tracker_session_diff

Instructions

Implementation Reference

• src/tools/activity.ts:105-148 (handler)

  The handler function `handleSessionDiff` that executes the tracker_session_diff tool logic. It queries activity_log since a given timestamp, aggregates by action and entity type, extracts highlights, and returns the full result.

  function handleSessionDiff(args: Record<string, unknown>) {
    const db = getDb();
    const since = args.since as string;
  
    const rows = db
      .prepare('SELECT * FROM activity_log WHERE created_at >= ? ORDER BY created_at ASC')
      .all(since) as Array<Record<string, unknown>>;
  
    const now = new Date().toISOString().replace('T', ' ').slice(0, 19);
  
    // Aggregate by action
    const summary: Record<string, number> = { created: 0, updated: 0, status_changed: 0, deleted: 0 };
    // Aggregate by entity_type -> action
    const byEntity: Record<string, Record<string, number>> = {};
  
    const highlights: string[] = [];
  
    for (const row of rows) {
      const action = row.action as string;
      const entityType = row.entity_type as string;
  
      summary[action] = (summary[action] ?? 0) + 1;
  
      if (!byEntity[entityType]) {
        byEntity[entityType] = { created: 0, updated: 0, status_changed: 0, deleted: 0 };
      }
      byEntity[entityType][action] = (byEntity[entityType][action] ?? 0) + 1;
  
      // Pick out highlights: status changes, creates, and deletes
      if (action === 'status_changed' || action === 'created' || action === 'deleted') {
        if (row.summary) highlights.push(row.summary as string);
      }
    }
  
    return {
      since,
      until: now,
      total_changes: rows.length,
      summary,
      by_entity_type: byEntity,
      highlights,
      activity: rows,
    };
  }

• src/tools/activity.ts:32-47 (schema)

  The tool definition/schema for 'tracker_session_diff' including its name, description, annotations, and inputSchema (requires `since` string).

  {
    name: 'tracker_session_diff',
    description:
      'Show what changed since a given timestamp. Returns aggregated summary with counts by action and entity type, plus highlights of key changes. Call this at the start of a session to understand what happened since the last one.',
    annotations: { title: 'Session Diff', readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: false },
    inputSchema: {
      type: 'object',
      properties: {
        since: {
          type: 'string',
          description: 'ISO 8601 datetime — show changes after this time (e.g. "2026-02-21T15:00:00")',
        },
      },
      required: ['since'],
    },
  },

• src/tools/activity.ts:241-245 (registration)

  The handlers export mapping the tool name 'tracker_session_diff' to the handleSessionDiff function.

  export const handlers: Record<string, ToolHandler> = {
    activity_log: handleActivityLog,
    tracker_session_diff: handleSessionDiff,
    task_batch_update: handleTaskBatchUpdate,
  };