OpenAI-Compatible SDKs

Codex Pooler provides narrow OpenAI-compatible /v1 support for selected SDK routes. It translates supported requests into Codex-compatible work, then sends them through the same Pool routing, limit checks, account selection, and accounting path used by Codex backend clients.

It doesn’t provide full OpenAI API parity.

Base URL and authentication

Use the /v1 base URL and a Pool API key:

Base URL:
https://pooler.example.com/v1

Authorization:
Bearer <pool-api-key>

For local setup, use http://localhost:4000/v1.

Python SDK

import os

from openai import OpenAI

client = OpenAI(
    api_key=os.environ["CODEX_POOLER_API_KEY"],
    base_url="https://pooler.example.com/v1",
)

response = client.responses.create(
    model="gpt-5.5",
    input="Write a short setup confirmation.",
)

print(response.output_text)

Node SDK

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.CODEX_POOLER_API_KEY,
  baseURL: "https://pooler.example.com/v1",
});

const response = await client.responses.create({
  model: "gpt-5.5",
  input: "Write a short setup confirmation.",
});

console.log(response.output_text);

Vercel AI SDK

import { createOpenAI } from "@ai-sdk/openai";
import { generateText } from "ai";

const pooler = createOpenAI({
  apiKey: process.env.CODEX_POOLER_API_KEY,
  baseURL: "https://pooler.example.com/v1",
});

const { text } = await generateText({
  model: pooler.responses("gpt-5.5"),
  prompt: "Write a short setup confirmation.",
});

console.log(text);

Selected route support

The OpenAI-compatible /v1 surface supports selected routes only:

• GET /v1/models
• POST /v1/responses
• GET /v1/responses, narrow Responses websocket compatibility only
• POST /v1/responses/compact
• POST /v1/chat/completions
• GET /v1/usage
• GET /v1/files
• POST /v1/files
• GET /v1/files/:file_id
• GET /v1/files/:file_id/content, deterministic unsupported content read after ownership checks
• DELETE /v1/files/:file_id, deterministic unsupported delete after ownership checks
• POST /v1/audio/transcriptions
• POST /v1/images/generations
• POST /v1/images/edits

The /v1 surface is compatibility over Codex routing, not a separate OpenAI engine. Supported requests still require a Pool API key and a Pool with eligible upstream capacity for the requested model.

Unsupported boundaries

These /v1 routes are unsupported and may return deterministic OpenAI-shaped unsupported endpoint errors when explicitly routed:

• POST /v1/images/variations
• POST /v1/embeddings
• POST /v1/batches
• POST /v1/moderations
• POST /v1/fine_tuning/jobs
• GET /v1/responses/:response_id
• POST /v1/responses/:response_id/cancel
• DELETE /v1/responses/:response_id
• /v1/realtime and OpenAI Realtime SDK websocket or session routes

GET /v1/responses is narrow Responses websocket compatibility, not /v1/realtime support. OpenAI Realtime SDK websocket and session routes are not supported.

MCP stays separate

The operator MCP endpoint is rooted at /mcp, not under /v1. It uses operator-owned MCP bearer tokens and returns metadata only.

MCP URL:
https://pooler.example.com/mcp

Authorization:
Bearer <operator-mcp-token>

Don’t use Pool API keys, browser sessions, cookies, query tokens, invite tokens, upstream tokens, or custom headers as MCP authentication.