Reference/API/Functions

List functions

List out all functions. The functions are sorted by creation date, with the most recently-created functions coming first

GET
/v1/function

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Query Parameters

limitinteger

Limit the number of objects to return

Minimum: 0
starting_afterstring

Pagination cursor id.

For example, if the final item in the last page you fetched had an id of foo, pass starting_after=foo to fetch the next page. Note: you may only pass one of starting_after and ending_before

Format: "uuid"
ending_beforestring

Pagination cursor id.

For example, if the initial item in the last page you fetched had an id of foo, pass ending_before=foo to fetch the previous page. Note: you may only pass one of starting_after and ending_before

Format: "uuid"
idsAny properties in string, array<string>

Filter search results to a particular set of object IDs. To specify a list of IDs, include the query param multiple times

function_namestring

Name of the function to search for

project_namestring

Name of the project to search for

project_idstring

Project id

Format: "uuid"
slugstring

Retrieve prompt with a specific slug

versionstring

Retrieve prompt at a specific version.

The version id can either be a transaction id (e.g. '1000192656880881099') or a version identifier (e.g. '81cd05ee665fdfb3').

org_namestring

Filter search results to within a particular organization

curl -X GET "https://api.braintrust.dev/v1/function?limit=0&starting_after=497f6eca-6276-4993-bfeb-53cbbbba6f08&ending_before=497f6eca-6276-4993-bfeb-53cbbbba6f08&ids=497f6eca-6276-4993-bfeb-53cbbbba6f08&function_name=string&project_name=string&project_id=497f6eca-6276-4993-bfeb-53cbbbba6f08&slug=string&version=string&org_name=string" \
  -H "Authorization: Bearer <token>"

Returns a list of function objects

{
  "objects": [
    {
      "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
      "_xact_id": "string",
      "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
      "log_id": "p",
      "org_id": "a40f5d1f-d889-42e9-94ea-b9b33585fc6b",
      "name": "string",
      "slug": "string",
      "description": "string",
      "created": "2019-08-24T14:15:22Z",
      "prompt_data": {
        "prompt": {
          "type": "completion",
          "content": "string"
        },
        "options": {
          "model": "string",
          "params": {
            "use_cache": true,
            "temperature": 0,
            "top_p": 0,
            "max_tokens": 0,
            "max_completion_tokens": 0,
            "frequency_penalty": 0,
            "presence_penalty": 0,
            "response_format": {
              "type": "json_object"
            },
            "tool_choice": "auto",
            "function_call": "auto",
            "n": 0,
            "stop": [
              "string"
            ],
            "reasoning_effort": "low"
          },
          "position": "string"
        },
        "parser": {
          "type": "llm_classifier",
          "use_cot": true,
          "choice_scores": {
            "property1": 1,
            "property2": 1
          }
        },
        "tool_functions": [
          {
            "type": "function",
            "id": "string"
          }
        ],
        "origin": {
          "prompt_id": "string",
          "project_id": "string",
          "prompt_version": "string"
        }
      },
      "tags": [
        "string"
      ],
      "metadata": {
        "property1": null,
        "property2": null
      },
      "function_type": "llm",
      "function_data": {
        "type": "prompt"
      },
      "origin": {
        "object_type": "organization",
        "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
        "internal": true
      },
      "function_schema": {
        "parameters": null,
        "returns": null
      }
    }
  ]
}

Create function

Create a new function. If there is an existing function in the project with the same slug as the one specified in the request, will return the existing function unmodified

POST
/v1/function

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Request Body

application/jsonOptional

Any desired information about the new function object

project_id
Required
string

Unique identifier for the project that the prompt belongs under

Format: "uuid"
name
Required
string

Name of the prompt

Minimum length: 1
slug
Required
string

Unique identifier for the prompt

Minimum length: 1
descriptionstring

Textual description of the prompt

prompt_dataobject

The prompt, model, and its parameters

tagsarray<string>

A list of tags for the prompt

function_typestring
Value in: "llm" | "scorer" | "task" | "tool" | null
function_data
Required
Any properties in prompt, code, global
originobject
function_schemaobject

