result.Presentation = message(status).Presentation
+	}
+	return result, nil
+}
+func spokenText(text string) string {
+	return strings.Map(func(r rune) rune {
+		if unicode.IsControl(r) && r != '\n' && r != '\t' {
+			return ' '
+		}
+		return r
+	}, text)
+}
+
+// The reference CLI prints repr(message)[1:-1]. Decode that representation
+// without evaluating Python or interpreting any received text as code.
+func decodeMessage(text string) (string, error) {
+	var output strings.Builder
+	for index := 0; index < len(text); index++ {
+		if text[index] != '\\' {
+			output.WriteByte(text[index])
+			continue
+		}
+		index++
+		if index >= len(text) {
+			return "", errors.New("trailing escape")
+		}
+		switch text[index] {
+		case '\\', '\'', '"':
+			output.WriteByte(text[index])
+		case 'n':
+			output.WriteByte('\n')
+		case 'r':
+			output.WriteByte('\r')
+		case 't':
+			output.WriteByte('\t')
+		case 'a':
+			output.WriteByte(7)
+		case 'b':
+			output.WriteByte(8)
+		case 'f':
+			output.WriteByte(12)
+		case 'v':
+			output.WriteByte(11)
+		case 'x', 'u', 'U':
+			width := 2
+			if text[index] == 'u' {
+				width = 4
+			}
+			if text[index] == 'U' {
+				width = 8
+			}
+			if index+width >= len(text) {
+				return "", errors.New("short escape")
+			}
+			raw := text[index+1 : index+1+width]
+			if _, err := hex.DecodeString(raw); err != nil {
+				return "", err
+			}
+			number, err := strconv.ParseUint(raw, 16, 32)
+			if err != nil || !utf8.ValidRune(rune(number)) {
+				return "", errors.New("invalid character")
+			}
+			output.WriteRune(rune(number))
+			index += width
+		default:
+			output.WriteByte('\\')
+			output.WriteByte(text[index])
+		}
+	}
+	result := output.String()
+	if !utf8.ValidString(result) {
+		return "", errors.New("invalid UTF-8")
+	}
+	return result, nil
+}

wormhole/src/transfer_integration_test.go

@@ -0,0 +1,121 @@
+package main
+
+import (
+	"context"
+	sdk "git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Opt-in because it contacts Magic Wormhole's public rendezvous/transport relay.
+// Only synthetic fixture data is sent; both endpoints and downloads are private
+// test instances. It does not use the user's clipboard or active reader.
+func TestRealWormholeTransfers(t *testing.T) {
+	if os.Getenv("CTHULHU_WORMHOLE_NETWORK_TEST") != "1" {
+		t.Skip("requires explicit real-relay check")
+	}
+	program, err := exec.LookPath("wormhole")
+	if err != nil {
+		t.Skip("Magic Wormhole not installed")
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 45*time.Second)
+	defer cancel()
+	sender := &wormhole{program: program, downloads: t.TempDir(), preferences: preferences{CopySendCode: true}}
+	receiver := &wormhole{program: program, downloads: t.TempDir(), preferences: preferences{SaveReceivedText: true}}
+	defer func() { cancel(); sender.workers.Wait(); receiver.workers.Wait() }()
+	exchange := func(item sdk.Item) sdk.Interaction {
+		t.Helper()
+		raw, err := sender.send(ctx, arguments(sdk.Submission{Item: &item}))
+		if err != nil || raw.(sdk.Interaction).Form == nil {
+			t.Fatal(raw, err)
+		}
+		sender.mutex.Lock()
+		job := sender.job
+		sender.mutex.Unlock()
+		code := ""
+		for code == "" {
+			raw, err = sender.poll(ctx, nil)
+			if err != nil {
+				t.Fatal("sender code", err)
+			}
+			result := raw.(sdk.Interaction)
+			if result.Clipboard != nil {
+				code = *result.Clipboard
+			}
+			if result.Done {
+				sender.mutex.Lock()
+				detail := job.diagnostic
+				sender.mutex.Unlock()
+				t.Fatal("sender failed before code", result.Speech, detail)
+			}
+			select {
+			case <-ctx.Done():
