Langdock Messages API
The Messages API from Langdock — 1 operation(s) for messages.
OpenAPI Specification
openapi: 3.0.0
info:
title: Langdock Agent Messages API
version: 3.0.0
servers:
- url: https://api.langdock.com
description: Production
security:
- bearerAuth: []
tags:
- name: Messages
paths:
/anthropic/{region}/v1/messages:
post:
tags:
- Messages
summary: Create a Message
description: 'Create a Message.
Send a structured list of input messages with text and/or image content, and the model will generate the next message in the conversation.
The Messages API can be used for either single queries or stateless multi-turn conversations.'
parameters:
- name: region
in: path
required: true
description: The region of the API to use.
schema:
type: string
enum:
- eu
- us
operationId: messages_post
responses:
'200':
description: Message object.
content:
application/json:
schema:
$ref: '#/components/schemas/Message'
4XX:
description: 'Error response.
See Anthropic''s [errors documentation](https://platform.claude.com/docs/en/api/errors) for more details.'
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/CreateMessageParams'
required: true
security:
- bearerAuth: []
components:
schemas:
Tool:
additionalProperties: false
properties:
description:
description: 'Description of what this tool does.
Tool descriptions should be as detailed as possible. The more information that the model has about what the tool is and how to use it, the better it will perform. You can use natural language descriptions to reinforce important aspects of the tool input JSON schema.'
example:
- Get the current weather in a given location
title: Description
type: string
name:
maxLength: 64
minLength: 1
pattern: ^[a-zA-Z0-9_-]{1,64}$
title: Name
type: string
input_schema:
allOf:
- $ref: '#/components/schemas/InputSchema'
description: '[JSON schema](https://json-schema.org/) for this tool''s input.
This defines the shape of the `input` that your tool accepts and that the model will produce.'
example:
- properties:
location:
description: The city and state, e.g. San Francisco, CA
type: string
unit:
description: Unit for the output - one of (celsius, fahrenheit)
type: string
required:
- location
type: object
required:
- name
- input_schema
title: Tool
type: object
RequestToolResultBlock:
additionalProperties: false
properties:
type:
enum:
- tool_result
title: Type
type: string
tool_use_id:
pattern: ^[a-zA-Z0-9_-]+$
title: Tool Use Id
type: string
is_error:
default: false
title: Is Error
type: boolean
content:
anyOf:
- type: string
x-stainless-skip:
- go
- items:
discriminator:
mapping:
image: '#/components/schemas/RequestImageBlock'
text: '#/components/schemas/RequestTextBlock'
propertyName: type
oneOf:
- $ref: '#/components/schemas/RequestTextBlock'
- $ref: '#/components/schemas/RequestImageBlock'
type: array
x-stainless-naming:
python:
type_name: Content
title: Content
required:
- type
- tool_use_id
title: Tool Result
type: object
ToolChoiceTool:
additionalProperties: false
description: The model will use the specified tool with `tool_choice.name`.
properties:
type:
enum:
- tool
title: Type
type: string
name:
description: The name of the tool to use.
title: Name
type: string
required:
- type
- name
title: ToolChoiceTool
type: object
Base64ImageSource:
additionalProperties: false
properties:
type:
enum:
- base64
title: Type
type: string
media_type:
enum:
- image/jpeg
- image/png
- image/gif
- image/webp
title: Media Type
type: string
data:
format: byte
title: Data
type: string
required:
- type
- media_type
- data
title: Base64ImageSource
type: object
Message:
example:
- content:
- text: Here is a haiku about cats:\n\nFeline grace and charm,\nPurring softly by the fire,\nCats reign supreme.
type: text
id: msg_013Zva2CMHLNnXjNJJKqJ2EF
model: claude-3-haiku-20240307
role: assistant
stop_reason: end_turn
stop_sequence: null
type: message
usage:
input_tokens: 14
output_tokens: 35
properties:
id:
description: 'Unique object identifier.