JSON schema for the function's parameters and return type

curl -X POST "https://api.braintrust.dev/v1/function" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
    "name": "string",
    "slug": "string",
    "description": "string",
    "prompt_data": {
      "prompt": {
        "type": "completion",
        "content": "string"
      },
      "options": {
        "model": "string",
        "params": {
          "use_cache": true,
          "temperature": 0,
          "top_p": 0,
          "max_tokens": 0,
          "max_completion_tokens": 0,
          "frequency_penalty": 0,
          "presence_penalty": 0,
          "response_format": {
            "type": "json_object"
          },
          "tool_choice": "auto",
          "function_call": "auto",
          "n": 0,
          "stop": [
            "string"
          ],
          "reasoning_effort": "low"
        },
        "position": "string"
      },
      "parser": {
        "type": "llm_classifier",
        "use_cot": true,
        "choice_scores": {
          "property1": 1,
          "property2": 1
        }
      },
      "tool_functions": [
        {
          "type": "function",
          "id": "string"
        }
      ],
      "origin": {
        "prompt_id": "string",
        "project_id": "string",
        "prompt_version": "string"
      }
    },
    "tags": [
      "string"
    ],
    "function_type": "llm",
    "function_data": {
      "type": "prompt"
    },
    "origin": {
      "object_type": "organization",
      "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
      "internal": true
    },
    "function_schema": {
      "parameters": null,
      "returns": null
    }
  }'

Returns the new function object

{
  "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
  "_xact_id": "string",
  "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
  "log_id": "p",
  "org_id": "a40f5d1f-d889-42e9-94ea-b9b33585fc6b",
  "name": "string",
  "slug": "string",
  "description": "string",
  "created": "2019-08-24T14:15:22Z",
  "prompt_data": {
    "prompt": {
      "type": "completion",
      "content": "string"
    },
    "options": {
      "model": "string",
      "params": {
        "use_cache": true,
        "temperature": 0,
        "top_p": 0,
        "max_tokens": 0,
        "max_completion_tokens": 0,
        "frequency_penalty": 0,
        "presence_penalty": 0,
        "response_format": {
          "type": "json_object"
        },
        "tool_choice": "auto",
        "function_call": "auto",
        "n": 0,
        "stop": [
          "string"
        ],
        "reasoning_effort": "low"
      },
      "position": "string"
    },
    "parser": {
      "type": "llm_classifier",
      "use_cot": true,
      "choice_scores": {
        "property1": 1,
        "property2": 1
      }
    },
    "tool_functions": [
      {
        "type": "function",
        "id": "string"
      }
    ],
    "origin": {
      "prompt_id": "string",
      "project_id": "string",
      "prompt_version": "string"
    }
  },
  "tags": [
    "string"
  ],
  "metadata": {
    "property1": null,
    "property2": null
  },
  "function_type": "llm",
  "function_data": {
    "type": "prompt"
  },
  "origin": {
    "object_type": "organization",
    "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
    "internal": true
  },
  "function_schema": {
    "parameters": null,
    "returns": null
  }
}

Create or replace function

Create or replace function. If there is an existing function in the project with the same slug as the one specified in the request, will replace the existing function with the provided fields

PUT
/v1/function

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Request Body

application/jsonOptional

Any desired information about the new function object

project_id
Required
string

Unique identifier for the project that the prompt belongs under

Format: "uuid"
name
Required
string

Name of the prompt

Minimum length: 1
slug
Required
string

Unique identifier for the prompt

Minimum length: 1
descriptionstring

Textual description of the prompt

prompt_dataobject

The prompt, model, and its parameters

tagsarray<string>

A list of tags for the prompt

function_typestring
Value in: "llm" | "scorer" | "task" | "tool" | null
function_data
Required
Any properties in prompt, code, global
originobject
function_schemaobject

