Writingmate Router: One OpenAI-Compatible API at Provider Price Plus 5%

Most AI routers hide their margin inside the token price. Writingmate Router does the opposite: you pay the provider's own price plus a flat 5%, and the charge is settled from the provider receipt. That is the whole pricing page.

It is live today at router.writingmate.ai.

What you get

• One endpoint for any OpenAI client. Set your base URL to https://router.writingmate.ai/v1, paste your Router key, and keep your code. Chat Completions, Responses, and legacy Completions are supported, with streaming on each.
• Free models with no card. Open models hosted on Groq, 5 requests per minute and 50 per day per account, on shared capacity. Good for agents, scripts, and trying things out.
• Paid models at cost plus 5%. OpenAI's current lineup is in the catalog: GPT-5.1, GPT-5 mini and nano, the GPT-4.1 family, GPT-4o and GPT-4o mini. Anthropic's Claude models are there too: Claude Sonnet 5, Opus 5, Fable 5.1, Sonnet 4.6, Opus 4.6 and 4.8, and Haiku 4.5. Prices are copied from OpenAI's official price list and shown next to each model. Every request reserves a worst case first, then settles to the actual cost from the receipt, so you are never billed an estimate.
• Prepaid, not subscription. Add funds from $20 with a card. Per-request, daily, and monthly caps protect the balance. Revoke a key at any time.
• Direct providers only. No aggregators in the path, no silent fallback to a model you did not ask for, and no prompt logging.

Why 5%

Five percent covers card fees, the server, and the daily reconciliation that checks our ledger against the provider's own cost report. It does not cover a sales team, which is why sign-up is self-serve and the pricing page fits in one sentence.

Get started in a minute

1. Create an account at router.writingmate.ai/sign-up, or sign in with your Writingmate account.
2. Create an API key.
3. Make a free request:

curl https://router.writingmate.ai/v1/chat/completions \
  -H "Authorization: Bearer $ROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"free/general","messages":[{"role":"user","content":"Say hello in five words."}]}'

Add funds when you want GPT-5.1 or Claude Sonnet. If you need a model that is not listed yet, write to hello@writingmate.ai and we will add it.