feat: sprints with burndown and carry-over

Plan sprints with dates and a goal, run one at a time per project, and
put tickets in them from the ticket page. The Sprints tab follows the one
under way with its progress and a burndown in tickets or points against
the ideal line. Closing a sprint sends what was left to the next one or
back to the backlog; the board can be filtered by sprint.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/api/tracker/application/src/index.ts

@@ -10,5 +10,6 @@ export * from './lib/workflows.service';
 export * from './lib/notifications.service';
 export * from './lib/notifications';
 export * from './lib/saved-filters.service';
+export * from './lib/sprints.service';
 export * from './lib/saved-filters/saved-filters';
 export * from './lib/tracker-application.module';

libs/api/tracker/application/src/lib/analytics/analytics.spec.ts

@@ -4,10 +4,13 @@ import {
   ReleaseReadModel,
   ReleaseStatus,
   StatusCategory as C,
+  SprintReadModel,
+  SprintStatus,
 } from '@task-stream/api/tracker/domain';
 import {
   computeProjectAnalytics,
   computeReleaseBurnup,
+  computeSprintBurndown,
   weekOf,
 } from './analytics';
 
@@ -182,3 +185,62 @@ describe('release burnup', () => {
     expect(at(burnup.done, '2026-10-14')).toBe(2);
   });
 });
+
+describe('sprint burndown', () => {
+  const sprint = {
+    id: 's1',
+    projectId: 'p',
+    startDate: '2026-10-12',
+    endDate: '2026-10-16',
+    status: SprintStatus.ACTIVE,
+    closedAt: null,
+  } as SprintReadModel;
+  const into = (issueId: string, at: string): IssueTimelineEntry => ({
+    id: `${issueId}:${++seq}`,
+    issueId,
+    projectId: 'p',
+    at,
+    kind: 'sprint',
+    sprintId: 's1',
+  });
+  // X (3 points) and Y (5) committed on Monday; Z (2) added on Tuesday.
+  // X done on Tuesday, Y cancelled on Wednesday. Today is Wednesday noon.
+  const issues = [
+    { ...issue('x', '2026-10-01T09:00:00Z', 'DONE', C.DONE), storyPoints: 3 },
+    {
+      ...issue('y', '2026-10-01T09:00:00Z', 'CANCELLED', C.CANCELLED),
+      storyPoints: 5,
+    },
+    { ...issue('z', '2026-10-01T09:00:00Z', 'TODO', C.TODO), storyPoints: 2 },
+  ] as IssueReadModel[];
+  const timeline = [
+    step('x', '2026-10-01T09:00:00Z', 'TODO', C.TODO),
+    step('y', '2026-10-01T09:00:00Z', 'TODO', C.TODO),
+    step('z', '2026-10-01T09:00:00Z', 'TODO', C.TODO),
+    into('x', '2026-10-12T08:00:00Z'),
+    into('y', '2026-10-12T08:00:00Z'),
+    into('z', '2026-10-13T10:00:00Z'),
+    step('x', '2026-10-13T16:00:00Z', 'DONE', C.DONE),
+    step('y', '2026-10-14T09:00:00Z', 'CANCELLED', C.CANCELLED),
+  ];
+
+  it('counts open tickets and points per day, and leaves the future blank', () => {
+    const burndown = computeSprintBurndown({
+      sprint,
+      issues,
+      timeline,
+      now: new Date('2026-10-14T12:00:00Z'),
+    });
+    expect(burndown.dates).toEqual([
+      '2026-10-12',
+      '2026-10-13',
+      '2026-10-14',
+      '2026-10-15',
+      '2026-10-16',
+    ]);
+    expect(burndown.scope).toEqual([2, 3, 2, null, null]);
+    expect(burndown.remaining).toEqual([2, 2, 1, null, null]);
+    expect(burndown.remainingPoints).toEqual([8, 7, 2, null, null]);
+    expect(burndown.ideal).toEqual([2, 1.5, 1, 0.5, 0]);
+  });
+});

libs/api/tracker/application/src/lib/analytics/analytics.ts

@@ -5,6 +5,8 @@ import {
   ProjectAnalyticsReadModel,
   ReleaseBurnupReadModel,
   ReleaseReadModel,
+  SprintBurndownReadModel,
+  SprintReadModel,
   StatusCategory,
   UserRefReadModel,
 } from '@task-stream/api/tracker/domain';
@@ -313,3 +315,85 @@ export function computeReleaseBurnup(
     done,
   };
 }
+
+export interface SprintBurndownInput {
+  sprint: SprintReadModel;
+  issues: IssueReadModel[];
+  timeline: IssueTimelineEntry[];
+  now: Date;
+}
+
+/**
+ * Per day of the sprint (start to end date, UTC): tickets in it, how many
+ * are still open and their points, and the ideal line. Points are today's
+ * estimates (their history is not kept). Days after today, or after the
+ * sprint closed, are null.
+ */
+export function computeSprintBurndown(
+  input: SprintBurndownInput,
+): SprintBurndownReadModel {
+  const { sprint } = input;
+  const steps = stepsByIssue(input.issues, input.timeline);
+  const points = new Map(input.issues.map((i) => [i.id, i.storyPoints ?? 0]));
+  const membership = new Map<
+    string,
+    { at: number; sprintId: string | null }[]
+  >();
+  for (const entry of input.timeline) {
+    if (entry.kind !== 'sprint') continue;
+    const list = membership.get(entry.issueId) ?? [];
+    list.push({ at: Date.parse(entry.at), sprintId: entry.sprintId ?? null });
+    membership.set(entry.issueId, list);
+  }
+  for (const list of membership.values()) list.sort((a, b) => a.at - b.at);
+
+  const start = Date.parse(`${sprint.startDate}T00:00:00Z`);
+  const end = Date.parse(`${sprint.endDate}T00:00:00Z`);
+  const last = Math.min(
+    sprint.closedAt ? Date.parse(sprint.closedAt) : input.now.getTime(),
+    end + DAY - 1,
+  );
+  const dayEnds = days(start, end + DAY - 1);
+  const scope: (number | null)[] = [];
+  const remaining: (number | null)[] = [];
+  const remainingPoints: (number | null)[] = [];
+  for (const time of dayEnds) {
+    // The day under way counts up to now; the ones to come are unknown.
+    const at = Math.min(time, last);
+    if (time - DAY >= last) {
+      scope.push(null);
+      remaining.push(null);
+      remainingPoints.push(null);
+      continue;
+    }
+    let inScope = 0;
+    let open = 0;
+    let openPoints = 0;
+    for (const [issueId, list] of membership) {
+      const current = list.filter((m) => m.at <= at).at(-1);
+      if (current?.sprintId !== sprint.id) continue;
+      const step = stepAt(steps.get(issueId) ?? [], at);
+      if (!step || step.category === StatusCategory.CANCELLED) continue;
+      inScope++;
+      if (step.category !== StatusCategory.DONE) {
+        open++;
+        openPoints += points.get(issueId) ?? 0;
+      }
+    }
+    scope.push(inScope);
+    remaining.push(open);
+    remainingPoints.push(openPoints);
+  }
+  const first = remaining[0] ?? 0;
+  const span = Math.max(dayEnds.length - 1, 1);
+  return {
+    sprintId: sprint.id,
+    dates: dayEnds.map(dayOf),
+    scope,
+    remaining,
+    remainingPoints,
+    ideal: dayEnds.map(
+      (_, i) => Math.round((first * (span - i) * 100) / span) / 100,
+    ),
+  };
+}

libs/api/tracker/application/src/lib/changes.service.ts

@@ -8,6 +8,7 @@ import {
   IssueChange,
   ProjectChange,
   ReleaseChange,
+  SprintChange,
 } from './ports/change-feed';
 import { CanViewProjectQuery } from './queries/can-view-project.query';
 import { GetIssueQuery } from './queries/get-issue.query';
@@ -52,6 +53,14 @@ export class ChangesService {
     return this.changeFeed.releases(projectId);
   }
 