JSON schema for the function's parameters and return type

curl -X PUT "https://api.braintrust.dev/v1/function" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
    "name": "string",
    "slug": "string",
    "description": "string",
    "prompt_data": {
      "prompt": {
        "type": "completion",
        "content": "string"
      },
      "options": {
        "model": "string",
        "params": {
          "use_cache": true,
          "temperature": 0,
          "top_p": 0,
          "max_tokens": 0,
          "max_completion_tokens": 0,
          "frequency_penalty": 0,
          "presence_penalty": 0,
          "response_format": {
            "type": "json_object"
          },
          "tool_choice": "auto",
          "function_call": "auto",
          "n": 0,
          "stop": [
            "string"
          ],
          "reasoning_effort": "low"
        },
        "position": "string"
      },
      "parser": {
        "type": "llm_classifier",
        "use_cot": true,
        "choice_scores": {
          "property1": 1,
          "property2": 1
        }
      },
      "tool_functions": [
        {
          "type": "function",
          "id": "string"
        }
      ],
      "origin": {
        "prompt_id": "string",
        "project_id": "string",
        "prompt_version": "string"
      }
    },
    "tags": [
      "string"
    ],
    "function_type": "llm",
    "function_data": {
      "type": "prompt"
    },
    "origin": {
      "object_type": "organization",
      "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
      "internal": true
    },
    "function_schema": {
      "parameters": null,
      "returns": null
    }
  }'

Returns the new function object

{
  "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
  "_xact_id": "string",
  "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
  "log_id": "p",
  "org_id": "a40f5d1f-d889-42e9-94ea-b9b33585fc6b",
  "name": "string",
  "slug": "string",
  "description": "string",
  "created": "2019-08-24T14:15:22Z",
  "prompt_data": {
    "prompt": {
      "type": "completion",
      "content": "string"
    },
    "options": {
      "model": "string",
      "params": {
        "use_cache": true,
        "temperature": 0,
        "top_p": 0,
        "max_tokens": 0,
        "max_completion_tokens": 0,
        "frequency_penalty": 0,
        "presence_penalty": 0,
        "response_format": {
          "type": "json_object"
        },
        "tool_choice": "auto",
        "function_call": "auto",
        "n": 0,
        "stop": [
          "string"
        ],
        "reasoning_effort": "low"
      },
      "position": "string"
    },
    "parser": {
      "type": "llm_classifier",
      "use_cot": true,
      "choice_scores": {
        "property1": 1,
        "property2": 1
      }
    },
    "tool_functions": [
      {
        "type": "function",
        "id": "string"
      }
    ],
    "origin": {
      "prompt_id": "string",
      "project_id": "string",
      "prompt_version": "string"
    }
  },
  "tags": [
    "string"
  ],
  "metadata": {
    "property1": null,
    "property2": null
  },
  "function_type": "llm",
  "function_data": {
    "type": "prompt"
  },
  "origin": {
    "object_type": "organization",
    "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
    "internal": true
  },
  "function_schema": {
    "parameters": null,
    "returns": null
  }
}

Get function

Get a function object by its id

GET
/v1/function/{function_id}

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Path Parameters

function_id
Required
string

Function id

Format: "uuid"

Query Parameters

versionstring

Retrieve prompt at a specific version.

The version id can either be a transaction id (e.g. '1000192656880881099') or a version identifier (e.g. '81cd05ee665fdfb3').

curl -X GET "https://api.braintrust.dev/v1/function/497f6eca-6276-4993-bfeb-53cbbbba6f08?version=string" \
  -H "Authorization: Bearer <token>"

