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/cofin/flow/tracernpx skills add cofin/flow --skill tracergit clone --depth 1 https://github.com/cofin/flowWhat 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 | $0.00038 | $0.00303 |
| Opus 5 | $0.00019 | $0.00151 |
| Sonnet 5 | $0.00008 | $0.00061 |
| Haiku 4.5 | $0.00004 | $0.00030 |
Grade A, and why
tracer 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 3d 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.
What it actually says
Tracer
Trace code from a known entry point, following evidence-linked edges until the question is answered.
Workflow
- Load the tracing strategy and mode-selection reference below.
- Select execution, dependency, or data mode from the question.
- Follow and record relevant edges, then synthesize the resulting map at the documented stop condition.
Guardrails
Do not open unrelated files, trace every branch indiscriminately, or cross a third-party boundary unless the question requires it.
Output
Return the selected mode, an ordered path or dependency/data map with file and symbol locations, transformations and side effects, and a concise answer to the original question.
Validation
Confirm every inspected node follows from a recorded edge and the trace stops only after the question or critical path is resolved.
Example
Map an HTTP handler through its service and repository to the database call, annotating the data transformation at each node.
References
- Tracing strategy — traversal and evidence procedure.
- Trace modes — mode selection and combination.
What ships with it
3 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.
- 3d ago First seen · 59 lines · 38 tokens per session scan A d992803ef11f
tracer is a skill published in the GitHub repository cofin/flow (15 stars, last pushed 4d ago), licensed Apache-2.0. It adds 38 tokens to every session and 303 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 2026-08-30.
Other skills, from other repositories
subagent-driven-development
Use when executing implementation plans with independent tasks in the current session.
write-documentation
Use when writing or substantially rewriting human-facing prose: documentation, README, guides, blog posts, emails, Slack messages, PR descriptions, release notes, or any text a human will read. Not for code comments, commit messages, or agent-to-agent communication.
document-release
Use when implementation on a branch is complete and it is about to be merged or PR'd — or when finishing-a-development-branch reaches its docs-audit gate — and after code changes are committed, to ensure all project documentation accurately reflects shipped code. Covers README, ARCHITECTURE, CONTRIBUTING, CHANGELOG…
finishing-a-development-branch
Use when implementation is complete, all tests pass, and you need to decide how to integrate the work - guides completion of development work by presenting structured options for merge, PR, or cleanup.
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
writing-plans
Use when you have a spec or requirements for a multi-step task, before touching code.