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

Most AI gateways hide their margin inside the token price. Writingmate Gateway 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 gateway.writingmate.ai.

What you get

• One endpoint for any OpenAI client. Set your base URL to https://gateway.writingmate.ai/v1, paste your Gateway 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. 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 gateway.writingmate.ai/sign-up, or sign in with your Writingmate account.
2. Create an API key.
3. Make a free request:

curl https://gateway.writingmate.ai/v1/chat/completions \
  -H "Authorization: Bearer $GATEWAY_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 GPT-4.1. If you need a model that is not listed yet, write to hello@writingmate.ai and we will add it.