Returns the function object

{
  "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
  "_xact_id": "string",
  "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
  "log_id": "p",
  "org_id": "a40f5d1f-d889-42e9-94ea-b9b33585fc6b",
  "name": "string",
  "slug": "string",
  "description": "string",
  "created": "2019-08-24T14:15:22Z",
  "prompt_data": {
    "prompt": {
      "type": "completion",
      "content": "string"
    },
    "options": {
      "model": "string",
      "params": {
        "use_cache": true,
        "temperature": 0,
        "top_p": 0,
        "max_tokens": 0,
        "max_completion_tokens": 0,
        "frequency_penalty": 0,
        "presence_penalty": 0,
        "response_format": {
          "type": "json_object"
        },
        "tool_choice": "auto",
        "function_call": "auto",
        "n": 0,
        "stop": [
          "string"
        ],
        "reasoning_effort": "low"
      },
      "position": "string"
    },
    "parser": {
      "type": "llm_classifier",
      "use_cot": true,
      "choice_scores": {
        "property1": 1,
        "property2": 1
      }
    },
    "tool_functions": [
      {
        "type": "function",
        "id": "string"
      }
    ],
    "origin": {
      "prompt_id": "string",
      "project_id": "string",
      "prompt_version": "string"
    }
  },
  "tags": [
    "string"
  ],
  "metadata": {
    "property1": null,
    "property2": null
  },
  "function_type": "llm",
  "function_data": {
    "type": "prompt"
  },
  "origin": {
    "object_type": "organization",
    "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
    "internal": true
  },
  "function_schema": {
    "parameters": null,
    "returns": null
  }
}

Partially update function

Partially update a function object. Specify the fields to update in the payload. Any object-type fields will be deep-merged with existing content. Currently we do not support removing fields or setting them to null.

PATCH
/v1/function/{function_id}

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Request Body

application/jsonOptional

Fields to update

namestring

Name of the prompt

descriptionstring

Textual description of the prompt

prompt_dataobject

The prompt, model, and its parameters

function_dataAny properties in prompt, code, global
tagsarray<string>

A list of tags for the prompt

Path Parameters

function_id
Required
string

Function id

Format: "uuid"
curl -X PATCH "https://api.braintrust.dev/v1/function/497f6eca-6276-4993-bfeb-53cbbbba6f08" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "string",
    "description": "string",
    "prompt_data": {
      "prompt": {
        "type": "completion",
        "content": "string"
      },
      "options": {
        "model": "string",
        "params": {
          "use_cache": true,
          "temperature": 0,
          "top_p": 0,
          "max_tokens": 0,
          "max_completion_tokens": 0,
          "frequency_penalty": 0,
          "presence_penalty": 0,
          "response_format": {
            "type": "json_object"
          },
          "tool_choice": "auto",
          "function_call": "auto",
          "n": 0,
          "stop": [
            "string"
          ],
          "reasoning_effort": "low"
        },
        "position": "string"
      },
      "parser": {
        "type": "llm_classifier",
        "use_cot": true,
        "choice_scores": {
          "property1": 1,
          "property2": 1
        }
      },
      "tool_functions": [
        {
          "type": "function",
          "id": "string"
        }
      ],
      "origin": {
        "prompt_id": "string",
        "project_id": "string",
        "prompt_version": "string"
      }
    },
    "function_data": {
      "type": "prompt"
    },
    "tags": [
      "string"
    ]
  }'

Returns the function object

{
  "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
  "_xact_id": "string",
  "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
  "log_id": "p",
  "org_id": "a40f5d1f-d889-42e9-94ea-b9b33585fc6b",
  "name": "string",
  "slug": "string",
  "description": "string",
  "created": "2019-08-24T14:15:22Z",
  "prompt_data": {
    "prompt": {
      "type": "completion",
      "content": "string"
    },
    "options": {
      "model": "string",
      "params": {
        "use_cache": true,
        "temperature": 0,
        "top_p": 0,
        "max_tokens": 0,
        "max_completion_tokens": 0,
        "frequency_penalty": 0,
        "presence_penalty": 0,
        "response_format": {
          "type": "json_object"
        },
        "tool_choice": "auto",
        "function_call": "auto",
        "n": 0,
        "stop": [
          "string"
        ],
        "reasoning_effort": "low"
      },
      "position": "string"
    },
    "parser": {
      "type": "llm_classifier",
      "use_cot": true,
      "choice_scores": {
        "property1": 1,
        "property2": 1
      }
    },
    "tool_functions": [
      {
        "type": "function",
        "id": "string"
      }
    ],
    "origin": {
      "prompt_id": "string",
      "project_id": "string",
      "prompt_version": "string"
    }
  },
  "tags": [
    "string"
  ],
  "metadata": {
    "property1": null,
    "property2": null
  },
  "function_type": "llm",
  "function_data": {
    "type": "prompt"
  },
  "origin": {
    "object_type": "organization",
    "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
    "internal": true
  },
  "function_schema": {
    "parameters": null,
    "returns": null
  }
}

