diff --git a/docs/plans/agenda-tags-eventos-impl.md b/docs/plans/agenda-tags-eventos-impl.md
new file mode 100644
index 00000000..0c93b9c5
--- /dev/null
+++ b/docs/plans/agenda-tags-eventos-impl.md
@@ -0,0 +1,86 @@
+# Impl: Agenda — tags para agrupar compromissos + filtro por tag na omnibox
+
+Status: aprovado
+Atualizado em: 2026-08-09
+Issue: #506
+Intenção: docs/plans/agenda-tags-eventos.md
+Appetite restante: herdado (~1 dia eng)
+
+## Leitura da intenção
+
+- **Outcome:** cada equipe agrupa os compromissos do jeito dela: tags livres no sheet de criação (chips, texto livre, sugestões das já usadas), rótulo leve no evento do calendário, e a agenda filtra por tag dentro da filter omnibox existente (C94), combinando com os demais filtros e persistindo no estado/URL como eles.
+- **O que NÃO negociar:** tag não é `Contact` nem a coleção `Tag` dos posts; texto livre (sugestões são autocomplete, não lista obrigatória); filtro é **dimensão da omnibox existente** (não barra/chips separados); liderança não acessa a agenda (inalterado); sem regressão em criação com horário, remanejo por arrasto (C15), filtros C94 e "Mais detalhes" (C91).
+- **O que reavaliar:** a hipótese de direção diz "a tag entra como opção da omnibox" — **isso já foi entregue pelo C94** (2026-08-09): `ActivityAgendaState.tag`, sugestões de `knownTags` (vazias visíveis), chips removíveis, `buildActivityAgendaWhere` com `tags: { contains }`, `restrictActivityAgendaState` por tags acessíveis, `loadAccessibleActivityTags` na página. O gap real do C105 está em: **(1)** campo de tags no sheet inline (`ActivityInlineCreate`), **(2)** rótulo de tag no evento do calendário, **(3)** tags via prefill do "Mais detalhes" (`buildActivityCreateHref`/`parseActivityCreatePrefill`), **(4)** threading de `knownTags` da página da agenda até o sheet.
+
+## Abordagem recomendada
+
+```mermaid
+flowchart LR
+  Page[agenda/page.tsx] -- knownTags --> Agenda[ActivityAgenda]
+  Agenda -- knownTags --> Sheet[ActivityInlineCreate]
+  Sheet --> TagInput[ActivityTagInput (extraído do ActivityForm)]
+  Sheet -- tagsJson --> Action[createActivityInline]
+  Sheet -- tags no href --> Prefill[buildActivityCreateHref]
+  Prefill --> Nova[/atividades/nova/]
+  Nova --> Form[ActivityForm → TagInput initialTags]
+  Agenda -- extendedProps.tags --> Event[renderEventContent → rótulo leve]
+```
+
+**Opções consideradas:**
+
+- **A)** Reusar o `TagInput` já existente em `ActivityForm.tsx` (hoje privado), extraindo-o para um componente compartilhado `src/components/campaign/activity/ActivityTagInput.tsx`, usado pelo sheet e pelo form.
+- **B)** Escrever um segundo campo de tags no sheet (duplicar).
+- **C)** Levar tags ao evento só via `title` (concatenar no texto) e pular prefill/mais detalhes.
+
+**Recomendação: A (+ C para o rótulo? não — rótulo dedicado).** A: 2 call sites com comportamento idêntico (chips, dedup, limite, datalist de sugestões) → extrair é DRY de conhecimento; a extração é refactor preservador de comportamento (mesmo hidden input `tagsJson`, mesmo limite `MAX_ACTIVITY_TAGS`/`MAX_ACTIVITY_TAG_LENGTH`), com adições retrocompatíveis: `name` prop (default `tagsJson`), `useId()` no datalist (2 instâncias simultâneas nunca acontecem, mas id fixo é risco barato de eliminar) e `onChange` opcional para o href do "Mais detalhes" (o sheet constrói o href em render a partir de estado React, não de FormData).
+
+**Rejeitadas:** B porque duplicaria dedup/limites/datalist e os dois campos divergiriam; C para o rótulo porque o aceite pede "rótulo leve de tag" no evento e misturar no título degrada busca/leitura (o `title` é usado em busca da lista e notificações).
+
+**Divergência da hipótese de direção da intenção:** a intenção (rascunho 2026-08-09) foi escrita antes do C94 entregar a dimensão Tag da omnibox; o impl plan assume isso e não reimplementa nada do filtro.
+
+### Componentes / mudanças
+
+- **`ActivityTagInput`** (`src/components/campaign/activity/ActivityTagInput.tsx`, NOVO): `TagInput` extraído de `ActivityForm.tsx` com as adições acima. Mesma UI (chips `bg-secondary`, botão ×, input com datalist, Enter/vírgula/Backspace, blur commit), hidden input `tagsJson`, `FieldDescription` ("Classificação livre do compromisso…").
+- **`ActivityInlineCreate`** (`src/components/campaign/activity/ActivityInlineCreate.tsx`): nova prop `knownTags?: string[]`; campo "Tags" (TagInput) após Local; submit envia `tags` parseados de `tagsJson` (parser inline espelhando `parseInlineResponsibles`, fail-closed); "Mais detalhes" inclui `tags` no prefill; estado espelho via `onChange` para o href.
+- **`ActivityAgenda`** (`src/components/campaign/activity/ActivityAgenda.tsx`): nova prop `knownTags?: string[]` repassada ao sheet; `toEventInput` ganha `tags` em `extendedProps`; `renderEventContent` renderiza linha de tags (≤2 + "+N") apenas em views timeGrid (week/day) e list, escondida no mês (denso) e no mobile (mesma media query da location).
+- **`ActivityAgenda.css`**: `.activity-agenda-event-tags` (muted, ellipsis, oculto em ≤767px junto com a location).
+- **`agenda/page.tsx`**: passa `knownTags` ao `ActivityAgenda` (já carrega `loadAccessibleActivityTags`).
+- **`activityUi.ts`**: `ActivityCreatePrefill.tags?: string[]`; `buildActivityCreateHref` serializa `tags` como **params repetidos** (`tags=a&tags=b` — tag livre pode conter vírgula, então nada de join por vírgula; JSON no URL é feio); `parseActivityCreatePrefill` lê `getAll('tags')` com fail-closed (trims, drop > `MAX_ACTIVITY_TAG_LENGTH`, cap `MAX_ACTIVITY_TAGS` — mesmo padrão do `title` bounded).
