Membrane Framework
membraneframework/membrane_core
Work with the Membrane multimedia streaming framework in Elixir.
Narrow bare rescue in Elixir so real errors like KeyError and typos propagate instead of being swallowed.
Install Narrow Bare Rescue
$ npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install oliver-kriska/claude-elixir-phoenix narrow-bare-rescue --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix.git skills-src && mkdir -p .claude/skills && cp -r skills-src/targets/pi/skills/narrow-bare-rescue .claude/skills/narrow-bare-rescue && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "narrow-bare-rescue" agent skill from https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescue into .claude/skills/narrow-bare-rescue/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "narrow-bare-rescue", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescueType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install oliver-kriska/claude-elixir-phoenix narrow-bare-rescue --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix.git skills-src && mkdir -p .agents/skills && cp -r skills-src/targets/pi/skills/narrow-bare-rescue .agents/skills/narrow-bare-rescue && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "narrow-bare-rescue" agent skill from https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescue into .agents/skills/narrow-bare-rescue/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "narrow-bare-rescue", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install oliver-kriska/claude-elixir-phoenix narrow-bare-rescue --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/targets/pi/skills/narrow-bare-rescue .cursor/skills/narrow-bare-rescue && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "narrow-bare-rescue" agent skill from https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescue into .cursor/skills/narrow-bare-rescue/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "narrow-bare-rescue", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/oliver-kriska/claude-elixir-phoenix.git --path targets/pi/skills/narrow-bare-rescue--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install oliver-kriska/claude-elixir-phoenix narrow-bare-rescue --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/targets/pi/skills/narrow-bare-rescue .gemini/skills/narrow-bare-rescue && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "narrow-bare-rescue" agent skill from https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescue into .gemini/skills/narrow-bare-rescue/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "narrow-bare-rescue", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install oliver-kriska/claude-elixir-phoenix narrow-bare-rescueInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix.git skills-src && mkdir -p .github/skills && cp -r skills-src/targets/pi/skills/narrow-bare-rescue .github/skills/narrow-bare-rescue && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "narrow-bare-rescue" agent skill from https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescue into .github/skills/narrow-bare-rescue/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "narrow-bare-rescue", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install oliver-kriska/claude-elixir-phoenix narrow-bare-rescue --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/targets/pi/skills/narrow-bare-rescue .opencode/skills/narrow-bare-rescue && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "narrow-bare-rescue" agent skill from https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/pi/skills/narrow-bare-rescue into .opencode/skills/narrow-bare-rescue/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "narrow-bare-rescue", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
narrow-bare-rescue- GitHub stars
- 565
- Token cost
- ~1.3k tokens
- SKILL.md length
- 606 words
- Files
- 3 (incl. references)
- Skills in repo
- 109
- Repo updated
- First seen
- Licence
- MIT
At a glance
Narrow bare rescue in Elixir so real errors like KeyError and typos propagate instead of being swallowed.
- Works in 4 steps: Find the sites → Determine the exception set for each… → Apply the narrowing → …
- Audit rescues and refactor error handling
- SKILL.md covers Why this matters, Iron Laws, The core transform and Workflow, plus 2 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Narrow Bare Rescue is an agent skill from oliver-kriska/claude-elixir-phoenix. Narrow bare rescue in Elixir so real errors like KeyError and typos propagate instead of being swallowed. Use to audit rescues and refactor error handling.
Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including reference files (for example `references/patterns.md` and `references/taxonomy.md`).
It sits in Development. It works with Elixir. The repository describes itself as: Claude Code plugin for Elixir/Phoenix/LiveView — 26 specialist agents, Iron Laws enforcement, and Tidewave MCP integration. Plan features with parallel research agents, execute… The licence is MIT.
When your agent uses it
- Audit rescues and refactor error handling
Example prompts
- “/narrow-bare-rescue”
Workflow steps
4 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 9767a82. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are bash and elixir).
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
erlang.org
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Narrow Bare Rescue loads about 1.3k tokens when it runs, and up to ~5k if it reads all its reference files. Until then it costs about 44 tokens; SKILL.md has 606 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from oliver-kriska/claude-elixir-phoenix at commit 9767a82, republished under its MIT licence (© oliver-kriska). 606 words, ~1,328 tokens.
