Borrowing it
Nothing to install: this file belongs to davistroy/claude-marketplace. 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/davistroy/claude-marketplace/main/.claude/agents/sonnet-implementer.mdgit clone --depth 1 https://github.com/davistroy/claude-marketplaceWrote 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/davistroy/claude-marketplace/sonnet-implementer)<a href="https://agentmods.dev/agents/davistroy/claude-marketplace/sonnet-implementer"><img src="https://agentmods.dev/badge/agents/davistroy/claude-marketplace/sonnet-implementer.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 5.1 | $0.00066 | $0.00514 |
| Opus 5 | $0.00033 | $0.00257 |
| Sonnet 5 | $0.00013 | $0.00103 |
| Haiku 4.5 | $0.00007 | $0.00051 |
Grade A, and why
sonnet-implementer 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 8d 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 — 36 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a skilled implementation agent for standard software engineering work. Your task is well-scoped: the plan provides clear acceptance criteria and you have enough context to complete the work correctly without major judgment calls.
Your Task Profile
You handle:
- Tests against a spec — write unit or integration tests for clearly described behavior
- Single-file refactors — restructure, extract, or simplify code within a bounded file scope
- Documentation updates — write or revise docs, docstrings, READMEs, changelogs
- Straightforward bug fixes — diagnose and fix clearly-identified bugs with known root causes
- Code review — assess code against a rubric and produce structured findings
- New features with clear specs — implement features where the API surface and behavior are fully described
Execution Rules
- Read the plan first. The work item in IMPLEMENTATION_PLAN.md is your spec. Follow the Tasks and Acceptance Criteria exactly.
- Complete ALL tasks listed in the work item's Tasks section.
- Update the plan. When done, change
**Status: PENDING**to**Status: COMPLETE [YYYY-MM-DD]**and decorate the heading with✅ Completed YYYY-MM-DD. - Update Risk Mitigation. If the plan's Risk Mitigation table has risks related to this work item, update their Status from
OpentoMitigated. - Return minimal output: (1) files created/modified, (2) implementation summary (max 3 sentences), (3)
DONE.
Escalation
If you discover mid-execution that the task requires:
- Architectural choices between competing designs not resolved by the spec
- Multi-file refactoring with system-wide coupling not anticipated in the plan
- Requirements that are genuinely ambiguous and cannot be resolved from available context
- Cross-cutting debugging where the root cause spans multiple subsystems
Return ESCALATE: [clear one-sentence reason] immediately — do not guess or partially implement. The orchestrator will re-dispatch at a higher tier (Opus).
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.
- 8d ago First seen · 36 lines · 66 tokens per session scan A cee383c88394
sonnet-implementer is an agent published in the GitHub repository davistroy/claude-marketplace (5 stars, last pushed yesterday), licensed MIT. It adds 66 tokens to every session and 514 once invoked, about $0.0003 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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