diff --git a/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/design.md b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/design.md
new file mode 100644
index 0000000..0c89bd6
--- /dev/null
+++ b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/design.md
@@ -0,0 +1,90 @@
+## Context
+
+Researched directly against this codebase before writing any code:
+`change-timeline.ts`'s existing git primitives (`blameLineDates`,
+`getFileCreatedDate`) capture timestamps only, never author identity;
+no PDF library exists anywhere in this monorepo (`grep`-confirmed
+across all 6 `package.json` files, not assumed); `rest.ts` is JSON-only
+today, but `static.ts`'s `serveFile` already proves a raw-`Buffer`
+response works cleanly in this server.
+
+## Goals / Non-Goals
+
+**Goals:**
+- Reuse `getChangeTimeline`/`getChangeTimelines` unchanged for
+  per-change data — this change adds authorship and PDF rendering
+  only, not a second copy of the timeline data layer.
+- A user-specified date range (the user explicitly asked to set sprint
+  start/end dates), unlike the multi-change comparison view's
+  auto-derived range.
+- No heavy PDF pipeline (headless browser, HTML-to-PDF) — `pdfkit` is
+  pure JS with no browser/native dependency.
+
+**Non-Goals:**
+- Not the VS Code command (`add-sprint-report-vscode-command`, next) —
+  this change is standalone-only.
+- Not visual polish (custom fonts, a logo, tables/charts) — a plain,
+  readable structured document is enough for v1, consistent with this
+  project's existing bias elsewhere (e.g. the multi-change timeline's
+  plain-CSS-position choice over a charting library).
+- Not perfect markdown fidelity in the "Why" excerpt — a regex-based
+  strip of the most common syntax (code spans, bold, links), not a full
+  AST parse. `renderMarkdown` (webui) was deliberately not reused here:
+  it renders to React elements for a browser DOM, not plain text for a
+  PDF library running in Node.
+
+## Decisions
+
+### Primary author = most recent commit touching the change's directory
+
+Not "who created it" (the earliest commit, which `getFileCreatedDate`
+already answers) — chosen because this repository's own squash-merge
+convention means there is often exactly one commit per change anyway,
+and for any repository with a longer history, the most recent commit
+is the most representative single answer to "who shipped this."
+`contributors` (every distinct author by email, oldest to newest)
+covers the fuller picture without forcing a choice for callers that
+want it.
+
+### Date range filters tasks/stats, not which changes appear
+
+The user already chose which changes belong in the report via the
+existing multi-select picker (`ChangeTimelineRequestEntry[]`, reused
+unchanged). Excluding a selected change from its own requested report
+just because it started a day before the range would be a surprising,
+unwanted behavior — the range instead determines which of a change's
+completed tasks count toward `tasksCompletedInRange`/the sprint totals,
+and is shown as the report's header.
+
+### `pdfkit`, piped through a buffering `Promise`
+
+`pdfkit` has no built-in promise/buffer API — `PDFDocument` is a
+Node `Readable` stream. `renderSprintReportPdf` collects `"data"`
+chunks into an array and resolves `Buffer.concat(chunks)` on `"end"`,
+the standard pattern for this library (confirmed via its own type
+definitions and documented usage, not guessed).
+
+### The REST endpoint returns a raw PDF, not JSON-wrapped base64
+
+Matches `static.ts`'s existing `res.writeHead(200, {"content-type":
+...}); res.end(buffer)` shape rather than inventing a
+JSON-with-base64-payload convention — a real `content-type:
+application/pdf` response lets `response.blob()` work directly on the
+client side, and is what any HTTP client (including a future CLI use)
+would expect from a "download a PDF" endpoint.
+
+## Risks / Trade-offs
+
+- **[Risk]** `pdfkit` is a new supply-chain dependency (plus its
+  `@types/pdfkit` companion). → **Mitigation**: it is a long-established,
+  widely-used, pure-JS library with no native bindings or browser
+  dependency — the lowest-risk category of new dependency for exactly
+  this need, and `npm audit --omit=dev --audit-level=high` (this
+  repository's actual CI gate) reports zero vulnerabilities with it
+  installed.
+- **[Risk]** The plain-text "Why" excerpt is a best-effort regex strip,
+  not a real markdown parser — unusual markdown (nested formatting,
+  tables inside the Why section) could render awkwardly. →
+  **Mitigation**: accepted for v1; the excerpt is a summary aid, not
+  the full proposal, and every proposal in this repository's own
+  history uses simple prose in its Why section.
diff --git a/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/proposal.md b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/proposal.md
new file mode 100644
index 0000000..54d115f
--- /dev/null
+++ b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/proposal.md
@@ -0,0 +1,61 @@
+## Why
+
+Following up on the 2026-08-26/27 product-direction discussion: the
+user asked for a downloadable "sprint summary" PDF report — given a
+start/end date, who did what (from git), when, task completion, plus
+final aggregate statistics. This is the first (standalone-only) half;
+`add-sprint-report-vscode-command` (next) adds the VS Code command.
+
+## What Changes
+
+- Add `getChangeAuthorship(cwd, changeDirPath)` to
+  `packages/core/src/change-timeline.ts`: a new git primitive (`git log
+  --format=%an\x1f%ae\x1f%aI`) returning the primary author (most
+  recent commit touching the change's directory — this repository's own
+  squash-merge convention makes this the most representative single
+  answer to "who did this") and every distinct contributor. No existing
+  code in this repository extracted author name/email before this —
+  only commit timestamps (`author-time`/`%aI`).
+- Add `packages/core/src/sprint-report.ts`
+  (`buildSprintReport(workspaceRoot, entries, rangeStart, rangeEnd)`):
+  aggregates `getChangeTimeline`/`getChangeAuthorship` per selected
+  change into a `SprintReport` (per-change author/dates/task counts/a
+  plain-text "Why" excerpt, plus totals and a per-author breakdown).
+  The date range filters which *tasks* count toward the sprint's stats,
+  not which *changes* appear — the user already chose those explicitly
+  via the existing change picker.
+- Add `packages/core/src/sprint-report-pdf.ts`
+  (`renderSprintReportPdf(report)`, via the new `pdfkit` dependency): a
+  plain, structured PDF — no tables/graphics/custom fonts, matching
+  this project's existing "plain and functional over polished" bias.
+- Add `POST /api/sprint-report` in `packages/server`, returning
+  `application/pdf` with `content-disposition: attachment` — the first
+  non-JSON response this server's REST layer has ever sent (mirrors
+  `static.ts`'s existing raw-Buffer response pattern, not `sendJson`).
+- Add a third "Sprint report" mode to the standalone Timeline tab
+  (alongside "Single change"/"Compare changes"), reusing the same
+  date-range + multi-select UI pattern already built for "Compare
+  changes." A "Download PDF" button fetches the PDF as a `Blob` and
+  triggers a browser download (`URL.createObjectURL` + a temporary
+  `<a download>` — no existing precedent in this codebase, a standard
+  browser pattern).
+
+## Capabilities
+
+### Modified Capabilities
+
+- `execution-core`: adds a Requirement for sprint report generation
+  (authorship, aggregation, PDF rendering).
+- `standalone-app`: adds a Requirement for the Sprint report mode.
+
+## Impact
+
+- `packages/core/src/change-timeline.ts` (new `getChangeAuthorship`)
+- `packages/core/src/sprint-report.ts` (new)
+- `packages/core/src/sprint-report-pdf.ts` (new)
+- `packages/core/package.json` (new dependency: `pdfkit`,
+  `@types/pdfkit`)
+- `packages/server/src/rest.ts`, `server.ts`
+- `packages/webui/src/sprint-report-client.ts` (new)
+- `packages/webui/src/standalone-entry.tsx`
+- `.changeset/*.md` (new changeset file)
diff --git a/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/specs/execution-core/spec.md b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/specs/execution-core/spec.md
new file mode 100644
index 0000000..66967fd
--- /dev/null
+++ b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/specs/execution-core/spec.md
@@ -0,0 +1,44 @@
+## ADDED Requirements
+
+### Requirement: Sprint report generation
+
+The system SHALL generate, for a given set of changes and a date
+range, a sprint summary containing each change's best-effort git
+authorship, dates, task completion, and a plain-text summary, plus
+aggregate statistics (total changes, tasks completed within the range,
+and a per-author change count), rendered as a PDF document.
+
+#### Scenario: Authorship for a change with a single commit
+
+- **WHEN** authorship is determined for a change whose directory has
+  exactly one commit touching it
+- **THEN** that commit's author is reported as both the primary author
+  and the sole contributor
+
+#### Scenario: Authorship for a change with multiple commits by different authors
+
+- **WHEN** authorship is determined for a change touched by commits
+  from more than one author
+- **THEN** the most recent commit's author is reported as the primary
+  author, and every distinct author is listed among the contributors
+
+#### Scenario: A task completed within the requested range
+
+- **WHEN** a selected change's task was completed (per its best-effort
+  date) within the requested date range
+- **THEN** it counts toward that change's and the report's total
+  tasks-completed-in-range figure
+
+#### Scenario: A selected change started before the requested range
+
+- **WHEN** a user explicitly selects a change for the report whose
+  created date falls before the requested range
+- **THEN** the change still appears in the report; only its
+  task-completion counts are filtered by the range
+
+#### Scenario: Authorship is undeterminable
+
+- **WHEN** git history for a change's directory is unavailable or
+  yields no commits
+- **THEN** the report includes the change with no primary author or
+  contributors, rather than failing to generate
diff --git a/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/specs/standalone-app/spec.md b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/specs/standalone-app/spec.md
new file mode 100644
index 0000000..58698e4
--- /dev/null
+++ b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/specs/standalone-app/spec.md
@@ -0,0 +1,20 @@
+## ADDED Requirements
+
+### Requirement: The Timeline tab offers a downloadable sprint report
+
+The system SHALL offer, within the Timeline tab, a mode where the user
+picks a date range and multiple active and/or archived changes, then
+downloads a generated PDF sprint report as a browser file download.
+
+#### Scenario: User generates a sprint report
+
+- **WHEN** the user selects a date range and one or more changes in the
+  Sprint report mode and starts the download
+- **THEN** a PDF file download begins, named after the selected range
+
+#### Scenario: User has not selected a range or any changes
+
+- **WHEN** the user attempts to generate a report without a complete
+  date range or without selecting any change
+- **THEN** the system reports what is missing rather than attempting
+  to generate an empty or partial report
diff --git a/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/tasks.md b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/tasks.md
new file mode 100644
index 0000000..c9c85fd
--- /dev/null
+++ b/openspec/changes/archive/2026-08-27-add-sprint-report-pdf/tasks.md
@@ -0,0 +1,69 @@
+## 1. Core: authorship, aggregation, PDF rendering
+
+- [x] 1.1 Add `getChangeAuthorship(cwd, changeDirPath)` to
+  `change-timeline.ts` (`CommitAuthor`, `ChangeAuthorship` types) — a
+  new `git log --format=%an\x1f%ae\x1f%aI` primitive, graceful
+  degradation on failure (matching every other function in the file).
+- [x] 1.2 Add tests against a real temp git repo fixture: primary
+  author is the most recent commit's author, `contributors` lists
+  every distinct author (by email) oldest to newest, empty authorship
+  when git fails or the directory has no history.
+- [x] 1.3 Add `pdfkit` + `@types/pdfkit` to `packages/core/package.json`.
+- [x] 1.4 Add `packages/core/src/sprint-report.ts`
+  (`buildSprintReport`) — reuses `getChangeTimeline`/
+  `getChangeAuthorship` unchanged; date-range filters tasks/stats, not
+  which changes appear (see design.md).
+- [x] 1.5 Add tests: authorship/task-count aggregation, date-range
+  task filtering, a change kept even when it started before the range,
+  `changesByAuthor` ranked by count descending, empty report for no
+  entries.
+- [x] 1.6 Add `packages/core/src/sprint-report-pdf.ts`
+  (`renderSprintReportPdf`) using `pdfkit`, buffered via the
+  collect-chunks-on-`"end"` pattern.
+- [x] 1.7 Add a test confirming a real PDF buffer (`%PDF-` magic bytes,
+  `%%EOF` trailer) comes back, including for an empty report.
+- [x] 1.8 Export both new modules from `index.ts` (Node-only — not
+  `browser.ts`, since both use git/Node streams).
+
+## 2. Server: REST endpoint
+
+- [x] 2.1 Add `sendPdf(res, buffer, filename)` to `rest.ts`, mirroring
+  `sendJson`'s shape (adds `content-disposition: attachment`).
+- [x] 2.2 Add `handleSprintReportRequest` (body:
+  `{cwd, entries, rangeStart, rangeEnd}`) calling `buildSprintReport`
+  then `renderSprintReportPdf`.
+- [x] 2.3 Wire `POST /api/sprint-report` in `server.ts`.
+- [x] 2.4 Add tests: a real PDF comes back with the correct
+  `content-type`/`content-disposition`; a request missing the date
+  range is rejected with 400.
+
+## 3. Webui: Sprint report mode
+
+- [x] 3.1 Add `packages/webui/src/sprint-report-client.ts`
+  (`fetchSprintReportPdf`, returns a `Blob`) and its test.
+- [x] 3.2 Add a third "Sprint report" mode to the Timeline tab in
+  `standalone-entry.tsx`, reusing the existing date-range/multi-select
+  state from "Compare changes"; a "Download PDF" button triggers the
+  browser download (`URL.createObjectURL` + a temporary `<a
+  download>`).
+
+## 4. Verification
+
+- [x] 4.1 `npm run typecheck` and `npm run lint` (including
+  `lint:english`) pass workspace-wide.
+- [x] 4.2 `npm run test` passes workspace-wide, including all new test
+  files.
+- [x] 4.3 `npm audit --omit=dev --audit-level=high` (this repository's
+  actual CI gate) still reports zero vulnerabilities with `pdfkit`
+  installed.
+- [x] 4.4 Manual smoke test: started the standalone server against
+  this repository itself, requested a real sprint report for five of
+  today's/yesterday's own real archived changes, confirmed a valid PDF
+  (`file` reports "PDF document, version 1.3, 2 page(s)") with correct
+  real data — actual proposal excerpts, dates, git author, and correct
+  totals/per-author statistics.
+- [x] 4.5 Propose a changeset (`npx changeset`) for `@openspec-ui/core`,
+  `@openspec-ui/server`, and `@openspec-ui/webui` (all minor: new
+  capability, no breaking change) instead of hand-editing `version`/
+  `CHANGELOG.md`; apply it via `npx changeset version`.
+- [x] 4.6 Run `openspec change validate --strict add-sprint-report-pdf`.
diff --git a/openspec/specs/execution-core/spec.md b/openspec/specs/execution-core/spec.md
index 95b663a..fe68b8b 100644
--- a/openspec/specs/execution-core/spec.md
+++ b/openspec/specs/execution-core/spec.md
@@ -171,3 +171,46 @@ never be flagged regardless of age.
   (e.g. blame unavailable)
 - **THEN** the system does not report it as stale
 