The format and length of IDs may change over time.'
example:
- msg_013Zva2CMHLNnXjNJJKqJ2EF
title: Id
type: string
type:
default: message
description: 'Object type.
For Messages, this is always `"message"`.'
enum:
- message
title: Type
type: string
role:
default: assistant
description: 'Conversational role of the generated message.
This will always be `"assistant"`.'
enum:
- agent
title: Role
type: string
content:
description: "Content generated by the model.\n\nThis is an array of content blocks, each of which has a `type` that determines its shape.\n\nExample:\n\n```json\n[{\"type\": \"text\", \"text\": \"Hi, I'm Claude.\"}]\n```\n\nIf the request input `messages` ended with an `agent` turn, then the response `content` will continue directly from that last turn. You can use this to constrain the model's output.\n\nFor example, if the input `messages` were:\n```json\n[\n {\"role\": \"user\", \"content\": \"What's the Greek name for Sun? (A) Sol (B) Helios (C) Sun\"},\n {\"role\": \"assistant\", \"content\": \"The best answer is (\"}\n]\n```\n\nThen the response `content` might be:\n\n```json\n[{\"type\": \"text\", \"text\": \"B)\"}]\n```"
example:
- - text: Hi! My name is Claude.
type: text
items:
$ref: '#/components/schemas/ContentBlock'
title: Content
type: array
model:
$ref: '#/components/schemas/Model'
stop_reason:
anyOf:
- enum:
- end_turn
- max_tokens
- stop_sequence
- tool_use
type: string
description: 'The reason that we stopped.
This may be one the following values:
* `"end_turn"`: the model reached a natural stopping point
* `"max_tokens"`: we exceeded the requested `max_tokens` or the model''s maximum
* `"stop_sequence"`: one of your provided custom `stop_sequences` was generated
* `"tool_use"`: the model invoked one or more tools
In non-streaming mode this value is always non-null. In streaming mode, it is null in the `message_start` event and non-null otherwise.'
title: Stop Reason
stop_sequence:
anyOf:
- type: string
default: null
description: 'Which custom stop sequence was generated, if any.
This value will be a non-null string if one of your custom stop sequences was generated.'
title: Stop Sequence
usage:
allOf:
- $ref: '#/components/schemas/Usage'
description: 'Input and output token counts, representing the underlying cost to our systems.
Under the hood, the API transforms requests into a format suitable for the model. The model''s output then goes through a parsing stage before becoming an API response. As a result, the token counts in `usage` will not match one-to-one with the exact visible content of an API request or response.
For example, `output_tokens` will be non-zero, even for an empty string response from Claude.'
example:
- input_tokens: 2095
output_tokens: 503
required:
- id
- type
- role
- content
- model
- stop_reason
- stop_sequence
- usage
title: Message
type: object
x-stainless-python-custom-imports:
- from .content_block import ContentBlock as ContentBlock
Model:
title: Model
description: The model that will complete your prompt. See [models](https://platform.claude.com/docs/en/docs/models-overview) for additional details and options.
type: string
ResponseTextBlock:
properties:
type:
default: text
enum:
- text
title: Type
type: string
text:
maxLength: 5000000
minLength: 0
title: Text
type: string
required:
- type
- text
title: Text
type: object
InputMessage:
additionalProperties: false
properties:
role:
enum:
- user
- agent
title: Role
type: string
content:
anyOf:
- type: string
x-stainless-skip:
- go
- items:
discriminator:
mapping:
image: '#/components/schemas/RequestImageBlock'
text: '#/components/schemas/RequestTextBlock'
tool_result: '#/components/schemas/RequestToolResultBlock'
tool_use: '#/components/schemas/RequestToolUseBlock'
propertyName: type
oneOf:
- $ref: '#/components/schemas/RequestTextBlock'
- $ref: '#/components/schemas/RequestImageBlock'
- $ref: '#/components/schemas/RequestToolUseBlock'
- $ref: '#/components/schemas/RequestToolResultBlock'
x-stainless-python-extend-union:
- ContentBlock
x-stainless-python-extend-union-imports:
- from .content_block import ContentBlock
type: array
example:
- type: text
text: What is a quaternion?
