Borrowing it
Nothing to install: this file belongs to tomcounsell/ai. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/tomcounsell/ai/main/.claude/skills-global/build-agent/SKILL.mdgit clone --depth 1 https://github.com/tomcounsell/aiWrote 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/tomcounsell/ai/build-agent)<a href="https://agentmods.dev/skills/tomcounsell/ai/build-agent"><img src="https://agentmods.dev/badge/skills/tomcounsell/ai/build-agent/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/tomcounsell/ai/build-agent"><img src="https://agentmods.dev/badge/skills/tomcounsell/ai/build-agent.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00053 | $0.02194 |
| Opus 5 | $0.00026 | $0.01097 |
| Sonnet 5 | $0.00011 | $0.00439 |
| Haiku 4.5 | $0.00005 | $0.00219 |
Grade B, and why
build-agent scanned grade B with 2 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 9d 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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
- Source the key from a `.env` in the working folder (chmod 600), never from chat. If `ANTHROPIC_API_KEY` Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
[references/cma-primitives.md](references/cma-primitives.md). **Always read this before any curl** — The source is not reproduced here
Licensed GPL-3.0
The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
What ships with it
2 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.
- 9d ago First seen · 143 lines · 53 tokens per session scan B c778a8f4903d
build-agent is a skill published in the GitHub repository tomcounsell/ai (24 stars, last pushed today), licensed GPL-3.0. It adds 53 tokens to every session and 2,194 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 2 findings (asks for root, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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