anthropic/claude-fable-5
Release date: 2026-06-09
1,000,000 context · $10.00/M input tokens · $50.00/M output tokens
Claude Fable 5 is Anthropic’s generally available Mythos-class model for autonomous knowledge work, advanced reasoning, and long-horizon coding. It supports text, image, and file inputs with text output, a 1M-token context window, up to 128K output tokens, always-on adaptive thinking, tool use, and structured outputs. Built from the same underlying model family as Claude Mythos 5 with stronger public-release safeguards, it is suited for complex software engineering, multi-step agent workflows, enterprise research, document analysis, and professional tasks that require sustained reasoning and reliability.
Pricing
Pay-per-use
No upfront costs, pay only for what you use
Try the model
API Usage
Use the following code examples to integrate with our API:
import OpenAI from 'openai';
if (!process.env.WAVESPEED_API_KEY) throw new Error('Set WAVESPEED_API_KEY');
const client = new OpenAI({
apiKey: process.env.WAVESPEED_API_KEY,
baseURL: 'https://llm.wavespeed.ai/v1',
timeout: 120_000,
maxRetries: 0,
});
try {
const response = await client.chat.completions.create({
model: 'anthropic/claude-fable-5',
messages: [{ role: 'user', content: 'Hello!' }],
});
const body = response as typeof response & { error?: { message?: string } };
if (body.error) throw new Error(body.error.message || 'LLM generation failed');
console.log(response.choices[0]?.message?.content ?? '');
} catch (error) {
console.error('LLM request failed:', error);
process.exitCode = 1;
}import OpenAI from 'openai';
if (!process.env.WAVESPEED_API_KEY) throw new Error('Set WAVESPEED_API_KEY');
const client = new OpenAI({
apiKey: process.env.WAVESPEED_API_KEY,
baseURL: 'https://llm.wavespeed.ai/v1',
timeout: 120_000,
maxRetries: 0,
});
try {
const response = await client.chat.completions.create({
model: 'anthropic/claude-fable-5',
messages: [{ role: 'user', content: 'Hello!' }],
});
const body = response as typeof response & { error?: { message?: string } };
if (body.error) throw new Error(body.error.message || 'LLM generation failed');
console.log(response.choices[0]?.message?.content ?? '');
} catch (error) {
console.error('LLM request failed:', error);
process.exitCode = 1;
}Model Introduction
Anthropic: Claude Fable 5
Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, with reasoning support and...
This model is available through the WaveSpeed AI OpenAI-compatible API for chat completions and compatible application workflows.
Why It Looks Great
- text+image+file->text architecture for Text, Image, file to Text workloads
- 1000000 context window for long prompts, document analysis, and multi-turn workflows
- Vision input support for image understanding and multimodal tasks
- Function calling and tool-use support for agentic application workflows
- Structured output support for JSON responses and schema-constrained generation
- Reasoning controls available through supported parameters
Key Features
- Context Window: 1000000 tokens
- Max Input: 872000 tokens
- Max Output: 128000 tokens
- Vision: Supported
- Function Calling: Supported
- Structured Outputs: Supported
- Image Generation: Not listed
- Audio Input: Not listed
- Supported Parameters: include_reasoning, max_completion_tokens, max_tokens, reasoning, reasoning_effort, response_format, stop, structured_outputs, tool_choice, tools, verbosity
Specifications
| Specification | Value |
|---|---|
| Provider | anthropic |
| Model Type | Chat Completions model |
| Architecture | text+image+file->text |
| Context Window | 1000000 tokens |
| Max Input | 872000 tokens |
| Max Output | 128000 tokens |
| Input | Text, Image, file |
| Output | Text |
| Vision | Supported |
| Function Calling | Supported |
| Structured Outputs | Supported |
| Release Date | June 9, 2026 |
How to Use
- Write your prompt - describe the task, provide context, and specify the desired output format.
- Submit - the model processes your request and returns the response.
API Integration
Base URL: https://llm.wavespeed.ai/v1 API Endpoint: chat/completions Model ID: anthropic/claude-fable-5
API Usage
Python SDK
from openai import OpenAI
client = OpenAI(
api_key="YOUR_API_KEY",
base_url="https://llm.wavespeed.ai/v1"
)
response = client.chat.completions.create(
model="anthropic/claude-fable-5",
messages=[{"role": "user", "content": "Hello!"}]
)
print(response.choices[0].message.content)cURL
curl https://llm.wavespeed.ai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "anthropic/claude-fable-5",
"messages": [{"role": "user", "content": "Hello!"}]
}'Notes
- Model: anthropic/claude-fable-5
- Provider: anthropic
Info
Supported Functionality
API Access Guide
Claude Fable 5 API
anthropic/claude-fable-5
Claude Fable 5 is Anthropic’s generally available Mythos-class model for autonomous knowledge work, advanced reasoning, and long-horizon coding. It supports text, image, and file inputs with text output, a 1M-token context window, up to 128K output tokens, always-on adaptive thinking, tool use, and structured outputs. Built from the same underlying model family as Claude Mythos 5 with stronger public-release safeguards, it is suited for complex software engineering, multi-step agent workflows, enterprise research, document analysis, and professional tasks that require sustained reasoning and reliability.
Input
$10 /M
Output
$50 /M
Context
1000K
Max Output
128K
Vision
Supported
Tool Use
Supported
Try Claude Fable 5 on WaveSpeedAI
Access Claude Fable 5 through our unified API — OpenAI-compatible, no cold starts, transparent pricing.
Frequently Asked Questions about Claude Fable 5
How much does Claude Fable 5 cost via the API?+
Pricing on WaveSpeedAI: $10.00 per million input tokens and $50.00 per million output tokens. Prompt caching and batch processing are billed separately and reduce effective cost on long, repetitive workloads.
What is the context window of Claude Fable 5?+
Claude Fable 5 supports up to 1000K tokens of context with up to 128K tokens of output per request.
Is Claude Fable 5 OpenAI-compatible?+
WaveSpeedAI exposes Claude Fable 5 at https://llm.wavespeed.ai/v1 through the OpenAI-compatible Chat Completions interface. Most OpenAI SDK clients work by changing the base URL and API key; optional fields depend on the selected model.
How do I get started with Claude Fable 5?+
Sign in to WaveSpeedAI, create an API key in Access Keys, then send a request to https://llm.wavespeed.ai/v1/chat/completions with the model id shown above. Check the current model catalog for availability, capabilities, and pricing.