Claude Fable 5 uses Claude code execution through Opper on the Messages endpoint, passed through as Anthropic defines it. It runs on Anthropic's own route, not on Bedrock or Vertex.
Paste this into your coding agent (Claude Code, Cursor, Codex, and more) and it will set up and build with Opper for you.
curl https://api.opper.ai/v3/compat/v1/messages \-H "Authorization: Bearer $OPPER_API_KEY" \-H "Content-Type: application/json" \-d '{"model": "anthropic/claude-fable-5", "max_tokens": 1024,"messages": [{"role": "user", "content": "Sum the first 50 primes and show your working."}],"tools": [{"type": "code_execution_20260521", "name": "code_execution"}]}'
Claude Fable 5 runs Claude code execution on the routes below.
| Provider | Region | Zero data retention | Training | Input | Output | Cache read |
|---|---|---|---|---|---|---|
| US | No | $10.00 | $50.00 | $1.00$12.50 write |
Claude Fable 5 by Anthropic, state-of-the-art generalist model with advanced vision and 1M token context for complex software engineering and reasoning.
Step-by-step setup for Claude code execution on each of these models through Opper.
GPT models write and run Python in a sandbox, on the Responses endpoint.
code_interpreterGemini runs code to work out its answer, on generateContent.
codeExecutionClaude drives a desktop through screenshots, clicks and typing in your agent loop.
computer_toolset