+				t.Fatal("relay did not produce a code", ctx.Err())
+			case <-time.After(20 * time.Millisecond):
+			}
+		}
+		raw, err = receiver.receive(ctx, arguments(sdk.Submission{Values: map[string]sdk.Value{"code": {Text: code}}}))
+		if err != nil || raw.(sdk.Interaction).Form == nil {
+			t.Fatal(raw, err)
+		}
+		var received sdk.Interaction
+		sendingDone := false
+		for !received.Done || !sendingDone {
+			if !received.Done {
+				raw, err = receiver.poll(ctx, nil)
+				if err != nil {
+					t.Fatal(err)
+				}
+				received = raw.(sdk.Interaction)
+			}
+			if !sendingDone {
+				raw, err = sender.poll(ctx, nil)
+				if err != nil {
+					t.Fatal(err)
+				}
+				result := raw.(sdk.Interaction)
+				sendingDone = result.Done
+				if sendingDone && result.Speech != "Wormhole transfer complete" {
+					t.Fatal("sender", result.Speech)
+				}
+			}
+			if received.Done && strings.Contains(received.Speech, "failed") {
+				t.Fatal("receiver", received.Speech)
+			}
+			select {
+			case <-ctx.Done():
+				t.Fatal("transfer timed out", ctx.Err())
+			case <-time.After(20 * time.Millisecond):
+			}
+		}
+		return received
+	}
+	text := "Synthetic Wormhole text\nSecond  line: é猫 and \\n literal"
+	if result := exchange(sdk.Item{Text: text}); result.Clipboard == nil || *result.Clipboard != text {
+		t.Fatalf("text changed: %+v", result)
+	}
+	source := t.TempDir()
+	file := filepath.Join(source, "one file.txt")
+	if err = os.WriteFile(file, []byte("Synthetic file contents\n"), 0600); err != nil {
+		t.Fatal(err)
+	}
+	if result := exchange(sdk.Item{Path: file}); result.Clipboard != nil || result.Speech != "Wormhole transfer received in Downloads" {
+		t.Fatal(result)
+	}
+	data, err := os.ReadFile(filepath.Join(receiver.downloads, "one file.txt"))
+	if err != nil || string(data) != "Synthetic file contents\n" {
+		t.Fatal(string(data), err)
+	}
+	folder := filepath.Join(source, "one folder")
+	os.MkdirAll(folder, 0700)
+	os.WriteFile(filepath.Join(folder, "nested.txt"), []byte("Synthetic folder contents\n"), 0600)
+	exchange(sdk.Item{Path: folder})
+	data, err = os.ReadFile(filepath.Join(receiver.downloads, "one folder", "nested.txt"))
+	if err != nil || string(data) != "Synthetic folder contents\n" {
+		t.Fatal(string(data), err)
+	}
+}

wormhole/src/wormhole_test.go

@@ -0,0 +1,264 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"git.stormux.org/storm/cthulhu/sdk/go/tentacle"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func arguments(value any) json.RawMessage { data, _ := json.Marshal(value); return data }
+func testWormhole(t *testing.T, script string) *wormhole {
+	t.Helper()
+	directory := t.TempDir()
+	program := filepath.Join(directory, "fake-wormhole")
+	if err := os.WriteFile(program, []byte("#!/bin/sh\n"+script), 0700); err != nil {
+		t.Fatal(err)
+	}
+	w := &wormhole{program: program, downloads: filepath.Join(directory, "Downloads"), settingsPath: filepath.Join(directory, "config", "wormhole.json")}
+	t.Cleanup(func() {
+		w.mutex.Lock()
+		if w.job != nil {
+			w.job.cancel()
+		}
+		w.mutex.Unlock()
+		w.workers.Wait()
+	})
+	return w
+}
+func completed(t *testing.T, w *wormhole) tentacle.Interaction {
+	t.Helper()
+	deadline := time.Now().Add(3 * time.Second)
+	for time.Now().Before(deadline) {
+		raw, err := w.poll(context.Background(), nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		result := raw.(tentacle.Interaction)
+		if result.Done {
+			return result
+		}
+		time.Sleep(time.Millisecond)
+	}
+	t.Fatal("transfer did not complete")
+	return tentacle.Interaction{}
+}
+func TestMenuPreferencesAndMissingDependency(t *testing.T) {
