decomp-implementer

An implementation agent that builds a from-scratch replacement for a dependency inside a yoink package.

In plain words
What is it for?
Use it during dependency decomposition to replace an API wrapper, orchestration layer, utility, or framework component used by the main package.
Why use it?
It turns a dependency evaluation into working replacement code and checks the result against the top-level package’s test suite.

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/theogbrand/yoink/decomp-implementer
Clone the repo
git clone --depth 1 https://github.com/theogbrand/yoink
Per session 35 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,205 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. 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 $0.00035 $0.01205
Opus 5 $0.00017 $0.00602
Sonnet 5 $0.00007 $0.00241
Haiku 4.5 $0.00003 $0.00120

Measured 2d ago against content hash 1edabbd8aa62, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

decomp-implementer scanned grade B with 1 finding 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 2d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

grep "^score:" .claude/decomp-implementer-loop/{sub_package}-iteration-<N>-run.log | tee -a .claude/decomp-implementer-loop/{sub_package}-scores.log
plugins/yoink/agents/decomp-implementer.md · 92 lines

How it starts

The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Decomposition Implementer — Build yoink_{sub_package}/

Read .claude/inner-yoink-loop.local.md for your runtime input variables. Your goal is to build yoink_{sub_package}/ — a from-scratch replacement for {sub_package}. Success means the yoink_{top_package}/ test suite passes entirely against your implementation.

Input

Read from .claude/inner-yoink-loop.local.md (JSON code block after YAML frontmatter):

Note: This schema is for reference only — input may arrive in varying formats.

{
  "top_package": { "type": "string", "description": "The top-level package being decomposed" },
  "sub_package": { "type": "string", "description": "The sub-package to build a replacement for" },
  "category": { "type": "string", "enum": ["API wrapper", "orchestration layer", "utility", "framework"], "description": "Classification of the library" },
  "strategy": { "type": "string", "description": "What to replace it with and how" },
  "functions_to_replace": { "type": "array", "items": { "type": "string" }, "description": "Specific functions/classes used by yoink_{top_package}/" },
  "reference_material": { "type": "string", "description": "API docs URL or library source path" },
  "acceptable_sub_dependencies": { "type": "array", "items": { "type": "string" }, "description": "What lower-level deps are OK to introduce" },
  "max_iterations": { "type": "integer", "description": "Maximum loop iterations before auto-stop" }
}

Rules

  • Implement real functionality. Your replacement must do what the original library actually does — make real HTTP calls, parse real responses, handle real errors. Do not implement stubs, mock helpers, or test-mode-only logic. If the tests use mocks, look past the mocks to understand what real behavior is being tested
  • One level only: decompose to the immediate next layer down (e.g., orchestration layer -> underlying SDKs, API wrapper -> raw HTTP). Do NOT skip levels
  • Use your input variables to guide your implementation
  • ONLY edit files within yoink_{sub_package}/
  • Never modify yoink_{top_package}/, test files, or .yoink/
  • Allowed imports: stdlib and the acceptable sub-dependencies from your input. Do not import anything else

Read the full file on GitHub · 92 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. 2d ago First seen · 92 lines · 35 tokens per session scan B 1edabbd8aa62

Subscribe to this mod's changes

decomp-implementer is an agent published in the GitHub repository theogbrand/yoink (35 stars, last pushed 5mo ago), licensed MIT. It adds 35 tokens to every session and 1,205 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.