Open source · 7 languages from one schema

Write your types once.Sync them everywhere.

Hand-written types drift the moment someone ships in a hurry. SyncLangs compiles one .syln schema into idiomatic TypeScript, Python, Go, Rust, Java, C++ and C#, so every codebase shares the exact same shapes.

user.sylnsource of truth
1# user.syln — one source of truth2type Role = "admin" | "member" | "guest"3 4struct User {5  id:        string6  email:     string7  role:      Role8  createdAt: datetime9  active:    bool = true10}
$ syln generate
Generates idiomatic code for
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#
TypeScript
Python
Go
Rust
Java
C++
C#

One source of truth, fanned out to seven codebases

Every target is generated from the same schema in a single pass. No adapters, no hand-written glue, no chance to drift apart.

user.syln
TypeScriptuser.ts
Pythonuser.py
Gouser.go
Rustuser.rs
JavaUser.java
C++user.hpp
C#User.cs

See the same schema in every language

The schema on the left is the contract. Pick a target and watch the exact, idiomatic output SyncLangs generates for it.

user.sylninput
# user.syln — one source of truthtype Role = "admin" | "member" | "guest" struct User {  id:        string  email:     string  role:      Role  createdAt: datetime  active:    bool = true}
user.ts
export type Role = "admin" | "member" | "guest"; export interface User {  id: string;  email: string;  role: Role;  createdAt: Date;  active: boolean;}

Three steps from schema to shipped

No runtime, no service to run. SyncLangs is a build-time generator that fits the workflow you already have.

01

Define once

Describe your types in a single readable .syln schema. Enums, structs, defaults, nested references, optionals. No boilerplate.

02

Generate everywhere

Run syln generate. Idiomatic, type-safe code lands in every target language at once, formatted the way each ecosystem expects.

03

Stay in sync

Change the schema, regenerate, commit. Every service speaks the same shapes. Drift becomes impossible by construction.

Built to keep contracts honest

SyncLangs replaces the brittle, hand-maintained type definitions scattered across your services with one schema that compiles to all of them.

One schema, seven languages

TypeScript, Python, Go, Rust, Java, C++ and C# stay byte-for-byte aligned from a single definition.

TypeScript
Python
Go
Rust
Java
C++
C#

Idiomatic output

Records in Java, dataclasses in Python, serde in Rust. Generated code reads like a human wrote it.

Drift is impossible

The schema is the contract. Regenerate and every service agrees on the exact same shape.

Zero runtime

Generation happens at build time. No agents, no reflection, nothing shipped to production.

Diff-friendly output

Deterministic generation means clean git diffs. You review intent, never noise.

Catch drift in CI

A single check fails the build when generated code drifts from the schema, before it ever reaches main.

Open & pluggable

MIT licensed with a pluggable generator backend. Add a target language without forking the core.

Free to build with. Priced for teams.

The generator is open source and always will be. Paid tiers add a shared registry and review tooling when you outgrow a single repo.

Open Source

$0forever

The full generator and all seven targets, no limits, MIT licensed.

  • All 7 language targets
  • Unlimited schemas
  • CI drift checks
  • Config + custom naming
  • MIT licensed
Install the CLI
Most popular

Team

$12per dev / month

A hosted schema registry and PR review tooling for teams sharing types across repos.

  • Everything in Open Source
  • Hosted schema registry
  • Versioned schema history
  • Breaking-change diffs in PRs
  • Priority support
Start free trial

Enterprise

Customtalk to us

Self-hosted registry, SSO, and compliance for large or regulated orgs.

  • Everything in Team
  • Self-hosted / air-gapped
  • SSO + audit logs
  • Custom language targets
  • SLA + onboarding
Contact sales

Questions, answered

Everything you need to know before you run syln init.

Stop syncing types by hand

Install the CLI, write one schema, and let SyncLangs keep every language in your stack in agreement.

Read the docs