title: Content
required:
- role
- content
title: InputMessage
type: object
RequestImageBlock:
additionalProperties: false
properties:
type:
enum:
- image
title: Type
type: string
source:
discriminator:
mapping:
base64: '#/components/schemas/Base64ImageSource'
propertyName: type
oneOf:
- $ref: '#/components/schemas/Base64ImageSource'
title: Source
required:
- type
- source
title: Image
type: object
ToolChoiceAny:
additionalProperties: false
description: The model will use any available tools.
properties:
type:
enum:
- any
title: Type
type: string
required:
- type
title: ToolChoiceAny
type: object
ResponseThinkingBlock:
type: object
description: A thinking content block containing Claude's reasoning process when extended thinking is enabled.
properties:
type:
type: string
enum:
- thinking
description: The type of content block.
thinking:
type: string
description: Claude's internal reasoning process.
signature:
type: string
description: A signature verifying the thinking block's authenticity.
required:
- type
- thinking
RequestTextBlock:
additionalProperties: false
properties:
type:
enum:
- text
title: Type
type: string
text:
minLength: 1
title: Text
type: string
required:
- type
- text
title: Text
type: object
NotFoundError:
properties:
type:
default: not_found_error
enum:
- not_found_error
title: Type
type: string
message:
default: Not found
title: Message
type: string
required:
- type
- message
title: NotFoundError
type: object
InputSchema:
additionalProperties: true
properties:
type:
enum:
- object
title: Type
type: string
properties:
anyOf:
- type: object
default: null
title: Properties
required:
- type
title: InputSchema
type: object
AuthenticationError:
properties:
type:
default: authentication_error
enum:
- authentication_error
title: Type
type: string
message:
default: Authentication error
title: Message
type: string
required:
- type
- message
title: AuthenticationError
type: object
CreateMessageParams:
additionalProperties: false
example:
max_tokens: 1024
messages:
- content: Write a haiku about cats.
role: user
model: claude-sonnet-4-20250514
properties:
model:
$ref: '#/components/schemas/Model'
messages:
description: "Input messages.\n\nAnthropic's models are trained to operate on alternating `user` and `agent` conversational turns. When creating a new `Message`, you specify the prior conversational turns with the `messages` parameter, and the model then generates the next `Message` in the conversation.\n\nEach input message must be an object with a `role` and `content`. You can specify a single `user`-role message, or you can include multiple `user` and `assistant` messages. The first message must always use the `user` role.\n\nIf the final message uses the `assistant` role, the response content will continue immediately from the content in that message. This can be used to constrain part of the model's response.\n\nExample with a single `user` message:\n\n```json\n[{\"role\": \"user\", \"content\": \"Hello, Claude\"}]\n```\n\nExample with multiple conversational turns:\n\n```json\n[\n {\"role\": \"user\", \"content\": \"Hello there.\"},\n {\"role\": \"assistant\", \"content\": \"Hi, I'm Claude. How can I help you?\"},\n {\"role\": \"user\", \"content\": \"Can you explain LLMs in plain English?\"},\n]\n```\n\nExample with a partially-filled response from Claude:\n\n```json\n[\n {\"role\": \"user\", \"content\": \"What's the Greek name for Sun? (A) Sol (B) Helios (C) Sun\"},\n {\"role\": \"assistant\", \"content\": \"The best answer is (\"},\n]\n```\n\nEach input message `content` may be either a single `string` or an array of content blocks, where each block has a specific `type`. Using a `string` for `content` is shorthand for an array of one content block of type `\"text\"`. The following input messages are equivalent:\n\n```json\n{\"role\": \"user\", \"content\": \"Hello, Claude\"}\n```\n\n```json\n{\"role\": \"user\", \"content\": [{\"type\": \"text\", \"text\": \"Hello, Claude\"}]}\n```\n\nStarting with Claude 3 models, you can also send image content blocks:\n\n```json\n{\"role\": \"user\", \"content\": [\n {\n \"type\": \"image\",\n \"source\": {\n \"type\": \"base64\",\n \"media_type\": \"image/jpeg\",\n \"data\": \"/9j/4AAQSkZJRg...\",\n }\n },\n {\"type\": \"text\", \"text\": \"What is in this image?\"}\n]}\n```\n\nWe currently support the `base64` source type for images, and the `image/jpeg`, `image/png`, `image/gif`, and `image/webp` media types.\n\nSee [examples](https://platform.claude.com/docs/en/api/messages-examples#vision) for more input examples.\n\nNote that if you want to include a [system prompt](https://platform.claude.com/docs/en/docs/system-prompts), you can use the top-level `system` parameter â€\" there is no `\"system\"` role for input messages in the Messages API."
