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The happy codex command starts a Codex-powered coding agent that provides AI assistance using OpenAI’s models.

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Syntax

happy codex [options]

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Description

Codex is an AI coding agent that:
  • Uses OpenAI’s language models
  • Provides intelligent code suggestions and modifications
  • Executes commands with configurable permissions
  • Supports mobile control and remote sessions
  • Integrates with Happy’s MCP (Model Context Protocol) server
You need to connect your OpenAI API key first using happy connect codex.

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Options

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--started-by
string
Indicates how the session was started. Options: daemon or terminal. Internal use
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--no-sandbox
flag
Disable Happy sandbox for this Codex session
happy codex --no-sandbox

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Setup

Before using Codex, you must connect your OpenAI API key: 
happy connect codex
This securely stores your API key in Happy cloud with end-to-end encryption.

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Examples

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Start Codex Session

happy codex
Launches the Codex agent with default settings.

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Disable Sandbox

happy codex --no-sandbox
Runs Codex without OS-level sandboxing restrictions.

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Check Connection Status

happy connect status
Verify your OpenAI API key is properly connected: 
🔌 Connection Status

  ✓  OpenAI Codex: connected (your-email@example.com)
  ○  Anthropic Claude: not connected
  ○  Google Gemini: not connected

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Output

When you start Codex, you’ll see an interactive terminal interface: 
Starting Codex agent...

[Codex Display]
╭─ Messages ─────────────────────────────────────╮
│                                                 │
│ User: Help me refactor this function           │
│ Assistant: I'll help you refactor that...       │
│                                                 │
╰─────────────────────────────────────────────────╯

Status: Ready
The interface shows:
  • User messages and prompts
  • Assistant responses
  • Tool executions and command outputs
  • Reasoning steps (thinking process)
  • Status updates

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Session Features

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Permission Modes

Codex respects permission modes set from the mobile app:
  • default: Ask before executing commands
  • effective: Auto-approve safe operations
  • bypassPermissions: Auto-approve all operations
  • yolo: No permission checks (dangerous)

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Model Selection

You can specify models from the mobile app. Common options:
  • gpt-4o (default)
  • gpt-4-turbo
  • gpt-3.5-turbo

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Reasoning and Tool Use

Codex provides visibility into its thought process: 
Tool: bash started (callId=call_123)
Executing: ls -la
Tool: bash completed (callId=call_123)
Result: [file listing]

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Session Management

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Remote Control

Control Codex from your mobile device:
  1. Start a Codex session on your computer
  2. Open the Happy mobile app
  3. Send prompts and receive real-time updates
  4. Abort or resume sessions remotely

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Session Resume

Codex automatically handles session continuation:
  • Previous context is preserved
  • Conversation history maintained
  • File modifications tracked

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Abort and Kill

# From mobile app: tap "Abort" button
# Stops current inference but keeps session alive

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MCP Integration

Codex includes Happy’s MCP server for enhanced capabilities:
  • Session metadata access
  • Permission management
  • Mobile device communication
  • Real-time updates
The MCP server runs automatically on a random port and bridges to Codex via STDIO.

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Configuration Files

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Codex Home Directory

~/.codex/
├── sessions/           # Session transcripts
│   └── <session-id>.jsonl
└── config/            # Configuration files

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Session Files

Codex stores sessions in JSONL format: 
{"type":"task_started","timestamp":1234567890}
{"type":"agent_message","message":"I'll help with that..."}
{"type":"exec_command_begin","command":"ls -la"}
{"type":"exec_command_end","output":"[results]"}

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Troubleshooting

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Authentication Required

If you see “Not authenticated with Happy”: 
happy auth login

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API Key Not Connected

If Codex fails to start: 
happy connect codex
Follow the OAuth flow to connect your OpenAI account.

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Check Logs

View detailed logs for debugging: 
happy doctor
Logs are stored in ~/.happy/logs/ or ~/.happy-dev/logs/.

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Session Stuck

If a Codex session becomes unresponsive: 
# Kill runaway processes
happy doctor clean

# Restart daemon
happy daemon stop
happy daemon start
Codex requires an active OpenAI account and API access. Usage is billed according to OpenAI’s pricing.