gen-anchor-events

Generate TypeScript event types from Anchor IDL files.

Installation

As a global package:

npm install -g @mayflower-fi/gen-anchor-events

As a local dependency:

npm install --save-dev @mayflower-fi/gen-anchor-events

Usage

Command Line Interface

After installation, you can use the gen-anchor-events command:

gen-anchor-events <idl-file> <output-file> [options]

Arguments:

• <idl-file>: Path to the IDL JSON file
• <output-file>: Path to the output TypeScript file

Options:

• -v, --verbose: Enable verbose output
• -h, --help: Display help information
• -V, --version: Display version number

Examples:

Basic usage:

gen-anchor-events ./idl/mayflower.json ./src/events.ts

With verbose output:

gen-anchor-events ./idl/program.json ./generated/types.ts --verbose

Using npx (without global installation):

npx @mayflower-fi/gen-anchor-events ./idl/program.json ./src/events.ts

From node_modules/.bin (when installed locally):

./node_modules/.bin/gen-anchor-events ./idl/program.json ./src/events.ts

Programmatic Usage

You can also use the library programmatically:

import { generateEventsFromIDL } from '@mayflower-fi/gen-anchor-events';

// Generate TypeScript events from IDL
generateEventsFromIDL('./idl/program.json', './src/events.ts');

Input Format

The tool expects an Anchor IDL JSON file with the following structure:

{
  "events": [
    {
      "name": "EventName",
      "fields": [
        {
          "name": "fieldName",
          "type": "u64" | "string" | "publicKey" | { "defined": "CustomType" }
        }
      ]
    }
  ],
  "types": [
    {
      "name": "CustomType",
      "type": {
        "kind": "struct",
        "fields": [
          {
            "name": "fieldName",
            "type": "string"
          }
        ]
      }
    }
  ]
}

Output

The tool generates TypeScript interfaces for all events and their custom types, plus utility types and functions:

• Event interfaces (e.g., UserCreated, UserUpdated)
• Custom type interfaces (e.g., UserData)
• EventRaw type for raw event data
• ParsedEvents type for organized event collections
• parseEvents() function for parsing raw events into organized collections

Example

Given an IDL with events, the tool generates:

// Generated event types from program.json
// Do not edit manually

import { BN, web3 } from "@coral-xyz/anchor";

export interface UserData {
  name: string;
  age: number;
  balance: BN;
}

export interface UserCreated {
  user: UserData;
  timestamp: BN;
}

export type ParsedEvents = {
  UserCreated: UserCreated[];
};

export function parseEvents(events: EventRaw[]): ParsedEvents {
  // ... parsing logic
}