+- **`ActivityForm.tsx`**: usa o componente extraído; `initialTags={initialValues?.tags ?? activity?.tags ?? []}`.
+- **Migration:** NÃO — o campo `tags` (hasMany text) já existe na collection desde C14; o filtro já filtra; sem schema/access/Consent novos.
+
+### Dados → forma (se aplicável)
+
+- Forma escolhida: rótulo textual leve (linha muted, `#tag`), não badge colorido — tag não tem identidade visual (corte da intenção); o filtro ativo já é o destaque. Rejeitadas: chips/badges por tag no evento (poluição visual em slots de 30 min), ocultar completamente (o aceite pede o rótulo).
+
+## Fases verificáveis
+
+1. **Utilities/prefill** — `ActivityCreatePrefill.tags` + `buildActivityCreateHref` + `parseActivityCreatePrefill`; testes unit em `activityUi.unit.spec.ts` (round-trip, limites, fail-closed). `pnpm test tests/unit/activityUi.unit.spec.ts`.
+2. **Extração + sheet + threading** — `ActivityTagInput.tsx`, `ActivityForm` usando o extraído, `ActivityInlineCreate` com campo/knownTags/submit/href, `ActivityAgenda` + página repassando `knownTags`; testes em `activityInlineCreate.unit.spec.tsx` (chip por Enter, save com tags, href com tags, sugestões do datalist). `pnpm test tests/unit/activityInlineCreate.unit.spec.tsx`.
+3. **Rótulo no evento** — `extendedProps.tags` + render condicional por view + CSS; teste de render no `activityAgendaInteractions.unit.spec.tsx` se o harness permitir (senão teste do view model já cobre `tags`).
+4. **Gates** — `pnpm gate:fast` na iteração; entrega com `pnpm push`.
+
+## Rabbit holes / Não escopo (engenharia)
+
+- Não tocar no chassis da omnibox compartilhada (a dimensão Tag já está lá; nada das demais listas muda).
+- Não mudar `MAX_ACTIVITY_TAGS`/`MAX_ACTIVITY_TAG_LENGTH` (ver Riscos — divergência da recomendação da intenção).
+- Não levar tags ao feed iCal (C92–C96 já usam `filterTag`/descrição; fora de escopo da intenção).
+- Não criar cores/taxonomia por tag; sem admin.
+
+### Adiado com gatilho (triage /simplify, 2026-08-09)
+
+- **Normalização de tags unificada.** O cleanup da sessão removeu a 3ª cópia (`parseInlineTags` — o sheet agora lê do estado espelho), mas restam dois parsers com política levemente diferente: `parseTagsFormData` (`src/utilities/activityFormData.ts`, server, slice, sem dedup) e `parseActivityPrefillTags` (`src/utilities/activityUi.ts`, URL, drop, dedup). **Gatilho:** um 3º ponto de parse de tags OU qualquer edição em `parseTagsFormData` → extrair `normalizeActivityTags` puro em `src/lib/schemas/activity.ts` com política por fronteira.
+- **Footer sticky do sheet** (scrola junto em viewports baixos): **Gatilho:** C103 (in-progress) remodela o sheet de criação — avaliar lá, não aqui.
+
+## Riscos e mitigação
+
+- **Limites 3 tags / ~24 chars da intenção vs 20/80 existentes (C14).** A intenção marca a recomendação como "(assumido — validar)" e "ajustável depois"; o código shipped usa 20/80 compartilhados com o composer de giro (C14), o parse de URL (`activityTag`) e o schema. Apertar agora seria regressão em comportamento shipped e quebraria tags existentes > 24 chars (o filtro as descartaria do URL). **Decisão proposta: manter 20/80**; "poucas tags" é satisfeito pela affordance da UI. Ajuste futuro é barato (constante única) — registrado como decisão do gate.
+- **Rótulo poluindo visões densas (mês).** Mitigação: render só em timeGrid/list + oculto no mobile (padrão da location); truncado com ellipsis e "+N".
+- **Conflito de merge com C103/C104** (in-progress em outros worktrees, mesma superfície — sheet). C105 toca `ActivityInlineCreate` de forma aditiva (campo novo + props); resolução de conflito no merge sequencial de main. Sem dependência de código deles.
+- **Extração do TagInput mudar o form cheio.** Refactor preservador: mesmos props nomeados, mesmo hidden input, mesmo datalist; `pnpm test` + gates pegam drift; o form cheio não tem teste unit próprio hoje (coberto por e2e/regressão).
+
+## Aceite de engenharia
+
+- [x] Aceite de produto da intenção ainda coberto (filtro já entregue por C94; sheet/rótulo/prefill entregues aqui)
+- [x] Invariantes AGENTS/engineering-standards (sem migration, sem access/Consent, ids em inglês, copy pt-BR)
+- [x] Testes de domínio previstos (unit: prefill tags, inline create com tags, rótulo)
diff --git a/src/app/(campaign)/campanha/(app)/agenda/page.tsx b/src/app/(campaign)/campanha/(app)/agenda/page.tsx
index b0fb58e2..17a79263 100644
--- a/src/app/(campaign)/campanha/(app)/agenda/page.tsx
+++ b/src/app/(campaign)/campanha/(app)/agenda/page.tsx
@@ -87,7 +87,11 @@ export default async function AgendaPage({ searchParams }: AgendaPageProps) {
           knownTags={knownTags}
         />
         <CampaignListResults>
-          <ActivityAgenda state={state} municipalityOptions={municipalityOptions} />
+          <ActivityAgenda
+            state={state}
+            municipalityOptions={municipalityOptions}
+            knownTags={knownTags}
+          />
         </CampaignListResults>
       </CampaignListPendingBoundary>
     </CampaignPageShell>
diff --git a/src/components/campaign/activity/ActivityAgenda.css b/src/components/campaign/activity/ActivityAgenda.css
index 774bdf85..e7acaf29 100644
--- a/src/components/campaign/activity/ActivityAgenda.css
+++ b/src/components/campaign/activity/ActivityAgenda.css
@@ -90,7 +90,8 @@
 }
 
