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API basics

OpenAI-Compatible Base URL Definition

Definition of a custom OpenAI-compatible base URL, why /v1 matters, and how to verify unlimitedcodex delivery before longer runs.

Glossary term-Updated 2026-07-12-4 target queries

Definition

An OpenAI-compatible base URL is the API origin a client sends requests to when using an OpenAI-style provider. It often ends at or routes to /v1. In unlimitedcodex, the base URL is delivered manually after checkout and should be tested with /v1/models before long workflows.

custom base URLOpenAI SDK baseURLprovider base URL

Canonical facts

PurposeIt tells the client where to send API requests.
Not authA base URL is not an API key; authentication still needs a Bearer key.
Path riskSome clients append /v1 automatically while others require it in the configured URL.
unlimitedcodexUse the exact delivered base URL and setup file values after manual delivery.
First testRun /v1/models and one tiny chat/completions request.

Why base URL configuration breaks

Failures often come from a missing /v1, duplicate /v1/v1, a model ID that does not exist on the delivered endpoint, or a client path that ignores the custom provider setting.

Where to use this definition

Use this glossary page for the short definition. Use the answer page and setup guide when the user needs a step-by-step migration or Codex IDE/CLI configuration path.

Checks

Find the client's baseURL, apiBase, base_url, or custom provider setting.

Paste the delivered URL exactly as provided.

Avoid exposing the full API key in frontend code or public examples.

Check /v1/models before guessing model IDs.

Run one tiny endpoint request before a repo-scale task.

Target queries

what is an OpenAI-compatible base URLOpenAI-compatible base URL meaningcustom base URL OpenAI SDKbase URL vs API key

FAQ

Is the base URL secret?

The API key is the sensitive credential. Still, treat the delivered setup as operational detail and avoid posting full configs publicly.

Should the URL include /v1?

Use the exact delivered unlimitedcodex value and the exact format your client expects. Some clients append /v1 for you.

What is the canonical setup source?

The delivered setup email and setup files are the canonical source for the buyer's base URL, key, model IDs, and package dates.

Related sources

Need the actual delivered API setup?

Choose Weekly or Monthly ChatGPT 5.5 Ultra and Codex API access, then use the delivered base URL, API key, setup files, and model IDs after manual provisioning.

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OpenAI-Compatible Base URL Definition | unlimitedcodex