AnthropicText Generation/v1/ai/chat

Claude Fable 5 API

Access Claude Fable 5 through one API key. Anthropic's creative writing flagship.

Anthropic's creative-first model. Claude Fable 5 is tuned for vivid long-form writing, storytelling, screenwriting, and stylistic range, with a 1M token context window.

Full Docs Get API Key — Free $5 Credit

No credit card required. Takes 30 seconds.

Claude Fable 5 API pricing

Pay per request from your YepAPI balance — no subscription, no monthly minimum. Prices updated September 27, 2026.

Token type	Price
Input	$14.77 / 1M tokens
Output	$73.85 / 1M tokens
Context window	1M tokens

What it costs	Per job	Per 1,000
Chat reply1K input + 500 output tokens	$0.052	$51.70
RAG answer8K input + 800 output tokens	$0.177	$177.24
Agent step with tools30K input + 2K output tokens	$0.591	$590.80
Long document summary100K input + 2K output tokens	$1.62	$1,624.70

2,400+

Developers

1.2M+

API calls served

100+

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see Claude Fable 5 respond in real time.

POST/v1/ai/chatanthropic/claude-fable-5

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

Claude Fable 5 specs

Provider	Anthropic
Model ID	anthropic/claude-fable-5
Endpoint	/v1/ai/chat
Type	Text Generation
Context window	1M tokens
Max output	32K tokens
Reasoning	No
OpenAI-compatible	Yes — /v1/ai/chat/completions

How to get a Claude Fable 5 API key

1
Create a free account
Sign up at yepapi.com with Google or email. It takes about 30 seconds and needs no card.
2
Create an API key
Open the dashboard, go to API Keys and create a key. Copy it — it starts with yep_sk_.
3
Call Claude Fable 5
Send a request to /v1/ai/chat with the x-api-key header and model "anthropic/claude-fable-5".
4
Pay as you go
Usage is billed per request from your balance. Top up any amount; there is no subscription.

Strengths

✓

Creative & long-form writing

Tuned by Anthropic for vivid long-form prose, with up to 32K output tokens per call so you can generate full chapters, scripts, or essays in a single completion without chunking.

✓

1M token context

A 1,000,000-token context window holds an entire manuscript, style bible, and prior drafts at once, letting the model keep voice and plot consistent across very long projects.

✓

Strong voice & stylistic range

Optimized for stylistic control: it holds a consistent narrative voice, switches registers on request, and matches reference samples more closely than general-purpose Claude models.

✓

Narrative and screenwriting

Trained for storytelling structure — scene beats, dialogue, and screenplay formatting — making it suited to fiction, screenwriting, and game narrative over factual Q&A.

Quick start

Copy this snippet and start making calls with Claude Fable 5.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "anthropic/claude-fable-5",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

Claude Fable 5 vs similar models

Every model below runs on the same API key — switch by changing the model ID.

Model	Provider	Price	Context
Claude Fable 5	Anthropic	$14.77 in / $73.85 out per 1M	1M
Claude Haiku 5.5	Anthropic	$0.15 in / $0.74 out per 1M	1M
Claude Haiku 4.5	Anthropic	$1.48 in / $7.38 out per 1M	200K
Claude Sonnet 5	Anthropic	$2.95 in / $14.77 out per 1M	1M
Claude Sonnet 5.5	Anthropic	$2.95 in / $14.77 out per 1M	1M
Claude Sonnet 4.6	Anthropic	$4.43 in / $22.15 out per 1M	1M
Nemotron 3 Super	NVIDIA	$0 in / $0 out per 1M	262K
Qwen3.7 Flash	Qwen	$0.04 in / $0.19 out per 1M	1M

Why use Claude Fable 5 through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

Claude Fable 5 API — pricing, context window & access

Claude Fable 5 is Anthropic's creative-first model, tuned for long-form writing, storytelling, and screenwriting rather than analytical or agentic work. It pairs a 1M-token context window with up to 32,000 output tokens per request, so you can draft and revise long narrative pieces in one pass.

Through YepAPI you call Claude Fable 5 over an OpenAI-compatible endpoint with a single API key — the same key that also reaches other Claude models, Gemini, Grok, Qwen, and Perplexity Sonar, plus SEO, SERP, and web-scraping endpoints.

What is Claude Fable 5?

Claude Fable 5 is Anthropic's creative-writing-oriented model. Where the Opus and Sonnet lines target reasoning and coding, Fable 5 is tuned for vivid prose, stylistic range, and narrative structure. It accepts up to 1,000,000 tokens of context and returns up to 32,000 output tokens, enough to hold a full manuscript plus a style guide while generating long, coherent passages. It is built for fiction, screenwriting, marketing copy, and any task where voice, tone, and continuity matter more than tool use or step-by-step math.

Build with Claude Fable 5 via YepAPI

Point your client at YepAPI's OpenAI-compatible /v1/ai/chat endpoint and set the model string to claude-fable-5. If you already use the OpenAI SDK, only the base URL and model name change. Switching between Fable 5 and any other model — say, dropping to Sonnet for an outline or Sonar for a fact check — is a one-string edit, with no new SDK or auth flow. One key covers every model on the platform.

Claude Fable 5 API pricing — $14.77 / $73.85 per 1M tokens

Claude Fable 5 costs $14.77 per 1M input tokens and $73.85 per 1M output tokens through YepAPI. Because creative work is output-heavy, the output rate dominates your bill — a 32K-token chapter draft costs roughly $2.36 in generation. Usage is metered per token with no minimums, so you pay only for the prose you actually generate.

Claude Fable 5 for fiction and screenwriting

Fable 5 shines on long-form creative tasks: novels, short fiction, screenplays, episodic scripts, and game dialogue. The 1M-token window lets you feed an entire series bible plus earlier chapters so the model preserves character voice and continuity. The 32K output ceiling means full scenes or chapters come back in one call. For writers who need stylistic consistency across a long project, it is purpose-built.

Try Claude Fable 5 free

New YepAPI accounts get $5 in free credit with no card required. That covers thousands of input tokens and a few full-length drafts, enough to test Fable 5's voice and continuity on your own material before you commit to paid usage.

Start generating in 30 seconds

$5 free credit on signup. No credit card required. Pay per call.

Get API Key

What developers say

“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
Marcus T.
SEO Platform Founder

“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
Priya S.
Full-Stack Developer

“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Jake R.
Indie Hacker

Frequently asked questions

Anthropic's creative-first model. Claude Fable 5 is tuned for vivid long-form writing, storytelling, screenwriting, and stylistic range, with a 1M token context window.

Claude Fable 5 costs $14.77 per 1M input tokens and $73.85 per 1M output tokens through YepAPI, billed per request with no monthly fee. For example, a chat reply (1K input + 500 output tokens) costs about $0.052.

Sign up at yepapi.com (Google or email, about 30 seconds), open the dashboard and create an API key. The same key works for Claude Fable 5 and every other model — no separate Anthropic account or waitlist.

New YepAPI accounts in most countries get free signup credit, enough to test Claude Fable 5 without a card. After that you pay per request at the rates above — there is no subscription.

Use "anthropic/claude-fable-5" as the model on /v1/ai/chat. The short alias "claude-fable" also works.

Yes. Point the OpenAI SDK at https://api.yepapi.com/v1/ai with your YepAPI key and set model to "anthropic/claude-fable-5". Streaming works the same way, so existing OpenAI code only needs the base URL and key changed.

Claude Fable 5 supports a 1M token context window with up to 32K output tokens per request.