Secure
Built for the path where untrusted input becomes a trusted identity.
- Bounded input parsing — ReDoS-safe
- Strict, canonical validation (strict rejects placeholders)
- Generic errors — never echoes the RUT
- Crypto-backed generate()
Features
Everything you need to trust a RUT in production.
rut.ts is a focused, hardened toolkit for Chilean RUT values — secure by default, fully typed, and fast everywhere your code runs.
Functions
12
Tests
523
Dependencies
0
Bundle size
~1.62 KB
Why rut.ts in production
Complete
Twelve focused functions that compose into anything.
- Validation, formatting, cleaning, decomposition, generation, verifier math
- Branded type guard, masking, comparison, and typed errors
- Non-throwing safe mode on every throwing function
- Full TypeScript types across the whole API surface
Fast
Lightweight and quick by design.
- <0.001 ms execution
- ~1.62 KB gzipped (full bundle)
- Tree-shakeable ESM, no side effects
- Optimized for frontend workloads
Multi-runtime
Runs everywhere your JS/TS runs.
- Zero dependencies, pure TypeScript
- Node, Deno, Bun, Edge, Vercel Functions
- React, Next.js, Astro, or vanilla browser
Reliable by proof
Every function is exercised against valid, invalid, and adversarial input — happy paths, edge cases, and safe mode included.
Test cases
523
Test suites
16
Pass rate
100%
Per suite
- validate()106
- format()69
- clean()62
- calculateVerifier()47
- equals()47
- getVerifier()41
- getBody()29
- decompose()21
- generate()19
- InvalidRutError18
- Property-based18
- isValidRut()15
- Differential harness13
- mask()13
- Built-bundle smoke4
- Compile-time types1
What's covered
Valid RUT shapes
- Formats with/without dots & hyphens
- K verifier (upper & lower case)
- 8 & 9-character RUTs
- All verifier digits 0–9 / K
Invalid RUT shapes
- Wrong verifier digit
- Leading-zero padding (rejected since 5.0.0)
- Too short / too long
- Invalid characters
- K not at the end
- Empty strings
- Non-string inputs
Edge cases
- Body bounds: 1.000.000 floor (7 digits) & 99.999.999 max
- Verifier digit 0
- Multiple K letters
- Special characters & whitespace
- Parentheses
Safe mode
- throwOnError: false on the 7 throwing helpers
- Null-return validation
- Combined options
Strict mode
- Suspicious / placeholder rejection
- Normal RUTs still pass
- Strict-mode edge cases
Incremental formatting
- Progressive formatting per length
- Hyphen at 8+ characters
- Leading zeros in incremental mode
- Very long / empty inputs