 .activity-agenda-event-time,
-.activity-agenda-event-location {
+.activity-agenda-event-location,
+.activity-agenda-event-tags {
   overflow: hidden;
   font-size: 0.6875rem;
   opacity: 0.82;
@@ -202,7 +203,8 @@
     flex-direction: column;
   }
 
-  .activity-agenda-event-location {
+  .activity-agenda-event-location,
+  .activity-agenda-event-tags {
     display: none;
   }
 }
diff --git a/src/components/campaign/activity/ActivityAgenda.tsx b/src/components/campaign/activity/ActivityAgenda.tsx
index d23b81a3..da15d350 100644
--- a/src/components/campaign/activity/ActivityAgenda.tsx
+++ b/src/components/campaign/activity/ActivityAgenda.tsx
@@ -57,6 +57,7 @@ type AgendaEventProps = {
   deputyPresent: boolean
   municipalityName: string | null
   locality: string | null
+  tags: string[]
 }
 
 const eventColors: Record<ActivityStatus, { color: string; contrastColor: string }> = {
@@ -95,12 +96,28 @@ const toEventInput = (event: ActivityAgendaEvent): EventInput => ({
     deputyPresent: event.deputyPresent,
     municipalityName: event.municipality?.name ?? null,
     locality: event.locality,
+    tags: event.tags,
   } satisfies AgendaEventProps,
 })
 
-const renderEventContent = ({ event, timeText }: EventDisplayInfo) => {
+/**
+ * C105 — the tag row is a light label, not a badge: tag has no visual
+ * identity (the active filter is the highlight). Two tags plus a "+N" cap
+ * the row so a dense slot never floods.
+ */
+export const tagsLabel = (tags: readonly string[]): string | null => {
+  if (tags.length === 0) return null
+  const shown = tags.slice(0, 2)
+  const overflow = tags.length - shown.length
+  const label = shown.map((tag) => `#${tag}`).join(' ')
+  return overflow > 0 ? `${label} +${overflow}` : label
+}
+
+const renderEventContent = ({ event, timeText, view }: EventDisplayInfo) => {
   const props = event.extendedProps as AgendaEventProps
   const location = [props.municipalityName, props.locality].filter(Boolean).join(' · ')
+  // The tag row only renders outside the dense month grid.
+  const tags = view.type.startsWith('dayGrid') ? null : tagsLabel(props.tags)
 
   return (
     <div className="activity-agenda-event-content">
@@ -115,6 +132,7 @@ const renderEventContent = ({ event, timeText }: EventDisplayInfo) => {
       </div>
       <span className="activity-agenda-event-title">{event.title}</span>
       {location ? <span className="activity-agenda-event-location">{location}</span> : null}
+      {tags ? <span className="activity-agenda-event-tags">{tags}</span> : null}
       <span className="activity-agenda-event-status">{activityStatusLabels[props.status]}</span>
     </div>
   )
@@ -123,9 +141,11 @@ const renderEventContent = ({ event, timeText }: EventDisplayInfo) => {
 export const ActivityAgenda = ({
   state,
   municipalityOptions = [],
+  knownTags,
 }: {
   state: ActivityAgendaState
   municipalityOptions?: RelationOption[]
+  knownTags?: string[]
 }) => {
   const containerRef = useRef<HTMLDivElement>(null)
   const calendarRef = useRef<CalendarRef>(null)
@@ -463,6 +483,7 @@ export const ActivityAgenda = ({
         isNarrow={isNarrow}
         agendaState={state}
         municipalityOptions={municipalityOptions}
+        knownTags={knownTags}
         onClose={() => setCreateDraft(null)}
         onCreated={() => {
           setCreateDraft(null)
diff --git a/src/components/campaign/activity/ActivityForm.tsx b/src/components/campaign/activity/ActivityForm.tsx
index 23778147..237d92ef 100644
--- a/src/components/campaign/activity/ActivityForm.tsx
+++ b/src/components/campaign/activity/ActivityForm.tsx
@@ -1,9 +1,10 @@
 'use client'
 
 import Link from 'next/link'
-import { useActionState, useState } from 'react'
+import { useActionState } from 'react'
 
