Platform: Z.aiAPI guide
Independent developer guide

OpenAI-Compatible Chat API Integration

OpenAI-compatible APIs can make it easier to reuse familiar client libraries when connecting an application to another model provider. You still need to update credentials and the base URL, select a supported model, and test the features your app depends on.

What this workflow helps you do

Z.ai documents compatibility with OpenAI SDK patterns, including chat completions. The provider’s documentation also notes that some interface differences remain. Keep provider configuration explicit and validate your application’s streaming, tool, structured-output, and error-handling paths after switching.

Practical steps

Change configuration in one place

Install a compatible SDK version, load the provider API key from a protected server-side secret, and set the documented base URL. Keep the model ID and endpoint in configuration rather than scattering provider values across the codebase. Do not reuse an API key from a different provider.

Example using Python

The following sketch follows the provider’s documented OpenAI Python SDK pattern. Keep the key in the environment and run this server-side. Confirm the currently supported model list and any parameters you need before using the request in production.

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["ZAI_API_KEY"],
    base_url="https://api.z.ai/api/paas/v4/",
)

response = client.chat.completions.create(
    model="glm-5.3",
    messages=[
        {"role": "user", "content": "Summarize this sanitized test input."}
    ],
)
print(response.choices[0].message.content)

Test compatibility with your application

A successful basic completion does not prove every feature is compatible. Test the exact request patterns your application uses: streaming, multi-turn messages, function calls, JSON output, timeouts, retries, and any multimodal inputs. Confirm error types and limits against the provider API reference.

Plan a reversible migration

Put the provider behind a small adapter or configuration flag. Route a controlled test workload first, compare output quality and timing, and log enough information to debug failures without storing credentials or sensitive prompts. Keep a straightforward rollback path until the new provider has passed your evaluation set.

Detailed implementation guidance

Use a migration checklist for an OpenAI-compatible endpoint

Before switching, list every SDK feature your application uses and verify its equivalent with the new provider: chat completions, streaming chunks, tool calls, structured output, multimodal messages, and error handling. Confirm the documented base URL, model ID, authentication header, and SDK version. Keep this checklist with the integration so future maintainers understand which parts of the compatibility surface were tested.

Keep provider differences out of product logic

An OpenAI-compatible chat API can reduce code changes, but provider-specific model identifiers and limits still exist. Put these values in a configuration object and translate common provider errors into your application’s own error types. If the new endpoint returns a shape your existing code does not expect, handle it in the adapter rather than scattering special cases through user-facing features.

Run a controlled cutover

Test the integration with representative, non-sensitive traffic before changing the default provider. Compare completion quality, response time, error rate, and cost using the same prompts. Test a rollback to the prior configuration and rotate any key that may have been exposed during setup. Compatibility is a useful starting point, but production readiness comes from validating the real application paths.

Quality and safety checks

Review generated output, protect secrets and private data, and run the checks your project requires. Model responses and tool calls should be treated as proposals until your application or a developer validates them.

Common questions about openai-compatible chat api integration

Can I keep my existing OpenAI SDK code?

The documented compatibility can let you reuse familiar SDK code, but you must set the provider base URL and key, choose a supported model, and test any provider-specific behavior your app uses.

Where should the API key live?

Store it on your server in an environment variable or secret manager. Do not put it in browser JavaScript, a mobile client, or a public source repository.

Related guides

Official references: OpenAI Python SDK compatibility and migration guide · Official API quick start · Confirm current model access, pricing, limits, and API behavior in provider documentation.