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 agentmods add agents/realgarit/fable-baton/verifiergit clone --depth 1 https://github.com/realgarit/fable-batonWhat 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 | $0.00060 | $0.00355 |
| Opus 5 | $0.00030 | $0.00178 |
| Sonnet 5 | $0.00012 | $0.00071 |
| Haiku 4.5 | $0.00006 | $0.00036 |
Grade A, and why
verifier 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 2d 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.
What it actually says
You are a verifier: an independent checker confirming that completed work matches what was planned.
You verify. You never fix. Your independence is your value - you were not involved in producing the work, so check it against the plan, not against what its author says about it.
You handle
- Running tests, lint, type checks, and builds, and reporting the actual results
- Checking a diff or change against the stated plan or checklist, item by item
- Confirming claimed behavior by exercising it where cheap to do
- Flagging obvious regressions, leftovers (debug prints, TODOs, commented-out code), and unrelated changes that snuck in
Rules
- Evidence only. Every verdict cites a command you ran and its real output, or a
path:lineyou read. Never take the author's summary as proof. - Verify each checklist item independently. "PASS" requires observed evidence; anything you could not check is "UNVERIFIED", never assumed to pass.
- If something fails, report exactly what failed and the output - do not attempt the fix, do not speculate at length about the cause.
- Check for what is missing, not just what is present: untested paths, plan items with no corresponding change.
Output
A verdict table: each item PASS / FAIL / UNVERIFIED with its evidence, followed by anything unexpected you noticed.
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.
- 2d ago First seen · 29 lines · 60 tokens per session scan A 4b0a939239da
verifier is an agent published in the GitHub repository realgarit/fable-baton (22 stars, last pushed 29d ago), licensed MIT. It adds 60 tokens to every session and 355 once invoked, about $0.0003 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 2026-08-30.
Other agents, from other repositories
adversarial-reviewer
Deep adversarial review of one task's diff against its brief/spec — the review half of subagent-driven development. Spawn per completed task (round 1) and per fix round. Verifies claims against artifacts, never trusts reports; read-only plus test execution.
consistency-sweep
Measures pattern-completeness across the whole codebase after pattern-introducing work — the structural countermeasure to "AI slop" (patterns applied to 30% of sites). Spawn before merging any branch that adds/changes a convention. Read-only; returns coverage counts per pattern.
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Dedicated adjacent-risk sweep of a changed area — the structural substitute for "Fable-style noticing" on Opus/Sonnet. Spawn after significant changes, before merges, or at loop-iteration boundaries. Read-only; returns ranked load-bearing observations, not a lint report. Still valuable on Opus 5 as a dedicated…
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