 import { ActivityDemandFields } from '@/components/campaign/activity/ActivityDemandFields'
+import { ActivityTagInput } from '@/components/campaign/activity/ActivityTagInput'
 import { ActivityTaskFields } from '@/components/campaign/activity/ActivityTaskFields'
 import type { ContactComboboxOption } from '@/components/campaign/shared/ContactCombobox'
 import {
@@ -18,13 +19,12 @@ import { Alert, AlertDescription, AlertTitle } from '@/components/ui/Alert'
 import { Button } from '@/components/ui/button'
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
 import { Checkbox } from '@/components/ui/Checkbox'
-import { Field, FieldDescription, FieldError, FieldGroup, FieldLabel } from '@/components/ui/field'
+import { Field, FieldError, FieldGroup, FieldLabel } from '@/components/ui/field'
 import { Input } from '@/components/ui/input'
 import { NativeSelect, NativeSelectOption } from '@/components/ui/native-select'
 import { Spinner } from '@/components/ui/Spinner'
 import { Textarea } from '@/components/ui/textarea'
 import { formatIsoAsBahiaDateTimeInput } from '@/lib/campaignTime'
-import { MAX_ACTIVITY_TAG_LENGTH, MAX_ACTIVITY_TAGS } from '@/lib/schemas/activity'
 import type { ActivityCreatePrefill } from '@/utilities/activityUi'
 import type { ActivityFormViewModel } from '@/utilities/activityViewModels'
 import { fieldError } from '@/utilities/campaignFormFields'
@@ -54,88 +54,6 @@ export type ActivityFormFieldsProps = {
   knownTags?: string[]
 }
 
-const TagInput = ({
-  initialTags = [],
-  knownTags = [],
-  error,
-}: {
-  initialTags?: string[]
-  knownTags?: string[]
-  error?: string
-}) => {
-  const [tags, setTags] = useState<string[]>(initialTags)
-  const [input, setInput] = useState('')
-
-  const datalistId = 'activity-tags-datalist'
-
-  const addTag = (raw: string) => {
-    const trimmed = raw.trim().slice(0, MAX_ACTIVITY_TAG_LENGTH)
-    if (!trimmed) return
-    if (tags.includes(trimmed)) return
-    if (tags.length >= MAX_ACTIVITY_TAGS) return
-    setTags((current) => [...current, trimmed])
-    setInput('')
-  }
-
-  const removeTag = (tag: string) => {
-    setTags((current) => current.filter((entry) => entry !== tag))
-  }
-
-  return (
-    <div className="flex flex-col gap-2">
-      <div className="flex flex-wrap items-center gap-2">
-        {tags.map((tag) => (
-          <span
-            key={tag}
-            className="inline-flex items-center gap-1 rounded-md bg-secondary px-2 py-1 text-xs"
-          >
-            {tag}
-            <button
-              type="button"
-              onClick={() => removeTag(tag)}
-              className="rounded-sm opacity-70 hover:opacity-100"
-              aria-label={`Remover tag ${tag}`}
-            >
-              ×
-            </button>
-          </span>
-        ))}
-        {tags.length < MAX_ACTIVITY_TAGS ? (
-          <Input
-            value={input}
-            onChange={(event) => setInput(event.target.value)}
-            onKeyDown={(event) => {
-              if (event.key === 'Enter' || event.key === ',') {
-                event.preventDefault()
-                addTag(input)
-              } else if (event.key === 'Backspace' && !input && tags.length > 0) {
-                setTags((current) => current.slice(0, -1))
-              }
-            }}
-            onBlur={() => addTag(input)}
-            placeholder={tags.length === 0 ? 'Ex.: comício, imprensa…' : 'Adicionar tag…'}
-            className="min-h-9 flex-1"
-            list={datalistId}
-            maxLength={MAX_ACTIVITY_TAG_LENGTH}
-          />
-        ) : null}
-        <datalist id={datalistId}>
-          {knownTags
-            .filter((tag) => !tags.includes(tag))
-            .map((tag) => (
-              <option key={tag} value={tag} />
-            ))}
-        </datalist>
-      </div>
-      <input type="hidden" name="tagsJson" value={JSON.stringify(tags)} />
-      <FieldDescription>
-        Classificação livre do compromisso. Digite e pressione Enter ou vírgula para adicionar.
-      </FieldDescription>
-      {error ? <FieldError>{error}</FieldError> : null}
-    </div>
-  )
-}
-
 const ActivityFormFields = ({
   municipalityOptions,
   organizationOptions,
@@ -184,8 +102,8 @@ const ActivityFormFields = ({
 
             <Field data-invalid={Boolean(errorFor('tagsJson'))}>
               <FieldLabel>Tags</FieldLabel>
-              <TagInput
-                initialTags={activity?.tags ?? []}
+              <ActivityTagInput
+                initialTags={initialValues?.tags ?? activity?.tags ?? []}
                 knownTags={knownTags}
                 error={errorFor('tagsJson')}
               />
diff --git a/src/components/campaign/activity/ActivityInlineCreate.tsx b/src/components/campaign/activity/ActivityInlineCreate.tsx
index 48e701a9..5bbfba8f 100644
--- a/src/components/campaign/activity/ActivityInlineCreate.tsx
+++ b/src/components/campaign/activity/ActivityInlineCreate.tsx
@@ -7,6 +7,7 @@ import { toast } from 'sonner'
 import { searchActivityResponsibleOptionsAction } from '@/app/(campaign)/campanha/(app)/atividades/contactSearchActions'
 import { createActivityInline } from '@/app/(campaign)/campanha/actions/activity'
 import { ActivityDateTimeField } from '@/components/campaign/activity/ActivityDateTimeField'
+import { ActivityTagInput } from '@/components/campaign/activity/ActivityTagInput'
 import type { RelationOption } from '@/components/campaign/shared/RelationMultiSelect'
 import { ResponsibleMultiSelect } from '@/components/campaign/shared/ResponsibleMultiSelect'
 import { StrictCombobox } from '@/components/campaign/shared/StrictCombobox'
@@ -50,6 +51,7 @@ type ActivityInlineCreateProps = {
   isNarrow: boolean
   agendaState: ActivityAgendaState
   municipalityOptions: RelationOption[]
+  knownTags?: string[]
   onClose: () => void
   onCreated: () => void
 }
@@ -57,17 +59,29 @@ type ActivityInlineCreateProps = {
 const inlineMunicipalityOptions = (options: RelationOption[]): StrictComboboxOption[] =>
   options.map((option) => ({ value: String(option.id), label: option.name }))
 
