Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add mathiasbourgoin/roster --skill roster-spec-infergit clone --depth 1 https://github.com/mathiasbourgoin/rosterWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/mathiasbourgoin/roster/roster-spec-infer)<a href="https://agentmods.dev/skills/mathiasbourgoin/roster/roster-spec-infer"><img src="https://agentmods.dev/badge/skills/mathiasbourgoin/roster/roster-spec-infer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/mathiasbourgoin/roster/roster-spec-infer"><img src="https://agentmods.dev/badge/skills/mathiasbourgoin/roster/roster-spec-infer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00082 | $0.02972 |
| Opus 5 | $0.00041 | $0.01486 |
| Sonnet 5 | $0.00016 | $0.00594 |
| Haiku 4.5 | $0.00008 | $0.00297 |
Grade A, and why
roster-spec-infer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 285 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Roster Spec-Infer
Reverse-engineer an evidence-tiered spec from an existing codebase. This is a
read-only analysis skill — it never modifies the target project. Every claim is
labeled by evidence strength: [E1] (test-proven), [E2] (code-inferred),
[E3] (doc-only). Conflicts between code and documentation are surfaced, never
silently resolved.
Input Contract
Required: <target> — a project root directory path (e.g. . or /path/to/project).
- If a file path is given: halt with "Target must be a directory (project root). Got:
<path>." - Slug derivation: lowercase the target directory's basename, replace spaces with
-, strip all non-alphanumeric/hyphen characters. Example:My Project!→my-project. - Collision check: if
specs/<slug>-inferred.mdalready exists, halt with: "Inferred spec already exists for<slug>. Overwrite? [y/N]" — stop if not confirmed.
Tunables:
| Tunable | Default | Effect |
|---|---|---|
include_git_history |
true |
Run Sub-agent 4 (Git History Miner) |
conflict_policy |
surface |
Only valid value in v1.0.0: always surface conflicts, never auto-resolve. Reserved for future extension. |
gap_threshold |
0 |
Register every uncovered public symbol as a GAP |
Steps
Sub-agent 1: Test Miner
Spawn a sub-agent (fresh context) with this prompt:
You are a Test Miner. Analyze the test suite of the target project and extract
behavioral assertions as evidence-tier-1 (E1) claims in Given/When/Then format.
Step 1 — Detect test framework (in this priority order):
- package.json `scripts.test` field
- pytest.ini / setup.cfg / pyproject.toml [tool.pytest]
- go.mod (go test ./...)
- pom.xml / build.gradle (mvn test / gradle test)
If no framework detected: emit "No test suite detected — all surfaces are E2/E3 or GAP."
and produce zero E1 claims. Stop.
Step 2 — Run the canonical test command. If exit code is non-zero: halt with:
"Test suite failed — E1 claims cannot be emitted. Fix test failures before
running roster-spec-infer."
Step 3 — Parse passing test files. For each behavioral assertion, produce one
E1 entry in Given/When/Then format:
- [E1] Given <setup/precondition>, When <action or call>, Then <assertion/outcome>
(evidence: <test-file>:<line>)
Use the actual test setup code as "Given", the call under test as "When", and
the assertion as "Then". If a test has multiple assertions, emit one E1 entry
per distinct behavioral claim, not per assertion line.
Cap at top-50 most-covered files if context limits are reached; note:
"Analysis limited to top N files due to context constraints."
Target directory: <target>
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 11d ago First seen · 285 lines · 82 tokens per session scan A 67d7d4516563
roster-spec-infer is a skill published in the GitHub repository mathiasbourgoin/roster (2 stars, last pushed 4d ago), licensed MIT. It adds 82 tokens to every session and 2,972 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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