tracker_session_diff

Compare project tracker changes since a specific timestamp to identify new tasks, updates, and completed work at session start.

Instructions

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.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`since`	Yes	ISO 8601 datetime — show changes after this time (e.g. "2026-02-21T15:00:00")

Implementation Reference

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

The handler function 'handleSessionDiff' that processes the 'tracker_session_diff' tool request by querying the activity log and aggregating the results.

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)

Tool definition and schema for 'tracker_session_diff' in the definitions array.

{
  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)

Tool registration mapping 'tracker_session_diff' to 'handleSessionDiff'.

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

Saga MCP