How to post to Instagram from OpenAI Codex

Set it up and post, step by step

Prompt to copy once Instagram is connected: Upload ./launch/slide-1.png, slide-2.png and demo.mp4, write an Instagram caption for the v2.4 launch from CHANGELOG.md, show it to me, and schedule the carousel for Tuesday at 6pm.

1. Add PostWire to Codex

   In your terminal run codex mcp add postwire --url https://postwire.io/api/mcp, then codex mcp login postwire. The browser opens PostWire's sign-in, which asks for your email and a 6-digit code and also creates a free PostWire account if you have none: no password and no card. codex mcp list, or /mcp inside Codex, shows postwire with its tools.

2. Or use an API key, for a box without a browser

   On a remote machine or in CI the sign-in cannot finish, so give Codex your key instead: copy it in the dashboard under API & MCP, set POSTWIRE_API_KEY, and put the entry in ~/.codex/config.toml with the variable's name, never the key itself:

   [mcp_servers.postwire]
   url = "https://postwire.io/api/mcp"
   bearer_token_env_var = "POSTWIRE_API_KEY"

3. Connect Instagram

   Ask "connect my Instagram". Codex calls create_connect_link and prints a one-hour link; open it and choose Log in with Instagram (no Facebook Page needed) or connect through a Facebook Page you manage. Instagram's API publishes only from Business or Creator accounts — switching a personal account is free, in the Instagram app's settings. PostWire never sees your password.

4. Give the post a photo or a video

   Instagram refuses text-only posts, and it fetches media from a link, so a file on your disk goes through an upload page: Codex asks for one (create_upload_link), you pick the file there, and get_uploaded_file hands Codex its link (up to 100 MB on the free plan and 1 GB on paid plans). A public https link works too, as photo_url or video_url, or a list in media for a carousel.

5. Ask for the caption

   "Write the Instagram caption for the launch." generate_posts returns a draft and publishes nothing: the hook in the first line, a short caption, at most 5 hashtags at the end, within Instagram's 2,200 characters. Ask for the TikTok or LinkedIn version in the same sentence and each comes back written for its own network.

6. Post now, or schedule it

   Say "post it" and Codex calls post_to_social. Say "schedule it for Tuesday at 6pm" and it calls schedule_post, up to 365 days ahead, or with run_at: "next_slot" for your next free posting hour. Two or more items in media make a carousel; Instagram crops every slide to the first one's shape. This is the call:

   {
     "name": "schedule_post",
     "arguments": {
       "platforms": ["instagram"],
       "per_platform": { "instagram": {
         "text": "v2.4 is here 🚀 Dark mode, 2x faster sync, 14 fixes. Swipe for the demo 👉 #buildinpublic #saas"
       } },
       "media": [
         { "url": "https://postwire.io/m/…/slide-1.png", "type": "image" },
         { "url": "https://postwire.io/m/…/slide-2.png", "type": "image" },
         { "url": "https://postwire.io/m/…/demo.mp4",    "type": "video" }
       ],
       "run_at": "2026-11-03T18:00:00-05:00"
     }
   }

7. Check that it went out

   Instagram processes a video before it can be published. If that takes longer than the call can wait, the result says processing and PostWire publishes it on its own a few minutes later; get_post_status or list_scheduled_posts shows when it is live.

Stories and trial reels are set through the REST API today, which Codex can call from the terminal with your key: POST /api/post with "options": {"instagram": {"post_type": "story"}} for a Story (Instagram's API takes no caption on Stories), or {"trial_reel": true} to show a Reel first to people who don't follow you. "What's scheduled on Instagram?" calls list_scheduled_posts. Prefer to set it up by hand first? Open the dashboard, connect the account under Accounts and copy your key under API & MCP.