Typesync, schema-first Firestore tooling that now validates stored data

Name: Typesync, schema-first Firestore tooling that now validates stored data
Availability: InStock
Author: anarkafkas

by anarkafkas·May 5, 2026·3 points·0 comments

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AI Analysis

●●SolidSolve My ProblemNiche Gem

Validates live Firestore docs against schema when other tools only generate types.

Strengths

•Single schema generates TypeScript, Python, and Swift models simultaneously.
•validate-data command catches schema drift in existing production documents.
•Mermaid diagram generation visualizes document relationships automatically.

Weaknesses

•Firestore-specific scope limits appeal compared to general schema tools like Zod.
•Security Rules generation is useful but competitors like Firebase Extensions exist.

Post Description

Hi HN,

I’ve been working on Typesync, an open-source CLI for Firestore projects.

The basic idea is that you define your Firestore models once in YAML or JSON, then generate the boring parts from that:

- TypeScript models - Python/Pydantic models - Swift models - Firestore Security Rules validators - Mermaid diagrams of the document structure

The new command I added is `validate-data`.

It walks selected Firestore collections and validates existing documents against Zod validators generated from the same schema. It reports the documents that don’t match.

Example:

```bash typesync validate-data \ --definition 'definition/*/*.yml' \ --model User \ --model Post \ --serviceAccount ./service-account.json ```