diff --git a/client/src/modules/version.js b/client/src/modules/version.js
index e23e393..bd6f97b 100644
--- a/client/src/modules/version.js
+++ b/client/src/modules/version.js
@@ -11,6 +11,13 @@
 // that the two files can drift, so a test asserts they agree
 // (client/test/moduleRegistry.test.js) rather than trusting a bump to remember
 // both.
+// 1.9.0 - a module may ship its own message bodies and rules:
+// `api.registerEngagementSeeds({ templates, ruleGroups })` (ENGAGEMENT.md Phase
+// 11b, decision 7). Nothing on this half changed - a seed is server-side data
+// and core's seeders write it on the boot path - but the bodies it ships are
+// edited through the template editor this half already renders, and an operator
+// meets them there. This file bumps for the reason at the top: the two halves
+// state ONE version, and a module declares one `coreApi` range against both.
 // 1.8.0 - the ceiling lattice gains `admin` (ENGAGEMENT.md Phase 11). Nothing on
 // this half changed: a ceiling is declared on the server's `api` and enforced
 // there, and the admin screens that render one read the vocabulary from
@@ -58,4 +65,4 @@
 // but the two halves state ONE version: a module declares a single coreApi range
 // and is served one chunk, so a client that claimed 1.0.0 while the server
 // answered 1.1.0 would be two answers to one question.
-export const MODULE_API_VERSION = '1.8.0'
+export const MODULE_API_VERSION = '1.9.0'
diff --git a/server/engagement-triggers.json b/server/engagement-triggers.json
index f873359..6bc05a8 100644
--- a/server/engagement-triggers.json
+++ b/server/engagement-triggers.json
@@ -1,6 +1,6 @@
 {
   "_comment": "Generated event-trigger inventory - the authoritative freeze of CORE's engagement contract (docs/website/ENGAGEMENT.md 4.3). Regenerate with `npm run engagement:manifest` in website/server. A renamed variable, a changed type or a widened ceiling breaks stored templates and rules, so the diff here is the review signal. A module ships its own copy in its bundle; this file never contains one.",
-  "moduleApiVersion": "1.8.0",
+  "moduleApiVersion": "1.9.0",
   "triggers": [
     {
       "id": "news.post",
diff --git a/server/src/engagement/moduleSeeds.js b/server/src/engagement/moduleSeeds.js
new file mode 100644
index 0000000..06e62b6
--- /dev/null
+++ b/server/src/engagement/moduleSeeds.js
@@ -0,0 +1,179 @@
+// ── Seeding what a module ships (ENGAGEMENT.md Phase 11b, decision 7) ──────
+//
+// Core's own bodies and rules are seeded from `seedDefaults()`, and a module's
+// cannot be: `server.js` calls `seedDefaults()` BEFORE it requires `app.js`, and
+// requiring `app.js` is what scans the volume and runs the loader. At the moment
+// core seeds, no module has registered anything at all.
+//
+// So this runs from `modules/lifecycle.js` `boot()` instead — after the
+// `installed_modules` reconcile, so a module the operator disabled or one that
+// failed to load is skipped rather than seeded, and BEFORE the `onBoot`
+// dispatch, so a module that warms a cache in `onBoot` may assume its rules
+// exist.
+//
+// **It reuses core's two seeders rather than reimplementing them**, which is the
+// whole argument for the registry existing (decision 7): `seedOne` owns the
+// `customized` skip and the `seed_version` comparison, `validateEmailBlocks`
+// owns what a renderable body is, and a module supplies data. A copy of either
+// living outside this directory would drift the first time core improved the
+// original — and the drift would surface as a mail somebody already received.
+//
+// ── The asymmetry, once more, because it is the thing to get right ─────────
+//
+// **Templates are re-ensured every boot.** A row carries `seed_key`,
+// `seed_version` and `customized`, so re-ensuring is how a better default
+// reaches a deployment without stealing an operator's edit (§4.6.1 property 3),
+// and a template added in a later module version reaches every deployment rather
+// than only fresh ones.