items:
$ref: '#/components/schemas/InputMessage'
title: Messages
type: array
max_tokens:
description: 'The maximum number of tokens to generate before stopping.
Note that Anthropic''s models may stop _before_ reaching this maximum. This parameter only specifies the absolute maximum number of tokens to generate.
Different models have different maximum values for this parameter. See [models](https://platform.claude.com/docs/en/docs/models-overview) for details.'
example:
- 1024
minimum: 1
title: Max Tokens
type: integer
stop_sequences:
description: 'Custom text sequences that will cause the model to stop generating.
Anthropic''s models will normally stop when they have naturally completed their turn, which will result in a response `stop_reason` of `"end_turn"`.
If you want the model to stop generating when it encounters custom strings of text, you can use the `stop_sequences` parameter. If the model encounters one of the custom sequences, the response `stop_reason` value will be `"stop_sequence"` and the response `stop_sequence` value will contain the matched stop sequence.'
items:
type: string
title: Stop Sequences
type: array
stream:
description: 'Whether to incrementally stream the response using server-sent events.
See [streaming](https://platform.claude.com/docs/en/build-with-claude/streaming) for details.'
title: Stream
type: boolean
system:
anyOf:
- type: string
x-stainless-skip:
- go
- items:
$ref: '#/components/schemas/RequestTextBlock'
type: array
description: 'System prompt.
A system prompt is a way of providing context and instructions to Claude, such as specifying a particular goal or role. See Anthropic''s [guide to system prompts](https://platform.claude.com/docs/en/docs/system-prompts).'
example:
- - text: Today's date is 2024-06-01.
type: text
- Today's date is 2023-01-01.
title: System
temperature:
description: 'Amount of randomness injected into the response.
Defaults to `1.0`. Ranges from `0.0` to `1.0`. Use `temperature` closer to `0.0` for analytical / multiple choice, and closer to `1.0` for creative and generative tasks.
Note that even with `temperature` of `0.0`, the results will not be fully deterministic.'
example:
- 1
maximum: 1
minimum: 0
title: Temperature
type: number
tool_choice:
description: How the model should use the provided tools. The model can use a specific tool, any available tool, or decide by itself.