Delete function

Delete a function object by its id

DELETE
/v1/function/{function_id}

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Path Parameters

function_id
Required
string

Function id

Format: "uuid"
curl -X DELETE "https://api.braintrust.dev/v1/function/497f6eca-6276-4993-bfeb-53cbbbba6f08" \
  -H "Authorization: Bearer <token>"

Returns the deleted function object

{
  "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
  "_xact_id": "string",
  "project_id": "405d8375-3514-403b-8c43-83ae74cfe0e9",
  "log_id": "p",
  "org_id": "a40f5d1f-d889-42e9-94ea-b9b33585fc6b",
  "name": "string",
  "slug": "string",
  "description": "string",
  "created": "2019-08-24T14:15:22Z",
  "prompt_data": {
    "prompt": {
      "type": "completion",
      "content": "string"
    },
    "options": {
      "model": "string",
      "params": {
        "use_cache": true,
        "temperature": 0,
        "top_p": 0,
        "max_tokens": 0,
        "max_completion_tokens": 0,
        "frequency_penalty": 0,
        "presence_penalty": 0,
        "response_format": {
          "type": "json_object"
        },
        "tool_choice": "auto",
        "function_call": "auto",
        "n": 0,
        "stop": [
          "string"
        ],
        "reasoning_effort": "low"
      },
      "position": "string"
    },
    "parser": {
      "type": "llm_classifier",
      "use_cot": true,
      "choice_scores": {
        "property1": 1,
        "property2": 1
      }
    },
    "tool_functions": [
      {
        "type": "function",
        "id": "string"
      }
    ],
    "origin": {
      "prompt_id": "string",
      "project_id": "string",
      "prompt_version": "string"
    }
  },
  "tags": [
    "string"
  ],
  "metadata": {
    "property1": null,
    "property2": null
  },
  "function_type": "llm",
  "function_data": {
    "type": "prompt"
  },
  "origin": {
    "object_type": "organization",
    "object_id": "463a83d0-a816-4902-abba-2486e0c0a0bb",
    "internal": true
  },
  "function_schema": {
    "parameters": null,
    "returns": null
  }
}

Invoke function

Invoke a function.

POST
/v1/function/{function_id}/invoke

Authorization

Authorization
Required
Bearer <token>

Most Braintrust endpoints are authenticated by providing your API key as a header Authorization: Bearer [api_key] to your HTTP request. You can create an API key in the Braintrust organization settings page.

In: header

Request Body

application/jsonOptional

Function invocation parameters

inputunknown

Argument to the function, which can be any JSON serializable value

expectedunknown

The expected output of the function

metadataobject

Any relevant metadata

messagesarray<Any properties in system, user, assistant, tool, function, fallback>

If the function is an LLM, additional messages to pass along to it

parentAny properties in span_parent_struct, string

Options for tracing the function call

streamboolean

Whether to stream the response. If true, results will be returned in the Braintrust SSE format.

modestring

The mode format of the returned value (defaults to 'auto')

Value in: "auto" | "parallel" | null
versionstring

The version of the function

Path Parameters

function_id
Required
string

Function id

Format: "uuid"
curl -X POST "https://api.braintrust.dev/v1/function/497f6eca-6276-4993-bfeb-53cbbbba6f08/invoke" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "input": null,
    "expected": null,
    "metadata": {
      "property1": null,
      "property2": null
    },
    "messages": [
      {
        "content": "",
        "role": "system",
        "name": "string"
      }
    ],
    "parent": {
      "object_type": "project_logs",
      "object_id": "string",
      "row_ids": {
        "id": "string",
        "span_id": "string",
        "root_span_id": "string"
      },
      "propagated_event": {
        "property1": null,
        "property2": null
      }
    },
    "stream": true,
    "mode": "auto",
    "version": "string"
  }'

Function invocation response

null

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