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Tasks: add-aggregate-other-rollup

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Created Updated openspec/changes/add-aggregate-other-rollup/tasks.mdView on GitHub →

1. Reference contract (schemas)

  • 1.1 Add other_count: { type: "integer", minimum: 0 } to AggregationResponseSchema in packages/reference-contract/src/public/index.ts. Document that it is emitted whenever a grouping dimension is present (zero when all groups fit; omitted for ungrouped aggregations). Reference the openspec change in the comment.
  • 1.2 Update the aggregateStream manifest summary in packages/reference-contract/src/public/index.ts to describe other_count and the truncation-detection guarantee.

2. Reference implementation

  • 2.1 reference-implementation/server/records.js: in the group_by branch, capture the sorted full group list before slicing; set response.other_count to the sum of counts in the truncated tail (sortedGroups.slice(aggregateRequest.limit)).
  • 2.2 reference-implementation/server/records.js: same change for the group_by_time branch.
  • 2.3 Confirm that ungrouped aggregation paths (scalar count, sum, min, max, count_distinct) do NOT emit other_count.

3. MCP adapter

  • 3.1 packages/mcp-server/src/tools.js: update the aggregate tool description to mention other_count so models know to check it for truncation detection without a second call.
  • 3.2 packages/mcp-server/src/tools.js: update summarizeAggregate to include other_count=N in the text summary when present on the RS response.

4. Tests

  • 4.1 reference-implementation/test/aggregate-time-buckets.test.js: add assert.equal(res.other_count, 0) to the existing scalar group_by test (all groups fit within limit).
  • 4.2 Same inline assertion for the existing group_by_time UTC-day test.
  • 4.3 New test: group_by other_count is the sum of counts for groups beyond limit — limit=2, 3 distinct values, asserts other_count=1.
  • 4.4 New test: group_by other_count is 0 when all groups fit within limit — limit=100, 3 groups, asserts other_count=0.
  • 4.5 New test: group_by_time other_count covers buckets truncated by limit — limit=2, 4 buckets, asserts other_count=2 (sum of tail counts).

5. Validation

  • 5.1 reference-implementation/test/aggregate-time-buckets.test.js: 16 tests pass (was 13).
  • 5.2 Full packages/mcp-server suite green (136 tests).
  • 5.3 openspec validate --all --strict green.
  • 5.4 git diff --check; grep changed public names for consistency.

Acceptance checks

Reproducible commands:

node --test reference-implementation/test/aggregate-time-buckets.test.js
node --test packages/mcp-server/test/aggregate-tool.test.js
node --test packages/mcp-server/test/*.test.js
openspec validate add-aggregate-other-rollup --strict
openspec validate --all --strict