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Claude Fable 5

15% OFFanthropic/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 a 1M-token context window. It is suited for long-running, complex, and asynchronous tasks that previously required frequent human check-ins.

Use in agentGet API key
Input price
$8.50$10.00USD / 1M tokens
Output price
$42.50$50.00USD / 1M tokens
Context window
1M
Max output
128K
Production route

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Playground

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1M context128K max outputVision
Input$10.00/M$8.50/MOutput$50.00/M$42.50/MCache read$1.00/M$0.85/MCache write$12.50/M$10.63/M
15% OFF
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Model card

Specifications

Pricing

Input
$8.50 / 1M tokens
Output
$42.50 / 1M tokens
Cache read
$0.85 / 1M tokens
Cache write
$10.63 / 1M tokens

Context & modalities

Context window
1,000,000 tokens
Max output
128,000 tokens
Input
Text, image
Output
Text

Capabilities

Chat
Supported
Vision
Supported
Reasoning
Supported
Structured output
Supported
Function calling
Supported
Audio input
Not supported

Access

Provider
Anthropic
Model ID
anthropic/claude-fable-5
Execution
sync
Base URL
https://api.sandbase.ai
API
Chat Completions API
Endpoint
/v1/chat/completions
API
Messages API
Endpoint
/v1/messages

Start building

Send your first request

Choose either supported API with unified authentication and usage tracking.

Production API
Chat Completions API endpoint
https://api.sandbase.ai/v1/chat/completions
Model ID
anthropic/claude-fable-5
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
  -X POST "https://api.sandbase.ai/v1/chat/completions" \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'SANDBASE_JSON'
{
  "model": "anthropic/claude-fable-5",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ],
  "max_tokens": 2048
}
SANDBASE_JSON
)
printf '%s\n' "$result"

Choose your model

Compare models

All language models
ModelContextInput / 1MOutput / 1MReleased
Claude Fable 5This model
Anthropic		1M$8.50$42.50Jun 9, 2026
Claude Haiku 5.5
Anthropic		1M$0.10$0.50Oct 7, 2026
Claude Fable 5.5
Anthropic		—Coming soonComing soonComing soon
Claude Sonnet 5.5
Anthropic		1M$2.00$10.00Sep 28, 2026
Claude Opus 5.5
Anthropic		1M$4.00$20.00Sep 22, 2026
Claude Fable 5.1
Anthropic		1M$10.00$50.00Sep 1, 2026

Questions

FAQ

How do I call Anthropic Claude Fable 5 through SandBase?

Create a SandBase API key, then send requests with the model ID "anthropic/claude-fable-5" to Chat Completions API (/v1/chat/completions) or Messages API (/v1/messages) at https://api.sandbase.ai. The request examples on this page show the exact payload.

How much does Anthropic Claude Fable 5 cost?

$8.50 per 1M input tokens and $42.50 per 1M output tokens with the current 15% discount (list price $10 / $50), billed per request from your SandBase balance.

What is the context window of Anthropic Claude Fable 5?

1M tokens of context, with up to 128K output tokens per response.

Which features does Anthropic Claude Fable 5 support?

Anthropic Claude Fable 5 supports vision (image input), reasoning, function calling, structured output. See Specifications above for the full list.

Do I need a separate Anthropic account?

No. One SandBase API key and balance gives you access to Anthropic Claude Fable 5 and the other models in the catalog; you do not need to sign up with Anthropic separately.