+//
+// **Rule groups are one-shot, each under its own settings guard.** Re-ensuring a
+// rule would resurrect one an operator deleted and reset one they enabled. This
+// is 11a's seed-key finding as a mechanism: a rule appended to an existing group
+// reaches fresh installs only, and a rule that must reach already-stamped
+// deployments takes a new group key. The module chooses; this file honours it.
+//
+// **Never throws.** It is on the boot path beside every other `safe()`-wrapped
+// step in `lifecycle.boot()`, and a body that would not seed costs the shipped
+// default — `renderByKey`'s fallback stays in charge — not the deployment.
+
+const templatesDb = require('../model/engagement/engagementTemplates.db')
+const rulesDb = require('../model/engagement/engagementRules.db')
+const settingsDb = require('../model/settings/settings.db')
+const emailBlocks = require('../emailBlocks')
+const log = require('../utils/logger')('engagement')
+
+/**
+ * The one-shot guard for one module's rule group.
+ *
+ * Namespaced by owner AND by group so two modules may use the same group name,
+ * and so a module can add a second group later without touching the first. Its
+ * VALUE is the timestamp — purely so an operator reading the settings table can
+ * tell when it ran; only its presence is read.
+ */
+const guardKey = (owner, group) => `engagement_module_rules_seeded:${owner}:${group}`
+
+/**
+ * Ensure one module's templates, and bring un-customized rows up to the current
+ * seed. Idempotent.
+ */
+async function seedModuleTemplates(owner, templates, deps = {}) {
+  const templates_ = deps.templatesDb || templatesDb
+  const counts = { inserted: 0, updated: 0, skipped: 0, invalid: 0 }
+  for (const seed of templates) {
+    // Validated against the block registry before it is stored, exactly as core's
+    // own seeds are and for the same reason: a shipped block array no renderer
+    // understands sitting in the table reads to an operator as their deployment
+    // being broken. Refusing to write it leaves the fallback in charge and puts
+    // the reason in the boot log, with the module named.
+    const { valid, errors } = emailBlocks.validateEmailBlocks(seed.blocks)
+    if (!valid) {
+      log.error('a module template is invalid and was not seeded', { owner, key: seed.key, errors })
+      counts.invalid += 1
+      continue
+    }
+    try {
+      counts[await templates_.seedOne(seed)] += 1
+    } catch (err) {
+      log.error('module template seed failed', { owner, key: seed.key, message: err.message })
+    }
+  }
+
+  // The third arm of §4.6.1 property 3: a customized row is never touched, and
+  // the fact that a better default now exists is surfaced instead of applied.
+  let stale = []
+  try {
+    stale = await templates_.staleCustomized(
+      templates.map((t) => ({ key: t.key, seedVersion: t.seedVersion })),
+    )
+  } catch {
+    stale = []
+  }
+  if (stale.length) {
+    log.info('customized module templates have a newer shipped default', {
+      owner,
+      keys: stale.map((t) => t.key),
+    })
+  }
+  return { ...counts, stale: stale.map((t) => t.key) }
+}
+
+/**
+ * Seed one named rule group, once, under its own guard.
+ *
+ * Mirrors `coreRules.seedGroup` deliberately, including the stamp-on-partial
+ * behaviour: re-running would duplicate the rules that DID insert, and a
+ * duplicate rule is two mails per event — worse than the one missing rule an
+ * operator can add from the Rules screen.
+ */
+async function seedRuleGroup(owner, group, deps = {}) {
+  const rules_ = deps.rulesDb || rulesDb
+  const settings_ = deps.settingsDb || settingsDb
+  const summary = { inserted: 0, skipped: 0 }
+  const key = guardKey(owner, group.key)
+  try {
+    const seen = await settings_.get(key)
+    if (seen) return { ...summary, skipped: group.rules.length }
+
+    for (const rule of group.rules) {
+      try {
+        await rules_.insert(rule)
+        summary.inserted += 1
+      } catch (err) {
+        log.error('module rule seed failed', {
+          owner,
+          group: group.key,
+          trigger: rule.trigger_id,
+          message: err.message,
+        })
+      }
+    }
+    await settings_.set(key, new Date().toISOString())
+    if (summary.inserted) {
+      log.info('seeded module engagement rules, all disabled', {
+        owner,
+        group: group.key,
+        rules: summary.inserted,
+        note: group.note || undefined,
+      })
+    }
+  } catch (err) {
+    log.error('module rule group seeding failed', { owner, group: group.key, message: err.message })
+  }
+  return summary
+}
+
+/**
+ * Seed every registered module's engagement content.
