Claude Fable 5.2 API

Claude Fable 5.2 is a chat model from Anthropic designed for complex reasoning and long-horizon agentic tasks.

Modalities
Image, TextText
In / Out price
$8/$40per 1M
Context window
1M tokens
Released
Nov 9, 2026

Claude Fable 5.2 overview

Claude Fable 5.2 by Anthropic

Claude Fable 5.2 provides robust capabilities for agentic work that runs for hours. It features a large context window and adaptive thinking to support multistep research and analysis.

Claude Fable 5.2 specs

Model ID
anthropic/claude-fable-5-2
Developer
Anthropic
Context window
1,000,000 tokens
Max output
128,000 tokens
Input
Image, Text
Output
Text
API
OpenAI-compatible, base URL https://api.aimlapi.com/v1

What Is Claude Fable 5.2 API?

Developed by Anthropic, Claude Fable 5.2 is a chat model engineered for demanding reasoning tasks and long-horizon agentic workflows.

The model is built to handle extensive sessions, including multistep research and the creation of finished documents through adaptive thinking.

Large Context Window

The model supports a 1M token context window for extensive data processing.

Adaptive Thinking

Always-on adaptive thinking allows for deeper reasoning during complex tasks.

High Output Capacity

Users can generate up to 128K output tokens for comprehensive document creation.

Multimodal Support

The model accepts both image and text inputs to produce text outputs.

Advanced Tooling

Capabilities include reasoning, streaming, tool usage, vision, and web search.

Use cases

Conducting complex multistep research projects.

Managing agent sessions that run for extended periods.

Analyzing data to produce finished documents.

Integrating web search and vision for comprehensive analysis.

Capabilities

  • Reasoning
  • Streaming
  • Function calling
  • Vision
  • Web search

Claude Fable 5.2 benchmarks by Artificial Analysis

See how Claude Fable 5.2 compares in intelligence and cost per task. Data retrieved Nov 9, 2026.

Intelligence

Index v5.0

Cost per task

USD / benchmark task

Claude Fable 5.2 API pricing

Claude Fable 5.2 pricing in US dollars
UsagePriceUnit
Input$81M tokens
Output$401M tokens
Cached input$0.21M tokens

Prices from the AI/ML API price list, checked on Nov 10, 2026.

Claude Fable 5.2 vs other models: token prices

AI/ML API input and output rates for 5 models, per million tokens.

AI/ML API model prices in USD per million tokens
ModelInputOutput
Claude Fable 5.2$8$40
Claude Haiku 5.5$0.1$0.5
Claude Sonnet 5.5$2$10
Claude Opus 5.5$4$20
Claude Fable 5.1$10$50

How to use the Claude Fable 5.2 API

View docs

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key
export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "anthropic/claude-fable-5-2",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'

Related articles

All posts

Claude Fable 5.2 FAQ

Who developed this model?

Claude Fable 5.2 was developed by Anthropic.

What is the maximum output length?

The model supports up to 128K output tokens.

What modalities does this model support?

It supports image and text inputs with text outputs.

What is the context window size?

The model features a 1M token context window.

How much does Claude Fable 5.2 cost?

Claude Fable 5.2 costs $8 / 1M tokens for input and $40 / 1M tokens for output on AI/ML API. Cached input is billed at $0.2 / 1M tokens.

What is the Claude Fable 5.2 model ID?

Use anthropic/claude-fable-5-2 as the model parameter. Requests go to the OpenAI-compatible endpoint with your AI/ML API key.

Start building with Claude Fable 5.2

Claude Fable 5.2 API

anthropic/claude-fable-5-2

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key
export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "anthropic/claude-fable-5-2",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'