+### Requirement: Sprint report generation
+
+The system SHALL generate, for a given set of changes and a date
+range, a sprint summary containing each change's best-effort git
+authorship, dates, task completion, and a plain-text summary, plus
+aggregate statistics (total changes, tasks completed within the range,
+and a per-author change count), rendered as a PDF document.
+
+#### Scenario: Authorship for a change with a single commit
+
+- **WHEN** authorship is determined for a change whose directory has
+  exactly one commit touching it
+- **THEN** that commit's author is reported as both the primary author
+  and the sole contributor
+
+#### Scenario: Authorship for a change with multiple commits by different authors
+
+- **WHEN** authorship is determined for a change touched by commits
+  from more than one author
+- **THEN** the most recent commit's author is reported as the primary
+  author, and every distinct author is listed among the contributors
+
+#### Scenario: A task completed within the requested range
+
+- **WHEN** a selected change's task was completed (per its best-effort
+  date) within the requested date range
+- **THEN** it counts toward that change's and the report's total
+  tasks-completed-in-range figure
+
+#### Scenario: A selected change started before the requested range
+
+- **WHEN** a user explicitly selects a change for the report whose
+  created date falls before the requested range
+- **THEN** the change still appears in the report; only its
+  task-completion counts are filtered by the range
+
+#### Scenario: Authorship is undeterminable
+
+- **WHEN** git history for a change's directory is unavailable or
+  yields no commits
+- **THEN** the report includes the change with no primary author or
+  contributors, rather than failing to generate
+
diff --git a/openspec/specs/standalone-app/spec.md b/openspec/specs/standalone-app/spec.md
index cc6ed1f..f63fac6 100644
--- a/openspec/specs/standalone-app/spec.md
+++ b/openspec/specs/standalone-app/spec.md
@@ -255,3 +255,22 @@ it when rendering a change's timeline.
   reloads) a change's timeline
 - **THEN** pending tasks are flagged stale according to the new value
 