+ *
+ * @param {object}   [deps]
+ * @param {Function} [deps.seeds]   () => [{ owner, templates, ruleGroups }]
+ * @param {Set}      [deps.skip]    owners not to seed (disabled or failed)
+ * @param {object}   [deps.templatesDb] / [deps.rulesDb] / [deps.settingsDb] — test seams
+ */
+async function seedModuleEngagement({ seeds, skip = new Set(), ...dbs } = {}) {
+  // eslint-disable-next-line global-require
+  const read = seeds || require('../modules/registries').allEngagementSeeds
+  const totals = { templates: 0, rules: 0 }
+
+  for (const entry of read()) {
+    if (skip.has(entry.owner)) {
+      log.info('skipping engagement seeds for a module that is not booting', { owner: entry.owner })
+      continue
+    }
+    const t = await seedModuleTemplates(entry.owner, entry.templates || [], dbs)
+    totals.templates += t.inserted + t.updated
+    for (const group of entry.ruleGroups || []) {
+      const r = await seedRuleGroup(entry.owner, group, dbs)
+      totals.rules += r.inserted
+    }
+    log.info('module engagement seeds ensured', { owner: entry.owner, ...t })
+  }
+  return totals
+}
+
+module.exports = {
+  seedModuleEngagement,
+  seedModuleTemplates,
+  seedRuleGroup,
+  guardKey,
+}
diff --git a/server/src/engagement/templateSeeds.js b/server/src/engagement/templateSeeds.js
index ea44d64..d77e0f0 100644
--- a/server/src/engagement/templateSeeds.js
+++ b/server/src/engagement/templateSeeds.js
@@ -44,6 +44,27 @@ const AMBIENT_VARIABLES = Object.freeze([
   { name: 'year', type: 'string', required: true, example: '2026' },
 ])
 
+
+// The per-DELIVERY additions, which are a different thing from the ambient set
+// above and are declared separately because they apply to a different set of
+// templates.
+//
+// `emailChannel.deliver` computes an unsubscribe token per recipient and merges
+// it LAST over the projection, so a body may always reference it — but a template
+// bound to a TRIGGER takes its variable list from that trigger's declaration
+// (`variablesFor`), and a trigger has no business declaring a fact about how the
+// mail was delivered. Without these, `{{unsubscribeUrl}}` renders correctly and
+// then the save-time undeclared-variable check refuses the first operator who
+// tries to EDIT the body around it.
+//
+// Found in Phase 11b, where module-uo's sixteen in-universe bodies are the first
+// trigger-bound templates in the system to carry an unsubscribe line of their
+// own: core's generic `notify.event` declares it in its own seed and is bound to
+// no trigger, so nothing had ever taken this path.
+const DELIVERY_VARIABLES = Object.freeze([
+  { name: 'unsubscribeUrl', type: 'string', required: false, example: 'https://example.com/unsubscribe/abc123' },
+])
+
 // A tiny helper so the block arrays below read as content rather than as JSON.
 const text = (id, body, opts = {}) => ({
   id,
@@ -296,4 +317,4 @@ function seedByKey(key) {
   return SEEDS.find((s) => s.key === key) || null
 }
 
-module.exports = { SEEDS, AMBIENT_VARIABLES, seedByKey }
+module.exports = { SEEDS, AMBIENT_VARIABLES, DELIVERY_VARIABLES, seedByKey }
diff --git a/server/src/engagement/templates.js b/server/src/engagement/templates.js
index 1b01205..4964be3 100644
--- a/server/src/engagement/templates.js
+++ b/server/src/engagement/templates.js
@@ -18,7 +18,7 @@ const templatesDb = require('../model/engagement/engagementTemplates.db')
 const settings = require('../model/settings/settings.model')
 const brand = require('../config/brand')
 const emailBlocks = require('../emailBlocks')
-const { SEEDS, AMBIENT_VARIABLES, seedByKey } = require('./templateSeeds')
+const { SEEDS, AMBIENT_VARIABLES, DELIVERY_VARIABLES, seedByKey } = require('./templateSeeds')
 // The trigger registry lives with the module registries, not here — a trigger is
 // something a MODULE declares (see engagement/index.js's header).
