digipin-ts

DIGIPIN (Digital Postal Index Number) is a national-level, geo-coded addressing grid developed by the Department of Posts, Ministry of Communications, Government of India. It provides a deterministic and reversible method to represent geographic locations in India using a 10-character alphanumeric code derived from latitude and longitude.

This repository contains a TypeScript implementation of the DIGIPIN algorithm, intended to enable consistent and correct adoption across platforms, applications, and systems.

What this repository provides

• Deterministic conversion from latitude / longitude → DIGIPIN
• Reversible conversion from DIGIPIN → geographic coordinates
• Comprehensive tests to ensure correctness
• Implementation aligned with the final DIGIPIN Technical Specification (March 2025)

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Specification reference

This project implements the DIGIPIN (Digital Postal Index Number) algorithm strictly according to the official technical specification published by the Department of Posts, Ministry of Communications, Government of India.

The authoritative specification is available at: https://www.indiapost.gov.in/digipin

All implementations in this repository aim to faithfully reproduce the behavior described in the final DIGIPIN Technical Document (March 2025).

This repository provides an independent implementation of the DIGIPIN specification and is not an official distribution of the Department of Posts unless explicitly stated otherwise.

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Design principles

• Specification-first: Implementation strictly follows the DIGIPIN technical specification.
• Deterministic: The same input always produces the same output, regardless of language or platform.
• No external dependencies: Core logic is self-contained.

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Usage

npm i @pranamphd/digipin

TypeScript

import { encode, decode, Location } from "@pranamphd/digipin";

const location: Location = { latitude: 28.6139, longitude: 77.209 }; // Example coordinates for Kartavya Path, New Delhi

const digipin = encode(location); // Encode coordinates to DIGIPIN
console.log(digipin); // Example output: "39J438TJC7"

const decodedLocation = decode(digipin); // Decode DIGIPIN back to coordinates
console.log(decodedLocation); // Example output: { latitude: 28.6139, longitude: 77.209 }

JavaScript (CommonJS)

const {encode, decode} = require("@pranamphd/digipin");

let location = { latitude: 28.6139, longitude: 77.209 }; // Example coordinates for Kartavya Path, New Delhi

let digipin = encode(location); // Encode coordinates to DIGIPIN
console.log(digipin); // Example output: "39J438TJC7"

let decodedLocation = decode(digipin); // Decode DIGIPIN back to coordinates
console.log(decodedLocation); // Example output: { latitude: 28.6139, longitude: 77.209 }

JavaScript (ESM)

import { encode, decode } from "@pranamphd/digipin";

let location = { latitude: 28.6139, longitude: 77.209 }; // Example coordinates for Kartavya Path, New Delhi

let digipin = encode(location); // Encode coordinates to DIGIPIN
console.log(digipin); // Example output: "39J438TJC7"

let decodedLocation = decode(digipin); // Decode DIGIPIN back to coordinates
console.log(decodedLocation); // Example output: { latitude: 28.6139, longitude: 77.209 }

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Status

This repository is under active development. The library interfaces (function and type signatures) may evolve until the first stable release (v1.0.0).

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License

This project is licensed under the Apache License, Version 2.0. See the LICENSE file for details.