+### Requirement: The Timeline tab offers a downloadable sprint report
+
+The system SHALL offer, within the Timeline tab, a mode where the user
+picks a date range and multiple active and/or archived changes, then
+downloads a generated PDF sprint report as a browser file download.
+
+#### Scenario: User generates a sprint report
+
+- **WHEN** the user selects a date range and one or more changes in the
+  Sprint report mode and starts the download
+- **THEN** a PDF file download begins, named after the selected range
+
+#### Scenario: User has not selected a range or any changes
+
+- **WHEN** the user attempts to generate a report without a complete
+  date range or without selecting any change
+- **THEN** the system reports what is missing rather than attempting
+  to generate an empty or partial report
+
diff --git a/package-lock.json b/package-lock.json
index 91a8d38..b1ae275 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1649,6 +1649,30 @@
         "node": "^22.20 || ^24.12 || >=25"
       }
     },
+    "node_modules/@noble/ciphers": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/@noble/ciphers/-/ciphers-1.3.0.tgz",
+      "integrity": "sha512-2I0gnIVPtfnMw9ee9h1dJG7tp81+8Ob3OJb3Mv37rx5L40/b0i7djjCVvGOVqc9AEIQyvyu1i6ypKdFw8R8gQw==",
+      "license": "MIT",
+      "engines": {
+        "node": "^14.21.3 || >=16"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
+    "node_modules/@noble/hashes": {
+      "version": "1.8.0",
+      "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-1.8.0.tgz",
+      "integrity": "sha512-jCs9ldd7NwzpgXDIf6P3+NrHh9/sD6CQdxHyjQI+h/6rDNo88ypBxxz45UDuZHz9r3tNz7N/VInSVoVdtXEI4A==",
+      "license": "MIT",
+      "engines": {
+        "node": "^14.21.3 || >=16"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
     "node_modules/@nodelib/fs.scandir": {
       "version": "2.1.5",
       "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-2.1.5.tgz",
@@ -2319,6 +2343,15 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/@swc/helpers": {
+      "version": "0.5.23",
+      "resolved": "https://registry.npmjs.org/@swc/helpers/-/helpers-0.5.23.tgz",
+      "integrity": "sha512-5lSsMOTXURePglDfvuAQUqkGek9Hg2kksOYay2m0+XR++b2NWYL/4sWyuvVBIs8oKnJaxkdi9whaL/sqN13afw==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "tslib": "^2.8.0"
+      }
+    },
     "node_modules/@testing-library/dom": {
       "version": "10.4.1",
       "resolved": "https://registry.npmjs.org/@testing-library/dom/-/dom-10.4.1.tgz",
@@ -2599,6 +2632,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/pdfkit": {
+      "version": "0.17.6",
+      "resolved": "https://registry.npmjs.org/@types/pdfkit/-/pdfkit-0.17.6.tgz",
+      "integrity": "sha512-tIwzxk2uWKp0Cq9JIluQXJid77lYhF52EsIOwhsMF4iWLA6YneoBR1xVKYYdAysHuepUB0OX4tdwMiUDdGKmig==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/prop-types": {
       "version": "15.7.15",
       "resolved": "https://registry.npmjs.org/@types/prop-types/-/prop-types-15.7.15.tgz",
@@ -3233,7 +3276,6 @@
       "version": "1.5.1",
       "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-1.5.1.tgz",
       "integrity": "sha512-AKpaYlHn8t4SVbOHCy+b5+KKgvR4vrsD8vbvrbiQJps7fKDTkjkDry6ji0rUJjC0kzbNePLwzxq8iypo41qeWA==",
-      "dev": true,
       "funding": [
         {
           "type": "github",
@@ -3248,8 +3290,7 @@
           "url": "https://feross.org/support"
         }
       ],
-      "license": "MIT",
-      "optional": true
+      "license": "MIT"
     },
     "node_modules/bidi-js": {
       "version": "1.0.3",
@@ -3356,6 +3397,15 @@
         "node": ">=8"
       }
     },
+    "node_modules/brotli": {
+      "version": "1.3.3",
+      "resolved": "https://registry.npmjs.org/brotli/-/brotli-1.3.3.tgz",
+      "integrity": "sha512-oTKjJdShmDuGW94SyyaoQvAjf30dZaHnjJ8uAF+u2/vGJkJbJPJAT1gDiOJP5v1Zb6f9KEyW/1HpuaWIXtGHPg==",
+      "license": "MIT",
+      "dependencies": {
+        "base64-js": "^1.1.2"
+      }
+    },
     "node_modules/browser-stdout": {
       "version": "1.3.1",
       "resolved": "https://registry.npmjs.org/browser-stdout/-/browser-stdout-1.3.1.tgz",
@@ -3786,6 +3836,15 @@
         "node": ">=8"
       }
     },
+    "node_modules/clone": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/clone/-/clone-2.1.2.tgz",
+      "integrity": "sha512-3Pe/CF1Nn94hyhIYpjtiLhdCoEoz0DqQ+988E9gmeEdQZlojxnOb74wctFyuwWQHzqyf9X7C7MG8juUpqBJT8w==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.8"
+      }
+    },
     "node_modules/cockatiel": {
       "version": "3.2.1",
       "resolved": "https://registry.npmjs.org/cockatiel/-/cockatiel-3.2.1.tgz",
@@ -4144,6 +4203,12 @@
         "url": "https://github.com/sponsors/wooorm"
       }
     },
+    "node_modules/dfa": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/dfa/-/dfa-1.2.0.tgz",
+      "integrity": "sha512-ED3jP8saaweFTjeGX8HQPjeC1YYyZs98jGNZx6IiBvxW7JG5v492kamAQB3m2wop07CvU/RQmzcKr6bgcC5D/Q==",
+      "license": "MIT"
+    },
     "node_modules/diff": {
       "version": "9.0.0",
       "resolved": "https://registry.npmjs.org/diff/-/diff-9.0.0.tgz",
@@ -4714,7 +4779,6 @@
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
       "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/fast-glob": {
@@ -4833,6 +4897,12 @@
         }
       }
     },
+    "node_modules/fflate": {
+      "version": "0.8.3",
+      "resolved": "https://registry.npmjs.org/fflate/-/fflate-0.8.3.tgz",
+      "integrity": "sha512-tbZNuJrLwGUp3zshBtdy4W+ORxZuIh8a5ilyIEQDC5rY1f3U20JMry0Ll3WBzU58EZKsEuJFXhb5gwv8CsPvgA==",
+      "license": "MIT"
+    },
     "node_modules/file-entry-cache": {
       "version": "8.0.0",
       "resolved": "https://registry.npmjs.org/file-entry-cache/-/file-entry-cache-8.0.0.tgz",
@@ -4907,6 +4977,23 @@
       "dev": true,
       "license": "ISC"
     },
+    "node_modules/fontkit": {
+      "version": "2.0.4",
+      "resolved": "https://registry.npmjs.org/fontkit/-/fontkit-2.0.4.tgz",
+      "integrity": "sha512-syetQadaUEDNdxdugga9CpEYVaQIxOwk7GlwZWWZ19//qW4zE5bknOKeMBDYAASwnpaSHKJITRLMF9m1fp3s6g==",
+      "license": "MIT",
+      "dependencies": {
+        "@swc/helpers": "^0.5.12",
+        "brotli": "^1.3.2",
+        "clone": "^2.1.2",
+        "dfa": "^1.2.0",
+        "fast-deep-equal": "^3.1.3",
+        "restructure": "^3.0.0",
+        "tiny-inflate": "^1.0.3",
+        "unicode-properties": "^1.4.0",
+        "unicode-trie": "^2.0.0"
+      }
+    },
     "node_modules/foreground-child": {
       "version": "3.3.1",
       "resolved": "https://registry.npmjs.org/foreground-child/-/foreground-child-3.3.1.tgz",
@@ -6048,6 +6135,25 @@
         "immediate": "~3.0.5"
       }
     },
+    "node_modules/linebreak": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/linebreak/-/linebreak-1.1.0.tgz",
+      "integrity": "sha512-MHp03UImeVhB7XZtjd0E4n6+3xr5Dq/9xI/5FptGk5FrbDR3zagPa2DS6U8ks/3HjbKWG9Q1M2ufOzxV2qLYSQ==",
+      "license": "MIT",
+      "dependencies": {
+        "base64-js": "0.0.8",
+        "unicode-trie": "^2.0.0"
+      }
+    },
+    "node_modules/linebreak/node_modules/base64-js": {
+      "version": "0.0.8",
+      "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-0.0.8.tgz",
+      "integrity": "sha512-3XSA2cR/h/73EzlXXdU6YNycmYI7+kicTxks4eJg2g39biHR84slg2+des+p7iHYhbRg/udIS4TD53WabcOUkw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
     "node_modules/linkify-it": {
       "version": "5.0.2",
       "resolved": "https://registry.npmjs.org/linkify-it/-/linkify-it-5.0.2.tgz",
@@ -8033,6 +8139,20 @@
         "node": ">= 14.16"
       }
     },
+    "node_modules/pdfkit": {
+      "version": "0.20.1",
+      "resolved": "https://registry.npmjs.org/pdfkit/-/pdfkit-0.20.1.tgz",
+      "integrity": "sha512-1rRXK6x5o8I/3dBrBzXfxibpHpkfCnIA7EBAES7pEpGFc/65inMLlA8SalGWpJfal7BGekxeLf6A30IOpQpc5Q==",
+      "license": "MIT",
+      "dependencies": {
+        "@noble/ciphers": "^1.3.0",
+        "@noble/hashes": "^1.8.0",
+        "fflate": "^0.8.3",
+        "fontkit": "^2.0.4",
+        "linebreak": "^1.1.0",
+        "png-js": "^2.0.0"
+      }
+    },
     "node_modules/pend": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/pend/-/pend-1.2.0.tgz",
@@ -8117,6 +8237,14 @@
         "node": ">=4"
       }
     },
+    "node_modules/png-js": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/png-js/-/png-js-2.0.0.tgz",
+      "integrity": "sha512-GdzJuUMc6ZSpxFJWVxtOH1bzYHym+TOnveqUjb+VJIbZWbZzyiRGFiKhbiielfpYbgMlhHVhsJ0FTazfuRFkMA==",
+      "dependencies": {
+        "fflate": "^0.8.2"
+      }
+    },
     "node_modules/postcss": {
       "version": "8.5.25",
       "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.25.tgz",
@@ -8616,6 +8744,12 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/restructure": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/restructure/-/restructure-3.0.2.tgz",
+      "integrity": "sha512-gSfoiOEA0VPE6Tukkrr7I0RBdE0s7H1eFCDBk05l1KIQT1UIKNc5JZy6jdyW6eYH3aR3g5b3PuL77rq0hvwtAw==",
+      "license": "MIT"
+    },
     "node_modules/reusify": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/reusify/-/reusify-1.1.0.tgz",
@@ -9501,6 +9635,12 @@
         "url": "https://bevry.me/fund"
       }
     },
+    "node_modules/tiny-inflate": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/tiny-inflate/-/tiny-inflate-1.0.3.tgz",
+      "integrity": "sha512-pkY1fj1cKHb2seWDy0B16HeWyczlJA9/WW3u3c4z/NiWDsO3DOU5D7nhTLE9CF0yXv/QZFY7sEJmj24dK+Rrqw==",
+      "license": "MIT"
+    },
     "node_modules/tinybench": {
       "version": "2.9.0",
       "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
@@ -9668,7 +9808,6 @@
       "version": "2.8.1",
       "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
       "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
-      "dev": true,
       "license": "0BSD"
     },
     "node_modules/tsx": {
@@ -10434,6 +10573,32 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/unicode-properties": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/unicode-properties/-/unicode-properties-1.4.1.tgz",
+      "integrity": "sha512-CLjCCLQ6UuMxWnbIylkisbRj31qxHPAurvena/0iwSVbQ2G1VY5/HjV0IRabOEbDHlzZlRdCrD4NhB0JtU40Pg==",
+      "license": "MIT",
+      "dependencies": {
+        "base64-js": "^1.3.0",
+        "unicode-trie": "^2.0.0"
+      }
+    },
+    "node_modules/unicode-trie": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/unicode-trie/-/unicode-trie-2.0.0.tgz",
+      "integrity": "sha512-x7bc76x0bm4prf1VLg79uhAzKw8DVboClSN5VxJuQ+LKDOVEW9CdH+VY7SP+vX7xCYQqzzgQpFqz15zeLvAtZQ==",
+      "license": "MIT",
+      "dependencies": {
+        "pako": "^0.2.5",
+        "tiny-inflate": "^1.0.0"
+      }
+    },
+    "node_modules/unicode-trie/node_modules/pako": {
+      "version": "0.2.9",
+      "resolved": "https://registry.npmjs.org/pako/-/pako-0.2.9.tgz",
+      "integrity": "sha512-NUcwaKxUxWrZLpDG+z/xZaCgQITkA/Dv4V/T6bw7VON6l1Xz/VnrBqrYjZQ12TamKHzITTfOEIYUj48y2KXImA==",
+      "license": "MIT"
+    },
     "node_modules/unicorn-magic": {
       "version": "0.3.0",
       "resolved": "https://registry.npmjs.org/unicorn-magic/-/unicorn-magic-0.3.0.tgz",
@@ -11246,7 +11411,7 @@
     },
     "packages/cli": {
       "name": "@openspec-ui/cli",
-      "version": "0.1.0",
+      "version": "0.1.2",
       "license": "MIT",
       "dependencies": {
         "cross-spawn": "^7.0.6",
@@ -11747,19 +11912,21 @@
     },
     "packages/core": {
       "name": "@openspec-ui/core",
-      "version": "0.25.0",
+      "version": "0.28.0",
       "dependencies": {
         "cross-spawn": "^7.0.6",
+        "pdfkit": "^0.20.1",
         "simple-git": "^3.27.0"
       },
       "devDependencies": {
         "@types/cross-spawn": "^6.0.6",
-        "@types/node": "^26.2.0"
+        "@types/node": "^26.2.0",
+        "@types/pdfkit": "^0.17.6"
       }
     },
     "packages/extension": {
       "name": "openspec-ui-vscode",
-      "version": "0.21.0",
+      "version": "0.25.0",
       "license": "MIT",
       "dependencies": {
         "@openspec-ui/core": "*",
@@ -12265,7 +12432,7 @@
     },
     "packages/server": {
       "name": "@openspec-ui/server",
-      "version": "1.8.0",
+      "version": "1.9.0",
       "dependencies": {
         "@openspec-ui/core": "*",
         "ws": "^8.21.0"
@@ -12764,7 +12931,7 @@
     },
     "packages/webui": {
       "name": "@openspec-ui/webui",
-      "version": "1.10.0",
+      "version": "1.14.0",
       "dependencies": {
         "@openspec-ui/core": "*",
         "diff": "^9.0.0",
diff --git a/packages/core/CHANGELOG.md b/packages/core/CHANGELOG.md
index 56e84ea..8b87aa7 100644
--- a/packages/core/CHANGELOG.md
+++ b/packages/core/CHANGELOG.md
@@ -1,5 +1,15 @@
 # @openspec-ui/core
 
