Passthrough API

Overview

The passthrough API proxies provider-native requests through Aurora without translating the request or response body.

Use it when a client library expects a provider's native API instead of the OpenAI-compatible API. For example, the Anthropic SDK sends requests to /v1/messages, so you can point it at Aurora's Anthropic passthrough base URL:

http://your-aurora-host/p/anthropic
 

The SDK sends:

POST /p/anthropic/v1/messages
 

Aurora normalizes the optional v1 segment and forwards the request upstream as Anthropic's native:

POST /messages
 

How it works

Passthrough routes use this shape:

/p/{provider}/{endpoint}
 

For Anthropic, these two paths map to the same upstream endpoint when ALLOW_PASSTHROUGH_V1_ALIAS=true, which is the default:

/p/anthropic/messages
/p/anthropic/v1/messages
 

Aurora handles gateway authentication first. If AURORA_MASTER_KEY or managed auth keys are enabled, the client must send an Aurora bearer token:

Authorization: Bearer sk-aurora-...
 

Aurora strips client Authorization and X-Api-Key headers before forwarding the request, then applies the upstream provider credential configured on the server. For Anthropic, Aurora uses its configured ANTHROPIC_API_KEY.

Because passthrough is provider-native, the response is also provider-native. For Anthropic messages, the response uses Anthropic's message schema, not an OpenAI chat completion schema.

Anthropic SDK example

Set the Anthropic SDK base URL to Aurora's Anthropic passthrough route. Use the Aurora token as Anthropic SDK bearer auth.

If your gateway does not require authentication, use a dummy SDK API key such as not-needed instead of auth_token or authToken. Aurora strips X-Api-Key from passthrough requests before forwarding them upstream.

Current limitations

Passthrough is intentionally narrow while the API is in beta.

• openai, anthropic, openrouter, zai, and vllm are enabled by default.
• Aurora does not translate passthrough request bodies or response bodies.
• Provider-native error bodies and status codes are proxied instead of converted into OpenAI-compatible responses.
• Features that depend on OpenAI-compatible request or response shapes may not apply to passthrough traffic in the same way as /v1 traffic.

Related environment variables

Passthrough routes are enabled by default:

ENABLE_PASSTHROUGH_ROUTES=true
ALLOW_PASSTHROUGH_V1_ALIAS=true
ENABLED_PASSTHROUGH_PROVIDERS=openai,anthropic,openrouter,zai,vllm
 

Set ENABLED_PASSTHROUGH_PROVIDERS to the provider types you want to expose.