-const parseInlineResponsibles = (
-  raw: FormDataEntryValue | null,
-): ActivityCreateInput['responsible'] => {
-  if (typeof raw !== 'string') return undefined
-  let parsed: unknown
+/**
+ * Bounded JSON-array read for the inline sheet's `responsiblesJson` hidden
+ * input: same 4 KB cap as the full form's `boundedJsonFormValue`, fail-closed
+ * on malformed or oversized payloads (the component generates the JSON, so a
+ * violation means tampering, not user input).
+ */
+const INLINE_JSON_MAX_BYTES = 4_000
+
+const parseInlineJsonArray = (raw: FormDataEntryValue | null): unknown[] | undefined => {
+  if (typeof raw !== 'string' || raw.length > INLINE_JSON_MAX_BYTES) return undefined
   try {
-    parsed = JSON.parse(raw)
+    const parsed: unknown = JSON.parse(raw)
+    return Array.isArray(parsed) && parsed.length > 0 ? parsed : undefined
   } catch {
     return undefined
   }
-  if (!Array.isArray(parsed) || parsed.length === 0) return undefined
+}
+
+const parseInlineResponsibles = (
+  raw: FormDataEntryValue | null,
+): ActivityCreateInput['responsible'] => {
+  const parsed = parseInlineJsonArray(raw)
+  if (!parsed) return undefined
 
   const entries: Array<{
     relationTo: 'campaignUser' | 'leadership' | 'stateDeputy'
@@ -85,18 +99,21 @@ const ActivityInlineCreateForm = ({
   endAt,
   agendaState,
   municipalityOptions,
+  knownTags,
   onCreated,
 }: {
   startAt: string
   endAt: string
   agendaState: ActivityAgendaState
   municipalityOptions: RelationOption[]
+  knownTags?: string[]
   onCreated: () => void
 }) => {
   const [title, setTitle] = useState('')
   const [start, setStart] = useState(formatIsoAsBahiaDateTimeInput(startAt))
   const [end, setEnd] = useState(formatIsoAsBahiaDateTimeInput(endAt))
   const [locality, setLocality] = useState('')
+  const [tags, setTags] = useState<string[]>([])
   const preselectedMunicipalityId =
     agendaState.municipality &&
     municipalityOptions.some((option) => option.id === agendaState.municipality)
@@ -109,11 +126,15 @@ const ActivityInlineCreateForm = ({
 
   const errorFor = (name: string) => fieldErrors[name]?.[0]
 
+  // C105 — the href mirrors the LIVE state (times edited in the sheet, typed
+  // tags), not the slot draft, so "Mais detalhes" carries everything the user
+  // actually filled.
   const moreDetailsHref = buildActivityCreateHref(agendaState, {
-    startAt,
-    endAt,
+    startAt: parseBahiaDateTimeInput(start) ?? undefined,
+    endAt: end ? (parseBahiaDateTimeInput(end) ?? undefined) : undefined,
     municipalityId: municipalityValue ? Number(municipalityValue) : undefined,
     title: title.trim() || undefined,
+    tags: tags.length > 0 ? tags : undefined,
   })
 
   const handleSubmit = async (event: FormEvent<HTMLFormElement>) => {
@@ -152,6 +173,9 @@ const ActivityInlineCreateForm = ({
         ...(endIso ? { endAt: endIso } : {}),
         ...(locality.trim() ? { locality: locality.trim() } : {}),
         ...(responsible ? { responsible } : {}),
+        // C105 — the tags mirror state (every chip mutation fires `onChange`),
+        // so the payload reads the same source the "Mais detalhes" href uses.
+        ...(tags.length > 0 ? { tags } : {}),
       })
       if (result.ok) {
         onCreated()
@@ -245,6 +269,11 @@ const ActivityInlineCreateForm = ({
         />
       </Field>
 
