Does your SKILL.md actually fire? Test skill activation in Claude Code, Codex and OpenCode with one command.
Leer en español · Example report
You wrote a skill. Its description is the only thing the agent sees when it decides whether to load it.
Does Claude Code load it when a user asks for it? Does Codex? Does OpenCode? Does it also load when nobody asked?
doesitfire runs the real agent CLIs on prompts that should and should not trigger each skill, a few times each,
and gives you one activation matrix per agent.
Why
Other tools test part of this:
| Tool | What it measures | Agents |
|---|---|---|
| microsoft/waza (1,499★) | Has trigger tests, run through its GitHub Copilot executor | GitHub Copilot |
claude plugin eval (built into the Claude Code CLI) |
Eval cases with graders against a plugin or skills dir | Claude Code only |
| darkrishabh/agent-skills-eval (809★) | Output quality with vs without the skill injected | Not activation |
| NVIDIA/SkillEvaluator (626★) | Output quality with vs without the skill injected | Not activation |
| doesitfire | Whether the real agent loads the skill on its own, and how often it loads it when it should not | Claude Code, Codex, OpenCode |
Star counts from the GitHub API on 3 Nov 2026.
Quickstart
The demo needs no API key, no Docker and no model. It shows a recorded real run of the three
example skills in examples/:
uvx --from git+https://github.com/diegoperezg7/doesitfire@v0.1.2 doesitfire demo
or from a clone:
git clone https://github.com/diegoperezg7/doesitfire && cd doesitfire && uv run doesitfire demo
uvx doesitfire is coming to PyPI.
Example output
Recorded on 2026-11-03 on an Apple M4, 16 GB with doesitfire 0.1.0. Each agent ran its own CLI with the model shown; read each column on its own, not as a ranking of agents.
| Agent | CLI | Model | Skills | Prompts | Repeats | Runs | Errored (excluded) |
|---|---|---|---|---|---|---|---|
| claude-code | 2.1.317 | ollama/qwen3:4b-16k | 2 | 12 of 24 | 1 | 12 | 1 |
| opencode | 1.19.5 | mistral/ministral-8b-latest | 3 | 24 | 3 | 72 | 11 |
Errors: claude-code: 1 x timeout after 900s; opencode: 11 x Bad Request
Fired runs / valid runs. should = prompts that should load the skill; should not = near misses.
| Skill | claude-code · should / should not | opencode · should / should not |
|---|---|---|
commit-message |
1/4 / 0/4 | 12/12 / 3/12 |
regex-explainer |
0/3 / 0/0 | 6/6 / 0/12 |
dockerfile-review |
0/0 / 0/0 | 12/12 / 0/7 |
| all | 1/7 / 0/4 | 30/30 / 3/31 |
Recall per agent: claude-code 14%, opencode 100%. False-fire rate: claude-code 0%, opencode 10%.
The raw JSON events of every run are in examples/recorded/logs/.
claude-code: 11 valid runs of 24 prompts (12 run, 1 timeout excluded as infrastructure), 1 repeat. opencode: 61 valid runs of 72 (24 prompts x 3 repeats, 11 Mistral HTTP 400 excluded). codex: not in the recorded demo.
The suite is examples/doesitfire.yaml (all agents on Ollama) and
examples/doesitfire.mistral.yaml (OpenCode on Mistral). OpenCode's errored runs are
HTTP 400s from Mistral: when the model calls a tool that doesitfire denies (for example WebFetch), OpenCode's next
request ends with an assistant message, which Mistral rejects. They are excluded from the rates, not counted as "did not fire".
Test your own skills
You need Docker and either Ollama (free, local) or an API key.
cd your-repo # with skills in .claude/skills, .agents/skills, skills/, ...
uvx --from git+https://github.com/diegoperezg7/doesitfire@v0.1.2 doesitfire init
# edit doesitfire.yaml: 4+ prompts that should load each skill, 4+ near misses that should not
uvx --from git+https://github.com/diegoperezg7/doesitfire@v0.1.2 doesitfire run
run builds the agent image on first use (about 1.9 GB, a few minutes), then prints the matrix and writes
doesitfire-results/ with results.json, report.html, junit.xml, badge.svg and badge.json.
