Building Adapters

Create custom adapters to integrate Yakmesh with any database, API, or platform.

What is an Adapter?

Adapters are plugins that connect Yakmesh to external systems. They implement a standard interface for fetching changes, applying updates, and synchronizing data across the mesh network.

BaseAdapter Interface

All adapters extend the BaseAdapter class:

import { BaseAdapter } from '@yakmesh/core/adapters';

class MyAdapter extends BaseAdapter {
  constructor(config) {
    super('my-adapter', '1.0.0');
    this.config = config;
  }

  async init() {
    // Initialize connection to your system
    this.db = await connectToDatabase(this.config.connectionString);
  }

  getSchema() {
    // Define what data this adapter manages
    return {
      tables: ['users', 'posts'],
      primaryKeys: { users: 'id', posts: 'id' }
    };
  }

  async fetchChanges(since) {
    // Return changes since the given timestamp
    return await this.db.query(
      'SELECT * FROM changes WHERE updated_at > ?',
      [since]
    );
  }

  async applyChange(change) {
    // Apply a change received from the mesh
    await this.db.query(
      'INSERT OR REPLACE INTO ?? SET ?',
      [change.table, change.data]
    );
  }

  async validate(data) {
    // Validate data before applying
    return { valid: true };
  }
}

Required Methods

Registering Your Adapter

import { YakmeshNode } from '@yakmesh/core';
import { MyAdapter } from './my-adapter.js';

const node = new YakmeshNode();

// Register the adapter
node.registerAdapter(new MyAdapter({
  connectionString: 'postgres://localhost/mydb'
}));

// Start the node
await node.start();

Example: SQLite Adapter

import { BaseAdapter } from '@yakmesh/core/adapters';
import initSqlJs from 'sql.js';

class SQLiteAdapter extends BaseAdapter {
  constructor(dbPath) {
    super('sqlite', '1.0.0');
    this.dbPath = dbPath;
  }

  async init() {
    const SQL = await initSqlJs();
    const data = fs.readFileSync(this.dbPath);
    this.db = new SQL.Database(data);
  }

  getSchema() {
    const tables = this.db.exec(
      "SELECT name FROM sqlite_master WHERE type='table'"
    );
    return { tables: tables[0].values.flat() };
  }

  async fetchChanges(since) {
    // Implementation depends on your change tracking strategy
  }

  async applyChange(change) {
    this.db.run(change.sql, change.params);
  }
}