+      <Field>
+        <FieldLabel>Tags</FieldLabel>
+        <ActivityTagInput knownTags={knownTags} onChange={setTags} />
+      </Field>
+
       <ResponsibleMultiSelect
         name="responsiblesJson"
         label="Responsáveis"
@@ -275,6 +304,7 @@ export const ActivityInlineCreate = ({
   isNarrow,
   agendaState,
   municipalityOptions,
+  knownTags,
   onClose,
   onCreated,
 }: ActivityInlineCreateProps) => {
@@ -286,6 +316,7 @@ export const ActivityInlineCreate = ({
       endAt={draft.endAt}
       agendaState={agendaState}
       municipalityOptions={municipalityOptions}
+      knownTags={knownTags}
       onCreated={onCreated}
     />
   )
@@ -313,7 +344,18 @@ export const ActivityInlineCreate = ({
       >
         <PopoverAnchor />
       </div>
-      <PopoverContent align="start" sideOffset={8} className="w-96 p-4">
+      {/* C105 — the tags field made the sheet taller. The height is capped at
+          the space Radix computed for the current placement
+          (`--radix-popper-available-height`, set by its `size` middleware):
+          the sheet always fits the viewport on its placed side and scrolls
+          internally instead of clipping fields off-screen (a static cap is
+          not enough — Radix runs shift before flip, so an overflowing
+          popover can end up with its top fields out of view). */}
+      <PopoverContent
+        align="start"
+        sideOffset={8}
+        className="max-h-(--radix-popper-available-height) w-96 overflow-y-auto p-4"
+      >
         {form}
       </PopoverContent>
     </Popover>
diff --git a/src/components/campaign/activity/ActivityTagInput.tsx b/src/components/campaign/activity/ActivityTagInput.tsx
new file mode 100644
index 00000000..9ec7a373
--- /dev/null
+++ b/src/components/campaign/activity/ActivityTagInput.tsx
@@ -0,0 +1,113 @@
+'use client'
+
+import { useId, useState } from 'react'
+
+import { FieldDescription, FieldError } from '@/components/ui/field'
+import { Input } from '@/components/ui/input'
+import { MAX_ACTIVITY_TAG_LENGTH, MAX_ACTIVITY_TAGS } from '@/lib/schemas/activity'
+
+/**
+ * C105 — free-form tag chips shared by the activity form and the agenda's
+ * inline create sheet (C91). Tags are typed freely, deduped and bounded;
+ * `knownTags` feed a datalist of tags already used in the campaign
+ * (autocomplete, never a curated list). The hidden input carries the JSON
+ * tags under `tagsJson` so the surrounding form's FormData contract stays
+ * untouched; `onChange` is an optional live mirror for consumers that build
+ * state from the tags before submit.
+ */
+export const ActivityTagInput = ({
+  initialTags = [],
+  knownTags = [],
+  error,
+  onChange,
+}: {
+  initialTags?: string[]
+  knownTags?: string[]
+  error?: string
+  onChange?: (tags: string[]) => void
+}) => {
+  const [tags, setTags] = useState<string[]>(initialTags)
+  const [input, setInput] = useState('')
+
+  const datalistId = useId()
+
+  const addTag = (raw: string) => {
+    const trimmed = raw.trim().slice(0, MAX_ACTIVITY_TAG_LENGTH)
+    if (!trimmed) return
+    if (tags.includes(trimmed)) return
+    if (tags.length >= MAX_ACTIVITY_TAGS) return
+    const next = [...tags, trimmed]
+    setTags(next)
+    setInput('')
+    onChange?.(next)
+  }
+
+  const removeTag = (tag: string) => {
+    const next = tags.filter((entry) => entry !== tag)
+    setTags(next)
+    onChange?.(next)
+  }
+
+  const removeLastTag = () => {
+    if (tags.length === 0) return
+    const next = tags.slice(0, -1)
+    setTags(next)
+    onChange?.(next)
+  }
+
+  return (
+    <div className="flex flex-col gap-2">
+      <div className="flex flex-wrap items-center gap-2">
+        {tags.map((tag) => (
+          <span
+            key={tag}
+            className="inline-flex items-center gap-1 rounded-md bg-secondary px-2 py-1 text-xs"
+          >
+            {tag}
+            <button
+              type="button"
+              onClick={() => removeTag(tag)}
+              className="rounded-sm opacity-70 hover:opacity-100"
+              aria-label={`Remover tag ${tag}`}
+            >
+              ×
+            </button>
+          </span>
+        ))}
+        {tags.length < MAX_ACTIVITY_TAGS ? (
+          <Input
+            value={input}
+            onChange={(event) => setInput(event.target.value)}
+            onKeyDown={(event) => {
+              if (event.key === 'Enter' || event.key === ',') {
+                event.preventDefault()
+                addTag(input)
+              } else if (event.key === 'Backspace' && !input) {
+                event.preventDefault()
+                removeLastTag()
+              }
+            }}
+            onBlur={() => addTag(input)}
+            placeholder={tags.length === 0 ? 'Ex.: comício, imprensa…' : 'Adicionar tag…'}
+            className="min-h-9 flex-1"
+            list={datalistId}
+            maxLength={MAX_ACTIVITY_TAG_LENGTH}
+            aria-label="Adicionar tag"
+          />
+        ) : null}
+        <datalist id={datalistId}>
+          {knownTags
+            .filter((tag) => !tags.includes(tag))
+            .map((tag) => (
+              <option key={tag} value={tag} />
+            ))}
+        </datalist>
+      </div>
+      <input type="hidden" name="tagsJson" value={JSON.stringify(tags)} />
+      <FieldDescription>
+        Classificação livre do compromisso. Digite e pressione Enter ou vírgula para adicionar.
+      </FieldDescription>
+      {error ? <FieldError>{error}</FieldError> : null}
+    </div>
+  )
+}
diff --git a/src/utilities/activityUi.ts b/src/utilities/activityUi.ts
index 404a5785..5053fe36 100644
--- a/src/utilities/activityUi.ts
+++ b/src/utilities/activityUi.ts
@@ -10,6 +10,7 @@ import { isContactSearchQueryReady, normalizeContactSearchQuery } from '@/lib/co
 import {
   activityStatuses,
   MAX_ACTIVITY_TAG_LENGTH,
+  MAX_ACTIVITY_TAGS,
   type ActivityStatus,
 } from '@/lib/schemas/activity'
 import {
@@ -280,6 +281,7 @@ export type ActivityCreatePrefill = {
   endAt?: string
   municipalityId?: number
   title?: string
+  tags?: string[]
 }
 
 export const buildActivityCreateHref = (
@@ -292,6 +294,9 @@ export const buildActivityCreateHref = (
   const municipalityId = prefill.municipalityId ?? agendaState.municipality
   if (municipalityId) params.set('municipality', String(municipalityId))
   if (prefill.title) params.set('title', prefill.title)
+  // C105 — repeated `tags` params: a free-form tag may contain a comma, so a
+  // comma-joined single value would corrupt the boundary between tags.
+  for (const tag of prefill.tags ?? []) params.append('tags', tag)
   params.set('returnTo', buildActivityAgendaHref(agendaState))
   return `/campanha/atividades/nova?${params.toString()}`
 }
@@ -359,6 +364,23 @@ const normalizedIsoInstant = (value: string | undefined): string | undefined =>
   return Number.isNaN(date.getTime()) ? undefined : date.toISOString()
 }
 
