# Use the API from Codex CLI > Let OpenAI Codex CLI publish to Ur Next Door: set UND_API_KEY, turn on network access in the sandbox, add an AGENTS.md note, and test with GET /me. Source: https://docs.urnextdoor.com/ai/codex-cli/ [Codex CLI](https://github.com/openai/codex) is OpenAI's coding agent for the terminal. Like Claude Code, it can run `curl` with your key from an environment variable. One difference matters: **Codex runs commands in a sandbox with network access turned off by default**, so a call to the API fails until you allow it. ## Step 1: Create a key for Codex In **Settings > API keys**, create a key named `Codex CLI` with the scopes `content`, `media` and `read` (plus `schedule` if needed). See [Create an API key](https://docs.urnextdoor.com/getting-started/create-api-key.md). ## Step 2: Put the key in the environment ```bash read -rs UND_API_KEY && export UND_API_KEY ``` Start Codex from the same terminal so it inherits the variable. Never paste the key into the Codex chat. ## Step 3: Allow network access Codex's default `workspace-write` sandbox blocks network access. Choose one: - **Approve each request.** When Codex wants to run `curl` against the API, it asks to run the command outside the sandbox. Approve it. This is the most careful option. - **Turn network on for the sandbox.** Add this to `~/.codex/config.toml`: **~/.codex/config.toml** ```toml [sandbox_workspace_write] network_access = true ``` Restart Codex after changing the file. Without one of these, `curl` fails with a connection or name resolution error and never reaches Ur Next Door. ## Step 4: Check that Codex can see the key Ask Codex to run this. It prints `set` without revealing the key: ```bash echo ${UND_API_KEY:+set} ``` If it prints nothing, Codex's commands are not receiving the variable. Codex decides which environment variables its commands see with the `shell_environment_policy` setting in `~/.codex/config.toml`; make sure that policy passes `UND_API_KEY` through (see the Codex configuration docs), then restart Codex. ## Step 5: Add an AGENTS.md note Codex reads `AGENTS.md` in your project folder. Add: **AGENTS.md** ```markdown ## Ur Next Door API - Read https://docs.urnextdoor.com/llms.txt before the first call and follow https://docs.urnextdoor.com/ai/system-prompt.txt. - Base URL: https://urnextdoor.com/api/v1. Contract: https://urnextdoor.com/api/v1/openapi.json - The key is in $UND_API_KEY. Use it only as -H "Authorization: Bearer $UND_API_KEY". Never print it. - Network calls need sandbox network access; ask me to approve if it is off. - Send an Idempotency-Key (a new UUID) on every POST and DELETE. - Show me a preview and wait for my yes before publishing. - Finish with the web_url of everything you created. ``` ## Step 6: Try it ```text Call GET https://urnextdoor.com/api/v1/me with my Ur Next Door key from $UND_API_KEY and tell me my plan and the key's scopes. Do not create anything. ``` Then ask it to draft and publish something. A create looks like this: **cURL** ```bash curl -X POST "https://urnextdoor.com/api/v1/posts" \ -H "Authorization: Bearer $UND_API_KEY" \ -H "Content-Type: application/json" \ -H "Idempotency-Key: $(uuidgen)" \ -d '{ "title": "Five easy ways to save water at home", "body": "

Small habits add up. These five saved our building a lot of water this summer.

", "tags": [ "water", "home" ] }' ``` **JavaScript** ```js const res = await fetch("https://urnextdoor.com/api/v1/posts", { method: "POST", headers: { Authorization: `Bearer ${process.env.UND_API_KEY}`, "Content-Type": "application/json", "Idempotency-Key": crypto.randomUUID(), }, body: JSON.stringify({ title: "Five easy ways to save water at home", body: "

Small habits add up. These five saved our building a lot of water this summer.

", tags: ["water", "home"], }), }); console.log(res.status, await res.json()); ``` **Python** ```python import os import uuid import requests api_key = os.environ["UND_API_KEY"] response = requests.post( "https://urnextdoor.com/api/v1/posts", headers={ "Authorization": f"Bearer {api_key}", "Idempotency-Key": str(uuid.uuid4()), }, json={ "title": "Five easy ways to save water at home", "body": "

Small habits add up. These five saved our building a lot of water this summer.

", "tags": ["water", "home"], }, timeout=30, ) print(response.status_code, response.json()) ``` **PHP** ```php 'Five easy ways to save water at home', 'body' => '

Small habits add up. These five saved our building a lot of water this summer.

', 'tags' => ['water', 'home'], ]; $ch = curl_init('https://urnextdoor.com/api/v1/posts'); curl_setopt_array($ch, [ CURLOPT_CUSTOMREQUEST => 'POST', CURLOPT_RETURNTRANSFER => true, CURLOPT_HTTPHEADER => [ 'Authorization: Bearer ' . $apiKey, 'Content-Type: application/json', 'Idempotency-Key: ' . bin2hex(random_bytes(16)), ], CURLOPT_POSTFIELDS => json_encode($payload), ]); $body = curl_exec($ch); $status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE); echo $status, PHP_EOL, $body, PHP_EOL; ``` Sample response: `201 Created` ```json { "ok": true, "id": 41, "slug": "five-easy-ways-to-save-water-at-home", "url": "/posts/five-easy-ways-to-save-water-at-home", "web_url": "https://urnextdoor.com/posts/five-easy-ways-to-save-water-at-home", "item": { "id": 41, "type": "post", "slug": "five-easy-ways-to-save-water-at-home" }, "request_id": "9f8e7d6c5b4a3921" } ``` ## Troubleshooting | Symptom | Fix | | --- | --- | | `Could not resolve host` or `Failed to connect` | Network is off in the sandbox. Approve the command or set `network_access = true`. | | `401 missing_api_key` | Codex's commands do not see `UND_API_KEY`. See step 4. | | `403 insufficient_scope` | Create a key with the missing scope. | | Codex prints the key | Stop the session, revoke the key, create a new one, and keep the AGENTS.md rule that forbids printing it. | ## Next steps - [System prompt](https://docs.urnextdoor.com/ai/system-prompt.md). - [Prompt recipes](https://docs.urnextdoor.com/ai/prompt-recipes.md). - [Upload images](https://docs.urnextdoor.com/guides/upload-images.md).