Authentication Patterns

Common authentication patterns for generated SDKs — Bearer, API key, Basic, and custom auth.

OpenAPI specs use various authentication schemes. AutoSDK generates appropriate constructors and auth handling for each.

HTTP Bearer Token

The most common pattern for AI APIs:

autosdk generate spec.json --security-scheme Http:Header:Bearer

Generated constructor:

public MyApiClient(string apiKey, HttpClient? httpClient = null)
{
    // Sets Authorization: Bearer {apiKey}
}

Usage:

using var client = new MyApiClient("sk-your-api-key");

SDKs using this: OpenAI, Anthropic, Mistral, Together, ElevenLabs, Jina, VoyageAI

API Key in Header

For APIs that use a custom header:

autosdk generate spec.json --security-scheme ApiKey:Header:x-api-key

Generated constructor:

public MyApiClient(string apiKey, HttpClient? httpClient = null)
{
    // Sets x-api-key: {apiKey} header
}

SDKs using this: Replicate, Leonardo

API Key in Query String

For APIs that pass the key as a query parameter:

autosdk generate spec.json --security-scheme ApiKey:Query:api_key

SDKs using this: Roboflow

HTTP Basic Auth

For APIs using username/password:

autosdk generate spec.json --security-scheme Http:Header:Basic

Generated constructor:

public MyApiClient(string username, string password,
    HttpClient? httpClient = null)
{
    // Sets Authorization: Basic {base64(username:password)}
}

SDKs using this: Langfuse (public key + secret key)

Custom Auth (Partial Hook)

When the generated auth doesn't match the provider's expectations, override with a partial hook:

// MyApiClient.Auth.cs
public partial class MyApiClient
{
    partial void Authorized(HttpRequestMessage request)
    {
        // Deepgram uses "Token" prefix instead of "Bearer"
        request.Headers.Authorization =
            new AuthenticationHeaderValue("Token", _apiKey);
    }
}

SDKs using this: Deepgram (Token prefix), Mem0 (Token prefix)

Multiple Security Schemes

Some APIs support multiple auth methods:

autosdk generate spec.json \
  --security-scheme Http:Header:Bearer \
  --security-scheme ApiKey:Header:x-api-key

Spec Patching for Missing Auth

Many specs don't properly define security schemes. Patch them in generate.sh:

# Add Bearer auth to a spec that's missing it
cat openapi.json | jq '
  .components.securitySchemes = {
    "BearerAuth": {
      "type": "http",
      "scheme": "bearer"
    }
  } |
  .security = [{"BearerAuth": []}]
' > patched.json

autosdk generate patched.json --output Generated

Converting apiKey to Bearer

Many specs define auth as apiKey type when it's actually Bearer:

cat openapi.json | jq '
  .components.securitySchemes = (
    .components.securitySchemes | to_entries | map(
      if .value.type == "apiKey" then
        .value = {"type": "http", "scheme": "bearer"}
      else . end
    ) | from_entries
  )
' > patched.json

This is the most common auth fix across tryAGI SDKs.

Authentication Patterns

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