GPT WORLD / INDEPENDENT CODEX FIELD MANUAL Source review · 2026-07-31

Retrospective edition / MCP

Treat MCP servers as external principals

Inventory server identity, transport, authentication, exposed tools, data returned, approvals, and failure behavior before enabling it.

01 / DECIDE

Architecture decision

Use it to connect governed external capabilities or data without rebuilding every integration as a custom function.

Inventory server identity, transport, authentication, exposed tools, data returned, approvals, and failure behavior before enabling it. Map input, output, state, and side effects as one observable path before deciding which layer owns treat mcp servers as external principals.

02 / BUILD

Three-step implementation

  1. 01

    Frame the contract

    Write down the caller, data classification, success condition, timeout, cancellation, and ownership. Use it to connect governed external capabilities or data without rebuilding every integration as a custom function.

  2. 02

    Build one narrow path

    Implement one end-to-end path with request correlation, typed state, and reversible failure handling. Inventory server identity, transport, authentication, exposed tools, data returned, approvals, and failure behavior before enabling it.

  3. 03

    Prove the outcome

    Turn acceptance into a repeatable fixture, contract test, or browser test. Negative tests prove an untrusted server, changed tool schema, expired credential, and injected content fail safely.

03 / BOUND

Production boundary

Only connect trusted servers, minimize tools, validate returned content, and keep high-impact calls behind approval.

04 / PROVE

Acceptance evidence

Negative tests prove an untrusted server, changed tool schema, expired credential, and injected content fail safely.

SOURCE / HTTP

Reproducible source probe

curl -fsSI 'https://developers.openai.com/api/docs/guides/tools-connectors-mcp' | sed -n '1,5p'