+/**
+ * C105 — bounded prefill tags: repeated `tags` params, trimmed, deduped,
+ * capped at the same limits the create schema enforces. Anything out of bounds
+ * is dropped (same drop semantics as the agenda filter's `activityTag`),
+ * never rejected — a prefill is a convenience, not a contract.
+ */
+const parseActivityPrefillTags = (value: string | string[] | undefined): string[] | undefined => {
+  if (value === undefined) return undefined
+  const tags: string[] = []
+  for (const entry of Array.isArray(value) ? value : [value]) {
+    if (tags.length >= MAX_ACTIVITY_TAGS) break
+    const tag = activityTag(entry)
+    if (tag && !tags.includes(tag)) tags.push(tag)
+  }
+  return tags.length > 0 ? tags : undefined
+}
+
 export const parseActivityCreatePrefill = (
   params: RawSearchParams,
   accessibleMunicipalityIDs: ReadonlySet<number>,
@@ -372,12 +394,14 @@ export const parseActivityCreatePrefill = (
 
   const title = normalizedText(firstValue(params.title))
   const trimmedTitle = title && title.length <= 160 ? title : undefined
+  const tags = parseActivityPrefillTags(params.tags)
 
   return {
     ...(startAt ? { startAt } : {}),
     ...(endAt ? { endAt } : {}),
     ...(municipalityId ? { municipalityId } : {}),
     ...(trimmedTitle ? { title: trimmedTitle } : {}),
+    ...(tags ? { tags } : {}),
   }
 }
 
diff --git a/tests/unit/activityAgendaInteractions.unit.spec.tsx b/tests/unit/activityAgendaInteractions.unit.spec.tsx
index d9b2f10b..9208bd2a 100644
--- a/tests/unit/activityAgendaInteractions.unit.spec.tsx
+++ b/tests/unit/activityAgendaInteractions.unit.spec.tsx
@@ -107,7 +107,7 @@ vi.mock('@fullcalendar/react', () => {
   return { default: CalendarMock }
 })
 
-import { ActivityAgenda } from '@/components/campaign/activity/ActivityAgenda'
+import { ActivityAgenda, tagsLabel } from '@/components/campaign/activity/ActivityAgenda'
 import { CampaignPageChromeProvider } from '@/components/campaign/shell/CampaignPageChromeContext'
 import { stubMatchMedia } from '../helpers/matchMedia'
 
@@ -118,6 +118,22 @@ const renderAgenda = (props: { state?: object } = {}) =>
     </CampaignPageChromeProvider>,
   )
 
+describe('tagsLabel (C105)', () => {
+  it('returns null without tags', () => {
+    expect(tagsLabel([])).toBeNull()
+  })
+
+  it('prefixes tags with # and joins them', () => {
+    expect(tagsLabel(['Caminhada'])).toBe('#Caminhada')
+    expect(tagsLabel(['Caminhada', 'Imprensa'])).toBe('#Caminhada #Imprensa')
+  })
+
+  it('caps the row at two tags with a +N overflow', () => {
+    expect(tagsLabel(['A', 'B', 'C'])).toBe('#A #B +1')
+    expect(tagsLabel(['A', 'B', 'C', 'D'])).toBe('#A #B +2')
+  })
+})
+
 describe('ActivityAgenda schedule failures', () => {
   // C101 — ActivityAgenda reads the viewport signal (useIsMobileMeasured);
   // jsdom has no matchMedia, so the harness pins the desktop layout (the
diff --git a/tests/unit/activityInlineCreate.unit.spec.tsx b/tests/unit/activityInlineCreate.unit.spec.tsx
index 7acc12c0..801cceec 100644
--- a/tests/unit/activityInlineCreate.unit.spec.tsx
+++ b/tests/unit/activityInlineCreate.unit.spec.tsx
@@ -42,12 +42,14 @@ const renderOverlay = ({
   draft = DRAFT,
   agendaState = {},
   isNarrow = false,
+  knownTags = [],
   onCreated = vi.fn(),
   onClose = vi.fn(),
 }: {
   draft?: ActivityInlineCreateDraft | null
   agendaState?: ActivityAgendaState
   isNarrow?: boolean
+  knownTags?: string[]
   onCreated?: () => void
   onClose?: () => void
 } = {}) =>
@@ -57,6 +59,7 @@ const renderOverlay = ({
       isNarrow={isNarrow}
       agendaState={agendaState}
       municipalityOptions={MUNICIPALITIES}
+      knownTags={knownTags}
       onClose={onClose}
       onCreated={onCreated}
     />,
@@ -191,6 +194,85 @@ describe('ActivityInlineCreate — overlay de criação inline', () => {
     )
   })
 
