implement

A feature implementation workflow that divides backend, frontend, and shared work among separate helper agents. It reads the feature’s specification and implementation plan before starting.

In plain words
What is it for?
Use it to implement a planned feature from its `spec.md` and `plan.md` files. It helps coordinate work across server-side code, user-interface code, and code shared by both.
Why use it?
It reduces the need to coordinate every part of a feature manually and lets independent backend and frontend work begin at the same time. It also uses project-specific agent instructions when they exist.

Command

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 commands/marcmallet/specforge/implement
Clone the repo
git clone --depth 1 https://github.com/marcmallet/specforge
Per session 15 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 588 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 $0.00015 $0.00588
Opus 5 $0.00008 $0.00294
Sonnet 5 $0.00003 $0.00118
Haiku 4.5 $0.00002 $0.00059

Measured 2d ago against content hash a1ea93789e13, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

implement 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.

commands/implement.md · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are coordinating the implementation of a feature using sub-agents.

Specs directory

Read the project config at: @.claude/specforge/config.json

If the file exists, use the value of the specsDir field as the base directory. If the file does not exist, fall back to .claude/specforge/ inside the current project.

The full path for this ticket is: /$ARGUMENTS/

Read the spec at: /$ARGUMENTS/spec.md Read the plan at: /$ARGUMENTS/plan.md (if it does not exist, generate the plan first before implementing)

Agent Detection

Before spawning any agents, check for project-level agents in .claude/agents/:

  • If .claude/agents/backend.md exists → use it for backend tasks, otherwise use the plugin's agents/backend.md
  • If .claude/agents/frontend.md exists → use it for frontend tasks, otherwise use the plugin's agents/frontend.md
  • If .claude/agents/shared.md exists → use it for shared tasks, otherwise use the plugin's agents/shared.md

Phase 1 — Run in parallel

Spawn the backend and frontend agents at the same time. Do not wait for one before starting the other.

Backend Agent

Pass it:

  • The full spec
  • The full plan
  • Only the tasks tagged [backend]
  • The Shared Contracts section from the plan

Frontend Agent

Pass it:

  • The full spec
  • The full plan
  • Only the tasks tagged [frontend]
  • The Shared Contracts section from the plan

Phase 2 — Run after Phase 1 completes

Wait for BOTH backend and frontend agents to finish before starting.

Shared Agent

Pass it:

  • The full spec
  • The full plan
  • Only the tasks tagged [both]
  • The Shared Contracts section from the plan
  • All files created or modified by the backend and frontend agents

After all agents finish

  1. Update the checklist in /$ARGUMENTS/plan.md marking all completed tasks as done
  2. If any agent reports an ambiguity, stop and ask the user before proceeding
  3. Do not implement anything outside the spec scope
  4. Summarise what was built, which agents were used (project or plugin), and list any deviations from the spec
  5. Remind the user to write tests for the implemented code
  6. Suggest the next step: "Ready to review? Run /specforge:review $ARGUMENTS"

Read the full file on GitHub · 66 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 · 66 lines · 15 tokens per session scan A a1ea93789e13

Subscribe to this mod's changes

implement is a command published in the GitHub repository marcmallet/specforge (9 stars, last pushed 4mo ago), licensed MIT. It adds 15 tokens to every session and 588 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 2026-08-31.