Protocol Details

Kraube API replicates the Claude Code CLI's HTTP protocol for OAuth subscription access. See the full protocol documentation in the repository.

Key Protocol Elements

Endpoint

POST https://api.anthropic.com/v1/messages?beta=true

Required Headers

Header	Value
Authorization	Bearer <access_token>
anthropic-dangerous-direct-browser-access	true
Anthropic-Version	2023-06-01
User-Agent	claude-cli/2.1.92 (external, cli)
x-app	cli
Anthropic-Beta	Model-specific beta features

Billing Header

A system prompt block is injected automatically:

x-anthropic-billing-header: cc_version=2.1.92.00a; cc_entrypoint=cli; cch=<hash>;

Without this, Sonnet and Opus models return 429.

Chrome TLS

OAuth requests require a Chrome TLS fingerprint (via uTLS). Cloudflare blocks Go's default TLS fingerprint.