+  async watchSprints(
+    viewerId: string,
+    projectId: string,
+  ): Promise<AsyncIterableIterator<SprintChange>> {
+    await this.assertCanView(viewerId, projectId);
+    return this.changeFeed.sprints(projectId);
+  }
+
   async watchProject(
     viewerId: string,
     projectId: string,

libs/api/tracker/application/src/lib/commands/command-handlers.ts

@@ -30,6 +30,7 @@ import { DetachFileCommandHandler } from './detach-file.command-handler';
 import { WatchIssueCommandHandler } from './watch-issue.command-handler';
 import { SetIssueParentCommandHandler } from './set-issue-parent.command-handler';
 import { RankIssueCommandHandler } from './rank-issue.command-handler';
+import { SPRINT_COMMAND_HANDLERS } from './sprint.command-handlers';
 import { DetachFromParentCommandHandler } from './detach-from-parent.command-handler';
 import {
   AddChecklistItemCommandHandler,
@@ -71,6 +72,7 @@ export const COMMAND_HANDLERS = [
   WatchIssueCommandHandler,
   SetIssueParentCommandHandler,
   RankIssueCommandHandler,
+  ...SPRINT_COMMAND_HANDLERS,
   AddChecklistItemCommandHandler,
   UpdateChecklistItemCommandHandler,
   RemoveChecklistItemCommandHandler,

libs/api/tracker/application/src/lib/commands/commands.spec.ts

@@ -31,6 +31,13 @@ import {
   InMemoryTrackerStreams,
 } from '../../testing/in-memory';
 import { TrackerStreamsRepository } from '../ports/tracker-streams.repository';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
+import { FindIssuesRepository } from '../ports/find-issues.repository';
+import {
+  CreateSprintCommand,
+  SetIssueSprintCommand,
+  StartSprintCommand,
+} from './sprint.commands';
 import { IssueTree } from './issue-tree';
 import { SetIssueParentCommand } from './set-issue-parent.command';
 import { RankIssueCommand } from './rank-issue.command';
@@ -63,6 +70,10 @@ import { WriteAccess } from './write-access';
 
 async function setup() {
   const store = new InMemoryEventStore();
+  const sprints = {
+    active: null as { id: string; name: string } | null,
+    findActive: async () => sprints.active,
+  };
   const files = new InMemoryAttachmentStorage();
   const users = new FakeUserDirectory()
     .add('owner')
@@ -92,6 +103,20 @@ async function setup() {
         provide: TrackerStreamsRepository,
         useValue: new InMemoryTrackerStreams(store),
       },
+      // Read-model lookups: the sprint under way is set by each test.
+      { provide: FindSprintsRepository, useValue: sprints },
+      {
+        provide: FindIssuesRepository,
+        useValue: {
+          sprintProgress: async () => ({
+            total: 0,
+            finished: 0,
+            percent: 0,
+            storyPoints: 0,
+            finishedStoryPoints: 0,
+          }),
+        },
+      },
     ],
   }).compile();
   await moduleRef.init();
@@ -103,6 +128,7 @@ async function setup() {
   return {
     store,
     files,
+    sprints,
     run,
     rehydrator: moduleRef.get(AggregateRehydrator),
   };
@@ -405,6 +431,51 @@ describe('tracker commands (event sourced)', () => {
     );
   });
 
+  it('plans and starts sprints, one under way at a time, and fills them', async () => {
+    const { run, rehydrator, sprints } = await setup();
+    const projectId = await projectWithTeam(run);
+    const plan = (name: string) =>
+      run(
+        new CreateSprintCommand(
+          'owner',
+          projectId,
+          name,
+          '2026-10-12',
+          '2026-10-23',
+        ),
+      );
+    const first = await plan('Sprint 1');
+    const second = await plan('Sprint 2');
+    await expect(
+      run(
+        new CreateSprintCommand(
+          'dev',
+          projectId,
+          'X',
+          '2026-10-12',
+          '2026-10-23',
+        ),
+      ),
+    ).rejects.toThrow(ForbiddenError);
+
+    await run(new StartSprintCommand('owner', first.id));
+    sprints.active = { id: first.id, name: 'Sprint 1' };
+    await expect(
+      run(new StartSprintCommand('owner', second.id)),
+    ).rejects.toThrow(/Sprint 1 is under way/);
+
+    const issue = await run(
+      new CreateIssueCommand('dev', projectId, IssueType.TASK, 'Login', {}),
+    );
+    await run(new SetIssueSprintCommand('dev', issue.id, first.id));
+    expect((await rehydrator.rehydrate(issue.id, Issue)).sprintId).toBe(
+      first.id,
+    );
+    await expect(
+      run(new SetIssueSprintCommand('pm', issue.id, null)),
+    ).rejects.toThrow(ForbiddenError);
+  });
+
   it('does not let viewers modify tickets', async () => {
     const { run } = await setup();
     const projectId = await projectWithTeam(run);

libs/api/tracker/application/src/lib/commands/index.ts

@@ -33,3 +33,4 @@ export * from './set-issue-parent.command';
 export * from './detach-from-parent.command';
 export * from './change-checklist.command';
 export * from './rank-issue.command';
+export * from './sprint.commands';