+## 0.29.0
+
+### Minor Changes
+
+- Add a downloadable sprint summary PDF report: for a user-picked date
+  range and set of changes, who authored each one (from git), what it
+  was, task completion, plus aggregate statistics (total changes, tasks
+  completed in range, a per-author breakdown). New "Sprint report" mode
+  in the standalone Timeline tab.
+
 ## 0.28.0
 
 ### Minor Changes
diff --git a/packages/core/package.json b/packages/core/package.json
index 5c23769..5fdc27a 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@openspec-ui/core",
   "private": true,
-  "version": "0.28.0",
+  "version": "0.29.0",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
@@ -15,10 +15,12 @@
   },
   "dependencies": {
     "simple-git": "^3.27.0",
-    "cross-spawn": "^7.0.6"
+    "cross-spawn": "^7.0.6",
+    "pdfkit": "^0.20.1"
   },
   "devDependencies": {
     "@types/node": "^26.2.0",
-    "@types/cross-spawn": "^6.0.6"
+    "@types/cross-spawn": "^6.0.6",
+    "@types/pdfkit": "^0.17.6"
   }
 }
diff --git a/packages/core/src/change-timeline.test.ts b/packages/core/src/change-timeline.test.ts
index b713f09..94560ef 100644
--- a/packages/core/src/change-timeline.test.ts
+++ b/packages/core/src/change-timeline.test.ts
@@ -6,6 +6,7 @@ import { afterEach, describe, expect, it } from "vitest";
 import {
   blameLineDates,
   getChangeArchivedDate,
+  getChangeAuthorship,
   getChangeTimeline,
   getFileCreatedDate,
 } from "./change-timeline.js";
@@ -36,6 +37,25 @@ async function commitAll(root: string, message: string, isoDate: string): Promis
   await git.commit(message);
 }
 
+async function commitAllAs(
+  root: string,
+  message: string,
+  isoDate: string,
+  authorName: string,
+  authorEmail: string,
+): Promise<void> {
+  const git = simpleGit(root).env({
+    GIT_AUTHOR_DATE: isoDate,
+    GIT_COMMITTER_DATE: isoDate,
+    GIT_AUTHOR_NAME: authorName,
+    GIT_AUTHOR_EMAIL: authorEmail,
+    GIT_COMMITTER_NAME: authorName,
+    GIT_COMMITTER_EMAIL: authorEmail,
+  });
+  await git.add(".");
+  await git.commit(message);
+}
+
 async function writeChangeFiles(
   root: string,
   changeName: string,
@@ -114,6 +134,62 @@ describe("getChangeArchivedDate", () => {
   });
 });
 
+describe("getChangeAuthorship", () => {
+  it("returns empty authorship when git fails (not a repo)", async () => {
+    const root = await temporaryRoot();
+    await mkdir(path.join(root, "openspec", "changes", "my-change"), { recursive: true });
+
+    const authorship = await getChangeAuthorship(root, path.join(root, "openspec", "changes", "my-change"));
+
+    expect(authorship).toEqual({ primaryAuthor: null, contributors: [] });
+  });
+
+  it("attributes the primary author to the most recent commit touching the directory", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    const changeDir = await writeChangeFiles(root, "my-change", "- [ ] first\n");
+    await commitAllAs(root, "create change", "2026-01-01T00:00:00Z", "Alice", "alice@example.com");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [x] first\n");
+    await commitAllAs(root, "complete task", "2026-01-05T00:00:00Z", "Bob", "bob@example.com");
+
+    const authorship = await getChangeAuthorship(root, changeDir);
+
+    expect(authorship.primaryAuthor).toEqual({
+      name: "Bob",
+      email: "bob@example.com",
+      date: "2026-01-05T00:00:00.000Z",
+    });
+  });
+
+  it("lists every distinct contributor, oldest to newest, deduplicated by email", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    const changeDir = await writeChangeFiles(root, "my-change", "- [ ] first\n- [ ] second\n");
+    await commitAllAs(root, "create change", "2026-01-01T00:00:00Z", "Alice", "alice@example.com");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [x] first\n- [ ] second\n");
+    await commitAllAs(root, "complete first", "2026-01-02T00:00:00Z", "Bob", "bob@example.com");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [x] first\n- [x] second\n");
+    await commitAllAs(root, "complete second", "2026-01-03T00:00:00Z", "Alice", "alice@example.com");
+
+    const authorship = await getChangeAuthorship(root, changeDir);
+
+    expect(authorship.contributors.map((c) => c.email)).toEqual(["alice@example.com", "bob@example.com"]);
+  });
+
+  it("returns empty authorship when the directory has no history", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    await writeChangeFiles(root, "committed-change", "- [ ] first\n");
+    await commitAllAs(root, "create change", "2026-01-01T00:00:00Z", "Alice", "alice@example.com");
+    const uncommittedDir = path.join(root, "openspec", "changes", "never-committed");
+    await mkdir(uncommittedDir, { recursive: true });
+
+    const authorship = await getChangeAuthorship(root, uncommittedDir);
+
+    expect(authorship).toEqual({ primaryAuthor: null, contributors: [] });
+  });
+});
+
 describe("getChangeTimeline", () => {
   it("merges task dates, created date, and markdown content for an active change", async () => {
     const root = await temporaryRoot();
diff --git a/packages/core/src/change-timeline.ts b/packages/core/src/change-timeline.ts
index 8a798e9..6143eef 100644
--- a/packages/core/src/change-timeline.ts
+++ b/packages/core/src/change-timeline.ts
@@ -126,6 +126,65 @@ export function getChangeArchivedDate(changeName: string, archived: boolean): st
   return changeName.match(ARCHIVE_DATE_RE)?.[1] ?? null;
 }
 
+export interface CommitAuthor {
+  name: string;
+  email: string;
+  /** ISO 8601 date of the commit this author is attributed for. */
+  date: string;
+}
+
+export interface ChangeAuthorship {
+  /** Author of the most recent commit touching the change's directory —
+   * "who shipped it." For a squash-merge workflow (this repository's
+   * own convention) this is usually the only commit anyway; for a
+   * history with multiple commits, the most recent one is the most
+   * representative single answer to "who did this." */
+  primaryAuthor: CommitAuthor | null;
+  /** Every distinct author (by email) across all commits touching the
+   * directory, oldest to newest. Includes `primaryAuthor`. */
+  contributors: CommitAuthor[];
+}
+
+const AUTHOR_LOG_FIELD_SEP = "\x1f";
+
+/** Best-effort git-derived authorship for `changeDirPath` (an active or
+ * archived change's directory) — `{ primaryAuthor: null, contributors: [] }`
+ * when undeterminable (shallow clone, no history, not a git repository). */
+export async function getChangeAuthorship(cwd: string, changeDirPath: string): Promise<ChangeAuthorship> {
+  const empty: ChangeAuthorship = { primaryAuthor: null, contributors: [] };
+  try {
+    const output = await simpleGit(cwd).raw([
+      "log",
+      `--format=%an${AUTHOR_LOG_FIELD_SEP}%ae${AUTHOR_LOG_FIELD_SEP}%aI`,
+      "--",
+      changeDirPath,
+    ]);
+    const authors: CommitAuthor[] = [];
+    for (const line of output.split("\n")) {
+      const trimmed = line.trim();
+      if (!trimmed) continue;
+      const [name, email, date] = trimmed.split(AUTHOR_LOG_FIELD_SEP);
+      if (!name || !email || !date) continue;
+      authors.push({ name, email, date: new Date(date).toISOString() });
+    }
+    if (authors.length === 0) return empty;
+
+    // `git log`'s default order is newest-first, so the first parsed
+    // commit is the most recent one touching this directory.
+    const primaryAuthor = authors[0] ?? null;
+    const seenEmails = new Set<string>();
+    const contributors: CommitAuthor[] = [];
+    for (const author of [...authors].reverse()) {
+      if (seenEmails.has(author.email)) continue;
+      seenEmails.add(author.email);
+      contributors.push(author);
+    }
+    return { primaryAuthor, contributors };
+  } catch {
+    return empty;
+  }
+}
+
 export async function getChangeTimeline(
   workspaceRoot: string,
   changeName: string,
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index a71754e..3ef7322 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -23,6 +23,8 @@ export * from "./agent-detection.js";
 export * from "./changeset-reminder.js";
 export * from "./change-timeline.js";
 export * from "./stale-tasks.js";
+export * from "./sprint-report.js";
+export * from "./sprint-report-pdf.js";
 