 const { eventTrigger } = require('../modules/registries')
@@ -84,6 +84,11 @@ function variablesFor(template) {
   if (template && template.trigger_id) {
     const declared = eventTrigger(template.trigger_id)
     if (declared && Array.isArray(declared.variables)) own.push(...declared.variables)
+    // A trigger-bound body is engagement mail, and engagement mail always carries
+    // an unsubscribe the channel computes per recipient. A trigger declares what
+    // HAPPENED and has no business declaring how the mail was sent, so the
+    // delivery facts are added here rather than to every declaration.
+    own.push(...DELIVERY_VARIABLES)
   } else if (template && template.seed_key) {
     const seed = seedByKey(template.seed_key)
     if (seed) own.push(...seed.variables)
diff --git a/server/src/modules/lifecycle.js b/server/src/modules/lifecycle.js
index 3a9eea3..ba78702 100644
--- a/server/src/modules/lifecycle.js
+++ b/server/src/modules/lifecycle.js
@@ -174,6 +174,32 @@ async function boot({ modules, model } = {}) {
     }
   }
 
+  // What a module SHIPS as engagement content — its message bodies and its
+  // seeded rules (ENGAGEMENT.md Phase 11b, decision 7).
+  //
+  // **Here rather than in `seedDefaults()`, and that is forced.** `server.js`
+  // seeds before it requires `app.js`, and requiring `app.js` is what scans the
+  // volume and runs the loader — so at the moment core seeds its own templates,
+  // no module has registered anything.
+  //
+  // **After the reconcile and before `onBoot`**, both deliberately: `disabled`
+  // is now known, so a module the operator switched off is skipped rather than
+  // having its rules quietly written; and a module that warms a cache in
+  // `onBoot` may assume its rules and bodies exist by then.
+  //
+  // Failed modules are skipped for the stronger reason. A module whose require
+  // or schema replay failed has registered nothing anyway — but one whose ROW
+  // says `startup_failed` may have registered before failing later, and seeding
+  // content for a module that is about to answer 503 puts rows in the operator's
+  // Rules screen for a thing that is not running.
+  const skip = new Set([
+    ...disabled,
+    ...scanned.filter((m) => m.state === 'startup_failed').map((m) => m.id),
+  ])
+  await safe('seeding module engagement content', () =>
+    // eslint-disable-next-line global-require
+    require('../engagement/moduleSeeds').seedModuleEngagement({ skip }))
+
   for (const { id, hook, ctx } of loader.bootable()) {
     try {
       // Awaited without a timeout, deliberately (§2.5): a slow onBoot delays the
diff --git a/server/src/modules/loader.js b/server/src/modules/loader.js
index d53b698..51bec59 100644
--- a/server/src/modules/loader.js
+++ b/server/src/modules/loader.js
@@ -356,6 +356,20 @@ function buildApi(record) {
       once('registerAudiences')
       record.staged.registerAudiences(audiences)
     },
+    // What the module SHIPS behind those two — its message bodies and its
+    // seeded rules (API 1.9.0, ENGAGEMENT.md Phase 11b decision 7). `once` for
+    // the same reason again, and here it is load-bearing rather than tidy: a
+    // rule belongs to exactly one named group, and merging two calls would make
+    // "which group is this rule in" — the question the one-shot guard answers —
+    // unanswerable.
+    //
+    // Data only. Nothing on the object is a function and nothing on it reaches a
+    // recipient: seeding writes rows that are `enabled = 0`, and a module still
+    // cannot send mail (§1.2).
+    registerEngagementSeeds(seeds) {
+      once('registerEngagementSeeds')
+      record.staged.registerEngagementSeeds(seeds)
+    },
     // The two lifecycle hooks (§2.5). Registered here, dispatched from
     // lifecycle.js — this file runs with no database and the hooks run with one.