libs/api/tracker/application/src/lib/commands/sprint.command-handlers.ts

@@ -0,0 +1,219 @@
+import { CommandHandler, EventPublisher, ICommandHandler } from '@nestjs/cqrs';
+import {
+  Issue,
+  Project,
+  Sprint,
+  SprintFactory,
+  SprintStatus,
+  StatusCategory,
+} from '@task-stream/api/tracker/domain';
+import { FindIssuesRepository } from '../ports/find-issues.repository';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
+import { CommandResult, ack } from './command-result';
+import {
+  CarryOverIssueCommand,
+  CloseSprintCommand,
+  CreateSprintCommand,
+  DeleteSprintCommand,
+  SetIssueSprintCommand,
+  StartSprintCommand,
+  UpdateSprintCommand,
+} from './sprint.commands';
+import { WriteAccess } from './write-access';
+
+/* Sprints are planned and run by whoever manages the project; any member puts tickets in them. */
+
+@CommandHandler(CreateSprintCommand)
+export class CreateSprintCommandHandler
+  implements ICommandHandler<CreateSprintCommand>
+{
+  constructor(
+    private readonly access: WriteAccess,
+    private readonly sprintFactory: SprintFactory,
+    private readonly eventPublisher: EventPublisher,
+  ) {}
+
+  async execute(command: CreateSprintCommand): Promise<CommandResult> {
+    const project = await this.access.project(command.projectId);
+    project.assertCanManage(command.actorId);
+    const sprint = this.sprintFactory.create(command.actorId, {
+      projectId: project.id,
+      name: command.name,
+      goal: command.goal,
+      startDate: command.startDate,
+      endDate: command.endDate,
+    });
+    this.eventPublisher.mergeObjectContext(sprint);
+    await sprint.commitAndWait();
+    return ack(sprint);
+  }
+}
+
+/** The sprint, checking the actor manages its project. */
+async function managedSprint(
+  access: WriteAccess,
+  sprintId: string,
+  actorId: string,
+): Promise<Sprint> {
+  const sprint = await access.sprint(sprintId);
+  (await access.project(sprint.projectId)).assertCanManage(actorId);
+  return sprint;
+}
+
+@CommandHandler(UpdateSprintCommand)
+export class UpdateSprintCommandHandler
+  implements ICommandHandler<UpdateSprintCommand>
+{
+  constructor(private readonly access: WriteAccess) {}
+
+  async execute(command: UpdateSprintCommand): Promise<CommandResult> {
+    const sprint = await managedSprint(
+      this.access,
+      command.sprintId,
+      command.actorId,
+    );
+    sprint.update(command.actorId, command.changes);
+    await sprint.commitAndWait();
+    return ack(sprint);
+  }
+}
+
+@CommandHandler(StartSprintCommand)
+export class StartSprintCommandHandler
+  implements ICommandHandler<StartSprintCommand>
+{
+  constructor(
+    private readonly access: WriteAccess,
+    private readonly findSprints: FindSprintsRepository,
+  ) {}
+
+  async execute(command: StartSprintCommand): Promise<CommandResult> {
+    const sprint = await managedSprint(
+      this.access,
+      command.sprintId,
+      command.actorId,
+    );
+    const active = await this.findSprints.findActive(sprint.projectId);
+    sprint.start(
+      command.actorId,
+      active && active.id !== sprint.id ? active : null,
+    );
+    await sprint.commitAndWait();
+    return ack(sprint);
+  }
+}
+
+@CommandHandler(CloseSprintCommand)
+export class CloseSprintCommandHandler
+  implements ICommandHandler<CloseSprintCommand>
+{
+  constructor(
+    private readonly access: WriteAccess,
+    private readonly findIssues: FindIssuesRepository,
+  ) {}
+
+  async execute(command: CloseSprintCommand): Promise<CommandResult> {
+    const sprint = await managedSprint(
+      this.access,
+      command.sprintId,
+      command.actorId,
+    );
+    const target = command.carryOverTo
+      ? await this.access.sprint(command.carryOverTo)
+      : null;
+    const progress = await this.findIssues.sprintProgress(sprint.id);
+    sprint.close(command.actorId, target, progress.total - progress.finished);
+    await sprint.commitAndWait();
+    return ack(sprint);
+  }
+}
+
+@CommandHandler(DeleteSprintCommand)
+export class DeleteSprintCommandHandler
+  implements ICommandHandler<DeleteSprintCommand>
+{
+  constructor(private readonly access: WriteAccess) {}
+
+  async execute(command: DeleteSprintCommand): Promise<CommandResult | void> {
+    if (command.cascade) {
+      // Saga: idempotent, the sprint may be gone already.
+      const sprint = await this.access.live(command.sprintId, Sprint);
+      if (!sprint) return;
+      sprint.delete(command.actorId, true);
+      await sprint.commitAndWait();
+      return;
+    }
+    const sprint = await managedSprint(
+      this.access,
+      command.sprintId,
+      command.actorId,
+    );
+    sprint.delete(command.actorId);
+    await sprint.commitAndWait();
+    return ack(sprint);
+  }
+}
+
+@CommandHandler(SetIssueSprintCommand)
+export class SetIssueSprintCommandHandler
+  implements ICommandHandler<SetIssueSprintCommand>
+{
+  constructor(private readonly access: WriteAccess) {}
+
+  async execute(command: SetIssueSprintCommand): Promise<CommandResult> {
+    const { issue, project } = await this.access.issueForContributor(
+      command.issueId,
+      command.actorId,
+    );
+    // A closed sprint keeps its tickets: neither side may be closed.
+    if (issue.sprintId) await this.access.openSprintOf(project, issue.sprintId);
+    if (command.sprintId)
+      await this.access.openSprintOf(project, command.sprintId);
+    issue.setSprint(command.actorId, command.sprintId);
+    await issue.commitAndWait();
+    return ack(issue);
+  }
+}
+
+const FINISHED = [StatusCategory.DONE, StatusCategory.CANCELLED];
+
+@CommandHandler(CarryOverIssueCommand)
+export class CarryOverIssueCommandHandler
+  implements ICommandHandler<CarryOverIssueCommand>
+{
+  constructor(private readonly access: WriteAccess) {}
+
+  async execute(command: CarryOverIssueCommand): Promise<void> {
+    const issue = await this.access.live(command.issueId, Issue);
+    // Gone, or it left that sprint meanwhile: nothing to do.
+    if (!issue || issue.sprintId !== command.fromSprintId) return;
+    const project = await this.access.live(issue.projectId, Project);
+    if (!project) return;
+    if (
+      command.onlyUnfinished &&
+      FINISHED.includes(project.workflow.categoryOf(issue.status))
+    )
+      return;
+    if (command.toSprintId) {
+      const target = await this.access.live(command.toSprintId, Sprint);
+      // The target closed or vanished meanwhile: back to the backlog instead.
+      const open =
+        target && !target.deleted && target.status !== SprintStatus.CLOSED;
+      issue.setSprint(command.actorId, open ? command.toSprintId : null);
+    } else {
+      issue.setSprint(command.actorId, null);
+    }
+    await issue.commitAndWait();
+  }
+}
+
+export const SPRINT_COMMAND_HANDLERS = [
+  CreateSprintCommandHandler,
+  UpdateSprintCommandHandler,
+  StartSprintCommandHandler,
+  CloseSprintCommandHandler,
+  DeleteSprintCommandHandler,
+  SetIssueSprintCommandHandler,
+  // Saga only.
+  CarryOverIssueCommandHandler,
+];

libs/api/tracker/application/src/lib/commands/sprint.commands.ts

@@ -0,0 +1,85 @@
+import { Command } from '@nestjs/cqrs';
+import { SprintDetails } from '@task-stream/api/tracker/domain';
+import { CommandResult } from './command-result';
+
+export class CreateSprintCommand extends Command<CommandResult> {
+  constructor(
+    public readonly actorId: string,
+    public readonly projectId: string,
+    public readonly name: string,
+    public readonly startDate: string,
+    public readonly endDate: string,
+    public readonly goal: string | null = null,
+  ) {
+    super();
+  }
+}
+
+export class UpdateSprintCommand extends Command<CommandResult> {
+  constructor(
+    public readonly actorId: string,
+    public readonly sprintId: string,
+    public readonly changes: SprintDetails,
+  ) {
+    super();
+  }
+}
+
+export class StartSprintCommand extends Command<CommandResult> {
+  constructor(
+    public readonly actorId: string,
+    public readonly sprintId: string,
+  ) {
+    super();
+  }
+}
+
+/** Ends a sprint; unfinished tickets go to `carryOverTo` (null: backlog). */
+export class CloseSprintCommand extends Command<CommandResult> {
+  constructor(
+    public readonly actorId: string,
+    public readonly sprintId: string,
+    public readonly carryOverTo: string | null,
+  ) {
+    super();
+  }
+}
+
+/** A planned sprint (people), or any sprint of a deleted project (`cascade`, saga). */
+export class DeleteSprintCommand extends Command<CommandResult | void> {
+  constructor(
+    public readonly actorId: string,
+    public readonly sprintId: string,
+    public readonly cascade = false,
+  ) {
+    super();
+  }
+}
+
+/** Puts a ticket in a sprint (null: back to the backlog). */
+export class SetIssueSprintCommand extends Command<CommandResult> {
+  constructor(
+    public readonly actorId: string,
+    public readonly issueId: string,
+    public readonly sprintId: string | null,
+  ) {
+    super();
+  }
+}
+
+/**
+ * Saga only: a sprint closed (or was deleted), so a ticket of it moves to
+ * `toSprintId` (null: backlog). With `onlyUnfinished`, finished ones stay as
+ * the record of what the sprint achieved.
+ */
+export class CarryOverIssueCommand extends Command<void> {
+  constructor(
+    public readonly actorId: string,
+    public readonly issueId: string,
+    public readonly fromSprintId: string,
+    public readonly toSprintId: string | null,
+    public readonly onlyUnfinished: boolean,
+  ) {
+    super();
+  }
+}

libs/api/tracker/application/src/lib/commands/write-access.ts

@@ -10,6 +10,7 @@ import {
   Issue,
   Project,
   Release,
+  Sprint,
 } from '@task-stream/api/tracker/domain';
 import { UserDirectory } from '../ports/user-directory';
 
@@ -38,6 +39,22 @@ export class WriteAccess {
     return this.load(id, Release);
   }
 
+  sprint(id: string): Promise<Sprint> {
+    return this.load(id, Sprint);
+  }
+
+  /** Sprint of the same project that still takes tickets (not closed). */
+  async openSprintOf(project: Project, sprintId: string): Promise<Sprint> {
+    const sprint = await this.sprint(sprintId);
+    if (sprint.projectId !== project.id) {
+      throw new BusinessRuleError(
+        `Sprint ${sprint.name} belongs to another project`,
+      );
+    }
+    sprint.assertAcceptsIssues();
+    return sprint;
+  }
+
   comment(id: string): Promise<Comment> {
     return this.load(id, Comment);
   }

libs/api/tracker/application/src/lib/event-handlers/activity-summary.ts

@@ -28,6 +28,12 @@ import {
   ReleaseCreatedEvent,
   ReleaseShippedEvent,
   ReleaseUpdatedEvent,
+  IssueSprintChangedEvent,
+  SprintClosedEvent,
+  SprintCreatedEvent,
+  SprintDeletedEvent,
+  SprintStartedEvent,
+  SprintUpdatedEvent,
   TrackerEvent,
 } from '@task-stream/api/tracker/domain';
 
