Anthropic Claude API - RouterBase

Overview

Anthropic’s Claude 4.x models on RouterBase, served through the standard OpenAI-compatible chat completions endpoint (streaming, tool calling, vision, per-user prompt caching).


Provider	Anthropic
Family	`claude`
Modality	Chat
Caching	Per-user prompt cache (automatic, isolated)

Models

anthropic/claude-fable-5
anthropic/claude-opus-5
anthropic/claude-opus-4.8
anthropic/claude-opus-4.7
anthropic/claude-opus-4.6
anthropic/claude-opus-4.5
anthropic/claude-sonnet-5
anthropic/claude-sonnet-4.6
anthropic/claude-sonnet-4.5
anthropic/claude-sonnet-4
anthropic/claude-haiku-4.5

Pricing is deliberately not reproduced here. Rates are set per model in the RouterBase catalogue and can be overridden per account, so any figure copied into this page is a snapshot that goes stale the next time a rate changes. Fetch the current rate for any model from the Models API:

GET /api/models/{model}/pricing

URL-encode the slash in the model id — e.g. anthropic%2Fclaude-fable-5.

Endpoint

POST https://routerbase.com/v1/chat/completions

Drop-in compatible with the OpenAI client — point it at https://routerbase.com/v1. See the full Chat Completions reference for every parameter, streaming, and prompt-caching details.

Quickstart

curl https://routerbase.com/v1/chat/completions \
  -H "Authorization: Bearer $ROUTERBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-sonnet-4.6",
    "messages": [{ "role": "user", "content": "Hello!" }]
  }'

Live catalogue + current rates: the Models API.