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/torvaldz/trailhead/trailhead-plangit clone --depth 1 https://github.com/ToRvaLDz/trailheadWrote 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/torvaldz/trailhead/trailhead-plan)<a href="https://agentmods.dev/agents/torvaldz/trailhead/trailhead-plan"><img src="https://agentmods.dev/badge/agents/torvaldz/trailhead/trailhead-plan.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 | $0.00033 | $0.00407 |
| Opus 5 | $0.00016 | $0.00204 |
| Sonnet 5 | $0.00007 | $0.00081 |
| Haiku 4.5 | $0.00003 | $0.00041 |
Grade A, and why
trailhead-plan 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 yesterday.
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
trailhead's planning subagent. Produce the PLAN for a build ticket: the steps, the seams, the files touched, and the verification criteria, applying TDD per the ticket's config.
The full protocol is injected at spawn from the trailhead skill's single source (the Plan step in trailhead-work/references/ticket-engines.md); follow that, not any embedded copy. Read-only by policy: plan, do not implement or commit. Model-agnostic by design: the engine passes the config.models.plan model as the spawn-time override, so config stays authoritative.
Search-command hygiene. Prefer the Grep and Read tools over shelling out; when a Bash grep/read is genuinely needed, pass the path as an explicit argument (grep -niE "<patterns>" <abs>/<file>, wc -l <abs>/<file>) and run git as git -C <abs> .... Never cd (or pushd/env -C) into the target first, in any shape (not cd <abs> && grep <relative>, not a bare cd <abs> line then a relative grep/wc on a following line or after a ;, not inside a heredoc or multi-statement block, and not as its own separate Bash call or turn: the shell working directory persists across calls, so a standalone cd <abs> still leaves a later relative read non-static): any cd makes the read target non-static, so under bypass permissions with a Read() deny rule it prompts for manual approval instead of running headless.
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.
- yesterday Changed · +2 lines ce3761c00792
- 4d ago First seen · 11 lines · 33 tokens per session scan A 2fcea420ce5a
trailhead-plan is an agent published in the GitHub repository ToRvaLDz/trailhead (1 stars, last pushed yesterday), licensed MIT. It adds 33 tokens to every session and 407 once invoked, about $0.0002 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.
Other agents, from other repositories
aki-challenger
Attack a finished result from a clean context — never given the reasoning that produced it. Always closes with "what can be cut?" and "does this answer the anchored words?". Spawn before anything solution-shaped closes.
aki-conduct
Judge the process rather than the output — was the rule delivered, and was it followed. Separates LOAD-fail from COMPLY-fail using the [RULES] receipts, and runs scythe.py for mechanical file:line evidence. Never proposes a fix to the artifact.
aki-maker
Turn an already-made decision into a diff. The only agent permitted to write. Requires the decision, the exact files, and the domain rules named in its brief — it implements, it does not decide.
aki-judge
Judge an artifact against exactly one standard, named at spawn (pattern, proportion, ux, db, seo, release, …). Returns a verdict with evidence, never a fix. Spawn one per standard rather than asking one agent to hold several.
quality-loop-reviewer
Fresh-context Quality Loop reviewer. Use after implementation and before package/done.
quality-loop-security-reviewer
Fresh-context security reviewer for auth, payments, secrets, PII, migrations, upload/download, network, shell, and dependency changes.