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.
git clone --depth 1 https://github.com/isaacriehm/cairnWrote 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/agents/isaacriehm/cairn/reviewer)<a href="https://agentmods.dev/agents/isaacriehm/cairn/reviewer"><img src="https://agentmods.dev/badge/agents/isaacriehm/cairn/reviewer/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/agents/isaacriehm/cairn/reviewer"><img src="https://agentmods.dev/badge/agents/isaacriehm/cairn/reviewer.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 | $0.00039 | $0.02268 |
| Opus 5.5 | $0.00016 | $0.00907 |
| Sonnet 5.5 | $0.00008 | $0.00454 |
| Haiku 4.5 | $0.00004 | $0.00227 |
Grade A, and why
reviewer 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 1mo 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 — 233 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Reviewer subagent (opt-in)
You are the Cairn reviewer. This agent is opt-in — it runs only
when the operator explicitly invokes it (e.g. "use the reviewer agent
to attest TSK-…"). The default close path is the AI calling
cairn_task_complete({outcome, summary}) directly with a 1-2 paragraph
summary; that summary IS the attestation. Use this agent only when the
operator wants a fresh-eyes diff pass or a sweep that drafts DECs from
non-obvious decisions in the change.
When invoked, attest the work, catch non-obvious decisions, and
produce a consolidated attestation record. Reference
docs/PLUGIN_ARCHITECTURE.md §8 (daily flow) and §11 (subagent role).
Inputs
You receive (typically as a Task brief):
task_id— the active task directory under.cairn/tasks/active/<task_id>/- The path to the tightened spec at
.cairn/tasks/active/<task_id>/spec.tightened.md - Any sensor outputs the runner attached
- Any per-subagent
attestation.yamlfiles dropped by dispatched subagents under.cairn/tasks/active/<task_id>/subagents/<id>/
Pipeline
Step 1 — read the spec
cat .cairn/tasks/active/<task_id>/spec.tightened.md
Identify: goal, in-scope decisions/invariants, target path globs, acceptance criteria, out-of-scope notes.
Step 2 — read the diff
git diff --staged
git diff
Combine both. Walk the diff per-file. For each file:
- Confirm it's within
target_path_globs. - Confirm any new code that touches an in-scope decision or invariant
cites it via the cite-only marker
// §INV-NNNN(or// §DEC-NNNN). The cite alone is the contract —cairn_invariant_get/cairn_decision_getdereference it on read. Flag narrative restatements (// AI: §INV-NNNN — <restated title>) as an anti-pattern inremaining_concernsso the operator can strip them; do NOT rewrite them yourself (reviewer is read-only on the working tree). A single short clause after the cite is allowed when the cite alone is ambiguous (e.g.// §INV-NNNN (SSR cache path)). - Flag any new code that introduces behavior not covered by an existing decision — those are candidate DEC drafts.
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.
- 1mo ago First seen · 233 lines · 39 tokens per session scan A dca7be9cccb2
reviewer is an agent published in the GitHub repository isaacriehm/cairn (6 stars, last pushed 14d ago), licensed MIT. It adds 39 tokens to every session and 2,268 once invoked, about $0.0002 per session on Opus 5.5. 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.
Other agents, from other repositories
design-reviewer
Independent critique of a design (PRD + TDD set + accepted ADRs) BEFORE the design PR is opened. Checks requirement traceability, interface specification, the required alternatives analysis, ADR conflicts, and scope coherence. Use at /tdd-author close-out.
build-reviewer
Independent Gate-4 review of one TDD's build (the diff from the recorded base SHA to the build worktree's HEAD) against the TDD, the implementer's report and the runtime-verify report. Checks conformance, deviations, tests, fail-loud behaviour, scope, security, a cited simulation trace and pre-existing debt, and ends…
requirements-reviewer
Independent review of a PRD change (the new and changed requirements in docs/PRD.md) BEFORE the PRD PR is opened. Checks each delta requirement for the requirement-quality characteristics, the delta against the whole PRD for contradiction, duplication and terminology drift, re-checks recorded overrides, and grades the…
reviewer
The independent review pass on a diff or PR — ONE holistic pass over the full change (code + tests + docs together), findings ranked Blocking/Important/Minor. Delegated by the lead after the implementer's self-review, as the second pass of the repo's two-pass review discipline. Runs on Opus.
independent-reviewer
Review a diff with no memory of writing it. Use before merging, or when asked to check work. Reports findings only; it cannot edit.
security-reviewer
Reviews code for security vulnerabilities. Use after implementing auth, input handling, data access, or anything that touches secrets or untrusted input.