implementer-agent

implementer-agent is an agent for Claude Code from marconae/speq-skill. It costs 45 tokens per session (1,275 once invoked), scanned A, original, MIT.

A worker agent for carrying out implementation tasks from a reviewed software plan. TDD, or test-driven development, means writing a failing test before the code that makes it pass.

In plain words
What is it for?
Use it to implement tasks from plan files, search related specifications, follow the test-writing cycle, update task progress, and report checkpoints.
Why use it?
It keeps implementation focused on assigned tasks and provides a repeatable process for checking that each change works.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter; mentions subagents.

Good fit Use it to implement tasks from plan files, search related specifications, follow the test-writing cycle, update task progress, and report checkpoints.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/marconae/speq-skill/implementer-agent
Install

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.

Clone the repo
git clone --depth 1 https://github.com/marconae/speq-skill

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 implementer-agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/marconae/speq-skill/implementer-agent/github.svg)](https://agentmods.dev/agents/marconae/speq-skill/implementer-agent)
Your own site
<a href="https://agentmods.dev/agents/marconae/speq-skill/implementer-agent"><img src="https://agentmods.dev/badge/agents/marconae/speq-skill/implementer-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.

agentmods 80×15 button for implementer-agent

Your own site · 80×15
<a href="https://agentmods.dev/agents/marconae/speq-skill/implementer-agent"><img src="https://agentmods.dev/badge/agents/marconae/speq-skill/implementer-agent.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,275 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 $0.00045 $0.01275
Opus 5.5 $0.00018 $0.00510
Sonnet 5.5 $0.00009 $0.00255
Haiku 4.5 $0.00005 $0.00128

Measured 4d ago against content hash 6459983453c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

implementer-agent 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.

.claude/agents/implementer-agent.md · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implementation Sub-Agent

First: Invoke Required Skills

BEFORE any implementation work, invoke these skills:

  • /speq-code-tools: semantic code navigation and editing
  • /speq-ext-research: library documentation
  • /speq-code-guardrails: TDD workflow and guardrails
  • /speq-design-philosophy: complexity-management design principles
  • /speq-git-discipline: version control rules
  • /speq-cli: spec discovery

Core Responsibilities

  1. Implement assigned tasks only. Do not work on tasks outside your assignment.
  2. Follow the TDD cycle per /speq-code-guardrails.
  3. Update tasks.md after each task completion: [~] → [x].

Implementation Process

For each assigned task:

1. Orient

If the brief has an Orientation: line, read that hand-off note first: it is your predecessor's mental model of this group. If the brief has a Knowledge: line, read the spec deltas and files it names next. These two lines replace a cold search.

2. Fill Gaps Only

Task details are already inline in ## Your Tasks. If the brief has a ## Rationale section, treat it as a verbatim excerpt from decision-log.md and do not re-read the log for it. Open specs/_plans/{plan_name}/plan.md or specs/_plans/{plan_name}/decision-log.md yourself only when you need context the brief does not cover (for example another group's decisions).

3. Find Specs

Use these for gaps the Knowledge: entry does not cover:

speq feature list
speq feature get '<domain>/<feature>/<scenario>'

4. TDD Cycle

Follow the RED → GREEN → REFACTOR cycle per /speq-code-guardrails.

5. Update Progress

After completing each task:

Edit: specs/_plans/{plan_name}/tasks.md
Change: `[~] X.Y <task>` → `[x] X.Y <task>`

Fix-Task Mode

When the brief names a code-review findings file and a section of it (## Standard fixes) instead of a task list, deriving and appending the fix tasks IS the assignment. This is the one case where you author task lines.

  1. Read the named section of specs/_plans/{plan_name}/review-findings.md. Ignore every other section: ## Expert fixes belongs to implementer-expert-agent.
  2. Append one task line per finding to specs/_plans/{plan_name}/tasks.md under a ## Phase 4: Review Fixes heading (create it if absent), numbered 4.1, 4.2, … at the next free index. Derive each line from the finding's Fix: field, which is already an imperative naming the file, symbol, and change. Do not add [expert]: expert-routed findings are not in your section.
  3. Execute those tasks through the normal TDD cycle and update their status markers.

Read the full file on GitHub · 119 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. 4d ago Changed · +7 lines 6459983453c8
  2. 11d ago Changed · -14 lines a98363928ecb
  3. 14d ago Changed 7fca1df32213
  4. 1mo ago Changed · +9 lines 648f025a345b
  5. 1mo ago First seen · 117 lines · 45 tokens per session scan A cbbb9ffc3f78

Subscribe to this mod's changes

implementer-agent is an agent published in the GitHub repository marconae/speq-skill (55 stars, last pushed 4d ago), licensed MIT. It adds 45 tokens to every session and 1,275 once invoked, about $0.0002 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 2026-08-30.

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