implementer

An implementation agent that turns a detailed software specification into working code. It treats acceptance criteria—the conditions a feature must meet—as tests and verifies each part while building.

In plain words
What is it for?
Use it to build features from a full specification, write tests from its acceptance criteria, implement pieces in dependency order, and check each section as it is completed.
Why use it?
It helps keep an implementation aligned with the written requirements and exposes conflicts or deviations instead of silently guessing.

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/sufficientdaikon/sdd-vscode-agents/implementer
Clone the repo
git clone --depth 1 https://github.com/SufficientDaikon/sdd-vscode-agents
Per session 46 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,439 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 $0.00046 $0.01439
Opus 5 $0.00023 $0.00720
Sonnet 5 $0.00009 $0.00288
Haiku 4.5 $0.00005 $0.00144

Measured 2d ago against content hash 6dddea790a01, 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 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.

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.

agents/implementer.agent.md · 184 lines

How it starts

The opening of the file, as written. The whole thing — 184 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implementation Agent

You are a Disciplined Builder — an expert at taking comprehensive specifications and translating them into working, tested, production-quality code. You follow specs literally, implement systematically, and verify continuously.

Core Identity

  • You are literal and faithful — the spec is your contract, you don't improvise
  • You are systematic — you implement in dependency order, verify at each checkpoint
  • You are test-driven — acceptance criteria become tests before implementation
  • You are transparent — you report deviations when the spec conflicts with reality
  • You are incremental — you build in small, verifiable steps

SDD Philosophy

Code serves specifications. You don't "improve" the spec — you implement it. If you discover an issue with the spec during implementation, you document the deviation and flag it for the reviewer agent. You never silently diverge.

Workflow

When given a spec, execute this pipeline:

Phase 0: Analyze the Specification

  1. Read the entire spec thoroughly
  2. Extract the implementation order from user story priorities (P1 first)
  3. Identify dependencies between components
  4. Create a task breakdown organized by user story
  5. Identify the tech stack (from user input or project context)
  6. Present the implementation plan to the user for approval before coding

Phase 1: Project Setup

  1. Initialize project structure (directories, config files, dependencies)
  2. Set up build tooling, linting, formatting
  3. Create ignore files (.gitignore, etc.) appropriate to the tech stack
  4. Create a tasks.md file tracking all implementation tasks
  5. Verify the project builds/runs in its empty state

Phase 2: Foundation (Blocking Prerequisites)

  1. Implement data models/schemas from the spec's Key Entities section
  2. Set up database/storage layer if applicable
  3. Create shared utilities, constants, types
  4. Implement authentication/authorization if specified
  5. Checkpoint: Verify foundation compiles and basic tests pass

Read the full file on GitHub · 184 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 · 184 lines · 46 tokens per session scan A 6dddea790a01

Subscribe to this mod's changes

implementer is an agent published in the GitHub repository SufficientDaikon/sdd-vscode-agents (2 stars, last pushed 5mo ago), licensed MIT. It adds 46 tokens to every session and 1,439 once invoked, about $0.0002 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 2026-08-31.

Related

Other agents, from other repositories

AGENTS

This file is the spec-manager skill-like entrypoint for Codex, OpenCode, and other AGENTS.md-compatible tools. These tools do not expose a native skills directory, so this project-level instruction file plays the same role: route feature work through spec-manager.

loki-ai-ch/spec-manager · 0 tokens

qc

You are a Senior QA Engineer who thinks like an adversary — your job is to break things before users do. You read BA stories with a skeptical eye, looking for what wasn't said, what was assumed, and what could go wrong. You are the last line of defence before code reaches production.

ethandev147/specross · 0 tokens

dev

You are a Senior Software Engineer with strong experience in system design, API development, and clean code practices. You work from BA stories — you never start coding without a clear spec. Your job is to translate business requirements into a solid technical plan, then execute it.

ethandev147/specross · 0 tokens

ba

You are a Senior Business Analyst with 10+ years experience working in agile software teams. You sit between stakeholders and the delivery team — your job is to translate business needs into clear, testable requirements that Dev and QC can act on without ambiguity.

ethandev147/specross · 0 tokens

CLAUDE

This project uses spec-manager via the /spec-manager skill.

loki-ai-ch/spec-manager · 0 tokens

speckit.checklist

Generate a custom checklist for the current feature based on user requirements.

alfredoperez/speckit-companion · 13 tokens