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/stjbrown/codemodekit/build-codemodekit-servernpx skills add stjbrown/codemodekit --skill build-codemodekit-servergit clone --depth 1 https://github.com/stjbrown/codemodekitWrote 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/stjbrown/codemodekit/build-codemodekit-server)<a href="https://agentmods.dev/skills/stjbrown/codemodekit/build-codemodekit-server"><img src="https://agentmods.dev/badge/skills/stjbrown/codemodekit/build-codemodekit-server.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 | $0.00090 | $0.00866 |
| Opus 5 | $0.00045 | $0.00433 |
| Sonnet 5 | $0.00018 | $0.00173 |
| Haiku 4.5 | $0.00009 | $0.00087 |
Grade A, and why
build-codemodekit-server 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 — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Build a CodeModeKit Server
Build a walking skeleton for the user's actual source, then verify it through the downstream MCP surface. Keep model-authored code in CodeModeKit's sandbox and host integrations behind tool providers.
Build workflow
- Inspect the repository, package manager, local instructions, existing MCP configuration, and relevant application functions. Do not overwrite unrelated work.
- Choose the source boundary:
- Use Local Tools for functions or APIs the application owns.
- Use
mcp.stdiofor a shell-free executable and argument array. - Use
mcp.httpfor a Streamable HTTP MCP endpoint. - Compose sources when one authored program needs more than one namespace.
- For a new project, prefer the generator. Read references/generator.md for commands and generated-file ownership.
- For a retrofit or custom server, read references/server-api.md, preserve the batteries-included facade, and expose compiler or sandbox configuration only when the user needs an expert override.
- Define an explicit tool policy. Read references/policy-and-security.md before enabling writes, handling credentials, or binding Streamable HTTP beyond loopback.
- Keep the initial implementation compact. A single
src/server.mjsis the default; split it only when domain code already has a natural module boundary. - If the project includes an Agent Plugin, run catalog sync and build, but do not pretend the generated runtime skill understands the domain. When an MCP client must discover the packaged skill, read references/experimental-skills.md and verify that extension separately. Invoke
$author-codemode-skillafter the server works. - Verify the downstream behavior using references/verification.md. Exercise
run_typescript, not merely imports or direct provider functions.
The walking skeleton is complete when one realistic downstream execution crosses compilation, QuickJS, policy, the bridge, and the chosen provider and returns the expected bounded value.
What ships with it
6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 · 49 lines · 90 tokens per session scan A 8720d18e87c3
build-codemodekit-server is a skill published in the GitHub repository stjbrown/codemodekit (1 stars, last pushed 12d ago), licensed Apache-2.0. It adds 90 tokens to every session and 866 once invoked, about $0.0005 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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