+  it('adiciona tags por Enter e as envia ao salvar (C105)', async () => {
+    const onCreated = vi.fn()
+    mocks.createInline.mockResolvedValue({ ok: true })
+    renderOverlay({ agendaState: { municipality: 12 }, onCreated })
+
+    const tagInput = screen.getByPlaceholderText('Ex.: comício, imprensa…')
+    fireEvent.change(tagInput, { target: { value: 'Panfletagem' } })
+    fireEvent.keyDown(tagInput, { key: 'Enter' })
+    expect(screen.getByLabelText('Remover tag Panfletagem')).toBeTruthy()
+
+    fireEvent.change(screen.getByLabelText('Título *'), {
+      target: { value: 'Panfletagem no centro' },
+    })
+    fireEvent.click(screen.getByRole('button', { name: 'Salvar' }))
+
+    await waitFor(() => expect(mocks.createInline).toHaveBeenCalledTimes(1))
+    expect(mocks.createInline).toHaveBeenCalledWith({
+      title: 'Panfletagem no centro',
+      municipality: 12,
+      startAt: '2026-08-07T16:00:00.000Z',
+      endAt: '2026-08-07T16:30:00.000Z',
+      tags: ['Panfletagem'],
+    })
+    expect(onCreated).toHaveBeenCalledTimes(1)
+  })
+
+  it('deduplica tags e permite remover um chip antes de salvar (C105)', async () => {
+    const onCreated = vi.fn()
+    mocks.createInline.mockResolvedValue({ ok: true })
+    renderOverlay({ agendaState: { municipality: 12 }, onCreated })
+
+    const tagInput = screen.getByPlaceholderText('Ex.: comício, imprensa…')
+    for (const tag of ['Comício', 'Comício', 'Caminhada']) {
+      fireEvent.change(tagInput, { target: { value: tag } })
+      fireEvent.keyDown(tagInput, { key: 'Enter' })
+    }
+    expect(screen.getByLabelText('Remover tag Comício')).toBeTruthy()
+    expect(screen.getByLabelText('Remover tag Caminhada')).toBeTruthy()
+
+    fireEvent.click(screen.getByLabelText('Remover tag Comício'))
+    fireEvent.change(screen.getByLabelText('Título *'), {
+      target: { value: 'Comício na feira' },
+    })
+    fireEvent.click(screen.getByRole('button', { name: 'Salvar' }))
+
+    await waitFor(() => expect(mocks.createInline).toHaveBeenCalledTimes(1))
+    expect(mocks.createInline).toHaveBeenCalledWith({
+      title: 'Comício na feira',
+      municipality: 12,
+      startAt: '2026-08-07T16:00:00.000Z',
+      endAt: '2026-08-07T16:30:00.000Z',
+      tags: ['Caminhada'],
+    })
+  })
+
+  it('oferece as tags já usadas como sugestões e as carrega no href de detalhes (C105)', () => {
+    renderOverlay({
+      agendaState: { municipality: 12 },
+      knownTags: ['Comício', 'Imprensa'],
+    })
+
+    // The overlay renders inside a popover portal, so the datalist lives on
+    // document.body, not in the container returned by render; the suggestion
+    // values are `value` attributes, not option text.
+    const datalist = document.querySelector('datalist')
+    const suggestionValues = [...(datalist?.querySelectorAll('option') ?? [])].map((option) =>
+      option.getAttribute('value'),
+    )
+    expect(suggestionValues).toContain('Comício')
+    expect(suggestionValues).toContain('Imprensa')
+
+    const tagInput = screen.getByPlaceholderText('Ex.: comício, imprensa…')
+    fireEvent.change(tagInput, { target: { value: 'Panfletagem' } })
+    fireEvent.keyDown(tagInput, { key: 'Enter' })
+
+    const link = screen.getByRole('link', { name: 'Mais detalhes' })
+    expect(link.getAttribute('href')).toContain('&tags=Panfletagem')
+  })
+
   it('não renderiza nada sem um rascunho de slot', () => {
     const { container } = renderOverlay({ draft: null })
     expect(container.firstChild).toBeNull()
diff --git a/tests/unit/activityUi.unit.spec.ts b/tests/unit/activityUi.unit.spec.ts
index 3c770117..1b73f204 100644
--- a/tests/unit/activityUi.unit.spec.ts
+++ b/tests/unit/activityUi.unit.spec.ts
@@ -408,6 +408,39 @@ describe('activity create prefill', () => {
     })
     expect(parseActivityCreatePrefill({ title: 'a'.repeat(200) }, new Set())).toEqual({})
   })
+
+  it('carries inline tags into the creation URL as repeated params (C105)', () => {
+    expect(
+      buildActivityCreateHref(
+        { municipality: 12 },
+        {
+          startAt: '2026-08-07T13:00:00.000Z',
+          municipalityId: 12,
+          title: 'Panfletagem',
+          tags: ['Panfletagem', 'Caminhada, café'],
+        },
+      ),
+    ).toBe(
+      '/campanha/atividades/nova?startAt=2026-08-07T13%3A00%3A00.000Z&municipality=12&title=Panfletagem&tags=Panfletagem&tags=Caminhada%2C+caf%C3%A9&returnTo=%2Fcampanha%2Fagenda%3Fmunicipality%3D12',
+    )
+  })
+
+  it('round-trips inline tags through the create prefill (C105)', () => {
+    expect(
+      parseActivityCreatePrefill(
+        { tags: [' Panfletagem ', 'Caminhada, café', 'Panfletagem'] },
+        new Set(),
+      ),
+    ).toEqual({ tags: ['Panfletagem', 'Caminhada, café'] })
+  })
+
+  it('drops oversized and out-of-bound tags from the prefill (C105)', () => {
+    const oversized = 'a'.repeat(81)
+    expect(parseActivityCreatePrefill({ tags: [oversized, '  '] }, new Set())).toEqual({})
+    expect(parseActivityCreatePrefill({ tags: ['válida', oversized] }, new Set())).toEqual({
+      tags: ['válida'],
+    })
+  })
 })
 
 describe('activity slot prefill (C91)', () => {