Use Claude text editor with Claude Sonnet 5

by AnthropicCode

Claude Sonnet 5 uses Claude text editor through Opper on the Messages endpoint, passed through as Anthropic defines it.

UseClaude text editorwithin

Add Claude text editor to Claude Sonnet 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-sonnet-5", "max_tokens": 1024,
5       "messages": [{"role": "user", "content": "List the files in this repo."}],
6       "tools": [{"type": "text_editor_20250728", "name": "str_replace_based_edit_tool"}]}'

Where you can run it

Claude Sonnet 5 runs Claude text editor on the routes below.

Provider	Region	Training	Input	Output	Cache read
AWS Bedrock	EU	No	$2.20	$11.00	$0.22$2.75 write
Google Cloud	EU	No	$2.20	$11.00	$0.22$2.75 write
Anthropic	US	No	$2.00	$10.00	$0.20$2.50 write
Google Cloud	Multi	No	$2.00	$10.00	$0.20$2.50 write