---
title: "Discussion on \"Idempotency Keys and the Immutable Audit Log: Two Patterns That Make Fintech APIs Boring (In a Good Way)\" | Hashnode"
description: "Discussion on \"Idempotency Keys and the Immutable Audit Log: Two Patterns That Make Fintech APIs Boring (In a Good Way)\". You have tapped Pay twice when the app froze and then held your breath. This week I built the two things that mean you never get charged twice, and that anyone can prove it later."
url: "https://hashnode.com/posts/idempotency-keys-and-the-immutable-audit-log/6a45e91bbf01697ed5832ab0"
---

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Discussion

# [Idempotency Keys and the Immutable Audit Log: Two Patterns That Make Fintech APIs Boring (In a Good Way)](https://notes.sohag.pro/idempotency-keys-and-the-immutable-audit-log?utm_source=hashnode&utm_medium=feed)

You have tapped Pay twice when the app froze and then held your breath. This week I built the two things that mean you never get charged twice, and that anyone can prove it later.

Jul 2 · 9 min read · notes.sohag.pro  
Read the article

-   [#go](https://hashnode.com/tag/go)
-   [#golang](https://hashnode.com/tag/golang)
-   [#fintech](https://hashnode.com/tag/fintech)
-   [#idempotency](https://hashnode.com/tag/idempotency)
-   [#postgres](https://hashnode.com/tag/postgres)

## Written by

[Sohag Hasan](https://hashnode.com/@sohag)

@sohag · Dhaka, Bangladesh

  
[View profile](https://hashnode.com/@sohag)

Tech Lead at MobyPay | Certified Laravel Developer | PHP JS GO | DevOps Enthusiast | Open to projects

WhoAmI => notes.sohag.pro/author

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