+	w := testWormhole(t, "exit 0\n")
+	raw, err := w.open(context.Background(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	result := raw.(tentacle.Interaction)
+	if result.Form.Title != "Wormhole menu" || len(result.Form.Elements[0].Items) != 4 {
+		t.Fatal(result)
+	}
+	if w.preferences.SaveReceivedText || w.preferences.CopySendCode {
+		t.Fatal("preferences should default off")
+	}
+	prefs := tentacle.Submission{Activated: "save", Values: map[string]tentacle.Value{"save-text": {Checked: true}, "copy-code": {Checked: true}}}
+	if _, err = w.savePreferences(context.Background(), arguments(prefs)); err != nil {
+		t.Fatal(err)
+	}
+	data, err := os.ReadFile(w.settingsPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var saved preferences
+	if json.Unmarshal(data, &saved) != nil || !saved.SaveReceivedText || !saved.CopySendCode {
+		t.Fatal(saved)
+	}
+	info, _ := os.Stat(w.settingsPath)
+	if info.Mode().Perm() != 0600 {
+		t.Fatal("settings are not private")
+	}
+	prefs.Cancelled = true
+	prefs.Values = nil
+	w.savePreferences(context.Background(), arguments(prefs))
+	if !w.preferences.CopySendCode {
+		t.Fatal("Cancel changed preferences")
+	}
+	w.program = filepath.Join(t.TempDir(), "missing")
+	raw, err = w.open(context.Background(), nil)
+	result = raw.(tentacle.Interaction)
+	if err != nil || result.Speech != "Magic wormhole is not installed" || !result.Uninterruptible {
+		t.Fatal(result, err)
+	}
+}
+
+func TestRegisteredSettingsAndDefaultShortcut(t *testing.T) {
+	w := testWormhole(t, "exit 0\n")
+	w.program = filepath.Join(t.TempDir(), "missing")
+	settings := 0
+	for _, command := range w.commands() {
+		if command.ID == "wormhole" {
+			if len(command.Bindings) != 2 {
+				t.Fatal(command.Bindings)
+			}
+			for index, layout := range []string{"desktop", "laptop"} {
+				binding := command.Bindings[index]
+				if binding.Layout != layout || binding.Scope != "global" || binding.Key != "Cthulhu+Ctrl+Shift+W" {
+					t.Fatal(binding)
+				}
+			}
+		}
+		if !command.Settings {
+			continue
+		}
+		settings++
+		value, err := command.Handle(context.Background(), nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		form := value.(tentacle.Interaction)
+		if !command.Interaction || !command.Presentation || form.Form.Title != "Wormhole preferences" || form.Next != "save-settings" {
+			t.Fatal(command, form)
+		}
+	}
+	if settings != 1 {
+		t.Fatalf("settings entry points: %d", settings)
+	}
+	value, err := w.saveSettings(context.Background(), arguments(tentacle.Submission{Activated: "save", Values: map[string]tentacle.Value{"copy-code": {Checked: true}}}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	result := value.(tentacle.Interaction)
+	if !result.Done || result.Form != nil || result.Next != "" || !w.preferences.CopySendCode {
+		t.Fatal(result)
+	}
+	data, err := os.ReadFile(w.settingsPath)
+	var saved preferences
+	if err != nil || json.Unmarshal(data, &saved) != nil || !saved.CopySendCode {
+		t.Fatal("settings did not persist", err)
+	}
+	_, err = w.saveSettings(context.Background(), arguments(tentacle.Submission{Cancelled: true}))
+	if err != nil || !w.preferences.CopySendCode {
+		t.Fatal("Cancel changed saved settings", err)
+	}
+}
+func TestSendPreservesClipboardTextAndCodePreference(t *testing.T) {
+	for _, copyCode := range []bool{false, true} {
+		t.Run(map[bool]string{false: "read-only", true: "copy-code"}[copyCode], func(t *testing.T) {
+			directory := t.TempDir()
+			capture := filepath.Join(directory, "sent")
+			// Use env-free literal single quoting for a temporary path controlled by the test.