     // Both are optional: a module with no warm-up and nothing to close simply
diff --git a/server/src/modules/registries.js b/server/src/modules/registries.js
index b35fc0b..ab9dbba 100644
--- a/server/src/modules/registries.js
+++ b/server/src/modules/registries.js
@@ -38,6 +38,19 @@
 //   5. `registerAudiences(audiences)`    — §5.1a. Named sets of user ids a
 //      module can resolve over its own data, for an operator to point a rule at.
 //
+// And a sixth, in Phase 11b (decision 7):
+//
+//   6. `registerEngagementSeeds({ templates, ruleGroups })` — the message BODIES
+//      and the shipped rules behind 4 and 5. A module declaring a trigger could
+//      say what its payload was and never say what it should read like, so a
+//      module's mail was core's generic body or nothing.
+//
+// **6 stores data and nothing else — no function, no handle.** A template is
+// blocks and a rule is columns, both validated here and both written by core's
+// own seeders (`engagement/moduleSeeds.js`), which is what keeps `seed_version`,
+// `customized` and the block registry in the one file that owns them. It is
+// emphatically not a send path: a module still cannot mail anyone (§1.2).
+//
 // **Triggers and notification streams share ONE id namespace** (the org lead's
 // §7.2 decision). A stream entry is a subscription toggle and a trigger is a
 // payload contract, so they stay two REGISTRATIONS with two shapes — but an id
@@ -111,6 +124,15 @@ const triggers = new Map()
 // trigger of the same name would be a collision between two unrelated things.
 const audiences = new Map()
 
+// owner → { templates: [...], ruleGroups: [...] } (ENGAGEMENT.md Phase 11b,
+// decision 7). What a module ships as CONTENT rather than as contract: the
+// bodies its triggers render through, and the rules an operator switches on.
+//
+// Keyed by owner and not by template key, because the seeder runs per module —
+// a module the operator disabled is skipped whole, and a module that failed to
+// load never gets here at all.
+const engagementSeeds = new Map()
+
 let coreRegistered = false
 
 // Stream ids that predate the module system and may not carry their owner's
@@ -723,6 +745,206 @@ function checkAudienceShape(entry) {
   }
 }
 
+// ── Engagement seeds (Phase 11b, decision 7) ───────────────────────────────
+//
+// **Two mechanisms, and the asymmetry between them is the whole design.**
+//
+// A TEMPLATE is re-ensured on every boot. Its row carries `seed_key`,
+// `seed_version` and `customized`, so re-ensuring is how a better default
+// reaches a deployment without stealing an operator's edit (§4.6.1 property 3),
+// and a template added in a later module version reaches every deployment rather
+// than only fresh ones.
+//
+// A RULE is the opposite. Re-ensuring one would resurrect a rule an operator
+// deleted and reset one they enabled — so rules arrive in named GROUPS, each
+// with its own one-shot settings guard. That is 11a's seed-key finding stated as
+// an API instead of as a warning: appending a rule to an existing group reaches
+// fresh installs only, and a rule that must reach deployments already stamped
+// takes a NEW group. The module names its groups, so the module makes that
+// choice knowingly.
+//
+// Everything below is a shape check. Nothing here writes: `engagement/
+// moduleSeeds.js` does, through the same `seedOne` and the same block validator
+// core's own seeds go through.
+
+// A module template key must be namespaced to its owner, for the same reason a
+// trigger id must: `engagement_templates.key` is UNIQUE across the table, so an
+// unprefixed `notify.event` from a module would collide with core's — and win or
+// lose depending on boot order, which is the worst of both.
+const TEMPLATE_KEY = /^[a-z][a-z0-9]*(?:[.-][a-z0-9]+)*$/
+const MAX_TEMPLATE_KEY = 96
+const SEED_GROUP_KEY = /^[a-z][a-z0-9]*(?:[-.][a-z0-9]+)*$/
+
+// The channels a seeded template may target. Deliberately a literal rather than
+// a read of the channel registry: this runs at registration time, which is
+// before any channel a module might add is registered, and a seed for a channel
+// nothing delivers is a row an operator can never use.
