Use Claude web fetch with Claude Opus 5.5

by AnthropicWeb fetch

Claude Opus 5.5 uses Claude web fetch through Opper on the Messages endpoint, passed through as Anthropic defines it. It runs on Anthropic's own route, not on Bedrock or Vertex.

UseClaude web fetchwithin

Add Claude web fetch to Claude Opus 5.5

Set up with agents

Paste this into your coding agent (Claude Code, Cursor, Codex, and more) and it will set up and build with Opper for you.

Get your API key

In your code

1curl https://api.opper.ai/v3/compat/v1/messages \
2  -H "Authorization: Bearer $OPPER_API_KEY" \
3  -H "Content-Type: application/json" \
4  -d '{"model": "anthropic/claude-opus-5-5", "max_tokens": 1024,
5       "messages": [{"role": "user", "content": "Summarise https://opper.ai/pricing"}],
6       "tools": [{"type": "web_fetch_20250910", "name": "web_fetch", "max_uses": 3}]}'

Where you can run it

Claude Opus 5.5 runs Claude web fetch on the routes below. Its route also sells priority processing: the same model at another price, picked per request with service_tier. How service tiers work.

Provider	Region	Zero data retention	Training	Input	Output	Cache read
Anthropic	US		No	$4.00	$20.00	$0.20$5.00 write

The model

Claude Opus 5.5

by Anthropic

Claude Opus 5.5, Anthropic's model for long-running agentic coding, computer use, and knowledge work, with always-on adaptive thinking, a 1M-token context, and 128K output.