+			w := testWormhole(t, "[ \"$1\" = send ] || exit 8\n[ \"$4\" = --text ] || exit 9\ncat > '"+capture+"'\nprintf 'Wormhole code is: 7-alpha-beta\\n' >&2\nsleep 0.1\n")
+			w.preferences.CopySendCode = copyCode
+			text := "one\ntwo\\three é猫"
+			raw, err := w.send(context.Background(), arguments(tentacle.Submission{Item: &tentacle.Item{Text: text}}))
+			if err != nil || raw.(tentacle.Interaction).Poll != "poll" {
+				t.Fatal(raw, err)
+			}
+			deadline := time.Now().Add(2 * time.Second)
+			for {
+				raw, err = w.poll(context.Background(), nil)
+				if err != nil {
+					t.Fatal(err)
+				}
+				result := raw.(tentacle.Interaction)
+				if result.Speech != "" {
+					if result.Speech != "Wormhole code: 7-alpha-beta" || (result.Clipboard != nil) != copyCode {
+						t.Fatal(result)
+					}
+					break
+				}
+				if time.Now().After(deadline) {
+					t.Fatal("code not announced")
+				}
+				time.Sleep(time.Millisecond)
+			}
+			if got := completed(t, w).Speech; got != "Wormhole transfer complete" {
+				t.Fatal(got)
+			}
+			data, err := os.ReadFile(capture)
+			if err != nil || string(data) != text {
+				t.Fatalf("sent=%q %v", data, err)
+			}
+		})
+	}
+}
+func TestReceiveTextPreferenceAndExactDecode(t *testing.T) {
+	for _, saveText := range []bool{false, true} {
+		w := testWormhole(t, "[ \"$1\" = receive ] || exit 8\nprintf '%s\\n' 'one\\ntwo\\\\three é猫'\n")
+		w.preferences.SaveReceivedText = saveText
+		raw, err := w.receive(context.Background(), arguments(tentacle.Submission{Values: map[string]tentacle.Value{"code": {Text: "7-alpha-beta"}}}))
+		if err != nil || raw.(tentacle.Interaction).Form == nil {
+			t.Fatal(raw, err)
+		}
+		result := completed(t, w)
+		expected := "one\ntwo\\three é猫"
+		if result.Speech != "Received text message: "+expected || (result.Clipboard != nil) != saveText {
+			t.Fatal(result)
+		}
+		if result.Clipboard != nil && *result.Clipboard != expected {
+			t.Fatal("clipboard was not exact")
+		}
+	}
+}
+func TestReceiveFilesDownloadsFailureAndCancellation(t *testing.T) {
+	w := testWormhole(t, "pwd > received.txt\n")
+	raw := arguments(tentacle.Submission{Values: map[string]tentacle.Value{"code": {Text: "7-alpha-beta"}}})
+	w.receive(context.Background(), raw)
+	if result := completed(t, w); result.Speech != "Wormhole transfer received in Downloads" || result.Clipboard != nil {
+		t.Fatal(result)
+	}
+	data, err := os.ReadFile(filepath.Join(w.downloads, "received.txt"))
+	if err != nil || strings.TrimSpace(string(data)) != w.downloads {
+		t.Fatal(string(data), err)
+	}
+	failure := testWormhole(t, "exit 12\n")
+	failure.receive(context.Background(), raw)
+	if result := completed(t, failure); !strings.Contains(result.Speech, "failed") {
+		t.Fatal(result)
+	}