@@ -37,6 +43,8 @@ export interface SummaryContext {
   issueKey: string;
   projectKey: string;
   releaseName: string;
+  /** '' when unknown (e.g. the sprint was deleted). */
+  sprintName: string;
   /** The project's workflow: names of statuses and types. */
   workflow: ProjectWorkflow;
 }
@@ -146,6 +154,12 @@ export function describeEvent(
   if (event instanceof IssueAttachmentRemovedEvent)
     return `${actor} quitó el adjunto ${event.fileName} de ${issueKey}`;
 
+  if (event instanceof IssueSprintChangedEvent) {
+    const sprint = ctx.sprintName ? `el sprint ${ctx.sprintName}` : 'un sprint';
+    return event.sprintId
+      ? `${actor} metió ${issueKey} en ${sprint}`
+      : `${actor} sacó ${issueKey} de ${sprint}`;
+  }
   if (event instanceof IssueParentChangedEvent) {
     return event.parentKey
       ? `${actor} colocó ${issueKey} bajo ${event.parentKey}`
@@ -178,5 +192,20 @@ export function describeEvent(
     return `${actor} publicó la release ${ctx.releaseName} 🚀`;
   if (event instanceof ReleaseArchivedEvent)
     return `${actor} archivó la release ${ctx.releaseName}`;
+  const sprint = ctx.sprintName || 'un sprint';
+  if (event instanceof SprintCreatedEvent)
+    return `${actor} planificó el sprint ${event.sprint.name}`;
+  if (event instanceof SprintUpdatedEvent)
+    return `${actor} actualizó el sprint ${sprint}`;
+  if (event instanceof SprintStartedEvent)
+    return `${actor} empezó el sprint ${sprint} 🏁`;
+  if (event instanceof SprintClosedEvent) {
+    const left = event.unfinishedIssues
+      ? `; ${event.unfinishedIssues} ticket(s) sin terminar pasan ${event.carryOverTo ? 'al siguiente sprint' : 'al backlog'}`
+      : '';
+    return `${actor} cerró el sprint ${sprint}${left}`;
+  }
+  if (event instanceof SprintDeletedEvent)
+    return `${actor} borró el sprint ${sprint}`;
   return `${actor}: ${event.constructor.name}`;
 }

libs/api/tracker/application/src/lib/event-handlers/activity.event-handler.ts

@@ -23,6 +23,12 @@ import {
   ProjectMemberRoleChangedEvent,
   ProjectUpdatedEvent,
   ReleaseArchivedEvent,
+  IssueSprintChangedEvent,
+  SprintClosedEvent,
+  SprintCreatedEvent,
+  SprintDeletedEvent,
+  SprintStartedEvent,
+  SprintUpdatedEvent,
   ReleaseCreatedEvent,
   ReleaseShippedEvent,
   ReleaseUpdatedEvent,
@@ -37,6 +43,7 @@ import { ChangeFeed } from '../ports/change-feed';
 import { FindIssuesRepository } from '../ports/find-issues.repository';
 import { FindProjectsRepository } from '../ports/find-projects.repository';
 import { FindReleasesRepository } from '../ports/find-releases.repository';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
 import { UpsertMaterializedActivityRepository } from '../ports/upsert-materialized-activity.repository';
 import { UserDirectory } from '../ports/user-directory';
 import { describeEvent } from './activity-summary';
@@ -70,6 +77,12 @@ import { versionOf } from './read-model-notifier';
   ReleaseUpdatedEvent,
   ReleaseShippedEvent,
   ReleaseArchivedEvent,
+  IssueSprintChangedEvent,
+  SprintCreatedEvent,
+  SprintUpdatedEvent,
+  SprintStartedEvent,
+  SprintClosedEvent,
+  SprintDeletedEvent,
 )
 export class ActivityEventHandler implements IEventHandler<TrackerEvent> {
   constructor(
@@ -77,6 +90,7 @@ export class ActivityEventHandler implements IEventHandler<TrackerEvent> {
     private readonly findProjects: FindProjectsRepository,
     private readonly findIssues: FindIssuesRepository,
     private readonly findReleases: FindReleasesRepository,
+    private readonly findSprints: FindSprintsRepository,
     private readonly users: UserDirectory,
     private readonly changeFeed: ChangeFeed,
   ) {}
@@ -93,6 +107,7 @@ export class ActivityEventHandler implements IEventHandler<TrackerEvent> {
     const release = releaseId
       ? await this.findReleases.findById(releaseId)
       : null;
+    const sprint = await this.sprintOf(event);
     const project = await this.findProjects.findById(event.projectId);
     // The project was deleted (cascade in progress): no feed to write to.
     if (!project) return;
@@ -118,6 +133,7 @@ export class ActivityEventHandler implements IEventHandler<TrackerEvent> {
         issueKey: issueKey ?? '',
         projectKey: project?.key ?? '',
         releaseName: release?.name ?? '',
+        sprintName: sprint,
         workflow: new ProjectWorkflow(
           project?.settings ?? DEFAULT_PROJECT_SETTINGS,
         ),
@@ -129,6 +145,17 @@ export class ActivityEventHandler implements IEventHandler<TrackerEvent> {
     }
   }
 
+  /** Name of the sprint the event is about ('' when it is gone). */
+  private async sprintOf(event: TrackerEvent): Promise<string> {
+    if (event instanceof SprintCreatedEvent) return event.sprint.name;
+    const id = event.constructor.name.startsWith('Sprint')
+      ? event.aggregateId
+      : event instanceof IssueSprintChangedEvent
+        ? (event.sprintId ?? event.previousSprintId)
+        : null;
+    return id ? ((await this.findSprints.findById(id))?.name ?? '') : '';
+  }
+
   private issueIdOf(event: TrackerEvent): string | null {
     if (event.constructor.name.startsWith('Issue')) return event.aggregateId;
     if (event instanceof CommentAddedEvent) return event.comment.issueId;

libs/api/tracker/application/src/lib/event-handlers/event-handlers.ts

@@ -31,6 +31,8 @@ import { IssueWatchersEventHandler } from './issue-watchers.event-handler';
 import { IssueParentChangedEventHandler } from './issue-parent-changed.event-handler';
 import { IssueChecklistEventHandler } from './issue-checklist.event-handler';
 import { IssueRankedEventHandler } from './issue-ranked.event-handler';
+import { SprintEventHandler } from './sprint.event-handler';
+import { IssueSprintChangedEventHandler } from './issue-sprint-changed.event-handler';
 
 /** Read-model projections (MongoDB) + realtime, fed by the EventsBridge. */
 export const EVENT_HANDLERS = [
@@ -66,6 +68,8 @@ export const EVENT_HANDLERS = [
   IssueParentChangedEventHandler,
   IssueChecklistEventHandler,
   IssueRankedEventHandler,
+  SprintEventHandler,
+  IssueSprintChangedEventHandler,
 ];
 
 export { ReadModelNotifier };

libs/api/tracker/application/src/lib/event-handlers/issue-created.event-handler.ts

@@ -50,6 +50,7 @@ export class IssueCreatedEventHandler
       assignee: users.ofNullable(issue.assigneeId),
       release: release ? { id: release.id, name: release.name } : null,
       parent: null,
+      sprint: null,
       rank: implicitRank(issue.number),
       labels: issue.labels,
       figmaUrl: issue.figmaUrl,

libs/api/tracker/application/src/lib/event-handlers/issue-sprint-changed.event-handler.ts

