diff --git a/src/server/routers/finalist.ts b/src/server/routers/finalist.ts
index 8f339b8..457bb52 100644
--- a/src/server/routers/finalist.ts
+++ b/src/server/routers/finalist.ts
@@ -1,10 +1,14 @@
 import { z } from 'zod'
 import { TRPCError } from '@trpc/server'
 import { CompetitionCategory } from '@prisma/client'
-import { router, adminProcedure } from '../trpc'
+import { router, adminProcedure, publicProcedure } from '../trpc'
 import { logAudit } from '../utils/audit'
-import { createPendingConfirmation } from '../services/finalist-confirmation'
+import {
+  createPendingConfirmation,
+  promoteNextWaitlistEntry,
+} from '../services/finalist-confirmation'
 import { sendFinalistConfirmationEmail } from '@/lib/email'
+import { verifyFinalistToken } from '@/lib/finalist-token'
 
 export const finalistRouter = router({
   /**
@@ -175,4 +179,188 @@ export const finalistRouter = router({
       })
       return { created }
     }),
+
+  /**
+   * Look up a confirmation by its public token. Surface the data needed to
+   * render the confirmation page: project, team members, current state.
+   */
+  getByToken: publicProcedure
+    .input(z.object({ token: z.string() }))
+    .query(async ({ ctx, input }) => {
+      const payload = verifyFinalistToken(input.token) // throws on bad sig / expired
+      const confirmation = await ctx.prisma.finalistConfirmation.findUnique({
+        where: { id: payload.confirmationId },
+        include: {
+          project: {
+            select: {
+              id: true,
+              title: true,
+              programId: true,
+              competitionCategory: true,
+              program: { select: { defaultAttendeeCap: true, name: true } },
+              teamMembers: {
+                select: {
+                  userId: true,
+                  role: true,
+                  user: { select: { id: true, name: true, email: true } },
+                },
+              },
+            },
+          },
+          attendingMembers: { select: { userId: true, needsVisa: true } },
+        },
+      })
+      if (!confirmation) throw new TRPCError({ code: 'NOT_FOUND' })
+      if (confirmation.token !== input.token) {
+        throw new TRPCError({ code: 'UNAUTHORIZED', message: 'Token mismatch' })
+      }
+      return confirmation
+    }),
+
+  /**
+   * Public confirm. Validates that all selected userIds are team members of
+   * the project, that the count is within the program's defaultAttendeeCap,
+   * and that the confirmation is still PENDING. Atomically writes
+   * status=CONFIRMED + AttendingMember rows.
+   */
+  confirm: publicProcedure
+    .input(
+      z.object({
+        token: z.string(),
+        attendingUserIds: z.array(z.string()).min(1),
+        visaFlags: z.record(z.string(), z.boolean()).default({}),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const payload = verifyFinalistToken(input.token)
+      const confirmation = await ctx.prisma.finalistConfirmation.findUnique({
+        where: { id: payload.confirmationId },
+        include: {
+          project: {
+            select: {
+              id: true,
+              programId: true,
+              program: { select: { defaultAttendeeCap: true } },
+              teamMembers: { select: { userId: true } },
+            },
+          },
+        },
+      })
+      if (!confirmation) throw new TRPCError({ code: 'NOT_FOUND' })
+      if (confirmation.token !== input.token) {
+        throw new TRPCError({ code: 'UNAUTHORIZED' })
+      }
+      if (confirmation.status !== 'PENDING') {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message: `Confirmation is ${confirmation.status}, not PENDING`,
+        })
+      }
+      const cap = confirmation.project.program.defaultAttendeeCap
+      if (input.attendingUserIds.length > cap) {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message: `Selection exceeds attendee cap of ${cap}`,
+        })
+      }
+      const teamUserIds = new Set(confirmation.project.teamMembers.map((tm) => tm.userId))
+      for (const uid of input.attendingUserIds) {
+        if (!teamUserIds.has(uid)) {
+          throw new TRPCError({
+            code: 'BAD_REQUEST',
+            message: `User ${uid} is not a team member of this project`,
+          })
+        }
+      }
+
+      await ctx.prisma.$transaction([
+        ctx.prisma.finalistConfirmation.update({
+          where: { id: confirmation.id },
+          data: { status: 'CONFIRMED', confirmedAt: new Date() },
+        }),
+        ctx.prisma.attendingMember.createMany({
+          data: input.attendingUserIds.map((userId) => ({
+            confirmationId: confirmation.id,
+            userId,
+            needsVisa: input.visaFlags[userId] ?? false,
+          })),
+        }),
+      ])
+      await logAudit({
+        prisma: ctx.prisma,
+        action: 'FINALIST_CONFIRMED',
+        entityType: 'FinalistConfirmation',
+        entityId: confirmation.id,
+        detailsJson: {
+          projectId: confirmation.projectId,
+          attendingUserIds: input.attendingUserIds,
+        },
+      })
+      return { ok: true }
+    }),
+
+  /**
+   * Public decline. Captures an optional reason. Triggers waitlist promotion
+   * for the same category. The freshly-promoted waitlist team gets its own
+   * fresh 24h-ish window (read from the round configJson; the round id is
+   * resolved via the project's most-recent grand-finale round, since the
+   * decliner won't pass it back).