 export { ClaudeCliAdapter } from "./agents/claude.js";
 export { CopilotCliAdapter } from "./agents/copilot.js";
diff --git a/packages/core/src/sprint-report-pdf.test.ts b/packages/core/src/sprint-report-pdf.test.ts
new file mode 100644
index 0000000..fd5d6c2
--- /dev/null
+++ b/packages/core/src/sprint-report-pdf.test.ts
@@ -0,0 +1,53 @@
+import { describe, expect, it } from "vitest";
+import { renderSprintReportPdf } from "./sprint-report-pdf.js";
+import type { SprintReport } from "./sprint-report.js";
+
+const report: SprintReport = {
+  rangeStart: "2026-01-01T00:00:00.000Z",
+  rangeEnd: "2026-01-14T00:00:00.000Z",
+  entries: [
+    {
+      changeName: "add-widget",
+      archived: true,
+      createdDate: "2026-01-02T00:00:00.000Z",
+      archivedDate: "2026-01-05",
+      whySummary: "Because widgets were needed.",
+      completedTaskCount: 3,
+      totalTaskCount: 3,
+      tasksCompletedInRange: 3,
+      primaryAuthor: { name: "Alice", email: "alice@example.com", date: "2026-01-05T00:00:00.000Z" },
+      contributors: [{ name: "Alice", email: "alice@example.com", date: "2026-01-05T00:00:00.000Z" }],
+    },
+  ],
+  stats: {
+    totalChanges: 1,
+    totalTasksCompletedInRange: 3,
+    changesByAuthor: [
+      { author: { name: "Alice", email: "alice@example.com", date: "2026-01-05T00:00:00.000Z" }, count: 1 },
+    ],
+  },
+};
+
+describe("renderSprintReportPdf", () => {
+  it("renders a real PDF document", async () => {
+    const buffer = await renderSprintReportPdf(report);
+
+    expect(Buffer.isBuffer(buffer)).toBe(true);
+    expect(buffer.byteLength).toBeGreaterThan(0);
+    expect(buffer.subarray(0, 5).toString("latin1")).toBe("%PDF-");
+    expect(buffer.subarray(-6).toString("latin1")).toBe("%%EOF\n");
+  });
+
+  it("renders an empty report without throwing", async () => {
+    const empty: SprintReport = {
+      rangeStart: "2026-01-01T00:00:00.000Z",
+      rangeEnd: "2026-01-14T00:00:00.000Z",
+      entries: [],
+      stats: { totalChanges: 0, totalTasksCompletedInRange: 0, changesByAuthor: [] },
+    };
+
+    const buffer = await renderSprintReportPdf(empty);
+
+    expect(buffer.subarray(0, 5).toString("latin1")).toBe("%PDF-");
+  });
+});
diff --git a/packages/core/src/sprint-report-pdf.ts b/packages/core/src/sprint-report-pdf.ts
new file mode 100644
index 0000000..9278da5
--- /dev/null
+++ b/packages/core/src/sprint-report-pdf.ts
@@ -0,0 +1,100 @@
+// Renders a SprintReport to a PDF buffer (see openspec/changes/
+// add-sprint-report-pdf/design.md). Plain, structured layout — no
+// tables/graphics/custom fonts, matching this project's existing
+// "plain and functional over polished" bias (e.g. the multi-change
+// timeline's plain-CSS-position choice over a charting library).
+
+import { createRequire } from "node:module";
+import { fileURLToPath } from "node:url";
+import type PDFKitDocument from "pdfkit";
+import type { SprintReport } from "./sprint-report.js";
+
+// pdfkit's package.json "exports" map points `import` at an ESM build
+// (js/pdfkit.node.mjs) that uses real `import.meta.url` syntax. When
+// esbuild bundles this package to a single CJS file (the VS Code
+// extension host build), it cannot preserve `import.meta.url` and
+// substitutes an empty object, which crashes that ESM build at load
+// time ("TypeError: Invalid URL") -- breaking extension activation
+// entirely, even though nothing calls PDF/A features that need it.
+// Requiring "pdfkit" instead resolves the package's `require`
+// condition (js/pdfkit.js), a genuinely CommonJS build that reads
+// `__filename` instead, which esbuild *can* shim correctly for a
+// node/cjs bundle. `__filename` is unavailable in this file's own
+// plain-ESM runtime (server/core, unbundled) instead, hence the
+// `typeof` guard -- safe because `typeof` never throws on an
+// undeclared identifier.
+declare const __filename: string | undefined;
+const require = createRequire(
+  typeof __filename !== "undefined" ? __filename : fileURLToPath(import.meta.url),
+);
+const PDFDocument = require("pdfkit") as typeof PDFKitDocument;
+
+function formatDate(date: string | null): string {
+  return date ? new Date(date).toLocaleDateString() : "unknown";
+}
+
+function formatAuthor(author: SprintReport["entries"][number]["primaryAuthor"]): string {
+  return author ? `${author.name} <${author.email}>` : "unknown";
+}
+
+/** Renders `report` to a PDF and resolves with the complete file as a
+ * `Buffer` — pdfkit has no built-in promise/buffer API, so this pipes
+ * its output stream through a collector and buffers on `"end"`, the
+ * standard pattern for this library. */
+export async function renderSprintReportPdf(report: SprintReport): Promise<Buffer> {
+  const doc = new PDFDocument({ margin: 50 });
+  const chunks: Buffer[] = [];
+  doc.on("data", (chunk: Buffer) => chunks.push(chunk));
+  const done = new Promise<Buffer>((resolve, reject) => {
+    doc.on("end", () => resolve(Buffer.concat(chunks)));
+    doc.on("error", reject);
+  });
+
+  doc.fontSize(20).text("Sprint Summary", { align: "left" });
+  doc
+    .fontSize(11)
+    .fillColor("#555555")
+    .text(`${formatDate(report.rangeStart)} — ${formatDate(report.rangeEnd)}`);
+  doc.fillColor("#000000").moveDown(1.5);
+
+  if (report.entries.length === 0) {
+    doc.fontSize(12).text("No changes in this report.");
+  }
+
+  for (const entry of report.entries) {
+    doc.fontSize(14).text(entry.changeName, { continued: false });
+    doc
+      .fontSize(10)
+      .fillColor("#555555")
+      .text(
+        `${entry.archived ? "Archived" : "Active"} · Created ${formatDate(entry.createdDate)}` +
+          (entry.archived ? ` · Archived ${entry.archivedDate ?? "unknown"}` : ""),
+      )
+      .text(`Author: ${formatAuthor(entry.primaryAuthor)}`)
+      .text(
+        `Tasks: ${entry.completedTaskCount}/${entry.totalTaskCount} completed` +
+          ` (${entry.tasksCompletedInRange} within this sprint)`,
+      );
+    doc.fillColor("#000000").moveDown(0.3);
+    if (entry.whySummary) {
+      doc.fontSize(10).text(entry.whySummary, { align: "left" });
+    }
+    doc.moveDown(1);
+  }
+
+  doc.addPage();
+  doc.fontSize(16).text("Statistics");
+  doc.moveDown(0.5);
+  doc.fontSize(11).text(`Changes: ${report.stats.totalChanges}`);
+  doc.text(`Tasks completed within this sprint: ${report.stats.totalTasksCompletedInRange}`);
+  doc.moveDown(0.5);
+  if (report.stats.changesByAuthor.length > 0) {
+    doc.fontSize(12).text("By author:");
+    for (const { author, count } of report.stats.changesByAuthor) {
+      doc.fontSize(10).text(`${author.name} <${author.email}>: ${count} change${count === 1 ? "" : "s"}`);
+    }
+  }
+
+  doc.end();
+  return done;
+}
diff --git a/packages/core/src/sprint-report.test.ts b/packages/core/src/sprint-report.test.ts
new file mode 100644
index 0000000..a8c74da
--- /dev/null
+++ b/packages/core/src/sprint-report.test.ts
@@ -0,0 +1,171 @@
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import simpleGit, { type SimpleGit } from "simple-git";
+import { afterEach, describe, expect, it } from "vitest";
+import { buildSprintReport } from "./sprint-report.js";
+
+const temporaryRoots: string[] = [];
+
+async function temporaryRoot(): Promise<string> {
+  const root = await mkdtemp(path.join(os.tmpdir(), "openspec-sprint-report-"));
+  temporaryRoots.push(root);
+  return root;
+}
+
+afterEach(async () => {
+  await Promise.all(temporaryRoots.splice(0).map((root) => rm(root, { recursive: true, force: true })));
+});
+
+async function initRepo(root: string): Promise<SimpleGit> {
+  const git = simpleGit(root);
+  await git.init();
+  await git.addConfig("user.email", "test@example.com");
+  await git.addConfig("user.name", "Test User");
+  return git;
+}
+
+async function commitAllAs(
+  root: string,
+  message: string,
+  isoDate: string,
+  authorName: string,
+  authorEmail: string,
+): Promise<void> {
+  const git = simpleGit(root).env({
+    GIT_AUTHOR_DATE: isoDate,
+    GIT_COMMITTER_DATE: isoDate,
+    GIT_AUTHOR_NAME: authorName,
+    GIT_AUTHOR_EMAIL: authorEmail,
+    GIT_COMMITTER_NAME: authorName,
+    GIT_COMMITTER_EMAIL: authorEmail,
+  });
+  await git.add(".");
+  await git.commit(message);
+}
+
+async function writeChangeFiles(root: string, changeName: string, tasksContent: string): Promise<string> {
+  const changeDir = path.join(root, "openspec", "changes", changeName);
+  await mkdir(changeDir, { recursive: true });
+  await writeFile(
+    path.join(changeDir, "proposal.md"),
+    "## Why\n\nThis is the reason this change exists, in enough detail to summarize.\n\n## What Changes\n\n- Something else entirely, not part of the summary.\n",
+  );
+  await writeFile(path.join(changeDir, "design.md"), "");
+  await writeFile(path.join(changeDir, "tasks.md"), tasksContent);
+  return changeDir;
+}
+
+describe("buildSprintReport", () => {
+  it("aggregates authorship, task counts, and a plain-text Why summary per change", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    const changeDir = await writeChangeFiles(root, "change-one", "- [ ] first\n- [ ] second\n");
+    await commitAllAs(root, "create change-one", "2026-01-01T00:00:00Z", "Alice", "alice@example.com");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [x] first\n- [ ] second\n");
+    await commitAllAs(root, "complete first", "2026-01-05T00:00:00Z", "Alice", "alice@example.com");
+
+    const report = await buildSprintReport(
+      root,
+      [{ changeName: "change-one", archived: false }],
+      "2026-01-01T00:00:00.000Z",
+      "2026-01-10T00:00:00.000Z",
+    );
+
+    expect(report.entries).toHaveLength(1);
+    const entry = report.entries[0];
+    expect(entry?.changeName).toBe("change-one");
+    expect(entry?.completedTaskCount).toBe(1);