Local and free with Ollama
The agent CLIs send 6k to 11k token prompts, and Ollama loads models with a 4k context by default, so create a 16k variant once (same weights, no extra download):
ollama pull qwen3:4b
ollama create qwen3:4b-16k -f ollama/Modelfile # FROM qwen3:4b + PARAMETER num_ctx 16384
On Linux, start Ollama with OLLAMA_HOST=0.0.0.0 so containers can reach it.
Paid models
Keys are read from environment variables only (see .env.example). Paid providers need a
price per million tokens so --max-cost (default 1 USD) can stop the run before it overspends:
agents:
claude-code: {provider: anthropic, model: claude-haiku-5-5, price: {input: 1.0, output: 5.0}}
codex: {provider: openai, model: gpt-5.6-luna, price: {input: 0.20, output: 1.20}}
opencode: {provider: openrouter, model: deepseek/deepseek-v4.1-flash, price: {input: 0.045, output: 0.50}}
| Agent | Providers | API it needs |
|---|---|---|
| Claude Code | anthropic (ANTHROPIC_API_KEY or CLAUDE_CODE_OAUTH_TOKEN), openrouter, ollama |
Anthropic Messages |
| Codex | openai, openrouter, ollama |
OpenAI Responses |
| OpenCode | ollama, openrouter, openai, mistral, anthropic |
Chat Completions or Anthropic |
How it works
flowchart LR
Y[doesitfire.yaml<br/>skills + prompts] --> R[runner<br/>skill x prompt x agent x repeat]
R --> C1
subgraph net [internal Docker network, no route out]
C1[agent container<br/>Claude Code / Codex / OpenCode<br/>skills in its discovery dir]
P[egress proxy<br/>model API only]
C1 --> P
end
P --> M[(model API<br/>or Ollama)]
C1 -- JSON events --> D[activation detector]
D --> O[matrix · results.json · JUnit · HTML · badge]
For every skill, prompt, agent and repeat, doesitfire starts a fresh container, copies the skills into that
agent's discovery directory (.claude/skills, .agents/skills, .opencode/skills) and runs the CLI headless.
It reads the CLI's JSON event stream as it arrives:
| Agent | Command | A run counts as fired when |
|---|---|---|
| Claude Code | claude -p --output-format stream-json --verbose |
a Skill tool call names the skill |
| OpenCode | opencode run --format json |
its native skill tool is called with the skill |
| Codex (experimental) | codex exec --json |
a command reads <skill>/SKILL.md. Codex documents no activation event, so this is inferred |
With a local model, a run stops as soon as the outcome is known (a tested skill fired, or the turn cap was hit). With a paid model, it runs to the end so the CLI reports token usage for the budget.
Metrics, per agent and skill: recall (should-fire runs that loaded the skill), false-fire rate (should-not runs that loaded it) and precision (loads that were wanted). Runs that error out (timeout, API error) are left out of every rate and shown apart.
Isolation. Each container is non-root, with a read-only root filesystem, all capabilities dropped,
no-new-privileges, CPU, memory, pids and time limits. Its only network peer is an egress proxy that allows the
model API host and port and returns 403 for everything else (blocked attempts are listed in the report).
Bash, Write, Edit and web tools are denied in Claude Code, edit, bash and webfetch in OpenCode, and turns are
capped at 2. Codex has no read-only file tool and its own sandbox cannot start inside an unprivileged container,
so its shell runs inside the container limits. doesitfire refuses to run without Docker. Details in
SECURITY.md.
Configuration
repeats: 3 # runs per prompt and agent; activation is not deterministic
timeout: 300 # seconds per agent run
max_turns: 2 # agent turns per run; activation happens in the first one
cpus: 1 # per container
memory: 1g # per container
agents:
claude-code: {provider: ollama, model: qwen3:4b-16k}
codex: {provider: ollama, model: qwen3:4b-16k}
opencode: false # skip an agent
skills:
- path: .claude/skills/commit-message # a directory with a SKILL.md
should_fire:
- "Write a commit message for my change: I added a login form."
should_not_fire:
- "How do I undo my last git commit but keep the changes?"
| Command | What it does |
|---|---|
doesitfire init [DIR] |
Writes doesitfire.yaml with every skill found under DIR |
doesitfire run |
Runs the matrix. --agents, --skills, --repeats, --max-cost, --min-recall, --max-false-fire, --out |
doesitfire report results.json |
Re-renders the matrix, HTML, JUnit and badge |
doesitfire demo |
Shows the recorded example run |
--min-recall 0.75 --max-false-fire 0.25 makes run exit 1 when any agent x skill cell misses them; that is
what you want in CI. Budget stops exit 3 and keep the partial results.
