Claude Fable 5
Call the default-enabled Claude Fable 5 model with the native Anthropic Messages protocol.
Claude Fable 5 is a default-enabled Anthropic-format model that uses native Messages request and response structures.
Model information
| Item | Value |
|---|---|
| Model ID | claude-fable-5 |
| Endpoint | POST /v1/messages |
| Request format | Anthropic Messages |
| Official input / output price | $10 / $50 per 1M tokens, before your account coefficient |
| Responses | Not supported |
Request parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
model | string | Yes | Use one of the IDs above returned for the current API key by GET /v1/models |
max_tokens | integer | Yes | Maximum output tokens |
messages | array | Yes | Array of user and assistant messages |
system | string / array | No | Top-level system instruction, not a message |
temperature | number | No | Maximum value is 1.0 |
stream | boolean | No | Set to true for Anthropic SSE events |
Request example
curl https://hopsapi.com/v1/messages \
-H "x-api-key: sk-YOUR_KEY" \
-H "anthropic-version: 2023-06-01" \
-H "content-type: application/json" \
-d '{"model":"claude-fable-5","max_tokens":512,
"system":"You are a concise technical writer.",
"messages":[{"role":"user","content":"Explain idempotency."}]}'Response example
This example shows the protocol shape only. Text, token counts, and additional fields such as id and model come from the live response.
{
"type": "message",
"role": "assistant",
"content": [
{
"type": "text",
"text": "Idempotency means that repeating an operation has the same effect as performing it once."
}
],
"stop_reason": "end_turn",
"usage": { "input_tokens": 28, "output_tokens": 36 }
}max_tokens is required. SDKs use the bare https://hopsapi.com base URL. See Anthropic
format for full protocol constraints and empty-text stream troubleshooting.