Claude Fable 5.1

Request ID claude-fable-5-1

Protocols

POST /v1/messages · How to call

Request parameters

`POST /v1/messages`

Field	Type	Required	Description
`model`	`string`	Required	Set the model ID to `claude-fable-5-1`.
`messages`	`object[]`	Required	Send `user` and `assistant` messages in order. Put system instructions in the top-level `system` field.
`messages[].content`	`string / object[]`	Required	The message body. Use plain text or an array of content blocks defined by the protocol.
`system`	`string / object[]`	Optional	System instructions as text or an array of text blocks.
`max_tokens`	`integer`	Required	Caps output tokens. The accepted limit depends on the model and endpoint.
`stream`	`boolean`	Optional	`true` requests an SSE stream. `false` requests a JSON response. Available modes depend on the endpoint.
`temperature`	`number`	Conditional	Controls sampling randomness. Accepted values and whether the field takes effect depend on the model and endpoint.
`top_p`	`number`	Conditional	Limits sampling candidates by cumulative probability. Use when the model and endpoint support it.

How to call

Follow the setup guide for this model to configure the client or build a request.

bash

claude --model claude-fable-5-1

Read the response

Anthropic Messages · Read blocks of type text in content[]. In a stream, process SSE content block events in order. JSON · SSE

Full integration guide

Model Capability Catalog · View pricing

Claude Fable 5 Guide

Choose Claude Fable 5 for suitable tasks, use the correct model identifier, and verify the model through Claude Code and example requests.

Anthropic Messages

Send a request in the Anthropic Messages format. This page covers direct HTTP calls, with Claude Code setup covered in the related guides.

Model Capability Catalog

Compare public text, image, and video models by normalized request ID, compatible protocols, supported clients, tool use, media capabilities, limits, and review date.