+const SEEDABLE_CHANNELS = ['email', 'inapp']
+
+// Core's own seed keys, which a module's rule MAY point at — that is §4.6.1
+// property 1 in force, and the nine plain bodies of decision 9 are exactly this.
+// Required lazily-safe: `templateSeeds` is pure data with no requires of its own.
+// eslint-disable-next-line global-require
+const coreTemplateKeys = () => new Set(require('../engagement/templateSeeds').SEEDS.map((s) => s.key))
+
+function checkSeedTemplate(owner, entry) {
+  const t = entry || {}
+  const where = `registerEngagementSeeds: template "${t.key}"`
+  if (!TEMPLATE_KEY.test(t.key || '') || t.key.length > MAX_TEMPLATE_KEY) {
+    throw new Error(`registerEngagementSeeds: bad template key "${t.key}"`)
+  }
+  if (!t.key.startsWith(`${owner}.`)) {
+    throw new Error(`${where} is not namespaced "${owner}."`)
+  }
+  if (!t.name) throw new Error(`${where} has no name`)
+  if (!SEEDABLE_CHANNELS.includes(t.channel)) {
+    throw new Error(`${where} has unknown channel "${t.channel}" (one of ${SEEDABLE_CHANNELS.join(', ')})`)
+  }
+  if (!Array.isArray(t.blocks) || !t.blocks.length) throw new Error(`${where} has no blocks`)
+  if (!Number.isInteger(t.seedVersion) || t.seedVersion < 1) {
+    throw new Error(`${where} needs an integer seedVersion of 1 or more`)
+  }
+  // An email body without a subject is a mail with an empty subject line, which
+  // no operator meant; an in-app body WITH one is a column the inbox does not
+  // read (`inapp.event` leaves it NULL and says why).
+  if (t.channel === 'email' && !t.subject) throw new Error(`${where} is an email body with no subject`)
+  if (t.channel !== 'email' && t.subject) {
+    throw new Error(`${where} is a ${t.channel} body and cannot carry a subject`)
+  }
+  // `protected` is core's alone. It means "the system breaks without this body",
+  // which is true of a password reset and true of nothing a module ships; a
+  // module marking its own template undeletable is a module taking an operator's
+  // delete button away.
+  if (t.protected) throw new Error(`${where} may not be protected — that flag is core's`)
+  return {
+    key: t.key,
+    name: t.name,
+    channel: t.channel,
+    subject: t.subject || null,
+    blocks: t.blocks,
+    seedVersion: t.seedVersion,
+    triggerId: t.triggerId || null,
+    triggerVersion: Number.isInteger(t.triggerVersion) ? t.triggerVersion : null,
+    protected: false,
+    status: 'published',
+  }
+}
+
+function checkSeedRule(owner, entry, ownTemplateKeys, coreKeys) {
+  const r = entry || {}
+  const where = `registerEngagementSeeds: rule for "${r.trigger_id}"`
+  if (!EVENT_ID.test(r.trigger_id || '')) {
+    throw new Error(`registerEngagementSeeds: bad rule trigger_id "${r.trigger_id}"`)
+  }
+  // A module seeds rules for ITS OWN triggers. Shipping one for core's — or for
+  // another module's — would mean uninstalling this module leaves a rule behind
+  // that nobody can explain, and two modules could ship two rules for the same
+  // event with neither aware of the other.
+  if (!namespaced(owner, r.trigger_id, LEGACY_STREAM_IDS)) {
+    throw new Error(`${where} is not namespaced "${owner}."`)
+  }
+  if (!r.name) throw new Error(`${where} has no name`)
+  if (!Array.isArray(r.channels) || !r.channels.length) throw new Error(`${where} has no channels`)
+  if (!r.audience) throw new Error(`${where} has no audience`)
+  if (!Number.isInteger(r.cooldown_seconds) || r.cooldown_seconds < 0) {
+    throw new Error(`${where} needs a cooldown_seconds of 0 or more`)
+  }
+  // Q3's hard ceiling, and the reason a seeded rule cannot omit it: it is what
+  // keeps a misconfiguration from becoming a mail storm, so a module may choose
+  // the number and may not decline to have one.