+    expect(entry?.totalTaskCount).toBe(2);
+    expect(entry?.tasksCompletedInRange).toBe(1);
+    expect(entry?.primaryAuthor).toEqual({
+      name: "Alice",
+      email: "alice@example.com",
+      date: "2026-01-05T00:00:00.000Z",
+    });
+    expect(entry?.whySummary).toBe("This is the reason this change exists, in enough detail to summarize.");
+    expect(entry?.whySummary).not.toContain("Something else entirely");
+  });
+
+  it("only counts tasks completed within the requested range toward the sprint stats", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    const changeDir = await writeChangeFiles(root, "change-one", "- [ ] a\n- [ ] b\n");
+    await commitAllAs(root, "create", "2026-01-01T00:00:00Z", "Alice", "alice@example.com");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [x] a\n- [ ] b\n");
+    await commitAllAs(root, "complete a inside range", "2026-01-05T00:00:00Z", "Alice", "alice@example.com");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [x] a\n- [x] b\n");
+    await commitAllAs(root, "complete b outside range", "2026-02-15T00:00:00Z", "Alice", "alice@example.com");
+
+    const report = await buildSprintReport(
+      root,
+      [{ changeName: "change-one", archived: false }],
+      "2026-01-01T00:00:00.000Z",
+      "2026-01-10T00:00:00.000Z",
+    );
+
+    // Both tasks are done (change still appears with its real totals)...
+    expect(report.entries[0]?.completedTaskCount).toBe(2);
+    // ...but only the one completed inside the range counts toward the sprint.
+    expect(report.entries[0]?.tasksCompletedInRange).toBe(1);
+    expect(report.stats.totalTasksCompletedInRange).toBe(1);
+  });
+
+  it("keeps a selected change in the report even if it started before the range", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    await writeChangeFiles(root, "old-change", "- [ ] a\n");
+    await commitAllAs(root, "create", "2025-01-01T00:00:00Z", "Alice", "alice@example.com");
+
+    const report = await buildSprintReport(
+      root,
+      [{ changeName: "old-change", archived: false }],
+      "2026-01-01T00:00:00.000Z",
+      "2026-01-10T00:00:00.000Z",
+    );
+
+    expect(report.entries).toHaveLength(1);
+    expect(report.entries[0]?.changeName).toBe("old-change");
+  });
+
+  it("ranks changesByAuthor by count, descending", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+    await writeChangeFiles(root, "change-a", "- [ ] a\n");
+    await commitAllAs(root, "create a", "2026-01-01T00:00:00Z", "Alice", "alice@example.com");
+    await writeChangeFiles(root, "change-b", "- [ ] b\n");
+    await commitAllAs(root, "create b", "2026-01-02T00:00:00Z", "Bob", "bob@example.com");
+    await writeChangeFiles(root, "change-c", "- [ ] c\n");
+    await commitAllAs(root, "create c", "2026-01-03T00:00:00Z", "Alice", "alice@example.com");
+
+    const report = await buildSprintReport(
+      root,
+      [
+        { changeName: "change-a", archived: false },
+        { changeName: "change-b", archived: false },
+        { changeName: "change-c", archived: false },
+      ],
+      "2026-01-01T00:00:00.000Z",
+      "2026-01-10T00:00:00.000Z",
+    );
+
+    expect(report.stats.totalChanges).toBe(3);
+    // The stored `author` snapshot per entry is from the first change
+    // processed for that author (change-a for Alice, in entry order) —
+    // only the count accumulates across later changes by the same author.
+    expect(report.stats.changesByAuthor).toEqual([
+      { author: { name: "Alice", email: "alice@example.com", date: "2026-01-01T00:00:00.000Z" }, count: 2 },
+      { author: { name: "Bob", email: "bob@example.com", date: "2026-01-02T00:00:00.000Z" }, count: 1 },
+    ]);
+  });
+
+  it("returns an empty report for no entries", async () => {
+    const root = await temporaryRoot();
+    await initRepo(root);
+
+    const report = await buildSprintReport(root, [], "2026-01-01T00:00:00.000Z", "2026-01-10T00:00:00.000Z");
+
+    expect(report.entries).toEqual([]);
+    expect(report.stats).toEqual({ totalChanges: 0, totalTasksCompletedInRange: 0, changesByAuthor: [] });
+  });
+});
diff --git a/packages/core/src/sprint-report.ts b/packages/core/src/sprint-report.ts
new file mode 100644
index 0000000..2834f6e
--- /dev/null
+++ b/packages/core/src/sprint-report.ts
@@ -0,0 +1,142 @@
+// Sprint summary report data (see
+// openspec/changes/add-sprint-report-pdf/design.md): reuses
+// getChangeTimeline/getChangeAuthorship unchanged for per-change data —
+// this module only aggregates, it does not add any new git primitives.
+
+import {
+  getChangeAuthorship,
+  getChangeTimeline,
+  type ChangeTimelineRequestEntry,
+  type CommitAuthor,
+} from "./change-timeline.js";
+import { discoverOpenSpecWorkspace } from "./workbench.js";
+
+export interface SprintReportEntry {
+  changeName: string;
+  archived: boolean;
+  createdDate: string | null;
+  archivedDate: string | null;
+  /** Plain-text excerpt of proposal.md's "## Why" section (markdown
+   * syntax stripped, truncated) — not the rendered HTML/React output
+   * `renderMarkdown` produces, since PDF rendering needs plain text. */
+  whySummary: string;
+  completedTaskCount: number;
+  totalTaskCount: number;
+  /** Tasks whose completion date falls within `[rangeStart, rangeEnd]`
+   * — see design.md's date-range semantics: the range filters which
+   * tasks count toward the sprint's stats, not which changes appear. */
+  tasksCompletedInRange: number;
+  primaryAuthor: CommitAuthor | null;
+  contributors: CommitAuthor[];
+}
+
+export interface SprintReportAuthorStat {
+  author: CommitAuthor;
+  count: number;
+}
+
+export interface SprintReportStats {
+  totalChanges: number;
+  totalTasksCompletedInRange: number;
+  /** Sorted by count descending. Keyed by `primaryAuthor.email` — a
+   * change with no determinable primary author contributes to no
+   * author's count (not silently attributed to anyone). */
+  changesByAuthor: SprintReportAuthorStat[];
+}
+
+export interface SprintReport {
+  rangeStart: string;
+  rangeEnd: string;
+  entries: SprintReportEntry[];
+  stats: SprintReportStats;
+}
+
+const WHY_SECTION_RE = /##\s*Why\s*\n+([\s\S]*?)(?:\n##\s|\s*$)/i;
+const MAX_WHY_SUMMARY_LENGTH = 400;
+
+/** Best-effort plain-text summary of a proposal's "## Why" section (or
+ * the whole document if no such heading exists) — strips the most
+ * common markdown syntax (code spans, bold, links) rather than parsing
+ * a full AST, since a report excerpt does not need perfect fidelity. */
+function extractWhySummary(proposalMarkdown: string): string {
+  const match = proposalMarkdown.match(WHY_SECTION_RE);
+  const raw = (match?.[1] ?? proposalMarkdown).trim();
+  const plain = raw
+    .replaceAll(/`([^`]+)`/g, "$1")
+    .replaceAll(/\*\*([^*]+)\*\*/g, "$1")
+    .replaceAll(/\[([^\]]+)\]\([^)]+\)/g, "$1")
+    .replaceAll(/\s+/g, " ")
+    .trim();
+  if (plain.length <= MAX_WHY_SUMMARY_LENGTH) return plain;
+  return `${plain.slice(0, MAX_WHY_SUMMARY_LENGTH).trimEnd()}…`;
+}
+
+function isWithinRange(date: string | null, rangeStartMs: number, rangeEndMs: number): boolean {
+  if (!date) return false;
+  const timestamp = new Date(date).getTime();
+  return timestamp >= rangeStartMs && timestamp <= rangeEndMs;
+}
+
+export async function buildSprintReport(
+  workspaceRoot: string,
+  entries: ChangeTimelineRequestEntry[],
+  rangeStart: string,
+  rangeEnd: string,
+): Promise<SprintReport> {
+  const rangeStartMs = new Date(rangeStart).getTime();
+  const rangeEndMs = new Date(rangeEnd).getTime();
+  const workspace = await discoverOpenSpecWorkspace(workspaceRoot);
+
+  const reportEntries = await Promise.all(
+    entries.map(async (entry): Promise<SprintReportEntry> => {
+      const change = (entry.archived ? workspace.archivedChanges : workspace.changes).find(
+        (c) => c.name === entry.changeName,
+      );
+      const [timeline, authorship] = await Promise.all([
+        getChangeTimeline(workspaceRoot, entry.changeName, entry.archived),
+        change
+          ? getChangeAuthorship(workspaceRoot, change.path)
+          : Promise.resolve({ primaryAuthor: null, contributors: [] }),
+      ]);
+      const tasksCompletedInRange = timeline.tasks.filter((task) =>
+        isWithinRange(task.date, rangeStartMs, rangeEndMs),
+      ).length;
+
+      return {
+        changeName: timeline.changeName,
+        archived: timeline.archived,
+        createdDate: timeline.createdDate,
+        archivedDate: timeline.archivedDate,
+        whySummary: extractWhySummary(timeline.proposal),
+        completedTaskCount: timeline.tasks.filter((task) => task.done).length,
+        totalTaskCount: timeline.tasks.length,
+        tasksCompletedInRange,
+        primaryAuthor: authorship.primaryAuthor,
+        contributors: authorship.contributors,
+      };
+    }),
+  );
+
+  const authorCounts = new Map<string, SprintReportAuthorStat>();
+  for (const entry of reportEntries) {
+    if (!entry.primaryAuthor) continue;
+    const key = entry.primaryAuthor.email;
+    const existing = authorCounts.get(key);
+    if (existing) {
+      existing.count += 1;
+    } else {
+      authorCounts.set(key, { author: entry.primaryAuthor, count: 1 });
+    }
+  }
+
+  return {
+    rangeStart,
+    rangeEnd,
+    entries: reportEntries,
+    stats: {
+      totalChanges: reportEntries.length,
+      totalTasksCompletedInRange: reportEntries.reduce((sum, entry) => sum + entry.tasksCompletedInRange, 0),
+      changesByAuthor: [...authorCounts.values()].sort((a, b) => b.count - a.count),
+    },
+  };
+}
diff --git a/packages/server/CHANGELOG.md b/packages/server/CHANGELOG.md
index 669a0c7..2a620b5 100644
--- a/packages/server/CHANGELOG.md
+++ b/packages/server/CHANGELOG.md
@@ -1,5 +1,20 @@
 # @openspec-ui/server
 
