ChatGPT, Codex & AI IDE Setup Guide¶

Connect your buyer agent to ChatGPT, OpenAI Codex, Cursor, Windsurf, or any MCP-compatible AI assistant.

Prerequisites¶

Same as Claude Desktop Setup — your developer must have deployed the buyer agent and generated credentials.

Your buyer agent MCP endpoint: https://your-buyer.example.com/mcp/ (Streamable HTTP — canonical)

Legacy SSE fallback: Older MCP clients that require SSE transport can connect to https://your-buyer.example.com/mcp-sse/sse instead.

Authentication is X-API-Key, not Bearer

When the server has API_KEY set, every request must carry the key in the X-API-Key header. The buyer agent does not read Authorization: Bearer tokens — a Bearer-only client will always get 401. Use a client that supports custom headers (configs below), or run without API_KEY in trusted/dev environments.

ChatGPT¶

ChatGPT natively supports MCP servers via Developer Mode.

Step 1: Enable Developer Mode¶

Open chatgpt.com
Go to Settings > Apps & Connectors > Advanced settings
Toggle Developer Mode on

Available on Plus, Pro, Business, Enterprise, and Education plans.

Step 2: Add the Buyer Agent¶

Go to Settings > Connectors (or Settings > Apps)
Click Create
Enter your MCP server URL: https://your-buyer.example.com/mcp/

ChatGPT connectors cannot send a custom X-API-Key header. Connect to a deployment running without API_KEY (trusted network), or front the agent with a proxy that injects the header.
Name it: Buyer Agent
Add a description: Manage campaigns, deals, pacing, approvals, and seller relationships
Click Create

Step 3: Use in a Chat¶

Start a new chat
Click the + button at the bottom
Select your buyer agent from the More menu
Start chatting: "List my active campaigns" or "Show me available CTV inventory from ESPN"

ChatGPT will call your buyer agent's MCP tools and show the results inline.

OpenAI Codex¶

Codex supports MCP servers via its config file.

Option A: CLI¶

codex mcp add buyer-agent --url https://your-buyer.example.com/mcp/

Option B: Config File¶

Edit ~/.codex/config.toml (global) or .codex/config.toml (project):

[mcp_servers.buyer-agent]
url = "https://your-buyer.example.com/mcp/"

[mcp_servers.buyer-agent.http_headers]
X-API-Key = "sk-operator-XXXXX"

Do not use bearer_token_env_var — it sends an Authorization: Bearer header, which the buyer agent ignores (guaranteed 401 when API_KEY is set). If your Codex version does not support custom HTTP headers, connect to a deployment without API_KEY or use a header-injecting proxy.

Verify¶

In Codex, type /mcp to see connected servers and available tools.

Cursor¶

Cursor supports MCP servers on all plans (including free).

Option A: Project-Level Config¶

Create .cursor/mcp.json in your project root:

{
  "mcpServers": {
    "buyer-agent": {
      "url": "https://your-buyer.example.com/mcp/",
      "headers": {
        "X-API-Key": "sk-operator-XXXXX"
      }
    }
  }
}

Option B: Global Config¶

Create ~/.cursor/mcp.json with the same format.

Using Environment Variables¶

{
  "mcpServers": {
    "buyer-agent": {
      "url": "https://your-buyer.example.com/mcp/",
      "headers": {
        "X-API-Key": "${env:BUYER_AGENT_API_KEY}"
      }
    }
  }
}

Windsurf¶

Windsurf supports MCP via its Cascade panel.

Option A: MCP Marketplace¶

Click the MCPs icon in the top-right of the Cascade panel
Search for your buyer agent or click Add Custom
Enter the MCP URL and credentials

Option B: Config File¶

Edit ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "buyer-agent": {
      "serverUrl": "https://your-buyer.example.com/mcp/",
      "headers": {
        "X-API-Key": "sk-operator-XXXXX"
      }
    }
  }
}

Available Tools (All Platforms)¶

Once connected, all platforms have access to the same 43 MCP tools:

Category	Examples
Foundation	`get_setup_status`, `health_check`, `get_config`
Setup Wizard	`run_setup_wizard`, `get_wizard_step`, `complete_wizard_step`, `skip_wizard_step`
Campaign Management	`list_campaigns`, `get_campaign_status`, `check_pacing`, `review_budgets`
Deal Library	`list_deals`, `search_deals`, `inspect_deal`, `import_deals_csv`, `create_deal_manual`
Seller Discovery	`discover_sellers`, `get_seller_media_kit`, `compare_sellers`
Negotiation	`start_negotiation`, `get_negotiation_status`, `list_active_negotiations`
Orders	`list_orders`, `get_order_status`, `transition_order`
Templates	`list_templates`, `create_template`, `instantiate_from_template`
Reporting	`get_deal_performance`, `get_campaign_report`, `get_pacing_report`
Approvals	`list_pending_approvals`, `approve_or_reject`
API Keys	`list_api_keys`, `create_api_key`, `revoke_api_key`
SSP Connectors	`list_ssp_connectors`, `import_deals_ssp`, `test_ssp_connection`
Contextual Enrichment (Mixpeek)	`classify_content`, `contextual_search`, `check_brand_safety`

See the MCP Tools Reference for the full tool catalog.

REST API Alternative¶

If your platform doesn't support MCP, a subset of operations is available over the REST API:

Base URL: https://your-buyer.example.com
Auth header: X-API-Key: sk-operator-XXXXX

The REST surface covers bookings (submit/status/approve), product search, events, and buyer orders — the deal library, wizard, negotiation, and reporting tools are MCP-only. See the API Overview.

For ChatGPT specifically, you can also create a Custom GPT with Actions pointing to the REST API's OpenAPI spec at https://your-buyer.example.com/openapi.json.