@@ -0,0 +1,31 @@
+import { EventsHandler, IEventHandler } from '@nestjs/cqrs';
+import { IssueSprintChangedEvent } from '@task-stream/api/tracker/domain';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
+import { UpsertMaterializedIssueRepository } from '../ports/upsert-materialized-issue.repository';
+import { ReadModelNotifier, versionOf } from './read-model-notifier';
+
+@EventsHandler(IssueSprintChangedEvent)
+export class IssueSprintChangedEventHandler
+  implements IEventHandler<IssueSprintChangedEvent>
+{
+  constructor(
+    private readonly upsertMaterializedIssueRepository: UpsertMaterializedIssueRepository,
+    private readonly findSprints: FindSprintsRepository,
+    private readonly notifier: ReadModelNotifier,
+  ) {}
+
+  async handle(event: IssueSprintChangedEvent) {
+    const sprint = event.sprintId
+      ? await this.findSprints.findById(event.sprintId)
+      : null;
+    await this.upsertMaterializedIssueRepository.upsert({
+      id: event.aggregateId,
+      sprint: event.sprintId
+        ? { id: event.sprintId, name: sprint?.name ?? '' }
+        : null,
+      updatedAt: event.occurredAt,
+      version: versionOf(event),
+    });
+    await this.notifier.issue(event.aggregateId, event);
+  }
+}

libs/api/tracker/application/src/lib/event-handlers/issue-timeline.event-handler.ts

@@ -3,6 +3,7 @@ import {
   DEFAULT_PROJECT_SETTINGS,
   IssueCreatedEvent,
   IssueReleaseChangedEvent,
+  IssueSprintChangedEvent,
   IssueStatusChangedEvent,
   ProjectWorkflow,
   TrackerEvent,
@@ -14,12 +15,13 @@ import { versionOf } from './read-model-notifier';
 
 /**
  * The life of every ticket, step by step: where it went (status + category)
- * and which release it joined. Statistics are computed from it.
+ * and which release and sprint it joined. Statistics are computed from it.
  */
 @EventsHandler(
   IssueCreatedEvent,
   IssueStatusChangedEvent,
   IssueReleaseChangedEvent,
+  IssueSprintChangedEvent,
 )
 export class IssueTimelineEventHandler implements IEventHandler<TrackerEvent> {
   constructor(
@@ -66,6 +68,14 @@ export class IssueTimelineEventHandler implements IEventHandler<TrackerEvent> {
         kind: 'release',
         releaseId: event.releaseId,
       });
+      return;
+    }
+    if (event instanceof IssueSprintChangedEvent) {
+      await this.timeline.record({
+        ...base,
+        kind: 'sprint',
+        sprintId: event.sprintId,
+      });
     }
   }
 

libs/api/tracker/application/src/lib/event-handlers/read-model-notifier.ts

@@ -5,6 +5,7 @@ import { FindCommentsRepository } from '../ports/find-comments.repository';
 import { FindIssuesRepository } from '../ports/find-issues.repository';
 import { FindProjectsRepository } from '../ports/find-projects.repository';
 import { FindReleasesRepository } from '../ports/find-releases.repository';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
 
 /** Position of the event in its stream (stamped by the event store). */
 export function versionOf(event: TrackerEvent): number {
@@ -23,6 +24,7 @@ export class ReadModelNotifier {
     private readonly findIssues: FindIssuesRepository,
     private readonly findComments: FindCommentsRepository,
     private readonly findReleases: FindReleasesRepository,
+    private readonly findSprints: FindSprintsRepository,
   ) {}
 
   async project(
@@ -63,6 +65,16 @@ export class ReadModelNotifier {
     await this.changeFeed.publishRelease({ ...this.meta(event), release });
   }
 
+  async sprint(sprintId: string, event: TrackerEvent): Promise<void> {
+    const sprint = await this.findSprints.findById(sprintId);
+    await this.changeFeed.publishSprint({
+      ...this.meta(event),
+      sprintId,
+      projectId: event.projectId,
+      sprint,
+    });
+  }
+
   private meta(event: TrackerEvent) {
     return {
       action: event.constructor.name,

libs/api/tracker/application/src/lib/event-handlers/sprint.event-handler.ts

@@ -0,0 +1,65 @@
+import { EventsHandler, IEventHandler } from '@nestjs/cqrs';
+import {
+  SprintClosedEvent,
+  SprintCreatedEvent,
+  SprintDeletedEvent,
+  SprintStartedEvent,
+  SprintStatus,
+  SprintUpdatedEvent,
+} from '@task-stream/api/tracker/domain';
+import { UpsertMaterializedIssueRepository } from '../ports/upsert-materialized-issue.repository';
+import { UpsertMaterializedSprintRepository } from '../ports/upsert-materialized-sprint.repository';
+import { ReadModelNotifier, versionOf } from './read-model-notifier';
+
+type SprintEvent =
+  | SprintCreatedEvent
+  | SprintUpdatedEvent
+  | SprintStartedEvent
+  | SprintClosedEvent
+  | SprintDeletedEvent;
+
+/** The sprints view (`sprints_view`), one document per sprint. */
+@EventsHandler(
+  SprintCreatedEvent,
+  SprintUpdatedEvent,
+  SprintStartedEvent,
+  SprintClosedEvent,
+  SprintDeletedEvent,
+)
+export class SprintEventHandler implements IEventHandler<SprintEvent> {
+  constructor(
+    private readonly sprints: UpsertMaterializedSprintRepository,
+    private readonly issues: UpsertMaterializedIssueRepository,
+    private readonly notifier: ReadModelNotifier,
+  ) {}
+
+  async handle(event: SprintEvent) {
+    const version = versionOf(event);
+    const id = event.aggregateId;
+    if (event instanceof SprintCreatedEvent) {
+      await this.sprints.upsert({ ...event.sprint, version });
+    } else if (event instanceof SprintUpdatedEvent) {
+      await this.sprints.upsert({ id, ...event.changes, version });
+      // Tickets show its name.
+      if (event.changes.name)
+        await this.issues.renameSprint(id, event.changes.name);
+    } else if (event instanceof SprintStartedEvent) {
+      await this.sprints.upsert({
+        id,
+        status: SprintStatus.ACTIVE,
+        startedAt: event.occurredAt,
+        version,
+      });
+    } else if (event instanceof SprintClosedEvent) {
+      await this.sprints.upsert({
+        id,
+        status: SprintStatus.CLOSED,
+        closedAt: event.occurredAt,
+        version,
+      });
+    } else {
+      await this.sprints.remove(id);
+    }
+    await this.notifier.sprint(id, event);
+  }
+}

libs/api/tracker/application/src/lib/ports/change-feed.ts

@@ -5,6 +5,7 @@ import {
   IssueReadModel,
   ProjectReadModel,
   ReleaseReadModel,
+  SprintReadModel,
 } from '@task-stream/api/tracker/domain';
 
 /** Every realtime message says which event caused it and the resulting version. */
@@ -30,6 +31,13 @@ export interface ReleaseChange extends Change {
   release: ReleaseReadModel;
 }
 
+export interface SprintChange extends Change {
+  /** Null when the sprint was deleted. */
+  sprint: SprintReadModel | null;
+  sprintId: string;
+  projectId: string;
+}
+
 export interface ProjectChange extends Change {
   project: ProjectReadModel;
 }
@@ -43,6 +51,7 @@ export abstract class ChangeFeed {
   abstract publishComment(change: CommentChange): Promise<void>;
   abstract publishActivity(activity: ActivityReadModel): Promise<void>;
   abstract publishRelease(change: ReleaseChange): Promise<void>;
+  abstract publishSprint(change: SprintChange): Promise<void>;
   /** @param notifyUserIds users whose project list changed (joined / left). */
   abstract publishProject(
     change: ProjectChange,
@@ -59,6 +68,7 @@ export abstract class ChangeFeed {
     projectId: string,
   ): AsyncIterableIterator<ActivityReadModel>;
   abstract releases(projectId: string): AsyncIterableIterator<ReleaseChange>;
+  abstract sprints(projectId: string): AsyncIterableIterator<SprintChange>;
   abstract project(projectId: string): AsyncIterableIterator<ProjectChange>;
   abstract userProjects(userId: string): AsyncIterableIterator<ProjectChange>;
   abstract notifications(

libs/api/tracker/application/src/lib/ports/find-issues.repository.ts

@@ -4,6 +4,7 @@ import {
   IssueReadModel,
   ProjectStatsReadModel,
   ReleaseProgressReadModel,
+  SprintProgressReadModel,
   StatusCategory,
 } from '@task-stream/api/tracker/domain';
 