Download SKILL.mdSave it as
.claude/skills/narrow-bare-rescue/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.- name
- narrow-bare-rescue
- description
- Narrow bare rescue in Elixir so real errors like KeyError and typos propagate instead of being swallowed. Use to audit rescues and refactor error handling.
Narrow Bare Rescue
Turn rescue _ -> fallback into rescue _ in [ExceptionType1, ExceptionType2] -> fallback
so programmer bugs propagate while known failure modes stay handled.
Why this matters
Bare rescues (rescue _ ->, rescue e -> — any form without an in clause) swallow
every exception, including UndefinedFunctionError from typos, KeyError from
misspelled map keys, and CompileError from bad HEEx templates. The symptom isn't a stack
trace — it's a silent {:error, :generic} or a nil fallback. Bugs that should surface
in tests or error reporters become quiet degradations.
The Erlang Secure Coding Guide makes
the same case at the BEAM level — rule LNG-002 ("Do Not Use catch") warns that the
legacy catch-all form conflates normal returns, throws, and errors. Bare rescue in Elixir
is the direct analogue.
Iron Laws
- Never leave
rescue _ ->orrescue e ->without aninclause. Every rescue must list exact exception types. The Credo check enforces this after cleanup lands. - Cover every exception the code path can actually raise. Narrowing that drops a real exception is a behavioral regression — trace each call in the body before committing.
- Never include programmer-bug exceptions in the list.
UndefinedFunctionError,CompileError,BadFunctionError, andBadArityErrormust propagate. - Use
reraise e, __STACKTRACE__, neverreraise e, []. Preserve the original stack trace so Oban retry metadata and error reporters show the real origin. - Run
mix compile --warnings-as-errorsbefore committing. Typos in exception module names only surface at compile time — the code looks fine until it loads.
The core transform
# Before — masks programmer bugs
def parse(body) do
Jason.decode!(body)
rescue
_ -> %{}
end
# After — catches only what can actually fail here
def parse(body) do
Jason.decode!(body)
rescue
_ in [Jason.DecodeError, ArgumentError] -> %{}
endApplies identically to try … rescue … and to function-body def … rescue ….
Workflow
The skill operates in three modes depending on scope:
- Single file —
/narrow-bare-rescue path/to/file.ex - Directory —
/narrow-bare-rescue lib/my_app/util/ - Whole project —
/narrow-bare-rescue --all
Whatever the scope, follow this sequence.
Step 1 — Find the sites
grep -rn "^\s*rescue\s*$" <scope> | head -200For each hit, read the 3 lines after to classify:
rescue _ ->orrescue var ->— bare, needs narrowingrescue _ in [...] ->orrescue var in Something ->— already typed, skiprescue ExceptionType ->(no variable binding) — already typed, skip
Show full SKILL.md (291 more words)Show less
Step 2 — Determine the exception set for each bare site
Read the try / def body and trace what each call can raise. Don't guess from the
function name — verify. Consult order:
Check
references/taxonomy.mdfor the work type (JSON, Ecto, Money, HTTP, etc.). Most sites map cleanly to one row.Grep deps for
defexceptionwhen a specific library isn't in the taxonomy:bash grep -rn "defexception" deps/<libname>/lib/ | head -10Check
raisecalls in the code path itself — if the body explicitly raisesRuntimeError, include it.
Priorities: cover everything the code can actually raise, exclude programmer-bug
exceptions (see Iron Law #3), and prefer specific types (Jason.DecodeError beats
ArgumentError if both could apply).
Step 3 — Apply the narrowing
For files with ≥3 rescues sharing a taxonomy, hoist to a module attribute — see
references/patterns.md for the module-attribute pattern, Oban reraise, ExCmd exit
errors, and is_exception/1 replacements.
Step 4 — Verify
After changes in each file (or cluster of files), run:
mix compile --warnings-as-errors
mix format <files_changed>
mix test <test_files_for_affected_modules>The compile step catches typos in exception module names — a real risk since you're writing module names from memory.
