SOMIN
SOMIN × Codex · MCP Quickstart · One-pager

Connect, install skills, build your first deck.

For users already familiar with the setup. Hit a snag? Use the full step-by-step manual — phase pointers below.
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Step 2-1Codex Plugins page with the settings gear beneath Manage
Plugins page — click the gear icon under Manage.
Step 2-2Codex plugin settings on the MCPs tab showing Add server
MCPs tab — click + Add server beside Servers.
Step 2-3Connect to a custom MCP form with Name and URL filled in
Connect to a custom MCP — Name and URL only, then Save.
Step 3-1Codex Browser settings page with the Browser toggle switched on
Settings → Browser — the toggle must be on.
Step 3-2Codex Configuration page with the Sandbox settings dropdown open on Full access
Configuration → Sandbox settings — set to Full access.
Step 4Codex installing somin-skill-library-sync and listing the skills found
Codex asks your role, lists the skills, then you reply “install all”.

1Sign in to Codex

  • ✓Open the Codex app, signed in to the ChatGPT account that should own the integration.
  • ✓Make sure you also have an active SOMIN workspace on the account Codex should see.

2Add the SOMIN MCP server

  • ✓Sidebar → Plugins → the gear icon under Manage → MCPs tab → + Add server.
  • ✓Fill the two fields below (Type stays Streamable HTTP). Leave Bearer token and Headers empty. Click Save.
Fields — copy each
Name
SOMIN
URL
https://cloud.somin.ai/_mcp
Leading underscore required — not /mcp. Type must be Streamable HTTP, not STDIO.
  • ✓Check the toggle beside SOMIN under Servers is on. Sessions load MCP config at start, so the link below opens a fresh chat.
  • ✓Run the workspace check ↗ and press Enter. A workspace list within ~4 s means you’re connected.

3Browser tool + sandbox access

Step 4 needs both: browser access to fetch the skills package from cloud.somin.ai, and full sandbox access to save it.

  • ✓Click your profile (bottom-left) → Settings → Browser under Integrations.
  • ✓Confirm “Let ChatGPT control the built-in browser” is toggled on.
  • ✓In the sidebar under Personal → Configuration → Sandbox settings → set the dropdown to Full access. Then Back to app.
Skip either and step 4 fails — no browser means nothing downloads, Workspace write means nothing saves. Full access lets Codex edit files outside the workspace; keep Approval policy on On request, and you can revert to Workspace write once skills are in.

4Install the SOMIN skills

  • ✓Open Codex with the skills install prompt ↗ and press Enter.
  • ✓Codex installs somin-skill-library-sync, then asks your role — reply brand, agency, Media Buyer or influencer.
  • ✓When Codex lists the skills it found, reply install all to save every one.
  • ✓Approve any file-write request, then check the skills under Plugins → Gear Icon → Skills.

5Run the brand-deck skill

  • ✓Open Codex with the deck prompt pre-filled ↗ and press Enter — the fresh chat is what loads your new skills.
  • ✓Pick a workspace, then a brand, when Codex asks.
  • ✓Success = Codex starts with /somin-scope-elicitation, runs /somin-brand-deck, styles with /somin-brand-guideline.
I have SOMIN MCP connected. Give me a list of workspaces that I can work with, once I choose, give me a list of brands available in my workspace, once I choose the brand, then build a 12-month strategy deck for the one I pick. Use /somin-brand-deck for the full analysis and /somin-brand-guideline for SOMIN styling. Start with /somin-scope-elicitation.

6Were not able to complete the manual?

If you still have questions or weren’t able to complete the steps, refer to the full step-by-step manual ↗ — it covers every step above in detail, with screenshots, fallback paths, and troubleshooting.

No Plugins in the sidebar? Profile → Settings → Integrations → Plugins → MCPs. Manual Phase 1A.
Add server greyed out? Managed ChatGPT Work workspace — an admin must allow it. Manual Phase 2.
Saved but not connecting? Re-check the URL (/_mcp, leading underscore), then restart Codex — MCP config loads at start-up. Manual Phases 1/3.
Skills download or save fails? Check the Browser toggle and Sandbox settings = Full access. Manual Phase 5.
Skills not used in step 5? Start a new chat — skills load when a session begins. Manual Phases 6–7.
Anything else: full manual · ask@somin.ai
SOMIN · Codex MCP quickstart · 2026
Data access comes from the MCP server; skills are the playbook. Both are needed.