discriminator:
mapping:
any: '#/components/schemas/ToolChoiceAny'
auto: '#/components/schemas/ToolChoiceAuto'
tool: '#/components/schemas/ToolChoiceTool'
propertyName: type
oneOf:
- $ref: '#/components/schemas/ToolChoiceAuto'
- $ref: '#/components/schemas/ToolChoiceAny'
- $ref: '#/components/schemas/ToolChoiceTool'
title: Tool Choice
tools:
description: "Definitions of tools that the model may use.\n\nIf you include `tools` in your API request, the model may return `tool_use` content blocks that represent the model's use of those tools. You can then run those tools using the tool input generated by the model and then optionally return results back to the model using `tool_result` content blocks.\n\nEach tool definition includes:\n\n* `name`: Name of the tool.\n* `description`: Optional, but strongly-recommended description of the tool.\n* `input_schema`: [JSON schema](https://json-schema.org/) for the tool `input` shape that the model will produce in `tool_use` output content blocks.\n\nFor example, if you defined `tools` as:\n\n```json\n[\n {\n \"name\": \"get_stock_price\",\n \"description\": \"Get the current stock price for a given ticker symbol.\",\n \"input_schema\": {\n \"type\": \"object\",\n \"properties\": {\n \"ticker\": {\n \"type\": \"string\",\n \"description\": \"The stock ticker symbol, e.g. AAPL for Apple Inc.\"\n }\n },\n \"required\": [\"ticker\"]\n }\n }\n]\n```\n\nAnd then asked the model \"What's the S&P 500 at today?\", the model might produce `tool_use` content blocks in the response like this:\n\n```json\n[\n {\n \"type\": \"tool_use\",\n \"id\": \"toolu_01D7FLrfh4GYq7yT1ULFeyMV\",\n \"name\": \"get_stock_price\",\n \"input\": { \"ticker\": \"^GSPC\" }\n }\n]\n```\n\nYou might then run your `get_stock_price` tool with `{\"ticker\": \"^GSPC\"}` as an input, and return the following back to the model in a subsequent `user` message:\n\n```json\n[\n {\n \"type\": \"tool_result\",\n \"tool_use_id\": \"toolu_01D7FLrfh4GYq7yT1ULFeyMV\",\n \"content\": \"259.75 USD\"\n }\n]\n```\n\nTools can be used for workflows that include running client-side tools and functions, or more generally whenever you want the model to produce a particular JSON structure of output.\n\nSee Anthropic's [guide](https://platform.claude.com/docs/en/docs/tool-use) for more details."
example:
- description: Get the current weather in a given location
input_schema:
properties:
location:
description: The city and state, e.g. San Francisco, CA
type: string
unit:
description: Unit for the output - one of (celsius, fahrenheit)
type: string
required:
- location
type: object
name: get_weather
items:
$ref: '#/components/schemas/Tool'
title: Tools
type: array
top_k:
description: 'Only sample from the top K options for each subsequent token.
Used to remove "long tail" low probability responses. [Learn more technical details here](https://towardsdatascience.com/how-to-write-expert-prompts-for-chatgpt-gpt-4-and-other-language-models-23133dc85550/).
Recommended for advanced use cases only. You usually only need to use `temperature`.'
example:
- 5
minimum: 0
title: Top K
type: integer
top_p:
description: 'Use nucleus sampling.
In nucleus sampling, we compute the cumulative distribution over all the options for each subsequent token in decreasing probability order and cut it off once it reaches a particular probability specified by `top_p`. You should either alter `temperature` or `top_p`, but not both.
Recommended for advanced use cases only. You usually only need to use `temperature`.'
example:
- 0.7
maximum: 1
minimum: 0
title: Top P
type: number
thinking:
$ref: '#/components/schemas/ThinkingConfig'
required:
- model
- messages
- max_tokens
title: CreateMessageParams
type: object
APIError:
properties:
type:
default: api_error
enum:
- api_error
title: Type
type: string
message:
default: Internal server error
title: Message
type: string
required:
- type
- message
title: APIError
type: object
Usage:
properties:
input_tokens:
description: The number of input tokens which were used.
example:
- 2095
title: Input Tokens
type: integer
output_tokens:
description: The number of output tokens which were used.
