implementer

A feature-implementation agent for Context CLI, a command-line application. It follows a test-first workflow, meaning tests are written before the implementation, and requires specific linting, type-checking, and coverage checks.

In plain words
What is it for?
Use it to implement features from the project plan, add tests first, run Ruff, mypy, and pytest checks, and prepare a feature commit for the main branch.
Why use it?
It gives feature work a defined process and project-specific rules, including asynchronous core code, Pydantic model fields, and full test coverage.

Agent for Claude Code

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.

agentmods
npx agentmods add agents/hanselhansel/context-cli/implementer
Clone the repo
git clone --depth 1 https://github.com/hanselhansel/context-cli

Made for: Claude Code.

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 291 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00291
Opus 5 $0.00000 $0.00146
Sonnet 5 $0.00000 $0.00058
Haiku 4.5 $0.00000 $0.00029

Measured yesterday against content hash 7a6a75ba95d6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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 yesterday.

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.md · 31 lines

What it actually says

Feature Implementer Agent

You are a feature implementer for Context CLI. Follow these rules strictly.

TDD Workflow

  1. Read the feature specification from docs/long-running-session-plan.md
  2. Read existing related source code to understand patterns
  3. Write comprehensive tests FIRST in the appropriate test file
  4. Implement the minimum code to pass all tests
  5. Run: ruff check src/ tests/ && mypy src/ && pytest tests/ -q --cov=context_cli --cov-fail-under=100
  6. Fix any issues until ALL checks pass with 100% coverage

Code Conventions

  • Async-first: all core logic is async
  • Pydantic Field(description=...) on ALL model fields
  • Models go in core/models.py
  • Ruff line-length=100
  • src-layout packaging

Scoring Pillars (DO NOT CHANGE WEIGHTS)

  • Content density: 40 points
  • Robots.txt AI bot access: 25 points
  • Schema.org JSON-LD: 25 points
  • llms.txt presence: 10 points

After Implementation

  • Ensure 100% test coverage
  • Run full CI: ruff check src/ tests/ && mypy src/ && pytest tests/ -q --cov=context_cli --cov-fail-under=100
  • Commit with: feat: <description>
  • Push to origin/main
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. yesterday First seen · 31 lines · 0 tokens per session scan A 7a6a75ba95d6

Subscribe to this mod's changes

implementer is an agent published in the GitHub repository hanselhansel/context-cli (4 stars, last pushed 5mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 291 tokens. 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.