+   */
+  decline: publicProcedure
+    .input(z.object({ token: z.string(), reason: z.string().max(500).optional() }))
+    .mutation(async ({ ctx, input }) => {
+      const payload = verifyFinalistToken(input.token)
+      const confirmation = await ctx.prisma.finalistConfirmation.findUnique({
+        where: { id: payload.confirmationId },
+        include: { project: { select: { programId: true } } },
+      })
+      if (!confirmation) throw new TRPCError({ code: 'NOT_FOUND' })
+      if (confirmation.token !== input.token) {
+        throw new TRPCError({ code: 'UNAUTHORIZED' })
+      }
+      if (confirmation.status !== 'PENDING') {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message: `Confirmation is ${confirmation.status}, not PENDING`,
+        })
+      }
+      await ctx.prisma.finalistConfirmation.update({
+        where: { id: confirmation.id },
+        data: {
+          status: 'DECLINED',
+          declinedAt: new Date(),
+          declineReason: input.reason ?? null,
+        },
+      })
+      await logAudit({
+        prisma: ctx.prisma,
+        action: 'FINALIST_DECLINED',
+        entityType: 'FinalistConfirmation',
+        entityId: confirmation.id,
+        detailsJson: {
+          projectId: confirmation.projectId,
+          reason: input.reason ?? null,
+        },
+      })
+
+      // Promote next waitlist entry in same category. windowHours pulled from
+      // the live grand-finale round in the program (LIVE_FINAL roundType).
+      const round = await ctx.prisma.round.findFirst({
+        where: {
+          competition: { programId: confirmation.project.programId },
+          roundType: 'LIVE_FINAL',
+        },
+        orderBy: { sortOrder: 'desc' },
+        select: { configJson: true },
+      })
+      const cfg = (round?.configJson ?? {}) as { confirmationWindowHours?: number }
+      const windowHours = cfg.confirmationWindowHours ?? 24
+      await promoteNextWaitlistEntry(ctx.prisma, {
+        programId: confirmation.project.programId,
+        category: confirmation.category,
+        windowHours,
+      })
+
+      return { ok: true }
+    }),
 })
diff --git a/src/server/services/finalist-confirmation.ts b/src/server/services/finalist-confirmation.ts
index 3446ee9..d1d7f43 100644
--- a/src/server/services/finalist-confirmation.ts
+++ b/src/server/services/finalist-confirmation.ts
@@ -1,14 +1,15 @@
 import type { CompetitionCategory, PrismaClient } from '@prisma/client'
 import { signFinalistToken } from '@/lib/finalist-token'
+import { sendFinalistConfirmationEmail } from '@/lib/email'
 
-type AnyPrisma = Pick<PrismaClient, 'finalistConfirmation'>
+type AnyPrisma = Pick<PrismaClient, 'finalistConfirmation' | 'waitlistEntry' | 'project'>
 
 /**
  * Create a PENDING FinalistConfirmation row with a signed token. Caller is
  * responsible for sending the notification email separately.
  */
 export async function createPendingConfirmation(
-  prisma: AnyPrisma,
+  prisma: Pick<PrismaClient, 'finalistConfirmation'>,
   args: {
     projectId: string
     category: CompetitionCategory
@@ -38,3 +39,69 @@ export async function createPendingConfirmation(
   })
   return { id, token, deadline }
 }
+
+/**
+ * Promote the lowest-ranked WAITING waitlist entry in the given category to
+ * PROMOTED, create a fresh PENDING confirmation for the project, and send
+ * the notification email. No-op if no WAITING entry exists.
