Codex Implement Skill

Delegate complex implementation tasks to the Codex agent for high-quality code.

When to Use

•Complex multi-file implementations
•Algorithms requiring careful design
•User explicitly wants Codex to implement

Steps

0. Check for Tmux

First, verify we're running in tmux. Run this check:

bash

[ -n "$TMUX" ] && echo "TMUX_OK" || echo "NOT_IN_TMUX"

If NOT_IN_TMUX: Stop immediately and tell the user:

"This skill requires tmux dual-pane mode. You're not in tmux.

Instead, just ask me naturally: 'implement this with codex' and I'll use the MCP tool which works without tmux."

Do not proceed with the remaining steps if not in tmux.

1. Resolve .agent-collab Directory

Before any file operations, resolve the .agent-collab directory so commands work outside the project root:

bash

AGENT_COLLAB_DIR="${AGENT_COLLAB_DIR:-}"
if [ -n "$AGENT_COLLAB_DIR" ]; then
  if [ -d "$AGENT_COLLAB_DIR/.agent-collab" ]; then
    AGENT_COLLAB_DIR="$AGENT_COLLAB_DIR/.agent-collab"
  elif [ ! -d "$AGENT_COLLAB_DIR" ]; then
    AGENT_COLLAB_DIR=""
  fi
fi

if [ -z "$AGENT_COLLAB_DIR" ]; then
  AGENT_COLLAB_DIR="$(pwd)"
  while [ "$AGENT_COLLAB_DIR" != "/" ] && [ ! -d "$AGENT_COLLAB_DIR/.agent-collab" ]; do
    AGENT_COLLAB_DIR="$(dirname "$AGENT_COLLAB_DIR")"
  done
  AGENT_COLLAB_DIR="$AGENT_COLLAB_DIR/.agent-collab"
fi

If $AGENT_COLLAB_DIR does not exist, stop and ask for the project root.

2. Gather Requirements

From user, collect:

•What needs implementing
•Target file paths
•Constraints and patterns to follow
•Dependencies and interfaces

3. Create Implementation Spec

Write to $AGENT_COLLAB_DIR/requests/task.md:

markdown

# Task Request for Codex

## Task Type: IMPLEMENT

## Timestamp
[Current timestamp]

## Implementation Request
[Detailed description]

## Target Files
- Primary: [FULL ABSOLUTE path, e.g. /Users/antor/project/src/feature.cpp]
- Secondary: [supporting file paths]

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

## Interfaces & Contracts
[Interfaces the code must satisfy]

## Context Files to Read
[List FULL ABSOLUTE paths of existing files Codex should read for context]

**NOTE: Codex runs in the same working directory and CAN read files directly.
Do NOT copy file contents here. Just list paths and Codex will read them.**

## Patterns to Follow
[Reference existing patterns by file path]

## Constraints
- [List constraints]

4. Update Status

Write pending to $AGENT_COLLAB_DIR/status

5. Trigger Codex

bash

tmux send-keys -t 1 '$read-task' && sleep 0.5 && tmux send-keys -t 1 Enter Enter

6. Notify User

Tell user briefly that implementation was delegated to Codex.

7. Wait for Codex (Background Polling)

Start a background polling loop to wait for Codex to complete. Run this EXACT bash command (with $AGENT_COLLAB_DIR/status) using the Bash tool with run_in_background: true:

bash

while [ "$(cat "$AGENT_COLLAB_DIR/status")" != "done" ]; do sleep 5; done; echo "CODEX_COMPLETE"

Note: Use 5 second intervals since implementations take longer.

CRITICAL: Use the resolved $AGENT_COLLAB_DIR/status path so polling works outside the project root. Use background execution so you can continue helping the user while waiting.

8. Auto-Read Response

When poll completes, automatically:

•Read $AGENT_COLLAB_DIR/responses/response.md
•Present the implementation to user
•Ask if user wants to integrate the code
•Reset $AGENT_COLLAB_DIR/status to idle