spec

A command that creates a technical specification with Codex. A technical specification describes a system or feature's requirements, design, interfaces, and implementation details.

In plain words
What is it for?
Use it to specify new features or systems, including their requirements, architecture, API, and implementation plan, then review or refine the result.
Why use it?
It turns a feature idea into a structured document that developers can use as a shared reference before coding.

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/rachittshah/cc-codex/spec
Clone the repo
git clone --depth 1 https://github.com/rachittshah/cc-codex
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 596 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 $0.00010 $0.00596
Opus 5 $0.00005 $0.00298
Sonnet 5 $0.00002 $0.00119
Haiku 4.5 $0.00001 $0.00060

Measured 2d ago against content hash 1b759aacc5fc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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 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/spec.md · 130 lines

How it starts

The opening of the file, as written. The whole thing — 130 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Create Technical Specification

Your task

You are receiving a request to create a comprehensive technical specification using Codex.

Steps

  1. Gather Requirements: Extract the feature/system to specify and any requirements

  2. Call Codex Specification Tool:

    • Use the mcp__codex__codex_spec tool
    • Provide title and description
    • Include requirements list if available
    • Pass session ID for context
  3. Process the Spec:

    • Parse the structured specification
    • Present in a clear, professional format
    • Include all sections: requirements, architecture, API, implementation
    • Make it implementation-ready
  4. Validate with User:

    • Ask if the spec is complete
    • Offer to refine specific sections
    • Suggest saving as documentation
    • Propose starting implementation

Example Usage

User: "/spec create a specification for rate limiting middleware"

Expected flow:

  1. Call codex_spec with title and description
  2. Receive comprehensive spec with architecture, API, implementation plan
  3. Present formatted specification
  4. Ask: "Spec complete. Shall I implement this now?"

Notes

  • Use for documenting new features/systems
  • Spec becomes the source of truth
  • Can be saved as .md file in docs/
  • Reference during implementation

Output Format

Present the specification like this:

# Technical Specification: [Title]

## Overview
[High-level description]

## Requirements

### Functional Requirements
1. [Requirement 1]
2. [Requirement 2]

### Non-Functional Requirements
1. [Performance requirement]
2. [Security requirement]
3. [Scalability requirement]

## Architecture

### Components

#### [Component 1]
**Responsibilities**:
- [Responsibility 1]
- [Responsibility 2]

#### [Component 2]
[... same structure ...]

### Data Flow
[Description of how data flows through the system]

### External Integrations
- [Integration 1]
- [Integration 2]

## API Design

### Endpoint: [METHOD] /path
**Description**: [What it does]

**Request**:
```json
{
  "field": "type"
}

Response:

{
  "result": "data"
}

Implementation

Phases

  1. [Phase 1 description]
  2. [Phase 2 description]

Technologies

  • [Technology 1]
  • [Technology 2]

Estimated Effort

[Time estimate]


Specification complete. Would you like me to:

  1. Save this as docs/[filename].md
  2. Start implementing Phase 1
  3. Refine any section

Read the full file on GitHub · 130 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 · 130 lines · 10 tokens per session scan A 1b759aacc5fc

Subscribe to this mod's changes

spec is a command published in the GitHub repository rachittshah/cc-codex (11 stars, last pushed 10mo ago), licensed Apache-2.0. It adds 10 tokens to every session and 596 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.