@@ -26,6 +27,9 @@ export interface IssueFilter {
   labels?: string[];
   /** Only the tickets hanging from this one. */
   parentId?: string;
+  sprintId?: string;
+  /** Only tickets in no sprint (wins over `sprintId`). */
+  noSprint?: boolean;
   /** RECENT (default): last updated first. RANK: backlog order. */
   sort?: IssueSort;
   search?: string;
@@ -63,6 +67,7 @@ export abstract class FindIssuesRepository {
   abstract findByProject(projectId: string): Promise<IssueReadModel[]>;
   /** Top-level tickets with others hanging from them, by key. */
   abstract epics(projectId: string): Promise<EpicReadModel[]>;
+  abstract sprintProgress(sprintId: string): Promise<SprintProgressReadModel>;
   abstract releaseProgress(
     releaseId: string,
   ): Promise<ReleaseProgressReadModel>;

libs/api/tracker/application/src/lib/ports/find-sprints.repository.ts

@@ -0,0 +1,9 @@
+import { SprintReadModel } from '@task-stream/api/tracker/domain';
+
+export abstract class FindSprintsRepository {
+  abstract findById(id: string): Promise<SprintReadModel | null>;
+  /** Active first, then planned by start date, then closed (newest first). */
+  abstract findByProject(projectId: string): Promise<SprintReadModel[]>;
+  /** The sprint under way in the project, if any. */
+  abstract findActive(projectId: string): Promise<SprintReadModel | null>;
+}

libs/api/tracker/application/src/lib/ports/index.ts

@@ -21,3 +21,5 @@ export * from './attachment-storage';
 export * from './notifications.repository';
 export * from './notification-mailer';
 export * from './saved-filters.repository';
+export * from './find-sprints.repository';
+export * from './upsert-materialized-sprint.repository';

libs/api/tracker/application/src/lib/ports/tracker-streams.repository.ts

@@ -7,6 +7,9 @@
 export abstract class TrackerStreamsRepository {
   abstract issueIdsOfProject(projectId: string): Promise<string[]>;
   abstract releaseIdsOfProject(projectId: string): Promise<string[]>;
+  abstract sprintIdsOfProject(projectId: string): Promise<string[]>;
+  /** Tickets that were ever put in `sprintId` (they may have left since). */
+  abstract issueIdsEverInSprint(sprintId: string): Promise<string[]>;
   abstract commentIdsOfIssue(issueId: string): Promise<string[]>;
   /** Tickets that were ever linked to `issueId` (they may have unlinked since). */
   abstract issueIdsLinkingTo(issueId: string): Promise<string[]>;

libs/api/tracker/application/src/lib/ports/upsert-materialized-issue.repository.ts

@@ -60,6 +60,8 @@ export abstract class UpsertMaterializedIssueRepository {
   ): Promise<void>;
   /** The ticket was deleted: its view, its timeline and the links shown on other tickets go. */
   abstract remove(issueId: string): Promise<void>;
+  /** Keeps the denormalised sprint name of every issue in sync. */
+  abstract renameSprint(sprintId: string, name: string): Promise<void>;
   /** Keeps the denormalised release name of every issue in sync. */
   abstract renameRelease(releaseId: string, name: string): Promise<void>;
 }

libs/api/tracker/application/src/lib/ports/upsert-materialized-sprint.repository.ts

@@ -0,0 +1,9 @@
+import { SprintReadModel } from '@task-stream/api/tracker/domain';
+
+export abstract class UpsertMaterializedSprintRepository {
+  /** Applied only if `version` is newer than the stored one (idempotent). */
+  abstract upsert(
+    sprint: Pick<SprintReadModel, 'id' | 'version'> & Partial<SprintReadModel>,
+  ): Promise<void>;
+  abstract remove(sprintId: string): Promise<void>;
+}

libs/api/tracker/application/src/lib/queries/index.ts

@@ -18,3 +18,4 @@ export * from './search-my-issues.query';
 export * from './get-public-projects.query';
 export * from './get-attachment.query';
 export * from './get-epics.query';
+export * from './sprint.queries';

libs/api/tracker/application/src/lib/queries/query-handlers.ts

@@ -17,6 +17,7 @@ import { GetReleasesQueryHandler } from './get-releases.query-handler';
 import { GetUpcomingReleasesQueryHandler } from './get-upcoming-releases.query-handler';
 import { SearchIssuesQueryHandler } from './search-issues.query-handler';
 import { GetEpicsQueryHandler } from './get-epics.query-handler';
+import { SPRINT_QUERY_HANDLERS } from './sprint.queries';
 import { SearchMyIssuesQueryHandler } from './search-my-issues.query-handler';
 
 export const QUERY_HANDLERS = [
@@ -38,6 +39,7 @@ export const QUERY_HANDLERS = [
   GetUpcomingReleasesQueryHandler,
   SearchIssuesQueryHandler,
   GetEpicsQueryHandler,
+  ...SPRINT_QUERY_HANDLERS,
   SearchMyIssuesQueryHandler,
   GetAttachmentQueryHandler,
 ];

libs/api/tracker/application/src/lib/queries/sprint.queries.ts

@@ -0,0 +1,159 @@
+import { IQueryHandler, Query, QueryHandler } from '@nestjs/cqrs';
+import {
+  SprintBurndownReadModel,
+  SprintProgressReadModel,
+  SprintReadModel,
+} from '@task-stream/api/tracker/domain';
+import { computeSprintBurndown } from '../analytics/analytics';
+import { FindIssuesRepository } from '../ports/find-issues.repository';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
+import { FindTimelineRepository } from '../ports/find-timeline.repository';
+import { ReadAccess } from './read-access';
+
+export class GetSprintsQuery extends Query<SprintReadModel[]> {
+  constructor(
+    /** Null: anonymous (public projects only). */
+    public readonly viewerId: string | null,
+    public readonly projectId: string,
+  ) {
+    super();
+  }
+}
+
+export class GetSprintQuery extends Query<SprintReadModel> {
+  constructor(
+    public readonly viewerId: string | null,
+    public readonly sprintId: string,
+  ) {
+    super();
+  }
+}
+
+export class GetSprintProgressQuery extends Query<SprintProgressReadModel> {
+  constructor(
+    public readonly viewerId: string | null,
+    public readonly sprintId: string,
+  ) {
+    super();
+  }
+}
+
+export class GetSprintBurndownQuery extends Query<SprintBurndownReadModel> {
+  constructor(
+    public readonly viewerId: string | null,
+    public readonly sprintId: string,
+  ) {
+    super();
+  }
+}
+
+/** The sprint, if the viewer may see its project (same error otherwise). */
+async function visibleSprint(
+  findSprints: FindSprintsRepository,
+  access: ReadAccess,
+  viewerId: string | null,
+  sprintId: string,
+): Promise<SprintReadModel> {
+  const sprint = access.assertFound(
+    await findSprints.findById(sprintId),
+    'Sprint',
+    sprintId,
+  );
+  await access.assertCanView(sprint.projectId, viewerId, {
+    entity: 'Sprint',
+    ref: sprintId,
+  });
+  return sprint;
+}
+
+@QueryHandler(GetSprintsQuery)
+export class GetSprintsQueryHandler
+  implements IQueryHandler<GetSprintsQuery, SprintReadModel[]>
+{
+  constructor(
+    private readonly findSprints: FindSprintsRepository,
+    private readonly access: ReadAccess,
+  ) {}
+
+  async execute(query: GetSprintsQuery): Promise<SprintReadModel[]> {
+    await this.access.assertCanView(query.projectId, query.viewerId);
+    return this.findSprints.findByProject(query.projectId);
+  }
+}
+
+@QueryHandler(GetSprintQuery)
+export class GetSprintQueryHandler
+  implements IQueryHandler<GetSprintQuery, SprintReadModel>
+{
+  constructor(
+    private readonly findSprints: FindSprintsRepository,
+    private readonly access: ReadAccess,
+  ) {}
+
+  execute(query: GetSprintQuery): Promise<SprintReadModel> {
+    return visibleSprint(
+      this.findSprints,
+      this.access,
+      query.viewerId,
+      query.sprintId,
+    );
+  }
+}
+
+@QueryHandler(GetSprintProgressQuery)
+export class GetSprintProgressQueryHandler
+  implements IQueryHandler<GetSprintProgressQuery, SprintProgressReadModel>
+{
+  constructor(
+    private readonly findSprints: FindSprintsRepository,
+    private readonly findIssues: FindIssuesRepository,
+    private readonly access: ReadAccess,
+  ) {}
+
+  async execute(
+    query: GetSprintProgressQuery,
+  ): Promise<SprintProgressReadModel> {
+    const sprint = await visibleSprint(
+      this.findSprints,
+      this.access,
+      query.viewerId,
+      query.sprintId,
+    );
+    return this.findIssues.sprintProgress(sprint.id);
+  }
+}
+
+@QueryHandler(GetSprintBurndownQuery)
+export class GetSprintBurndownQueryHandler
+  implements IQueryHandler<GetSprintBurndownQuery, SprintBurndownReadModel>
+{
+  constructor(
+    private readonly findSprints: FindSprintsRepository,
+    private readonly findIssues: FindIssuesRepository,
+    private readonly findTimeline: FindTimelineRepository,
+    private readonly access: ReadAccess,
+  ) {}
+
+  async execute(
+    query: GetSprintBurndownQuery,
+  ): Promise<SprintBurndownReadModel> {
+    const sprint = await visibleSprint(
+      this.findSprints,
+      this.access,
+      query.viewerId,
+      query.sprintId,
+    );
+    const [issues, timeline] = await Promise.all([
+      this.findIssues.findByProject(sprint.projectId),
+      this.findTimeline.findByProject(sprint.projectId),
+    ]);
+    return computeSprintBurndown({ sprint, issues, timeline, now: new Date() });
+  }
+}
+
+export const SPRINT_QUERY_HANDLERS = [
+  GetSprintsQueryHandler,
+  GetSprintQueryHandler,
+  GetSprintProgressQueryHandler,
+  GetSprintBurndownQueryHandler,
+];