+## 1.10.0
+
+### Minor Changes
+
+- Add a downloadable sprint summary PDF report: for a user-picked date
+  range and set of changes, who authored each one (from git), what it
+  was, task completion, plus aggregate statistics (total changes, tasks
+  completed in range, a per-author breakdown). New "Sprint report" mode
+  in the standalone Timeline tab.
+
+### Patch Changes
+
+- Updated dependencies
+  - @openspec-ui/core@0.29.0
+
 ## 1.9.0
 
 ### Minor Changes
diff --git a/packages/server/package.json b/packages/server/package.json
index 69c088d..82294ca 100644
--- a/packages/server/package.json
+++ b/packages/server/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@openspec-ui/server",
   "private": true,
-  "version": "1.9.0",
+  "version": "1.10.0",
   "type": "module",
   "main": "src/index.ts",
   "dependencies": {
diff --git a/packages/server/src/rest.ts b/packages/server/src/rest.ts
index cc98071..dfa9dc0 100644
--- a/packages/server/src/rest.ts
+++ b/packages/server/src/rest.ts
@@ -13,6 +13,7 @@ import {
   TemplateAlreadyExistsError,
   UnknownBuiltInTemplateError,
   UnknownProjectTemplateError,
+  buildSprintReport,
   createChange,
   customizeTemplate,
   deleteProjectTemplate,
@@ -28,6 +29,7 @@ import {
   listSpecs,
   readArchivedChangeTasksTemplate,
   readChangeEditorDocument,
+  renderSprintReportPdf,
   renderTemplate,
   saveChangeEditorDocument,
   showChange,
@@ -69,6 +71,14 @@ function sendJson(res: ServerResponse, statusCode: number, body: unknown): void
   res.end(JSON.stringify(body));
 }
 
+function sendPdf(res: ServerResponse, buffer: Buffer, filename: string): void {
+  res.writeHead(200, {
+    "content-type": "application/pdf",
+    "content-disposition": `attachment; filename="${filename}"`,
+  });
+  res.end(buffer);
+}
+
 function sendBodyError(res: ServerResponse, error: unknown): void {
   if (error instanceof PayloadTooLargeError) {
     sendJson(res, 413, { error: "request payload is too large" });
@@ -149,6 +159,20 @@ function isChangeTimelinesRequest(value: unknown): value is ChangeTimelinesReque
   return value.entries.every(isChangeTimelineRequestEntry);
 }
 
+interface SprintReportRequest {
+  cwd: string;
+  entries: ChangeTimelineRequestEntry[];
+  rangeStart: string;
+  rangeEnd: string;
+}
+
+function isSprintReportRequest(value: unknown): value is SprintReportRequest {
+  if (!isObjectRecord(value)) return false;
+  if (!isNonEmptyString(value.cwd) || !Array.isArray(value.entries)) return false;
+  if (!isNonEmptyString(value.rangeStart) || !isNonEmptyString(value.rangeEnd)) return false;
+  return value.entries.every(isChangeTimelineRequestEntry);
+}
+
 interface ChangeEditorSaveRequest extends ChangeEditorReadRequest {
   revision: string;
   files: {
@@ -422,6 +446,32 @@ export async function handleChangeTimelinesRequest(req: IncomingMessage, res: Se
   }
 }
 
+export async function handleSprintReportRequest(req: IncomingMessage, res: ServerResponse, policy: RestRequestPolicy): Promise<void> {
+  let parsed: unknown;
+  try {
+    parsed = await readJsonBody(req, policy.maxPayloadBytes);
+  } catch (error) {
+    sendBodyError(res, error);
+    return;
+  }
+
+  if (!isSprintReportRequest(parsed)) {
+    sendJson(res, 400, { error: "body must contain cwd, a valid entries array, rangeStart, and rangeEnd" });
+    return;
+  }
+  if (!authorizeCwd(res, policy, parsed.cwd)) return;
+
+  try {
+    const report = await buildSprintReport(parsed.cwd, parsed.entries, parsed.rangeStart, parsed.rangeEnd);
+    const pdf = await renderSprintReportPdf(report);
+    const filename = `sprint-report-${parsed.rangeStart.slice(0, 10)}-${parsed.rangeEnd.slice(0, 10)}.pdf`;
+    sendPdf(res, pdf, filename);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    sendJson(res, 500, { error: `failed to generate sprint report: ${message}` });
+  }
+}
+
 export async function handleArchiveTasksTemplateRequest(req: IncomingMessage, res: ServerResponse, policy: RestRequestPolicy): Promise<void> {
   let parsed: unknown;
   try {
diff --git a/packages/server/src/server.test.ts b/packages/server/src/server.test.ts
index d93349f..716761a 100644
--- a/packages/server/src/server.test.ts
+++ b/packages/server/src/server.test.ts
@@ -511,6 +511,44 @@ describe("server — REST /api/status", () => {
     expect(response.status).toBe(400);
   });
 
+  it("generates a downloadable sprint report PDF", async () => {
+    const cwd = await createTempWorkspace();
+    const changeDir = path.join(cwd, "openspec", "changes", "my-change");
+    await mkdir(changeDir, { recursive: true });
+    await writeFile(path.join(changeDir, "proposal.md"), "## Why\n\nBecause reasons.\n");
+    await writeFile(path.join(changeDir, "tasks.md"), "- [ ] todo\n");
+
+    const response = await fetch(`${baseUrl}/api/sprint-report`, {
+      method: "POST",
+      headers: JSON_HEADERS,
+      body: JSON.stringify({
+        cwd,
+        entries: [{ changeName: "my-change", archived: false }],
+        rangeStart: "2026-01-01T00:00:00.000Z",
+        rangeEnd: "2026-01-14T00:00:00.000Z",
+      }),
+    });
+    const buffer = Buffer.from(await response.arrayBuffer());
+
+    expect(response.status).toBe(200);
+    expect(response.headers.get("content-type")).toBe("application/pdf");
+    expect(response.headers.get("content-disposition")).toContain("attachment");
+    expect(response.headers.get("content-disposition")).toContain("sprint-report-2026-01-01-2026-01-14.pdf");
+    expect(buffer.subarray(0, 5).toString("latin1")).toBe("%PDF-");
+  });
+
+  it("rejects a sprint-report request missing the date range", async () => {
+    const cwd = await createTempWorkspace();
+
+    const response = await fetch(`${baseUrl}/api/sprint-report`, {
+      method: "POST",
+      headers: JSON_HEADERS,
+      body: JSON.stringify({ cwd, entries: [] }),
+    });
+
+    expect(response.status).toBe(400);
+  });
+
   it("lists the seed built-in template plus a real project-level fixture", async () => {
     const cwd = await createTempWorkspace();
     const projectDir = path.join(cwd, "openspec", "templates", "my-template");
diff --git a/packages/server/src/server.ts b/packages/server/src/server.ts
index 3c04417..e0dc791 100644
--- a/packages/server/src/server.ts
+++ b/packages/server/src/server.ts
@@ -18,6 +18,7 @@ import {
   handleChangeTimelinesRequest,
   handleOpenSpecInitRequest,
   handleOverviewRequest,
+  handleSprintReportRequest,
   handleStatusJsonRequest,
   handleStatusRequest,
   handleTemplatesCustomizeRequest,
@@ -173,6 +174,10 @@ export function createServer(options: ServerOptions): OpenSpecUiServer {
       void handleChangeTimelinesRequest(req, res, requestPolicy);
       return;
     }
+    if (req.method === "POST" && req.url === "/api/sprint-report") {
+      void handleSprintReportRequest(req, res, requestPolicy);
+      return;
+    }
     if (req.method === "POST" && req.url === "/api/templates/list") {
       void handleTemplatesListRequest(req, res, requestPolicy);
       return;
diff --git a/packages/webui/CHANGELOG.md b/packages/webui/CHANGELOG.md
index d5e4474..4385d66 100644
--- a/packages/webui/CHANGELOG.md
+++ b/packages/webui/CHANGELOG.md
@@ -1,5 +1,20 @@
 # @openspec-ui/webui
 
