Claude Fable 5.2 is Anthropic's most capable widely released model and the successor to Claude Fable 5.1, built for the most demanding reasoning and long-horizon agentic work at a lower price than its predecessor. It has a 1M-token context window (the maximum is also the default) and produces up to 128K output tokens in a single response. Thinking is always on — the model reasons adaptively on every request and you control depth with an effort level from low through max — while the raw chain of thought is never returned (you get a summary or an empty thinking field). It accepts text, images and documents and returns text, with native tool use / function calling and structured (JSON) outputs. Hard tasks can run for several minutes in a single turn, which suits multi-step agents, deep code work and long-horizon planning. Served through an OpenAI-compatible API and the native Anthropic Messages API.
OpenAI-compatible — keep the SDK you already use
https://api.orcarouter.ai/v1https://api.orcarouter.aiimport os
from openai import OpenAI
client = OpenAI(
base_url="https://api.orcarouter.ai/v1",
api_key=os.environ["ORCAROUTER_API_KEY"],
)
response = client.chat.completions.create(
model="anthropic/claude-fable-5.2",
messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstoolsverbosity| Input / 1M tokens | $8.00 |
|---|---|
| Output / 1M tokens | $40.00 |
| Cache read / 1M | $0.200 |
| Cache write / 1M | $10.00 |
| Currency | USD |
Estimate based on list price
Estimate only — actual token counts depend on the provider's tokenizer.
What developers are saying this week
GET /api/public/models/anthropic/claude-fable-5.2Open @misc{orcarouter_claude_fable_5_2,
title = {Claude Fable 5.2 API},
author = {Anthropic},
year = {2026},
howpublished = {OrcaRouter},
url = {https://www.orcarouter.ai/models/anthropic/claude-fable-5.2}
}Anthropic. (2026). Claude Fable 5.2 API. OrcaRouter. https://www.orcarouter.ai/models/anthropic/claude-fable-5.2