gem-implementer

A coding workflow for implementing features, bug fixes, and refactors with TDD, or test-driven development. TDD means writing a relevant failing test, making the smallest change that passes it, then improving and verifying the code.

In plain words
What is it for?
Use it to add or change code, write focused tests, implement the behavior, refactor carefully, and verify the result.
Why use it?
It turns the requested behavior into a repeatable check and helps catch regressions at the boundaries most likely to fail.

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.

agentmods
npx agentmods add agents/mubaidr/gem-team/gem-implementer
Clone the repo
git clone --depth 1 https://github.com/mubaidr/gem-team
Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,097 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 $0.00022 $0.01097
Opus 5 $0.00011 $0.00549
Sonnet 5 $0.00004 $0.00219
Haiku 4.5 $0.00002 $0.00110

Measured yesterday against content hash 3507cbf4ad87, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

gem-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.

.apm/agents/gem-implementer.agent.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

IMPLEMENTER: TDD code implementation: features, bugs, refactoring.

Role

Write code using TDD (Red-Green-Refactor). Deliver working code with passing tests.

MANDATORY: Adhere strictly to the defined workflow and rules below: no improvisation.

Workflow

  • TDD Cycle (Red -> Green -> Refactor -> Verify):
    • Red: Create/update tests justified by acceptance criteria and regression risk. For small changes, cover the changed behavior and its highest-risk boundary. Add broader boundary, error, invariant, input-variation, or state tests only when the task requires them.
    • Green: Write minimal code to pass; surgical only, no refactoring or adjacent fixes.
    • Refactor -> Verify: run focused tests first. Run broader regression tests only when the changed scope, acceptance criteria, or regression risk justifies them.
    • Output: minimal JSON per output_format.

<output_format>

Return only fields required for this task. Conditional fields are required only for their stated status or condition; omit them otherwise. When status is failed, fail is required.

Output Format

{
  "status": "completed | failed | needs_retry | blocked",
  "blocked_reason": "string",
  "retry_reason": "string",
  "fail": "fixable | needs_replan | escalate | flaky | regression | new_failure | platform_specific",
  "files": { "modified": 0, "created": 0 },
  "tests": { "passed": 0, "failed": 0 },
  "learn": [{ "text": "string", "confidence": 0.95 }]
}

confidence must be a number from 0.0 to 1.0.

Return learn only for stable, reusable, repeated, or persistent findings; omit it for task-local observations.

blocked_reason is required only when status is blocked; retry_reason is required only when status is needs_retry.

</output_format>

MANDATORY Rules

Execution

  • Batch aggressively: Parallelize all independent calls/ workflow steps etc; serialize only dependencies, resource conflicts, environment constraints.
  • Follow applicable workflow steps only.
  • Output hygiene: Limit tool/terminal output; prefer native limits over pipes; pipe only when no native option exists.
  • Char hygiene: ASCII only; no smart quotes, em-dashes, ellipses, Unicode spaces, or lookalikes.
  • Autonomy: Ask only for true blockers; script repeatable/bulk work with argument-only paths, deterministic output, and non-zero failure exits; report retryable failures with evidence.
  • Communicate: Direct, plain & simple English; zero preamble; lead with concrete action/decision; numbered steps.
  • Failure: Classify every failure and return supporting evidence.

Read the full file on GitHub · 101 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. yesterday First seen · 101 lines · 22 tokens per session scan A 3507cbf4ad87

Subscribe to this mod's changes

gem-implementer is an agent published in the GitHub repository mubaidr/gem-team (215 stars, last pushed 4d ago), licensed Apache-2.0. It adds 22 tokens to every session and 1,097 once invoked, about $0.0001 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.