engram-mcp

Instructions

Implementation Reference

• engram.ts:301-328 (handler)

  The core implementation of the 'forget' method in the Engram class. This async function deletes memories from the SQLite database by sessionId, with optional filters for a specific memory ID or a 'before' date timestamp. Returns the number of deleted records.

  /**
   * Forget (delete) memories
   */
  async forget(
    sessionId: string,
    options?: { before?: Date; id?: string }
  ): Promise<number> {
    await this.init();
  
    if (options?.id) {
      const result = await this.db.run(
        'DELETE FROM memories WHERE session_id = ? AND id = ?',
        [sessionId, options.id]
      );
      return result.changes || 0;
    }
  
    let sql = 'DELETE FROM memories WHERE session_id = ?';
    const params: (string | number)[] = [sessionId];
  
    if (options?.before) {
      sql += ' AND timestamp < ?';
      params.push(options.before.getTime());
    }
  
    const result = await this.db.run(sql, params);
    return result.changes || 0;
  }

• src/index.ts:240-246 (handler)

  MCP tool handler for 'forget' - extracts options (id, before) from args, calls memory.forget() with the sessionId and options, and returns a human-readable response with the count of deleted memories.

  case 'forget': {
    const opts: Parameters<typeof memory.forget>[1] = {};
    if (args.id) opts.id = args.id as string;
    if (args.before) opts.before = new Date(args.before as string);
    const deleted = await memory.forget(args.sessionId as string, opts);
    return { content: [{ type: 'text', text: `Deleted ${deleted} memor${deleted === 1 ? 'y' : 'ies'}.` }] };
  }

• src/index.ts:79-91 (registration)

  Tool registration for 'forget' - defines the tool name, description ('Delete session memories. Delete all, one by ID, or entries before a date.'), and inputSchema with sessionId (required), id, and before properties.

  {
    name: 'forget',
    description: 'Delete session memories. Delete all, one by ID, or entries before a date.',
    inputSchema: {
      type: 'object',
      properties: {
        sessionId:  { type: 'string', description: 'Session identifier' },
        id:         { type: 'string', description: 'Specific memory ID to delete (optional)' },
        before:     { type: 'string', description: 'ISO date — delete entries before this date (optional)' },
      },
      required: ['sessionId'],
    },
  },