Overview

RouterPlus is an LLM gateway. One API key and one prepaid balance give you models from many providers, over an OpenAI-compatible API and an Anthropic-compatible API.

Every chat model works on both APIs. RouterPlus translates requests, streams and errors between them. You pay the listed per-token prices, and each billed response states its cost in usage.cost.

Get a key

1. 01
   Open Sign up. Complete Clerk authentication and email verification.
2. 02
   Save the first API key shown after sign-in.
3. 03
   Buy credits in Billing. Signup does not add free credit.

If you have an account, sign in and create another key at API keys.

If purchase matching is offered for your account, Billing shows the cap and remaining matching credit.

Make a call

export TM_API_KEY=tm_vk_...

curl -N https://dev2-api.routerplus.com/v1/chat/completions \
  -H "Authorization: Bearer $TM_API_KEY" \
  -H "content-type: application/json" \
  -d '{"model":"claude-haiku-4-5","stream":true,"max_tokens":60,"messages":[{"role":"user","content":"hello"}]}'

The last usage chunk of the stream has the token counts and cost: the USD amount this request debited.

With an SDK, change only the base URL and the key:

import os
from openai import OpenAI

client = OpenAI(base_url="https://demo-api.routerplus.com/v1", api_key=os.environ["TM_API_KEY"])
r = client.chat.completions.create(
    model="claude-haiku-4-5",   # a Claude model over the OpenAI format
    max_tokens=60,
    messages=[{"role": "user", "content": "hello"}],
)
print(r.model_dump()["usage"]["cost"])  # USD debit for this request

import os
import anthropic

client = anthropic.Anthropic(base_url="https://demo-api.routerplus.com", api_key=os.environ["TM_API_KEY"])
msg = client.messages.create(
    model="gpt-4o-mini",        # a GPT model over the Anthropic format
    max_tokens=60,
    messages=[{"role": "user", "content": "hello"}],
)

Two APIs, one key

The key works on both APIs, as Authorization: Bearer or x-api-key. The API you use does not limit the model: OpenAI-format code can call Claude models, and Anthropic-format code can call GPT models. See Authentication.

How requests behave

• Cost. Every billed response has usage.cost in USD. It covers the full debit, including attempts that failed over before your answer started. See Pricing & billing.
• Failover. Before any output reaches you, RouterPlus fails over to another provider. After output starts, the request stays with that provider. A failure then ends the stream with one error event. See Routing & failover.
• Keep-alives. During a silence, the stream sends a keep-alive every 15 seconds. See Streaming.
• No substitution. An unknown model id returns a 404 that names the id you sent. RouterPlus does not pick another model.
• Strict requests. n>1 returns a 400. Content or a parameter that cannot be translated returns a typed 400 that names the field. RouterPlus drops unknown top-level parameters and names each one in the x-tm-dropped-params header. See Wire compatibility.
• Metadata only. Metering and logs record token counts, timings, outcomes and cost. See Data policy.

Gateway endpoints

All gateway endpoints at https://demo-api.routerplus.com take your API key.

Site

Where next