example:
- 503
title: Output Tokens
type: integer
required:
- input_tokens
- output_tokens
title: Usage
type: object
ErrorResponse:
properties:
type:
default: error
enum:
- error
title: Type
type: string
error:
discriminator:
mapping:
api_error: '#/components/schemas/APIError'
authentication_error: '#/components/schemas/AuthenticationError'
invalid_request_error: '#/components/schemas/InvalidRequestError'
not_found_error: '#/components/schemas/NotFoundError'
overloaded_error: '#/components/schemas/OverloadedError'
permission_error: '#/components/schemas/PermissionError'
rate_limit_error: '#/components/schemas/RateLimitError'
propertyName: type
oneOf:
- $ref: '#/components/schemas/InvalidRequestError'
- $ref: '#/components/schemas/AuthenticationError'
- $ref: '#/components/schemas/PermissionError'
- $ref: '#/components/schemas/NotFoundError'
- $ref: '#/components/schemas/RateLimitError'
- $ref: '#/components/schemas/APIError'
- $ref: '#/components/schemas/OverloadedError'
title: Error
required:
- type
- error
title: ErrorResponse
type: object
InvalidRequestError:
properties:
type:
default: invalid_request_error
enum:
- invalid_request_error
title: Type
type: string
message:
default: Invalid request
title: Message
type: string
required:
- type
- message
title: InvalidRequestError
type: object
ToolChoiceAuto:
additionalProperties: false
description: The model will automatically decide whether to use tools.
properties:
type:
enum:
- auto
title: Type
type: string
required:
- type
title: ToolChoiceAuto
type: object
ContentBlock:
discriminator:
mapping:
text: '#/components/schemas/ResponseTextBlock'
tool_use: '#/components/schemas/ResponseToolUseBlock'
thinking: '#/components/schemas/ResponseThinkingBlock'
propertyName: type
oneOf:
- $ref: '#/components/schemas/ResponseTextBlock'
- $ref: '#/components/schemas/ResponseToolUseBlock'
- $ref: '#/components/schemas/ResponseThinkingBlock'
PermissionError:
properties:
type:
default: permission_error
enum:
- permission_error
title: Type
type: string
message:
default: Permission denied
title: Message
type: string
required:
- type
- message
title: PermissionError
type: object
ThinkingConfig:
type: object
title: Thinking
description: 'Configuration for enabling Claude''s extended thinking. When enabled, responses include `thinking` content blocks showing Claude''s reasoning process before the final answer.
See [extended thinking](https://platform.claude.com/docs/en/build-with-claude/extended-thinking) for details.'
properties:
type:
type: string
enum:
- enabled
description: Must be "enabled" to activate extended thinking.
budget_tokens:
type: integer
minimum: 1024
description: Maximum number of tokens Claude can use for thinking. Must be ≥1024 and less than max_tokens.
required:
- type
- budget_tokens
ResponseToolUseBlock:
properties:
type:
default: tool_use
enum:
- tool_use
title: Type
type: string
id:
pattern: ^[a-zA-Z0-9_-]+$
title: Id
type: string
name:
minLength: 1
title: Name
type: string
input:
title: Input
type: object
required:
- type
- id
- name
- input
title: Tool Use
type: object
RequestToolUseBlock:
additionalProperties: false
properties:
type:
enum:
- tool_use
title: Type
type: string
id:
pattern: ^[a-zA-Z0-9_-]+$
title: Id
type: string
name:
maxLength: 64
minLength: 1
pattern: ^[a-zA-Z0-9_-]{1,64}$
title: Name
type: string
input:
title: Input
type: object
required:
- type
- id
- name
- input
title: Tool Use
type: object
OverloadedError:
properties:
type:
default: overloaded_error
enum:
- overloaded_error
title: Type
type: string
message:
default: Overloaded
title: Message
type: string
required:
- type
- message
title: OverloadedError
type: object
RateLimitError:
properties:
type:
default: rate_limit_error
enum:
- rate_limit_error
title: Type
type: string
message:
default: Rate limited
title: Message
type: string
required:
- type
- message
title: RateLimitError
type: object
securitySchemes:
bearerAuth:
type: http
scheme: bearer
bearerFormat: API Key
description: API key as Bearer token. Format "Bearer YOUR_API_KEY"