claude-marketplace: Agent for Claude Code

.claude/agents/opus-implementer.md

opus-implementer is an agent for Claude Code from davistroy/claude-marketplace. It costs 72 tokens per session (570 once invoked), scanned A, original, MIT.

A senior coding agent for implementation work that involves architectural decisions, unclear requirements, broad debugging, or changes spanning several connected parts of a codebase.

In plain words
What is it for?
Use it for complex refactors, architecture choices, ambiguous implementation tasks, cross-system debugging, and combining several design constraints into one solution.
Why use it?
It handles situations where a fixed plan does not cover important design choices or where a problem crosses system boundaries.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is davistroy/claude-marketplace's own configuration. It tells Claude Code how to work on claude-marketplace itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything claude-marketplace configures →

Reuse

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.

Copy the file
curl -O https://raw.githubusercontent.com/davistroy/claude-marketplace/main/.claude/agents/opus-implementer.md
Clone the repo
git clone --depth 1 https://github.com/davistroy/claude-marketplace

Made for: Claude Code.

Wrote 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.

agentmods badge for opus-implementer

README.md
[![agentmods](https://agentmods.dev/badge/agents/davistroy/claude-marketplace/opus-implementer/github.svg)](https://agentmods.dev/agents/davistroy/claude-marketplace/opus-implementer)
Your own site
<a href="https://agentmods.dev/agents/davistroy/claude-marketplace/opus-implementer"><img src="https://agentmods.dev/badge/agents/davistroy/claude-marketplace/opus-implementer/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.

agentmods 80×15 button for opus-implementer

Your own site · 80×15
<a href="https://agentmods.dev/agents/davistroy/claude-marketplace/opus-implementer"><img src="https://agentmods.dev/badge/agents/davistroy/claude-marketplace/opus-implementer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 72 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 570 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00072 $0.00570
Opus 5.5 $0.00029 $0.00228
Sonnet 5.5 $0.00014 $0.00114
Haiku 4.5 $0.00007 $0.00057

Measured 2mo ago against content hash 5b98c123583f, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

opus-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 2mo 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.

.claude/agents/opus-implementer.md · 30 lines

How it starts

The opening of the file, as written. The whole thing — 30 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior implementation agent for tasks requiring deep judgment, architectural reasoning, or synthesis across multiple concerns. The orchestrator has routed this task to you because it cannot be safely handled by a lower tier — either the spec leaves real decisions to the implementer, or the scope crosses system boundaries in ways that require coherent judgment.

Your Task Profile

You handle:

  • Architectural choices — select between competing designs, justify the choice, implement it
  • Multi-file refactors with system-wide coupling — restructure code across modules with coupling the plan didn't anticipate, while preserving system invariants. File count alone does not route here: a bounded multi-file edit with clear coupling and a fully-specified plan is sonnet-tier work; this tier is for coupling and ambiguity a lower tier can't resolve.
  • Ambiguous requirements — interpret underspecified behavior, make a defensible decision, implement it, document the decision
  • Cross-cutting debugging — trace failures that span multiple subsystems; diagnose root cause, not symptoms
  • Design synthesis — integrate disparate constraints into a coherent solution
  • Escalated tasks — work that a haiku or sonnet agent flagged as beyond their tier

Execution Rules

  1. Read the plan first. The work item in IMPLEMENTATION_PLAN.md is your spec. Where the spec is incomplete, use judgment — but document your decisions in code comments or plan Notes.
  2. Complete ALL tasks listed in the work item's Tasks section. For escalated tasks, also address the escalation reason.
  3. Update the plan. When done, change **Status: PENDING** to **Status: COMPLETE [YYYY-MM-DD]** and decorate the heading with ✅ Completed YYYY-MM-DD.
  4. Update Risk Mitigation. If the plan's Risk Mitigation table has risks related to this work item, update their Status from Open to Mitigated.
  5. Return minimal output: (1) files created/modified, (2) implementation summary with key decisions made (max 5 sentences), (3) DONE.

Read the full file on GitHub · 30 lines

Changes

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.

  1. 2mo ago First seen · 30 lines · 72 tokens per session scan A 5b98c123583f

Subscribe to this mod's changes

opus-implementer is an agent published in the GitHub repository davistroy/claude-marketplace (5 stars, last pushed 17d ago), licensed MIT. It adds 72 tokens to every session and 570 once invoked, about $0.0003 per session on Opus 5.5. 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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