---
title: Codex Local
summary: OpenAI Codex local adapter setup and configuration
---

The `codex_local` adapter runs OpenAI's Codex CLI locally. It supports session persistence via `previous_response_id` chaining and skills injection through the global Codex skills directory.

## Prerequisites

- Codex CLI installed (`codex` command available)
- `OPENAI_API_KEY` set in the environment or agent config

## Configuration Fields

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `cwd` | string | Yes | Working directory for the agent process (absolute path; created automatically if missing when permissions allow) |
| `model` | string | No | Model to use |
| `promptTemplate` | string | No | Prompt used for all runs |
| `env` | object | No | Environment variables (supports secret refs) |
| `timeoutSec` | number | No | Process timeout (0 = no timeout) |
| `graceSec` | number | No | Grace period before force-kill |
| `fastMode` | boolean | No | Enables Codex Fast mode. Currently supported on `gpt-5.4` only and burns credits faster |
| `dangerouslyBypassApprovalsAndSandbox` | boolean | No | Skip safety checks (dev only) |

## Session Persistence

Codex uses `previous_response_id` for session continuity. The adapter serializes and restores this across heartbeats, allowing the agent to maintain conversation context.

## Skills Injection

The adapter symlinks Paperclip skills into the global Codex skills directory (`~/.codex/skills`). Existing user skills are not overwritten.

## Fast Mode

When `fastMode` is enabled, Paperclip adds Codex config overrides equivalent to:

```sh
-c 'service_tier="fast"' -c 'features.fast_mode=true'
```

Paperclip currently applies that only when the selected model is `gpt-5.4`. On other models, the toggle is preserved in config but ignored at execution time to avoid unsupported runs.

## Managed `CODEX_HOME`

When Paperclip is running inside a managed worktree instance (`PAPERCLIP_IN_WORKTREE=true`), the adapter instead uses a worktree-isolated `CODEX_HOME` under the Paperclip instance so Codex skills, sessions, logs, and other runtime state do not leak across checkouts. It seeds that isolated home from the user's main Codex home for shared auth/config continuity.

### Per-agent isolation and auth seeding

For `codex_local` agents the server isolation guard pins each agent to a per-agent home (`<instance>/companies/<companyId>/agents/<agentId>/codex-home`) and sets `OPENAI_API_KEY=""` so an agent can never spend against the host API key or share another agent's Codex state.

A managed home is created empty, so the adapter must provision auth into it before launching Codex — otherwise the agent runs with zero credentials and the provider returns `401 Missing bearer`. The seeding contract:

- **Managed homes** (the default home and any configured `CODEX_HOME` under the company tree) are always seeded: the ChatGPT-subscription `auth.json` is symlinked from the host Codex home, or, when a per-agent `OPENAI_API_KEY` is configured, an API-key `auth.json` is written instead.
- **Genuine external overrides** (a `CODEX_HOME` outside the Paperclip-managed company tree) are treated as self-managed and are never seeded or overwritten.
- **Fail-fast guard:** if a managed home ends up with no usable `auth.json` and no configured API key, the run fails with an explicit `adapter_failed` ("no Codex credentials provisioned for managed home …") rather than emitting an unauthenticated request.

## Manual Local CLI

For manual local CLI usage outside heartbeat runs (for example running as `codexcoder` directly), use:

```sh
pnpm paperclipai agent local-cli codexcoder --company-id <company-id>
```

This installs any missing skills, creates an agent API key, and prints shell exports to run as that agent.

## Instructions Resolution

If `instructionsFilePath` is configured, Paperclip reads that file and prepends it to the stdin prompt sent to `codex exec` on every run.

This is separate from any workspace-level instruction discovery that Codex itself performs in the run `cwd`. Paperclip does not disable Codex-native repo instruction files, so a repo-local `AGENTS.md` may still be loaded by Codex in addition to the Paperclip-managed agent instructions.

## Environment Test

The environment test checks:

- Codex CLI is installed and accessible
- Working directory is absolute and available (auto-created if missing and permitted)
- Authentication signal (`OPENAI_API_KEY` presence)
- A live hello probe (`codex exec --json -` with prompt `Respond with hello.`) to verify the CLI can actually run