Call functions from your app

Amazon Bedrock Studio functions let a model include information that it has no previous knowledge of in its response. For example, you can use a function to include dynamic information in a model's response such as a weather forecast, sports results, or traffic conditions.

In Amazon Bedrock Studio, a function calls an API hosted outside of Amazon Bedrock Studio. You either create the API yourself, or use an existing API. To create an API, you can use Amazon API Gateway.

To use a function in Amazon Bedrock Studio you add a function component to your app. As part of the function, you define an OpenAPI schema for the API that you want the model to call. You also specify how to authenticate the call to the API. When a model receives a prompt, it uses the schema and the prompt to determine if an API should be called and the parameters that the API should receive. If the API is called, the response from the model includes the output from the API.

APIs that you call in a function must have a response size that is less than 20K.

When add a function to an app, you need to specify the app's system prompt. The system prompt needs to be at least 40 characters long and should mention the new skills that the new function introduces.

You can use functions in a Chat app.

Function schema

Amazon Bedrock Studio has the following requirements for the schema that you use to create a function.

Valid components for globally-scoped security requirements

Bedrock Studio only honors globally-scoped security requirements. That is, Bedrock Studio ignores security requirements indicated in operation objects.

When the requirement array contains a security scheme object with type http and scheme of bearer or basic, the array must contain a single entry. Bedrock Studio ignores further entries.

When the requirement array contains a security scheme object with type apiKey, you can have a maximum of 2 entries.

For example, if you have the following components:

"components": {
  "securitySchemes": {
    "api_key_1": {
      "type": "apiKey",
      "name": "appid1",
      "in": "query"
    },
    "api_key_2": {
      "type": "apiKey",
      "name": "appid2",
      "in": "header"
    },
    "api_key_3": {
      "type": "apiKey",
      "name": "appid3",
      "in": "cookie"
    },
    "bearer_1": {
      "type": "http",
      "scheme": "bearer",
    },
    "bearer_2": {
      "type": "http",
      "scheme": "bearer",
    },
    "basic_1": {
      "type": "http",
      "scheme": "basic",
    },
    "basic_2": {
      "type": "http",
      "scheme": "basic",
    },
    "http_digest": {
      "type": "http",
      "scheme": "digest"
    },
    "oauth2_1": {
      "type": "oauth2"
    }
  }
}

The following are valid:

# 1 API key
"security": [
  {
    "api_key_1": []
  }
],

# 2 API keys
"security": {
  {
    "api_key_1": [],
    "api_key_2": []
  }
}

# Bearer
"security": {
   "bearer_1": []
}

# Basic
"security": {
   "basic_1": []
}

The following are invalid:

# Invalid: `type` must only be `apiKey` or `http`
"security": {
  "oauth2_1": []
}

# Invalid: `scheme` must only be `basic` or `bearer` if `type` is `http`
"security": {
  "http_digest": []
}

# Invalid: `security` must only contain 1 entry if `type` is `basic` or `bearer`
"security": {
  "basic_1": [],
  "basic_2": []
}

# Invalid: `security` must not contain varying security types
"security": {
  "api_key_1": [],
  "basic_1": []
}

# Invalid: API key must only have `in` property set to `header` or `query` 
"security": {
  "api_key_1": [],
  "api_key_3": []
}

# Invalid: `security` must not have more than 2 API keys
"security": {
  {
    "api_key_1": [],
    "api_key_2": [],
    "api_key_3": []
  }
}

Authentication methods

Amazon Bedrock Studio supports the following methods for authenticating function calls to an API server. If you authenticate a function call, make sure the credentials you provide are correct as Bedrock Studio doesn't verify the credentials before you use them in a function call.