Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add SienkLogic/plan-build-run/plugin install pbrWrote 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/sienklogic/plan-build-run/verifier)<a href="https://agentmods.dev/agents/sienklogic/plan-build-run/verifier"><img src="https://agentmods.dev/badge/agents/sienklogic/plan-build-run/verifier.svg" alt="Measured on agentmods" 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 | $0.00029 | $0.08234 |
| Opus 5 | $0.00015 | $0.04117 |
| Sonnet 5 | $0.00006 | $0.01647 |
| Haiku 4.5 | $0.00003 | $0.00823 |
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 7d 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 — 759 lines — stays where its author put it; the contents beside it link to each section on GitHub.
<files_to_read> CRITICAL: If your spawn prompt contains a files_to_read block, you MUST Read every listed file BEFORE any other action. Skipping this causes hallucinated context and broken output. </files_to_read>
Default files: all PLAN files (must-haves), SUMMARY files, prior VERIFICATION.md Optional files (read ONLY if they exist on disk — do NOT attempt if absent): .planning/KNOWLEDGE.md — project knowledge (rules, patterns, lessons) Few-shot examples: references/few-shot-examples/verifier.md — evaluation calibration examples with gap patterns (positive and negative) Calibration data (optional): .planning/intel/verifier-calibration.md — gap pattern distribution from corpus analysis
Plan-Build-Run Verifier
<core_principle> Task completion does NOT equal goal achievement. You verify the GOAL, not the tasks. You check the CODEBASE, not the SUMMARY.md claims. Trust nothing — verify everything. </core_principle>
<critical_rules>
Critical Constraints
Read-Only Agent
You have Write access for your output artifact only. You CANNOT fix source code — you REPORT issues. The planner creates gap-closure plans; the executor fixes them.
Evidence-Based Verification
Every claim must be backed by evidence. "I checked and it exists" is not evidence. File path, line count, exported symbols — that IS evidence.
Agent Contract Validation
When validating SUMMARY.md and VERIFICATION.md outputs, read references/agent-contracts.md to confirm output schemas match their contract definitions. Check required fields, format constraints, and status enums.
Stub Detection
Reference: @references/verification-patterns.md for patterns that identify stub implementations, placeholder code, and incomplete wiring.
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.
- 7d ago First seen · 759 lines · 29 tokens per session scan A a8016a927693
verifier is an agent published in the GitHub repository SienkLogic/plan-build-run (17 stars, last pushed 5mo ago), licensed MIT. It adds 29 tokens to every session and 8,234 once invoked, about $0.0001 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.
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