# Claude Fable 5.1 API

Claude Fable 5.1 is Anthropic's model for demanding reasoning and long-horizon agentic work, with adaptive thinking always on, a 1M-token context window and up to 128K output tokens; list price $10.00 in / $50.00 out per 1M tokens, provider list as at 1 November 2026.

- Provider: Anthropic
- Model ID: claude-fable-5-1
- Type: Chat
- Region: Global (provider global routing)
- Context window: 1,000,000 tokens
- Max output: 128,000 tokens
- Modalities: text, vision, tools, reasoning
- Endpoints: OpenAI Chat Completions https://api.seedrise.ai/v1; Anthropic Messages https://api.seedrise.ai
- Prices checked: 1 November 2026

## Provider list price

Provider list price as at 1 November 2026, per 1M tokens. AUD at a reference rate of 1 USD = 1.53 AUD; invoices use the rate on the day.

| Token type | USD | AUD |
|---|---:|---:|
| Input | 10.00 | 15.30 |
| Output | 50.00 | 76.50 |
| Cached input | 0.25 | 0.38 |

Your Seedrise rate is quoted per account against this list price. Request a rate card: https://seedrise.ai/contact?model=claude-fable-5-1

Global: runs on the provider's global routing only and cannot be pinned to an Australian region. Fable 5.1 is enabled per key on request, and prompts and outputs may be retained on the provider side for up to 30 days for safety review.

## Strengths

- Adaptive thinking is always on, with high as the default effort level
- 1M-token context window and up to 128K output tokens per request
- Cache reads list at $0.25 per 1M tokens, which lowers the cost of long agent runs that resend the same context
- Text and image input with tool use

## Typical use cases

- Multi-step agents that plan and execute over long sessions
- Hard reasoning and analysis where Claude Opus 5.5 at higher effort still falls short
- Reviewing and refactoring large codebases in one context
- Research synthesis across long documents

## Quickstart

A first request with curl. Replace sk-... with your Seedrise key.

```bash
curl https://api.seedrise.ai/v1/chat/completions \
  -H "Authorization: Bearer sk-..." \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-fable-5-1","messages":[{"role":"user","content":"Hello"}]}'
```

OpenAI SDK, Python:

```python
from openai import OpenAI

client = OpenAI(base_url="https://api.seedrise.ai/v1", api_key="sk-...")

r = client.chat.completions.create(
    model="claude-fable-5-1",
    messages=[{"role": "user", "content": "Summarise this contract in three bullets."}],
)
print(r.choices[0].message.content)
```

Claude Code talks Anthropic Messages, so it points at the root URL:

```bash
export ANTHROPIC_BASE_URL="https://api.seedrise.ai"
export ANTHROPIC_AUTH_TOKEN="sk-..."                     # your Seedrise key
export ANTHROPIC_API_KEY=""                             # clear any personal key
export ANTHROPIC_DEFAULT_OPUS_MODEL="claude-opus-5-5"
export ANTHROPIC_DEFAULT_SONNET_MODEL="claude-sonnet-5-5"
export ANTHROPIC_DEFAULT_HAIKU_MODEL="claude-haiku-5-5"
export CLAUDE_CODE_SUBAGENT_MODEL="claude-sonnet-5-5"
export CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1
export ANTHROPIC_DEFAULT_FABLE_MODEL="claude-fable-5-1"
claude
```

Full guide: https://seedrise.ai/claude-code

## Where it runs

Global: Served on the provider's global routing.

## Related models

- [Claude Opus 5.5](https://seedrise.ai/models/claude-opus-5-5): US$4.00 input · US$20.00 output per 1M tokens, AU
- [Claude Sonnet 5.5](https://seedrise.ai/models/claude-sonnet-5-5): US$2.00 input · US$10.00 output per 1M tokens, AU
- [Claude Haiku 5.5](https://seedrise.ai/models/claude-haiku-5-5): US$0.10 input · US$0.50 output per 1M tokens, AU
- [GPT-6 Astra](https://seedrise.ai/models/gpt-6-astra): US$10.00 input · US$50.00 output per 1M tokens, Global
- [GPT-6.1 Sol](https://seedrise.ai/models/gpt-6.1-sol): US$2.00 input · US$10.00 output per 1M tokens, Global
- [Gemini 4 Argon](https://seedrise.ai/models/gemini-4-argon): US$2.00 input · US$10.00 output per 1M tokens, Global

## FAQ

### What is the model ID for Claude Fable 5.1?

Use claude-fable-5-1 as the model field, with no vendor prefix. It works on the OpenAI-compatible endpoint at https://api.seedrise.ai/v1 and on Anthropic Messages at https://api.seedrise.ai. GET /v1/models returns the IDs your key can call.

### How does the Seedrise rate for Claude Fable 5.1 compare to the list price?

Anthropic's list price as at 1 November 2026 is US$10.00 per 1M input tokens and US$50.00 per 1M output tokens. Seedrise quotes rates per account against the provider's published list price for the same routing. Volume and committed tiers sit below list.

### What is the context window and max output of Claude Fable 5.1?

Claude Fable 5.1 has a context window of 1,000,000 tokens and a maximum output of 128,000 tokens, per the provider documentation checked on 1 November 2026.

### Can Claude Fable 5.1 run in Australia?

Not at present. Claude Fable 5.1 is served on the provider's global routing. Models marked AU in the model library can be pinned to Sydney or Melbourne on request.

### Can Claude Fable 5.1 be pinned to Sydney or Melbourne?

No. Fable 5.1 runs on global routing only. If inference must stay in Australia, use Claude Opus 5.5, Sonnet 5.5 or Haiku 5.5, which can be pinned to Sydney or Melbourne on request.

### How does Claude Fable 5.1 compare with Claude Opus 5.5 on price?

At provider list as at 1 November 2026, Fable 5.1 is $10.00 in / $50.00 out per 1M tokens and Opus 5.5 is $4.00 in / $20.00 out. Anthropic suggests starting with Opus 5.5 and moving to Fable 5.1 for demanding reasoning and long-horizon agentic work.

Seedrise is an independent provider and is not affiliated with or endorsed by Anthropic. Claude is a trademark of Anthropic, PBC.

Model names are trademarks of their respective providers.

Source: https://seedrise.ai/models/claude-fable-5-1