+	cancelled := testWormhole(t, "exec sleep 30\n")
+	cancelled.receive(context.Background(), raw)
+	result, err := cancelled.control(context.Background(), arguments(tentacle.Submission{Cancelled: true}))
+	if err != nil || result.(tentacle.Interaction).Speech != "Wormhole transfer cancelled" {
+		t.Fatal(result, err)
+	}
+	joined := make(chan struct{})
+	go func() { cancelled.workers.Wait(); close(joined) }()
+	select {
+	case <-joined:
+	case <-time.After(2 * time.Second):
+		t.Fatal("cancel left child running")
+	}
+}
+func TestMessageDecode(t *testing.T) {
+	cases := map[string]string{`line\nsecond`: "line\nsecond", `slash\\n`: `slash\n`, `it\'s`: "it's", `é\x00\u200b\U0001f600`: "é\x00\u200b😀"}
+	for input, expected := range cases {
+		got, err := decodeMessage(input)
+		if err != nil || got != expected {
+			t.Fatalf("%q => %q %v", input, got, err)
+		}
+	}
+	for _, input := range []string{`bad\`, `bad\x1`, `bad\uZZZZ`, `bad\Uffffffff`} {
+		if _, err := decodeMessage(input); err == nil {
+			t.Fatal("accepted", input)
+		}
+	}
+}
+func TestRejectUnavailableFilesAndInvalidCodes(t *testing.T) {
+	w := testWormhole(t, "exit 0\n")
+	for _, code := range []string{"", "--help", "a-alpha-beta", "7-alpha-", "7-alpha;touch-x"} {
+		result, err := w.receive(context.Background(), arguments(tentacle.Submission{Values: map[string]tentacle.Value{"code": {Text: code}}}))
+		if err != nil || result.(tentacle.Interaction).Speech != "Invalid Wormhole code" {
+			t.Fatal(result, err)
+		}
+	}
+	if _, err := localPath("file://remote/thing"); err == nil {
+		t.Fatal("accepted remote URI")
+	}
+	if _, err := localPath("relative"); err == nil {
+		t.Fatal("accepted guessed relative path")
+	}
+	raw, err := w.send(context.Background(), arguments(tentacle.Submission{Item: &tentacle.Item{Path: "/this/file/does/not/exist"}}))
+	if err != nil || raw.(tentacle.Interaction).Speech != "The file or folder path is unavailable" {
+		t.Fatal(raw, err)
+	}
+}

wormhole/tentacle.toml

@@ -0,0 +1,23 @@
+format-version = 1
+id = "wormhole"
+name = "Wormhole"
+description = "Send a focused line or clipboard item and receive files, folders, and text with Magic Wormhole."
+version = "0.1.2"
+authors = ["Storm Dragon"]
+license = "GPL-3.0-or-later"
+source = "https://git.stormux.org/storm/cthulhu-tentacles"
+help = "README.md"
+runtime = "native"
+platforms = ["linux"]
+entry-point = ["bin/wormhole-tentacle"]
+apis = ["commands", "presentation", "interaction"]
+capabilities = ["presentation", "interaction"]
+
+[protocol]
+major = 1
+minor = 0
+
+[requirements]
+reader = "Cthulhu with interactive Tentacle settings support"
+runtime = "Magic Wormhole CLI (wormhole); xclip for clipboard operations"
+build = "Go 1.24 or newer and the adjacent cthulhu source checkout"