+ */
+export async function promoteNextWaitlistEntry(
+  prisma: AnyPrisma,
+  args: { programId: string; category: CompetitionCategory; windowHours: number },
+): Promise<{ promoted: boolean; entryId?: string; confirmationId?: string }> {
+  const entry = await prisma.waitlistEntry.findFirst({
+    where: {
+      programId: args.programId,
+      category: args.category,
+      status: 'WAITING',
+    },
+    orderBy: { rank: 'asc' },
+  })
+  if (!entry) return { promoted: false }
+
+  await prisma.waitlistEntry.update({
+    where: { id: entry.id },
+    data: { status: 'PROMOTED' },
+  })
+
+  const { id: confirmationId, token, deadline } = await createPendingConfirmation(prisma, {
+    projectId: entry.projectId,
+    category: args.category,
+    windowHours: args.windowHours,
+    promotedFromWaitlistEntryId: entry.id,
+  })
+
+  // Send email — log and continue on failure.
+  const project = await prisma.project.findUnique({
+    where: { id: entry.projectId },
+    select: {
+      title: true,
+      teamMembers: {
+        where: { role: 'LEAD' },
+        take: 1,
+        select: { user: { select: { email: true, name: true } } },
+      },
+    },
+  })
+  const lead = project?.teamMembers[0]?.user
+  if (lead?.email && project) {
+    const baseUrl = (process.env.NEXTAUTH_URL ?? 'http://localhost:3000').replace(/\/$/, '')
+    const confirmUrl = `${baseUrl}/finalist/confirm/${token}`
+    try {
+      await sendFinalistConfirmationEmail(
+        lead.email,
+        lead.name ?? null,
+        project.title,
+        deadline,
+        confirmUrl,
+      )
+    } catch (err) {
+      console.error(
+        `[promoteNextWaitlistEntry] failed to send email for project ${entry.projectId}:`,
+        err,
+      )
+    }
+  }
+
+  return { promoted: true, entryId: entry.id, confirmationId }
+}
diff --git a/tests/unit/finalist-confirmation.test.ts b/tests/unit/finalist-confirmation.test.ts
index 7572f74..d663fa4 100644
--- a/tests/unit/finalist-confirmation.test.ts
+++ b/tests/unit/finalist-confirmation.test.ts
@@ -187,3 +187,366 @@ describe('finalist.selectFinalists', () => {
     ).rejects.toThrow(/category mismatch/i)
   })
 })
+
+describe('finalist.confirm and decline (public)', () => {
+  const programIds: string[] = []
+  const userIds: string[] = []
+
+  afterAll(async () => {
+    for (const programId of programIds) {
+      await prisma.attendingMember.deleteMany({
+        where: { confirmation: { project: { programId } } },
+      })
+      await prisma.finalistConfirmation.deleteMany({ where: { project: { programId } } })
+      await prisma.waitlistEntry.deleteMany({ where: { programId } })
+      await cleanupTestData(programId, [])
+    }
+    if (userIds.length > 0) {
+      await prisma.user.deleteMany({ where: { id: { in: userIds } } })
+    }
+  })
+
+  async function setupPendingConfirmation(programName: string) {
+    const program = await createTestProgram({ name: programName })
+    programIds.push(program.id)
+    const lead = await prisma.user.create({
+      data: {
+        id: uid('user'),
+        email: `lead_${uid()}@test.local`,
+        name: 'Team Lead',
+        role: 'APPLICANT',
+        roles: ['APPLICANT'],
+        status: 'ACTIVE',
+      },
+    })
+    userIds.push(lead.id)
+    const teammate = await prisma.user.create({
+      data: {
+        id: uid('user'),
+        email: `mate_${uid()}@test.local`,
+        name: 'Teammate',
+        role: 'APPLICANT',
+        roles: ['APPLICANT'],
+        status: 'ACTIVE',
+      },
+    })
+    userIds.push(teammate.id)
+    const project = await createTestProject(program.id, {
+      title: 'Confirmable Project',
+      competitionCategory: 'STARTUP',
+    })
+    await prisma.teamMember.createMany({
+      data: [
+        { projectId: project.id, userId: lead.id, role: 'LEAD' },
+        { projectId: project.id, userId: teammate.id, role: 'MEMBER' },
+      ],
+    })
+    const competition = await createTestCompetition(program.id, { status: 'ACTIVE' })
+    const round = await createTestRound(competition.id, {
+      roundType: 'LIVE_FINAL',
+      configJson: { confirmationWindowHours: 24 },
+    })
+    return { program, lead, teammate, project, round }
+  }
+
+  it('confirm with valid token + valid attendees succeeds', async () => {
+    const { program, lead, teammate, project } = await setupPendingConfirmation(
+      `confirm-ok-${uid()}`,
+    )
