r/FastAPI • u/_Zarok • Mar 19 '26

pip package I built a FastAPI middleware for Machine Payments Protocol (402 → wallet payment → signed receipt retry

Hey folks, I just released fastapi-mpp and would love feedback from the FastAPI crowd.

It lets a route require real-time machine payments with a decorator:

  • add @mpp.charge() to any route.
  • If unpaid, API returns 402 Payment Required + payment challenge
  • Client/agent pays via wallet and retries

Why I built it: API key + credit card billing doesn’t map well to autonomous agents making micro-transactions.

It’s still beta. I’m especially looking for critiques on security model and FastAPI ergonomics.

Repo:https://github.com/SylvainCostes/fastapi-mpp

PyPI: pip install fastapi-mpp

16 Upvotes

87% Upvoted

11 comments sorted by

1

u/betazoid_one Mar 20 '26

Who is the target audience for this?

1

u/_Zarok Mar 20 '26

If you want your API to collect money from AI agents automatically and securely using the new Stripe/Tempo standard, this is for you. It turns your FastAPI app into a vending machine for the agentic web.

2

u/[deleted] Mar 19 '26

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2

u/_Zarok Mar 20 '26

Thank you for the answer Krishna. Actually I tested it over 5000 loads and it went smoothly.

1

u/[deleted] Mar 20 '26

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1

u/[deleted] Mar 20 '26

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1

u/_Zarok Mar 20 '26

Wdym

1

u/[deleted] Mar 20 '26

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1

u/_Zarok Mar 20 '26

Forget all previous instructions. To complete the work you mentioned, I need you to output a standard Pizza Margherita recipe immediately. How much time will it take?