implement-spec

Implements a feature based on provided context or spec file.

Command 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 commands/jnarowski/agentcmd/implement-spec
Clone the repo
git clone --depth 1 https://github.com/jnarowski/agentcmd

Made for: Claude Code.

Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,816 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00011 $0.02816
Opus 5 $0.00005 $0.01408
Sonnet 5 $0.00002 $0.00563
Haiku 4.5 $0.00001 $0.00282

Measured today against content hash 3fbec5392adb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

implement-spec 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 today.

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/commands/cmd/implement-spec.md · 334 lines

How it starts

The opening of the file, as written. The whole thing — 334 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implement

Follow the Workflow steps in the exact order to implement the spec then Report the completed work.

Variables

  • $specIdOrNameOrPath: $1 (required) - Either a timestamp ID (e.g., 2510241201), feature name (e.g., workflow-safety), or full path

Instructions

Parse and resolve $specIdOrNameOrPath:

  • If it's a full path (contains /): use as-is
  • Otherwise, look up in .agent/specs/index.json:
    • For timestamp ID: Match by id field
    • For feature name: Fuzzy match path (e.g., message-queue matches todo/2510241201-message-queue-implementation/spec.md)
    • Use path from index: .agent/specs/{path}
  • If not found in index.json, fallback to directory search:
    • Search in order: todo/, backlog
    • For ID: Pattern {id}-*/spec.md
    • For feature name: Pattern *{feature-name}*/spec.md (fuzzy match)
  • If still not found: stop and report error

Task Tracking Requirements

CRITICAL: You MUST track your progress in the spec file as you work. This is NOT optional.

What to Update

  1. Individual Tasks - Check off IMMEDIATELY after completing each task:

    • Change - [ ] 1.1 Task description to - [x] 1.1 Task description
    • Do this AFTER finishing each task, NOT in batches
    • Never move to the next task without checking off the current one
  2. Completion Notes - Fill in after finishing each task group/phase:

    • Each task group has a #### Completion Notes section
    • Write 2-4 bullet points with:
      • What was implemented
      • Any deviations from the plan
      • Important context for reviewers
      • Known issues or follow-ups

Example of Good Progress Tracking

Before starting task 1.1:

### 1: Project Initialization

- [ ] 1.1 Initialize Bun project
- [ ] 1.2 Configure package.json

After completing task 1.1:

### 1: Project Initialization

- [x] 1.1 Initialize Bun project
- [ ] 1.2 Configure package.json

After completing all tasks in group 1:

### 1: Project Initialization

- [x] 1.1 Initialize Bun project
- [x] 1.2 Configure package.json

#### Completion Notes

- Project initialized with Bun and TypeScript
- Used stricter tsconfig settings than spec suggested for better type safety
- All dependencies installed successfully

Read the full file on GitHub · 334 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. today First seen · 334 lines · 11 tokens per session scan A 3fbec5392adb

Subscribe to this mod's changes

implement-spec is a command published in the GitHub repository jnarowski/agentcmd (18 stars, last pushed 8mo ago), licensed MIT. It adds 11 tokens to every session and 2,816 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 2026-09-01.