Claude Fable 5 on QuickSilver Pro
Claude Fable 5: $4.00 input / $20.00 output per 1M tokens, 60% below Anthropic list ($10.00 / $50.00). Context: 1M tokens. Maximum output: 128K tokens.
Unlocks with your first top-up from $5
At a glance
For developers building multi-step reasoning and long-running agent workflows.
Pricing comparison ($/1M tokens)
| Provider | Input | Output | vs QSP |
|---|---|---|---|
| QuickSilver Pro | $4.00 | $20.00 | lowest-cost |
| Anthropic list price (Anthropic API) | $10.00 | $50.00 | 60% lower |
When to use
Use Claude Fable 5 for Mythos-class reasoning workflows. Context: 1M tokens; maximum output: 128K tokens. It retains forced `tool_choice`, while Claude Fable 5.1 steers it to `auto`; both rewrite assistant prefill and drop `temperature`/`top_p`.
When to use something else
Switch to the successor Claude Fable 5.1: it has 1M context / 128K maximum output tokens, with base output priced at 1× this model. For base output savings, use Claude Sonnet 5.5: 1M context / 128K maximum output tokens at 0.25× this model’s output price. This model has no separate long-context price tier.
Quickstart (curl)
curl https://api.quicksilverpro.io/v1/chat/completions \
-H "Authorization: Bearer $QSP_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-fable-5",
"messages": [{"role": "user", "content": "Hello!"}]
}'import os
from openai import OpenAI
client = OpenAI(
base_url="https://api.quicksilverpro.io/v1",
api_key=os.environ["QSP_KEY"],
)
response = client.chat.completions.create(
model="claude-fable-5",
messages=[{"role": "user", "content": "Hello!"}],
)
print(response.choices[0].message.content)OpenAI-compatible. One-line migration via base_url.
FAQ
Claude Fable 5 costs $4.00 input / $20.00 output per 1M tokens. Anthropic list is $10.00 / $50.00; the discount is 60% on both base rates.
The catalog has no separate long-context tier for Claude Fable 5. Base rates apply within its 1M-token context.
The gateway drops `temperature` and `top_p`. This model rejects a trailing assistant prefill, so the gateway rewrites it as a user continuation turn carrying the prefix.
The gateway retains a forced `tool_choice` on this model. Claude `response_format` with `json_schema` is advisory. Use a tool with `strict: true` for enforced argument shape; forced tool choice can require that tool call.
Catalog capabilities: text input, text output, image input, streaming, reasoning and tool calling. For Claude image requests, the gateway fetches public remote image URLs and inlines the image data. An inaccessible or rejected URL fails the request; inline base64 is also supported.