claude-fable-5 work again with zero changes. Sonnet 5 (claude-sonnet-5) launched June 30. Latest news →ClaudeFieldGuide › Model ID
The Claude Fable 5 model ID is claude-fable-5 — exactly that string, with no date suffix. Pass it as the model parameter on the Claude API Messages endpoint. Appending a date (for example claude-fable-5-20260609) returns a 404 not_found_error — no dated snapshot exists.
Current Claude model IDs
| Model | Model ID (use this) | Context | Input / Output per MTok |
|---|---|---|---|
| Claude Fable 5 | claude-fable-5 | 1M | $10 / $50 |
| Claude Opus 4.8 | claude-opus-4-8 | 1M | $5 / $25 |
| Claude Sonnet 5 (new Jun 30) | claude-sonnet-5 | 1M | $2 / $10 intro thru Aug 31, then $3 / $15 |
| Claude Sonnet 4.6 | claude-sonnet-4-6 | 1M | $3 / $15 |
| Claude Haiku 4.5 | claude-haiku-4-5 | 200K | $1 / $5 |
Use the exact alias strings as written. Date-suffixed variants you may recall from older Claude models do not apply to these aliases — appending one returns a 404.
Code example
The ID goes in the model field. Fable 5 takes adaptive thinking only — there is no budget_tokens and no sampling parameters (see common 400 errors):
from anthropic import Anthropic
client = Anthropic()
response = client.messages.create(
model="claude-fable-5", # <- the model ID, no date suffix
max_tokens=16000,
output_config={"effort": "high"},
messages=[{"role": "user", "content": "Hello, Claude"}],
)
print(response.content[0].text)
On Amazon Bedrock
The first-party Claude API and Claude Platform on AWS use the bare string claude-fable-5. Amazon Bedrock prefixes every Claude ID with the provider namespace: anthropic.claude-fable-5. Using the bare ID against Bedrock — or the prefixed ID against the first-party API — returns a 404.
Moral: it is just claude-fable-5. The only twist is the anthropic. prefix on Bedrock. Next steps in Start, and copy-paste recipes in the Cookbook.