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 skills/leifericf/agentic-sdk/maintain-toolchainnpx skills add leifericf/agentic-sdk --skill maintain-toolchaingit clone --depth 1 https://github.com/leifericf/agentic-sdkWrote 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/leifericf/agentic-sdk/maintain-toolchain)<a href="https://agentmods.dev/skills/leifericf/agentic-sdk/maintain-toolchain"><img src="https://agentmods.dev/badge/skills/leifericf/agentic-sdk/maintain-toolchain.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 | $0.00039 | $0.00997 |
| Opus 5 | $0.00019 | $0.00498 |
| Sonnet 5 | $0.00008 | $0.00199 |
| Haiku 4.5 | $0.00004 | $0.00100 |
Grade A, and why
maintain-toolchain 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 4d 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 — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.
maintain-toolchain
Role: keep the toolchain pinned, diagnosed, and bumped, and keep the investigated ceiling from being re-spiked.
One law: the pin is the pin. Every lane runs the
pinned toolchain and only the pinned toolchain. The pin lives in the
descriptor (the :lanes commands assume it) and in the language-native
pin files (.zig-version plus build.zig.zon's minimum_zig_version
for Zig; .tool-versions or per-language version files for other
stacks; lockfiles where the language uses them). Never substitute a host
toolchain of a different version to make a lane pass. That is an
infrastructure failure to report, not to work around.
The doctor check
A doctor lane diagnoses the toolchain: it reads the pin, runs the host's
version command, and compares. It reports the resolved path, the running
version, the pinned version, and whether they match. Run it first when a
lane reports a toolchain problem. The doctor command is itself a lane in
the descriptor's table (commonly under :pre-land or a :doctor slot
the verifier runs on demand); it is not hardcoded here.
How lanes report the pin
A lane whose pinned toolchain is absent or mismatched hard-fails; it never silently passes on a different version. The line is exactly:
FAIL <lane>: pinned <tool> missing (repro: <doctor command>)
This applies to every lane in the table; the tier verdict is then
VERDICT: FAIL. Diagnose with the doctor check before touching
anything else; a missing pin is fixed by installing the pinned
toolchain, not by loosening the pin.
The bump ritual
A pin bump is deliberate and lands as its own commit.
- Update every pin site in lockstep: the descriptor, the language- native version files, the CI workflow's setup action, and any lockfile. Identical version in every site, one change.
- Regenerate whatever the toolchain produces (stencils, bindings, generated headers, format baselines) and commit the regeneration in the same change.
- The doctor check must report a match; the full lane table (all three tiers) must pass on the new pin before the bump commits.
- Commit alone, category-first subject (for example
Build: Bump pinned toolchain), no version number in the message.
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.
- 4d ago First seen · 97 lines · 39 tokens per session scan A 70a71e270a23
maintain-toolchain is a skill published in the GitHub repository leifericf/agentic-sdk (5 stars, last pushed 2d ago), licensed MIT. It adds 39 tokens to every session and 997 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.
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