Provider compatibility

Aperture routes LLM requests to multiple providers, each with different base URLs, authentication methods, and API formats. This reference lists the supported providers, their compatibility flags, authorization types, and pricing options.

This page is part of the Aperture reference documentation. For field-level configuration details, refer to the Aperture configuration reference. For step-by-step provider setup, refer to the set up LLM providers guides. To configure coding agents to connect through Aperture, refer to the set up LLM clients guides.

Provider matrix

The following table summarizes how to configure each supported provider type:

Compatibility flags

The compatibility object in a provider configuration specifies which API formats the provider supports. These flags determine which endpoints Aperture exposes for the provider's models.

Enable the flags that match the API formats your provider supports. For providers that serve models from multiple vendors (such as Vertex AI with both Gemini and Anthropic models), enable multiple flags.

Additional provider fields

In addition to baseurl, apikey, authorization, models, compatibility, cost_basis, name, add_headers, and model_cost_map, providers support the following optional fields:

Authorization types

Different providers require different authorization header formats. Set the authorization field on the provider to specify which format to use.

Custom headers

Some providers require additional headers beyond the standard authorization field. Use add_headers on the provider to include custom headers in every request Aperture sends to that provider. Each entry is a string in "Header-Name: value" format:

{
  "providers": {
    "example-provider": {
      "baseurl": "https://api.example.com/",
      "apikey": "<your-key>",
      "authorization": "bearer",
      "models": ["model-name"],
      "add_headers": [
        "Custom-Header: value"
      ]
    }
  }
}

Each string in the array must follow the "Header-Name: value" format.

Cost basis

Aperture estimates the dollar cost of every LLM request. Cost estimates power quotas, hook metadata, and the per-model pricing shown in the Aperture dashboard.

Aperture auto-infers pricing for known providers based on the provider's compatibility flags (for example, anthropic_messages maps to Anthropic pricing). For providers where auto-inference does not apply, you can set cost_basis explicitly on the provider.

To disable auto-inference globally, set auto_cost_basis to false at the top level of the configuration.

{
  "auto_cost_basis": false,
  "providers": {
    "anthropic": {
      "cost_basis": "anthropic"
    }
  }
}

When auto_cost_basis is false, only providers with an explicit cost_basis produce cost estimates.

Model cost map

When a model name does not appear in the pricing database (for example, after adding a new or custom model), you can use model_cost_map to map it to a known model for pricing purposes:

{
  "providers": {
    "anthropic": {
      "cost_basis": "anthropic",
      "model_cost_map": [
        {"match": "claude-opus-9-*", "as": "claude-opus-4-6"},
        {"match": "claude-*-preview*", "as": "claude-sonnet-4-5", "adjustment": 1.1}
      ]
    }
  }
}

In this example, requests to any claude-opus-9-* model are priced like claude-opus-4-6, and preview models are priced like claude-sonnet-4-5 with a 10% markup.

Each entry supports the following fields:

• match: Glob pattern against the model name. Uses Go's path.Match syntax, where * matches any sequence of non-separator characters and ? matches a single character.
• as: Replacement model name for the pricing lookup.
• adjustment: Price multiplier (optional, default 1.0). Use 1.5 to mark up 50%.

Aperture uses the first matching entry.