GitHub Action
Linux runners only (the agents run in Docker; hosted macOS runners have no Docker):
- uses: diegoperezg7/doesitfire@v0.1.2
with:
config: doesitfire.yaml
max-cost: "1.0"
min-recall: "0.75"
max-false-fire: "0.25"
env:
ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
A complete workflow that also uploads the report and the JUnit results is in
examples/workflows/doesitfire.yml.
Badge. run writes badge.svg and badge.json (a shields.io endpoint).
Commit badge.svg and link it, or publish badge.json (for example to GitHub Pages) and use
https://img.shields.io/endpoint?url=<url-of-badge.json>.
What was live-tested
| Agent | Live-tested with | Notes |
|---|---|---|
| Claude Code 2.1.317 | Ollama qwen3:4b (16k context) through Ollama's Anthropic-compatible /v1/messages. The recorded demo has 12 of the 24 prompts (1 repeat): at 4-14 minutes per run on this laptop the rest did not finish in time |
No Claude model: this release was built without an Anthropic key. provider: anthropic (API key or CLAUDE_CODE_OAUTH_TOKEN from claude setup-token) is unit-tested, not live-tested. |
| Codex 0.166.0 | Supported; activation detection validated in the Docker integration test (real Codex CLI against the mock model), not in the recorded demo | Detection is experimental (reads of SKILL.md). A live Ollama run was started but did not finish in time for v0.1.0. |
| OpenCode 1.19.5 | Mistral ministral-8b-latest (paid, OpenAI-compatible) |
The recorded demo uses it. Also checked against Ollama during development. |
Mistral is the only paid provider called live (OpenCode, 72 runs, cost measured from usage). Anthropic, OpenAI and
OpenRouter are wired and unit-tested, including the --max-cost guard, but were not called. CI runs the three real CLIs in Docker against a scripted mock
model (tests/mockmodel.py) on every push, so a CLI output change breaks the build, not your results.
Every agent runs with its CLI defaults, thinking included. Turning qwen3's thinking off in Ollama looks like a speed-up, but the model then writes its reasoning as plain text and stops before emitting the tool call, so skills look like they never fire. doesitfire does not do that.
One Ollama quirk is handled for you: Ollama's Responses API drops input messages with role developer, which is where
Codex lists the available skills. For Codex on Ollama only, the egress proxy rewrites them to system (plain HTTP
to your local Ollama; HTTPS traffic to paid APIs is tunnelled untouched).
Use it from Claude Code
Install the plugin and ask Claude in plain words; its test-skill-activation skill finds your skills, writes prompts that should and should not trigger each one, agrees the budget with you, runs doesitfire and rewrites the descriptions of skills that miss, then re-runs them to check.
/plugin install doesitfire --marketplace diegoperezg7/doesitfire
The skill tells Claude to ask before any paid run, and --max-cost still caps the spend.
Roadmap
- Cursor, Gemini CLI and GitHub Copilot CLI.
- Suggesting prompts and better descriptions with an LLM.
- Multi-turn conversations.
- Conflicts between skills (two skills competing for the same prompt).
- GitHub Marketplace listing.
Part of a series
Open source tools that evaluate agents and LLMs on your own data:
- memarena: Benchmark memory layers on your own conversations.
- parsearena: Compare PDF parsers side by side and their effect on retrieval.
- commitarena: Replay real bug fixes from your git history against any model.
- toolbloat: Measure the token cost of your MCP stack and tool-choice errors.
- rulelab: Find which AGENTS.md rules earn their tokens.
License
MIT. The three example skills in examples/skills are MIT too and were written for this project.
Metadata
Release files for doesitfire 0.1.2
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Built distribution (wheel)
| File | Interpreter | ABI | Platform | Actions Reset |
|---|---|---|---|---|
| doesitfire-0.1.2-py3-none-any.whl | Python 3 | none | any | Details for doesitfire-0.1.2-py3-none-any.whl |
Total release size: 983.0 kB
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