Scope
This skill narrows bare rescue clauses. It does not:
- Auto-narrow blindly — behavior preservation matters; trace each call path first
- Touch rescues that are already typed (
rescue e in [X] ->) — those are correct - Cover
catchclauses — throws and exits from the process are a separate concern - Replace
try/rescuewithwithor error-tuple plumbing — that's a larger refactor
References
references/taxonomy.md— verified exception types per work category, plus library-specific gotchas (NimbleCSV, Plug, Phoenix LiveView tokenizer)references/patterns.md— special patterns:is_exception/1, Oban reraise, ExCmd exit errors, module-attribute hoisting, partitioning large cleanups, the regression-prevention Credo check- Erlang Secure Coding Guide — LNG-002: Do Not Use
catch— BEAM-level rationale for preferring narrowtry ... catch/try ... rescueover the legacy catch-all form
© oliver-kriska, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 2 other files (references) in targets/pi/skills/narrow-bare-rescue of oliver-kriska/claude-elixir-phoenix.
- SKILL.md
- references/patterns.md
- references/taxonomy.md
Open the folder on GitHubat commit 9767a82
Compare with similar skills
Narrow Bare Rescue next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Narrow Bare Rescue this skilloliver-kriska/claude-elixir-phoenix | 565 | — | ~1.3k | Automated safety check: Pass | MIT | |
| Membrane Frameworkmembraneframework/membrane_core | 1.5k | — | ~4.2k | Automated safety check: Pass | Apache-2.0 | |
| Elixirstreamband/hydra-srt | 147 | — | ~804 | Automated safety check: Pass | Apache-2.0 | |
| Idiomatic Elixirgeorgeguimaraes/elixir-agent-tools | 184 | — | ~2.1k | Automated safety check: Pass | Apache-2.0 | |
| Alefxberg-io/alef | 100 | — | ~1.7k | Automated safety check: Pass | MIT | |
| Releasedmkenney/xamal | 106 | — | ~873 | Automated safety check: Pass | MIT |
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Categories
Questions about Narrow Bare Rescue
What does Narrow Bare Rescue do?
Narrow bare rescue in Elixir so real errors like KeyError and typos propagate instead of being swallowed. Narrow Bare Rescue is an agent skill from oliver-kriska/claude-elixir-phoenix. Narrow bare rescue in Elixir so real errors like KeyError and typos propagate instead of being swallowed.
When should I use Narrow Bare Rescue?
Narrow Bare Rescue fits situations like: audit rescues and refactor error handling.
How do I install Narrow Bare Rescue in Claude Code?
Run `npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a claude-code`. Or copy the skill folder (targets/pi/skills/narrow-bare-rescue in oliver-kriska/claude-elixir-phoenix) into .claude/skills/narrow-bare-rescue in your project. Claude Code loads it when a task matches its description.
How do I install Narrow Bare Rescue in Codex?
Run `npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a codex`. Or copy the skill folder (targets/pi/skills/narrow-bare-rescue in oliver-kriska/claude-elixir-phoenix) into .agents/skills/narrow-bare-rescue in your project. Codex loads it when a task matches its description.
Can I use Narrow Bare Rescue in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add oliver-kriska/claude-elixir-phoenix --skill narrow-bare-rescue -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/narrow-bare-rescue, .gemini/skills/narrow-bare-rescue, .github/skills/narrow-bare-rescue and .opencode/skills/narrow-bare-rescue in your project.
What does Narrow Bare Rescue need to run?
SKILL.md names no scripts, command-line tools or credentials: Narrow Bare Rescue is instructions for the agent only.
Does Narrow Bare Rescue access the network?
SKILL.md names 1 domain. As links in the text: erlang.org. This is read from the text; nothing was executed.
Is Narrow Bare Rescue safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Narrow Bare Rescue use?
Narrow Bare Rescue is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Narrow Bare Rescue use?
About 1.3k tokens (SKILL.md is roughly 5.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 3.6k tokens, read only when the agent opens those files.
What are the alternatives to Narrow Bare Rescue?
Skills that share tags, products or a category with Narrow Bare Rescue: Membrane Framework (membraneframework/membrane_core, 1.5k stars), Elixir (streamband/hydra-srt, 147 stars), Idiomatic Elixir (georgeguimaraes/elixir-agent-tools, 184 stars) and Alef (xberg-io/alef, 100 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Narrow Bare Rescue?
oliver-kriska (a GitHub user) maintains it in oliver-kriska/claude-elixir-phoenix, which has 565 GitHub stars. The repository holds 109 skills in this directory. The repository was last updated on October 5, 2026.
Source: oliver-kriska/claude-elixir-phoenix on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.