libs/api/tracker/application/src/lib/sagas/project-deletion.saga.ts

@@ -9,6 +9,7 @@ import { DeleteIssueCommand } from '../commands/delete-issue.command';
 import { DeleteReleaseCommand } from '../commands/delete-release.command';
 import { DetachFromParentCommand } from '../commands/detach-from-parent.command';
 import { DropLinksToIssueCommand } from '../commands/drop-links-to-issue.command';
+import { DeleteSprintCommand } from '../commands/sprint.commands';
 import { PurgeCommentCommand } from '../commands/purge-comment.command';
 import { TrackerStreamsRepository } from '../ports/tracker-streams.repository';
 
@@ -17,6 +18,7 @@ import { TrackerStreamsRepository } from '../ports/tracker-streams.repository';
  * with its own "deleted" event):
  *
  *   ProjectDeleted → DeleteIssue (each ticket) + DeleteRelease (each release)
+ *                    + DeleteSprint (each sprint, as a cascade)
  *   IssueDeleted   → PurgeComment (each comment) + DropLinksToIssue (tickets
  *                    of other projects that pointed to it) + DetachFromParent
  *                    (tickets that hung from it go back to the top)
@@ -34,11 +36,14 @@ export class ProjectDeletionSaga {
       ofType(ProjectDeletedEvent),
       mergeMap((event) =>
         from(this.contentsOf(event.projectId)).pipe(
-          mergeMap(({ issueIds, releaseIds }) => [
+          mergeMap(({ issueIds, releaseIds, sprintIds }) => [
             ...issueIds.map((id) => new DeleteIssueCommand(event.actorId, id)),
             ...releaseIds.map(
               (id) => new DeleteReleaseCommand(event.actorId, id),
             ),
+            ...sprintIds.map(
+              (id) => new DeleteSprintCommand(event.actorId, id, true),
+            ),
           ]),
         ),
       ),
@@ -76,11 +81,12 @@ export class ProjectDeletionSaga {
     );
 
   private async contentsOf(projectId: string) {
-    const [issueIds, releaseIds] = await Promise.all([
+    const [issueIds, releaseIds, sprintIds] = await Promise.all([
       this.streams.issueIdsOfProject(projectId),
       this.streams.releaseIdsOfProject(projectId),
+      this.streams.sprintIdsOfProject(projectId),
     ]);
-    return { issueIds, releaseIds };
+    return { issueIds, releaseIds, sprintIds };
   }
 
   private async dependentsOf(issueId: string) {

libs/api/tracker/application/src/lib/sagas/sagas.spec.ts

@@ -47,6 +47,15 @@ import { LinkIssuesCommand } from '../commands/link-issues.command';
 import { AssignIssueCommand } from '../commands/assign-issue.command';
 import { WriteAccess } from '../commands/write-access';
 import { IssueTree } from '../commands/issue-tree';
+import {
+  CloseSprintCommand,
+  CreateSprintCommand,
+  DeleteSprintCommand,
+  SetIssueSprintCommand,
+  StartSprintCommand,
+} from '../commands/sprint.commands';
+import { FindSprintsRepository } from '../ports/find-sprints.repository';
+import { SprintCarryOverSaga } from './sprint-carry-over.saga';
 import { FindIssuesRepository } from '../ports/find-issues.repository';
 import { IssueNumbersRepository } from '../ports/issue-numbers.repository';
 import { ProjectKeysRepository } from '../ports/project-keys.repository';
@@ -73,6 +82,7 @@ async function setup() {
       ProjectDeletionSaga,
       ReleaseArchivedSaga,
       UserDeactivatedSaga,
+      SprintCarryOverSaga,
       WriteAccess,
       IssueTree,
       AggregateRehydrator,
@@ -90,11 +100,22 @@ async function setup() {
         provide: TrackerStreamsRepository,
         useValue: new InMemoryTrackerStreams(store),
       },
+      {
+        provide: FindSprintsRepository,
+        useValue: { findActive: async () => null },
+      },
       {
         provide: FindIssuesRepository,
         useValue: {
           findOpenAssignedTo: async (userId: string) =>
             (openAssigned.get(userId) ?? []).map((id) => ({ id })),
+          sprintProgress: async () => ({
+            total: 2,
+            finished: 1,
+            percent: 50,
+            storyPoints: 0,
+            finishedStoryPoints: 0,
+          }),
         },
       },
     ],
@@ -109,6 +130,7 @@ async function setup() {
     ...Object.values(moduleRef.get(ProjectDeletionSaga)),
     ...Object.values(moduleRef.get(ReleaseArchivedSaga)),
     ...Object.values(moduleRef.get(UserDeactivatedSaga)),
+    ...Object.values(moduleRef.get(SprintCarryOverSaga)),
   ].filter((value): value is ISaga => typeof value === 'function');
 
   /** What the events bridge does: every stored event through every saga, until quiet. */
@@ -206,6 +228,41 @@ describe('sagas', () => {
     expect((await rehydrator.rehydrate(child, Issue)).parentId).toBeNull();
   });
 
+  it('closing a sprint carries its unfinished tickets over; deleting one empties it', async () => {
+    const { run, drain, rehydrator } = await setup();
+    const web = (await run(new CreateProjectCommand('owner', 'WEB', 'Web'))).id;
+    const sprint = async (name: string) =>
+      (
+        await run(
+          new CreateSprintCommand(
+            'owner',
+            web,
+            name,
+            '2026-10-12',
+            '2026-10-23',
+          ),
+        )
+      ).id;
+    const [one, two] = [await sprint('One'), await sprint('Two')];
+    const open = (await run(ticket(web, 'open'))).id;
+    const done = (await run(ticket(web, 'done'))).id;
+    for (const id of [open, done])
+      await run(new SetIssueSprintCommand('owner', id, one));
+    for (const status of ['TODO', 'IN_PROGRESS', 'IN_REVIEW', 'DONE'])
+      await run(new ChangeIssueStatusCommand('owner', done, status));
+
+    await run(new StartSprintCommand('owner', one));
+    await run(new CloseSprintCommand('owner', one, two));
+    await drain();
+
+    expect((await rehydrator.rehydrate(open, Issue)).sprintId).toBe(two);
+    expect((await rehydrator.rehydrate(done, Issue)).sprintId).toBe(one);
+
+    await run(new DeleteSprintCommand('owner', two));
+    await drain();
+    expect((await rehydrator.rehydrate(open, Issue)).sprintId).toBeNull();
+  });
+
   it('only the owner deletes a project', async () => {
     const { run } = await setup();
     const web = (await run(new CreateProjectCommand('owner', 'WEB', 'Web'))).id;

libs/api/tracker/application/src/lib/sagas/sagas.ts

@@ -2,6 +2,7 @@ import { ProjectDeletionSaga } from './project-deletion.saga';
 import { ReleaseArchivedSaga } from './release-archived.saga';
 import { UserDeactivatedSaga } from './user-deactivated.saga';
 import { CommentersFollowSaga } from './commenters-follow.saga';
+import { SprintCarryOverSaga } from './sprint-carry-over.saga';
 