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const adminCaller = createCaller(finalistRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    const round = await prisma.round.findFirstOrThrow({
+      where: { competition: { programId: program.id } },
+    })
+    await adminCaller.selectFinalists({
+      programId: program.id,
+      category: 'STARTUP',
+      projectIds: [project.id],
+      roundId: round.id,
+    })
+    const confirmation = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { projectId: project.id },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await publicCaller.confirm({
+      token: confirmation.token,
+      attendingUserIds: [lead.id, teammate.id],
+      visaFlags: { [teammate.id]: true },
+    })
+    const updated = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { id: confirmation.id },
+      include: { attendingMembers: true },
+    })
+    expect(updated.status).toBe('CONFIRMED')
+    expect(updated.attendingMembers).toHaveLength(2)
+    const visaForTeammate = updated.attendingMembers.find((a) => a.userId === teammate.id)
+    expect(visaForTeammate?.needsVisa).toBe(true)
+    const visaForLead = updated.attendingMembers.find((a) => a.userId === lead.id)
+    expect(visaForLead?.needsVisa).toBe(false)
+  })
+
+  it('confirm rejects userIds not in the project team', async () => {
+    const { program, project } = await setupPendingConfirmation(`confirm-bad-${uid()}`)
+    const outsider = await prisma.user.create({
+      data: {
+        id: uid('user'),
+        email: `outsider_${uid()}@test.local`,
+        name: 'Outsider',
+        role: 'APPLICANT',
+        roles: ['APPLICANT'],
+        status: 'ACTIVE',
+      },
+    })
+    userIds.push(outsider.id)
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const adminCaller = createCaller(finalistRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    const round = await prisma.round.findFirstOrThrow({
+      where: { competition: { programId: program.id } },
+    })
+    await adminCaller.selectFinalists({
+      programId: program.id,
+      category: 'STARTUP',
+      projectIds: [project.id],
+      roundId: round.id,
+    })
+    const confirmation = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { projectId: project.id },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await expect(
+      publicCaller.confirm({
+        token: confirmation.token,
+        attendingUserIds: [outsider.id],
+        visaFlags: {},
+      }),
+    ).rejects.toThrow(/not a team member/i)
+  })
+
+  it('confirm rejects when attendee count > program.defaultAttendeeCap', async () => {
+    const { program, lead, teammate, project } = await setupPendingConfirmation(
+      `confirm-cap-${uid()}`,
+    )
+    await prisma.program.update({ where: { id: program.id }, data: { defaultAttendeeCap: 1 } })
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const adminCaller = createCaller(finalistRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    const round = await prisma.round.findFirstOrThrow({
+      where: { competition: { programId: program.id } },
+    })
+    await adminCaller.selectFinalists({
+      programId: program.id,
+      category: 'STARTUP',
+      projectIds: [project.id],
+      roundId: round.id,
+    })
+    const confirmation = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { projectId: project.id },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await expect(
+      publicCaller.confirm({
+        token: confirmation.token,
+        attendingUserIds: [lead.id, teammate.id],
+        visaFlags: {},
+      }),
+    ).rejects.toThrow(/attendee cap/i)
+  })
+
+  it('decline marks the confirmation DECLINED with optional reason', async () => {
+    const { program, project } = await setupPendingConfirmation(`decline-${uid()}`)
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const adminCaller = createCaller(finalistRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    const round = await prisma.round.findFirstOrThrow({
+      where: { competition: { programId: program.id } },
+    })
+    await adminCaller.selectFinalists({
+      programId: program.id,
+      category: 'STARTUP',
+      projectIds: [project.id],
+      roundId: round.id,
+    })
+    const confirmation = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { projectId: project.id },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await publicCaller.decline({ token: confirmation.token, reason: 'team disbanded' })
