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Getting started

indycheck validates 12 Indian IDs — PAN, Aadhaar, GSTIN, IFSC, UPI ID, mobile number, PIN code, TAN, CIN, LLPIN, Voter ID (EPIC) and vehicle numbers — offline. No API keys, no network calls, no per-check fees. One Rust core, with bindings for JavaScript/TypeScript, Python and Rust.

These docs are in English for v0.2.0. The error messages in the package itself are bilingual: every result carries both reason_en and reason_hi.

Install

Section titled “Install”
Terminal window
# JavaScript / TypeScript
npm install indycheck


# Python
pip install indycheck


# Rust
cargo add indycheck

Requires Node 18+, Python 3.9+, or Rust 1.85+. There are zero runtime dependencies in every binding — the Rust core is compiled in.

Your first validation

Section titled “Your first validation”
// JavaScript / TypeScript
import { validatePan } from 'indycheck';


const r = validatePan('AAAPL1234C');
console.log(r.ok);        // true
console.log(r.code);      // 'VALID'
console.log(r.parsed);    // { entity: 'Individual', entity_code: 'P' }
# Python
from indycheck import validate_pan


r = validate_pan("AAAPL1234C")
print(r.ok)          # True
print(r.code)        # 'VALID'
print(r.parsed)      # {'entity': 'Individual', 'entity_code': 'P'}
// Rust
use indycheck::validate_pan;


let r = validate_pan("AAAPL1234C");
assert!(r.ok);
println!("{}", r.code); // VALID

What a result looks like

Section titled “What a result looks like”

Every validator returns the same shape:

{
  "ok": true,
  "type": "pan",
  "value": "AAAPL1234C",
  "normalized": "AAAPL1234C",
  "code": "VALID",
  "reason_en": "Valid format.",
  "reason_hi": "मान्य प्रारूप।",
  "parsed": {
    "entity": "Individual",
    "entity_code": "P"
  }
}

And a failure:

{
  "ok": false,
  "type": "pan",
  "value": "AAAPL12345",
  "code": "INVALID_FORMAT",
  "reason_en": "PAN format must be 5 letters, 4 digits, 1 letter (e.g. ABCDE1234F). PAN has no public checksum, so only the format is checked.",
  "reason_hi": "PAN ka format 5 akshar, 4 digit, 1 akshar hona chahiye (jaise ABCDE1234F). PAN ka koi public checksum nahi hai, isliye sirf format check hota hai"
}

Use code for branching in your code, and reason_en / reason_hi for showing errors to users. See API & error codes for the full list.

All validators

Section titled “All validators”
Function Checks Example
validateMobile 10 digits, starts 6–9 9876543210
validatePan Format only (entity reported, not enforced) AAAPL1234C
validateAadhaar 12 digits + Verhoeff checksum 234567890124
validateGstin Format + Mod-36 Luhn checksum 27AAAPL1234C1ZE
validateIfsc Bank code + 0 + branch code SBIN0001234
validateUpi handle@bank format 9876543210@paytm
validatePincode 6 digits, first digit 1–9 781001
validateTan 4 letters + 5 digits + 1 letter, format only MUMB12345C
validateCin 21-char company structure, format only U12345DL2025PTC123456
validateLlpin 3 letters + 4 digits, format only AAA-1234
validateEpic 3 letters + 7 digits, format only ABC1234567
validateVehicle State format (8–10 chars) or Bharat (BH) series YYBH####XX, format only DL01AB1234 / 22BH1234AA

TAN, CIN, LLPIN, Voter ID and vehicle numbers have no public checksum — for those, indycheck checks the format only. (IFSC, UPI, mobile and PIN code are format-only too.)

There is also a generic entry point — validate('pan', value) — handy when the type comes from user input, plus detect(value) to guess the type, generate(type) for test data, and mask() / format() for display. Try everything live in the playground.

Batch validation

Section titled “Batch validation”

Validators are pure functions with no I/O, so batching is just a loop:

import { validate } from 'indycheck';


const rows = ['AAAPL1234C', 'AAAPL12345', '9876543210'];
const results = rows.map((v) => validate('pan', v));
const bad = results.filter((r) => !r.ok);
console.log(`${bad.length} of ${rows.length} failed`);

What indycheck does NOT do

Section titled “What indycheck does NOT do”

Next steps

Section titled “Next steps”