 /** Reactions to events that change other aggregates (run by the events bridge). */
 export const SAGAS = [
@@ -9,4 +10,5 @@ export const SAGAS = [
   ReleaseArchivedSaga,
   UserDeactivatedSaga,
   CommentersFollowSaga,
+  SprintCarryOverSaga,
 ];

libs/api/tracker/application/src/lib/sagas/sprint-carry-over.saga.ts

@@ -0,0 +1,46 @@
+import { Injectable } from '@nestjs/common';
+import { ICommand, IEvent, ofType, Saga } from '@nestjs/cqrs';
+import {
+  SprintClosedEvent,
+  SprintDeletedEvent,
+} from '@task-stream/api/tracker/domain';
+import { from, mergeMap, Observable } from 'rxjs';
+import { CarryOverIssueCommand } from '../commands/sprint.commands';
+import { TrackerStreamsRepository } from '../ports/tracker-streams.repository';
+
+/**
+ * When a sprint ends, what was left moves on:
+ *
+ *   SprintClosed  → CarryOverIssue for its unfinished tickets, to the sprint
+ *                   chosen when closing it (or back to the backlog)
+ *   SprintDeleted → CarryOverIssue for all its tickets, back to the backlog
+ *
+ * Who was in the sprint comes from the event store. The moves are
+ * attributed to whoever closed or deleted the sprint.
+ */
+@Injectable()
+export class SprintCarryOverSaga {
+  constructor(private readonly streams: TrackerStreamsRepository) {}
+
+  @Saga()
+  sprintEnded = (events$: Observable<IEvent>): Observable<ICommand> =>
+    events$.pipe(
+      ofType(SprintClosedEvent, SprintDeletedEvent),
+      mergeMap((event) =>
+        from(this.streams.issueIdsEverInSprint(event.aggregateId)).pipe(
+          mergeMap((issueIds) =>
+            issueIds.map(
+              (issueId) =>
+                new CarryOverIssueCommand(
+                  event.actorId,
+                  issueId,
+                  event.aggregateId,
+                  event instanceof SprintClosedEvent ? event.carryOverTo : null,
+                  event instanceof SprintClosedEvent,
+                ),
+            ),
+          ),
+        ),
+      ),
+    );
+}

libs/api/tracker/application/src/lib/sprints.service.ts

@@ -0,0 +1,122 @@
+import { Injectable } from '@nestjs/common';
+import { CommandBus, QueryBus } from '@nestjs/cqrs';
+import {
+  SprintBurndownReadModel,
+  SprintDetails,
+  SprintProgressReadModel,
+  SprintReadModel,
+} from '@task-stream/api/tracker/domain';
+import { CommandResult } from './commands/command-result';
+import {
+  CloseSprintCommand,
+  CreateSprintCommand,
+  DeleteSprintCommand,
+  SetIssueSprintCommand,
+  StartSprintCommand,
+  UpdateSprintCommand,
+} from './commands/sprint.commands';
+import {
+  GetSprintBurndownQuery,
+  GetSprintProgressQuery,
+  GetSprintQuery,
+  GetSprintsQuery,
+} from './queries/sprint.queries';
+
+export interface CreateSprintInput {
+  projectId: string;
+  name: string;
+  goal?: string | null;
+  startDate: string;
+  endDate: string;
+}
+
+/** Sprints: plan them, run them, close them (and what was left moves on). */
+@Injectable()
+export class SprintsService {
+  constructor(
+    private readonly commandBus: CommandBus,
+    private readonly queryBus: QueryBus,
+  ) {}
+
+  list(viewerId: string | null, projectId: string): Promise<SprintReadModel[]> {
+    return this.queryBus.execute(new GetSprintsQuery(viewerId, projectId));
+  }
+
+  findOne(viewerId: string | null, sprintId: string): Promise<SprintReadModel> {
+    return this.queryBus.execute(new GetSprintQuery(viewerId, sprintId));
+  }
+
+  progress(
+    viewerId: string | null,
+    sprintId: string,
+  ): Promise<SprintProgressReadModel> {
+    return this.queryBus.execute(
+      new GetSprintProgressQuery(viewerId, sprintId),
+    );
+  }
+
+  burndown(
+    viewerId: string | null,
+    sprintId: string,
+  ): Promise<SprintBurndownReadModel> {
+    return this.queryBus.execute(
+      new GetSprintBurndownQuery(viewerId, sprintId),
+    );
+  }
+
+  create(actorId: string, input: CreateSprintInput): Promise<CommandResult> {
+    return this.commandBus.execute(
+      new CreateSprintCommand(
+        actorId,
+        input.projectId,
+        input.name,
+        input.startDate,
+        input.endDate,
+        input.goal ?? null,
+      ),
+    );
+  }
+
+  update(
+    actorId: string,
+    sprintId: string,
+    changes: SprintDetails,
+  ): Promise<CommandResult> {
+    return this.commandBus.execute(
+      new UpdateSprintCommand(actorId, sprintId, changes),
+    );
+  }
+
+  start(actorId: string, sprintId: string): Promise<CommandResult> {
+    return this.commandBus.execute(new StartSprintCommand(actorId, sprintId));
+  }
+
+  /** Unfinished tickets go to `carryOverTo` (null: the backlog). */
+  close(
+    actorId: string,
+    sprintId: string,
+    carryOverTo: string | null,
+  ): Promise<CommandResult> {
+    return this.commandBus.execute(
+      new CloseSprintCommand(actorId, sprintId, carryOverTo),
+    );
+  }
+
+  /** Planned sprints only; its tickets go back to the backlog. */
+  delete(actorId: string, sprintId: string): Promise<CommandResult> {
+    return this.commandBus.execute(
+      new DeleteSprintCommand(actorId, sprintId),
+    ) as Promise<CommandResult>;
+  }
+
+  /** Puts a ticket in a sprint (null: back to the backlog). */
+  setIssueSprint(
+    actorId: string,
+    issueId: string,
+    sprintId: string | null,
+  ): Promise<CommandResult> {
+    return this.commandBus.execute(
+      new SetIssueSprintCommand(actorId, issueId, sprintId),
+    );
+  }
+}

libs/api/tracker/application/src/lib/tracker-application.module.ts

@@ -31,6 +31,7 @@ import {
 
 import { SAVED_FILTERS } from './saved-filters/saved-filters';
 import { SavedFiltersService } from './saved-filters.service';
+import { SprintsService } from './sprints.service';
 
 /** Notifications: derived from events, kept and dismissed per person. */
 const NOTIFICATIONS = [
@@ -51,6 +52,7 @@ const SERVICES = [
   WorkflowsService,
   NotificationsService,
   SavedFiltersService,
+  SprintsService,
 ];
 
 /**

libs/api/tracker/application/src/testing/in-memory.ts

@@ -243,6 +243,20 @@ export class InMemoryTrackerStreams extends TrackerStreamsRepository {
     );
   }
 
+  async sprintIdsOfProject(projectId: string) {
+    return this.streams(
+      'SprintCreatedEvent',
+      (d) => d['projectId'] === projectId,
+    );
+  }
+
+  async issueIdsEverInSprint(sprintId: string) {
+    return this.streams(
+      'IssueSprintChangedEvent',
+      (d) => d['sprintId'] === sprintId,
+    );
+  }
+
   async commentIdsOfIssue(issueId: string) {
     return this.streams(
       'CommentAddedEvent',