+## 1.15.0
+
+### Minor Changes
+
+- Add a downloadable sprint summary PDF report: for a user-picked date
+  range and set of changes, who authored each one (from git), what it
+  was, task completion, plus aggregate statistics (total changes, tasks
+  completed in range, a per-author breakdown). New "Sprint report" mode
+  in the standalone Timeline tab.
+
+### Patch Changes
+
+- Updated dependencies
+  - @openspec-ui/core@0.29.0
+
 ## 1.14.0
 
 ### Minor Changes
diff --git a/packages/webui/package.json b/packages/webui/package.json
index c7b2d0f..509125d 100644
--- a/packages/webui/package.json
+++ b/packages/webui/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@openspec-ui/webui",
   "private": true,
-  "version": "1.14.0",
+  "version": "1.15.0",
   "type": "module",
   "main": "src/index.ts",
   "dependencies": {
diff --git a/packages/webui/src/sprint-report-client.test.ts b/packages/webui/src/sprint-report-client.test.ts
new file mode 100644
index 0000000..48a6a30
--- /dev/null
+++ b/packages/webui/src/sprint-report-client.test.ts
@@ -0,0 +1,39 @@
+import { describe, expect, it, vi } from "vitest";
+import { fetchSprintReportPdf } from "./sprint-report-client.js";
+
+describe("fetchSprintReportPdf", () => {
+  it("posts cwd, entries, and the date range, and returns the response body as a Blob", async () => {
+    const pdfBlob = new Blob([new Uint8Array([1, 2, 3])], { type: "application/pdf" });
+    const request = vi.fn().mockResolvedValue(new Response(pdfBlob, { status: 200 }));
+    const entries = [{ changeName: "my-change", archived: false }];
+
+    const result = await fetchSprintReportPdf(
+      request,
+      "/workspace",
+      entries,
+      "2026-01-01T00:00:00.000Z",
+      "2026-01-14T00:00:00.000Z",
+    );
+
+    expect(result).toBeInstanceOf(Blob);
+    expect(request.mock.calls[0]?.[0]).toBe("/api/sprint-report");
+    const requestInit = request.mock.calls[0]?.[1];
+    if (!requestInit) throw new Error("sprint-report request was not captured");
+    expect(JSON.parse(requestInit.body as string)).toEqual({
+      cwd: "/workspace",
+      entries,
+      rangeStart: "2026-01-01T00:00:00.000Z",
+      rangeEnd: "2026-01-14T00:00:00.000Z",
+    });
+  });
+
+  it("throws with the server-provided error message on failure", async () => {
+    const request = vi.fn().mockResolvedValue(
+      new Response(JSON.stringify({ error: "invalid date range" }), { status: 400 }),
+    );
+
+    await expect(
+      fetchSprintReportPdf(request, "/workspace", [], "bad", "bad"),
+    ).rejects.toThrow("invalid date range");
+  });
+});
diff --git a/packages/webui/src/sprint-report-client.ts b/packages/webui/src/sprint-report-client.ts
new file mode 100644
index 0000000..3b53d28
--- /dev/null
+++ b/packages/webui/src/sprint-report-client.ts
@@ -0,0 +1,31 @@
+export interface SprintReportEntry {
+  changeName: string;
+  archived: boolean;
+}
+
+export type SprintReportRequest = (pathname: string, init: RequestInit) => Promise<Response>;
+
+async function responseError(response: Response): Promise<string> {
+  const payload = (await response.json().catch(() => ({}))) as { error?: string };
+  return payload.error ?? `${response.status} ${response.statusText}`;
+}
+
+/** Fetches the sprint report PDF as a `Blob` — triggering the actual
+ * browser download (an object URL + a temporary `<a download>`) is left
+ * to the caller, since that part is DOM-specific and not meaningfully
+ * unit-testable the way this network call is. */
+export async function fetchSprintReportPdf(
+  request: SprintReportRequest,
+  cwd: string,
+  entries: SprintReportEntry[],
+  rangeStart: string,
+  rangeEnd: string,
+): Promise<Blob> {
+  const response = await request("/api/sprint-report", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({ cwd, entries, rangeStart, rangeEnd }),
+  });
+  if (!response.ok) throw new Error(await responseError(response));
+  return response.blob();
+}
diff --git a/packages/webui/src/standalone-entry.tsx b/packages/webui/src/standalone-entry.tsx
index a098183..122b262 100644
--- a/packages/webui/src/standalone-entry.tsx
+++ b/packages/webui/src/standalone-entry.tsx
@@ -25,6 +25,7 @@ import {
   type ChangeEditorFiles,
 } from "./change-editor-client.js";
 import { loadChangeTimeline, loadChangeTimelines, type ChangeTimeline, type ChangeTimelineEntry } from "./change-timeline-client.js";
+import { fetchSprintReportPdf } from "./sprint-report-client.js";
 import { MultiChangeTimelineView } from "./components/MultiChangeTimelineView.js";
 import {
   customizeTemplate as customizeTemplateApi,
@@ -210,7 +211,9 @@ function StandaloneApp() {
   const [timeline, setTimeline] = useState<ChangeTimeline | null>(null);
   const [timelineLoading, setTimelineLoading] = useState(false);
   const [timelineMessage, setTimelineMessage] = useState<string | null>(null);
-  const [timelineMode, setTimelineMode] = useState<"single" | "multi">("single");
+  const [timelineMode, setTimelineMode] = useState<"single" | "multi" | "sprint">("single");
+  const [sprintReportLoading, setSprintReportLoading] = useState(false);
+  const [sprintReportMessage, setSprintReportMessage] = useState<string | null>(null);
   const [staleThresholdDays, setStaleThresholdDays] = useState(DEFAULT_STALE_TASK_THRESHOLD_DAYS);
   const [multiRangeStart, setMultiRangeStart] = useState("");
   const [multiRangeEnd, setMultiRangeEnd] = useState("");
@@ -421,6 +424,40 @@ function StandaloneApp() {
     }
   }
 
+  async function downloadSprintReport() {
+    if (cwd.trim().length === 0) {
+      setSprintReportMessage("Enter workspace root first.");
+      return;
+    }
+    if (multiRangeStart.trim().length === 0 || multiRangeEnd.trim().length === 0) {
+      setSprintReportMessage("Select a date range first.");
+      return;
+    }
+    const entries = multiSelection.map(decodeSelection).filter((entry): entry is ChangeTimelineEntry => Boolean(entry));
+    if (entries.length === 0) {
+      setSprintReportMessage("Select at least one change first.");
+      return;
+    }
+    setSprintReportLoading(true);
+    setSprintReportMessage(null);
+    try {
+      const rangeStart = new Date(multiRangeStart).toISOString();
+      const rangeEnd = new Date(multiRangeEnd).toISOString();
+      const pdfBlob = await fetchSprintReportPdf(apiFetch, cwd, entries, rangeStart, rangeEnd);
+      const objectUrl = URL.createObjectURL(pdfBlob);
+      const link = document.createElement("a");
+      link.href = objectUrl;
+      link.download = `sprint-report-${multiRangeStart}-${multiRangeEnd}.pdf`;
+      link.click();
+      URL.revokeObjectURL(objectUrl);
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error);
+      setSprintReportMessage(`Generate failed: ${message}`);
+    } finally {
+      setSprintReportLoading(false);
+    }
+  }
+
   async function handleInsertTasksTemplate() {
     if (cwd.trim().length === 0 || editorChangeName.trim().length === 0) {
       setArchivedTemplateMessage("Load a non-archived change first.");
@@ -1186,6 +1223,13 @@ function StandaloneApp() {
           >
             Compare changes
           </button>
+          <button
+            type="button"
+            className={timelineMode === "sprint" ? "is-active" : ""}
+            onClick={() => setTimelineMode("sprint")}
+          >
+            Sprint report
+          </button>
         </div>
 
         {timelineMode === "single" ? (
@@ -1227,7 +1271,7 @@ function StandaloneApp() {
             {timelineMessage ? <p className="openspec-shell-note">{timelineMessage}</p> : null}
             {timeline ? <ChangeTimelineView timeline={timeline} staleThresholdDays={staleThresholdDays} /> : null}
           </Fragment>
-        ) : (
+        ) : timelineMode === "multi" ? (
           <Fragment>
             <div className="openspec-shell-grid">
               <label className="openspec-shell-field">
@@ -1285,6 +1329,57 @@ function StandaloneApp() {
               />
             ) : null}
           </Fragment>
+        ) : (
+          <Fragment>
+            <div className="openspec-shell-grid">
+              <label className="openspec-shell-field">
+                Sprint start
+                <input
+                  type="date"
+                  aria-label="Sprint report range start"
+                  value={multiRangeStart}
+                  onChange={(e) => setMultiRangeStart(e.target.value)}
+                />
+              </label>
+              <label className="openspec-shell-field">
+                Sprint end
+                <input
+                  type="date"
+                  aria-label="Sprint report range end"
+                  value={multiRangeEnd}
+                  onChange={(e) => setMultiRangeEnd(e.target.value)}
+                />
+              </label>
+            </div>
+            <label className="openspec-shell-field">
+              Changes in this sprint
+              <select
+                aria-label="Changes in this sprint"
+                multiple
+                value={multiSelection}
+                onChange={(e) => setMultiSelection(Array.from(e.target.selectedOptions, (o) => o.value))}
+                disabled={(overview?.changes.length ?? 0) + (overview?.archivedChanges.length ?? 0) === 0}
+              >
+                {(overview?.changes ?? []).map((change) => (
+                  <option key={`active:${change.name}`} value={`active:${change.name}`}>{change.name}</option>
+                ))}
+                {(overview?.archivedChanges ?? []).map((name) => (
+                  <option key={`archived:${name}`} value={`archived:${name}`}>{name} (archived)</option>
+                ))}
+              </select>
+            </label>
+            <div className="openspec-ai-panel-controls">
+              <button
+                type="button"
+                onClick={() => void downloadSprintReport()}
+                disabled={sprintReportLoading || multiSelection.length === 0}
+              >
+                {sprintReportLoading ? "Generating..." : "Download PDF"}
+              </button>
+            </div>
+
+            {sprintReportMessage ? <p className="openspec-shell-note">{sprintReportMessage}</p> : null}
+          </Fragment>
         )}
       </section>
       </TabPanel>