+    const updated = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { id: confirmation.id },
+    })
+    expect(updated.status).toBe('DECLINED')
+    expect(updated.declineReason).toBe('team disbanded')
+    expect(updated.declinedAt).not.toBeNull()
+  })
+
+  it('decline triggers next waitlist entry promotion', async () => {
+    const { program, project } = await setupPendingConfirmation(`decline-cascade-${uid()}`)
+    // Create a waitlist entry for a different project in the same category
+    const backupProject = await createTestProject(program.id, {
+      title: 'Backup',
+      competitionCategory: 'STARTUP',
+    })
+    const backupLead = await prisma.user.create({
+      data: {
+        id: uid('user'),
+        email: `backup_${uid()}@test.local`,
+        name: 'Backup Lead',
+        role: 'APPLICANT',
+        roles: ['APPLICANT'],
+        status: 'ACTIVE',
+      },
+    })
+    userIds.push(backupLead.id)
+    await prisma.teamMember.create({
+      data: { projectId: backupProject.id, userId: backupLead.id, role: 'LEAD' },
+    })
+    const waitlistEntry = await prisma.waitlistEntry.create({
+      data: {
+        programId: program.id,
+        projectId: backupProject.id,
+        category: 'STARTUP',
+        rank: 1,
+        status: 'WAITING',
+      },
+    })
+
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const adminCaller = createCaller(finalistRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    const round = await prisma.round.findFirstOrThrow({
+      where: { competition: { programId: program.id } },
+    })
+    await adminCaller.selectFinalists({
+      programId: program.id,
+      category: 'STARTUP',
+      projectIds: [project.id],
+      roundId: round.id,
+    })
+    const original = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { projectId: project.id },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await publicCaller.decline({ token: original.token })
+
+    // Backup project should now have a PENDING confirmation
+    const promoted = await prisma.finalistConfirmation.findUnique({
+      where: { projectId: backupProject.id },
+    })
+    expect(promoted).not.toBeNull()
+    expect(promoted?.status).toBe('PENDING')
+    expect(promoted?.promotedFromWaitlistEntryId).toBe(waitlistEntry.id)
+
+    const updatedEntry = await prisma.waitlistEntry.findUniqueOrThrow({
+      where: { id: waitlistEntry.id },
+    })
+    expect(updatedEntry.status).toBe('PROMOTED')
+  })
+
+  it('decline succeeds even when waitlist is empty', async () => {
+    const { program, project } = await setupPendingConfirmation(`decline-empty-${uid()}`)
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const adminCaller = createCaller(finalistRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    const round = await prisma.round.findFirstOrThrow({
+      where: { competition: { programId: program.id } },
+    })
+    await adminCaller.selectFinalists({
+      programId: program.id,
+      category: 'STARTUP',
+      projectIds: [project.id],
+      roundId: round.id,
+    })
+    const confirmation = await prisma.finalistConfirmation.findUniqueOrThrow({
+      where: { projectId: project.id },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await expect(publicCaller.decline({ token: confirmation.token })).resolves.toEqual({
+      ok: true,
+    })
+  })
+
+  it('getByToken rejects expired tokens', async () => {
+    const { program, project } = await setupPendingConfirmation(`confirm-expired-${uid()}`)
+    // Manually create a confirmation with a past deadline + signed-expired token
+    const { signFinalistToken } = await import('../../src/lib/finalist-token')
+    const id = `cmfc_expired_${uid()}`
+    const expiredExp = Math.floor(Date.now() / 1000) - 60
+    const token = signFinalistToken({ confirmationId: id, exp: expiredExp })
+    await prisma.finalistConfirmation.create({
+      data: {
+        id,
+        projectId: project.id,
+        category: 'STARTUP',
+        status: 'PENDING',
+        deadline: new Date(Date.now() - 60_000),
+        token,
+      },
+    })
+    const publicCaller = finalistRouter.createCaller({
+      session: null,
+      prisma,
+      ip: '127.0.0.1',
+      userAgent: 'vitest',
+    } as never)
+    await expect(publicCaller.getByToken({ token })).rejects.toThrow(/expired/i)
+    // Cleanup
+    await prisma.finalistConfirmation.delete({ where: { id } })
+    void program
+  })
+})