Claude Fable 5 API

Fable 5 has been superseded by Fable 5.1

Claude Fable 5.1 launched on 2026-09-01 at the same input and output price as Fable 5 ($10 / $50), with cache reads down from $1.00 to $0.25. In the official benchmarks Terminal-Bench 4.0 rose from 42.0% to 55.8% and Terminal-Bench-Science from 24.7% to 52.6%. Use Fable 5.1 for new work; when migrating, note that forced tool use returns 400.

See Fable 5.1 pricing, benchmarks and migration guide

Catalog pricing snapshot

Prices are per 1M tokens; request-time pricing controls settlement.

Official price source: https://platform.claude.com/docs/en/about-claude/models/overview

Model capabilities

Context

1,000,000 tokens

Max output

128,000 tokens

Streaming

Supported

Tools

Supported

Vision

Supported

Supported API forms

/v1/messages

Send a request

/v1/messages

curl https://api.wokey.ai/v1/messages \
  -H "x-api-key: $WOKEY_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-fable-5","max_tokens":1024,"messages":[{"role":"user","content":"Hello"}]}'

Use Claude Fable 5 in your tools

The gateway is https://api.wokey.ai (OpenAI-compatible clients usually take https://api.wokey.ai/v1), and the model ID is claude-fable-5. Open the guide for the client you use.

• Use Claude Fable 5 in Claude Code: Anthropic Messages · base URL and API key setup
• Use Claude Fable 5 in Claude Desktop: Anthropic Messages · base URL and API key setup
• Claude API cost calculator: what Claude Fable 5 costs per month: Compare monthly cost on the Anthropic API, OpenRouter and Wokey for your usage and cache hit rate.
• OpenRouter alternative: Wokey vs OpenRouter: Compare token prices, payment fees, API forms, and upstream sources.
• Verifiable AI API: check a Claude Fable 5 response came from the official upstream: Which responses carry a tee.proof, and what a proof does and does not show.
• Verify a Claude Fable 5 response online: AI API relay verifier: Paste a response with its tee.proof and check it locally in your browser; nothing is uploaded.

Claude Code

export ANTHROPIC_BASE_URL="https://api.wokey.ai"
export ANTHROPIC_AUTH_TOKEN="$WOKEY_API_KEY"
export ANTHROPIC_MODEL="claude-fable-5"

Example production call

These usage values come from a completed Claude Fable 5 call that succeeded on its first attempt and was reconciled with its bill.

Total input

166288

Output

942

Cached share of input

97.1%

Call duration

19.43 s

Usage field example

Compiled from this call’s billing record. input_tokens is uncached input; cache reads and writes are separate.

{
  "model": "claude-fable-5",
  "usage": {
    "input_tokens": 2,
    "output_tokens": 942,
    "cache_read_input_tokens": 161461,
    "cache_creation_input_tokens": 4825
  }
}

Token accounting

These are the final per-million-token rates recorded for this call.

Billed amount

$0.061846

Cost = sum of tokens × their rate ÷ 1,000,000, rounded to six decimals after summing.

Source of this call

The transport record points to api.anthropic.com with OAuth authorization. Usage was metered upstream and the request returned HTTP 200.

Verify Prompt Cache

1. Keep the system, tools, and conversation prefix fixed and mark cache_control according to the cache rules.
2. Check cache_creation_input_tokens on the first response, then reuse the prefix and check cache_read_input_tokens on the next.
3. Reconcile uncached input, cache reads, cache writes, and output separately. Total input is the sum of the three input buckets.

Frequently asked questions

Related models and documentation

• Claude Fable 5.1
• Claude Opus 5
• Claude Opus 4.8
• Claude Opus 4.7
• API documentation
• All models and pricing
• Provider Node