+  if (!Number.isInteger(r.max_sends_per_hour) || r.max_sends_per_hour < 1) {
+    throw new Error(`${where} needs a max_sends_per_hour of 1 or more`)
+  }
+  const keys = r.template_keys || {}
+  if (!keys || typeof keys !== 'object' || Array.isArray(keys)) {
+    throw new Error(`${where} needs a template_keys object`)
+  }
+  for (const [channel, key] of Object.entries(keys)) {
+    // `digest` is a template slot rather than a channel — the digest worker's
+    // body for a rule whose email channel is set to digest mode — so it is
+    // allowed here and absent from `channels`.
+    if (!ownTemplateKeys.has(key) && !coreKeys.has(key)) {
+      throw new Error(
+        `${where} names template "${key}" for ${channel}, which is neither one of its own seeds nor core's`,
+      )
+    }
+  }
+  return {
+    trigger_id: r.trigger_id,
+    name: r.name,
+    audience: r.audience,
+    audience_segment_id: null,
+    channels: [...r.channels],
+    template_keys: { ...keys },
+    conditions: r.conditions === undefined ? null : r.conditions,
+    cooldown_seconds: r.cooldown_seconds,
+    delay_seconds: Number.isInteger(r.delay_seconds) ? r.delay_seconds : 0,
+    cancel_on: Array.isArray(r.cancel_on) ? [...r.cancel_on] : [],
+    // Never negotiable and never a parameter (Q3). A module that could ship an
+    // enabled rule could mail a deployment's whole user table on the strength of
+    // an upgrade nobody read the release note for.
+    enabled: 0,
+    updated_by: null,
+  }
+}
+
+/**
+ * `registerEngagementSeeds({ templates, ruleGroups })`.
+ *
+ * Validated whole, exactly as `apply()` validates: a module that got one of
+ * thirty-two templates wrong ships none of them, and finds out at boot with the
+ * offending key named rather than at send time with a half-seeded table.
+ */
+function checkEngagementSeeds(owner, entry) {
+  const e = entry || {}
+  if (e.templates !== undefined && !Array.isArray(e.templates)) {
+    throw new Error('registerEngagementSeeds: templates must be an array')
+  }
+  if (e.ruleGroups !== undefined && !Array.isArray(e.ruleGroups)) {
+    throw new Error('registerEngagementSeeds: ruleGroups must be an array')
+  }
+  const templates = []
+  const seenKeys = new Set()
+  for (const t of e.templates || []) {
+    const checked = checkSeedTemplate(owner, t)
+    if (seenKeys.has(checked.key)) {
+      throw new Error(`registerEngagementSeeds: template "${checked.key}" declared twice`)
+    }
+    seenKeys.add(checked.key)
+    templates.push(checked)
+  }
+
+  const coreKeys = coreTemplateKeys()
+  const ruleGroups = []
+  const seenGroups = new Set()
+  for (const g of e.ruleGroups || []) {
+    const group = g || {}
+    if (!SEED_GROUP_KEY.test(group.key || '')) {
+      throw new Error(`registerEngagementSeeds: bad rule group key "${group.key}"`)
+    }
+    if (seenGroups.has(group.key)) {
+      throw new Error(`registerEngagementSeeds: rule group "${group.key}" declared twice`)
+    }
+    seenGroups.add(group.key)
+    if (!Array.isArray(group.rules) || !group.rules.length) {
+      throw new Error(`registerEngagementSeeds: rule group "${group.key}" has no rules`)
+    }
+    ruleGroups.push({
+      key: group.key,
+      note: group.note || '',
+      rules: group.rules.map((r) => checkSeedRule(owner, r, seenKeys, coreKeys)),
+    })
+  }
+  return { templates, ruleGroups }
+}
+
+/** Every registrant's seeds, in registration order. What the seeder walks. */
+const allEngagementSeeds = () =>
+  [...engagementSeeds.entries()].map(([owner, seeds]) => ({ owner, ...seeds }))
+
+/** One registrant's, or null. */
+const engagementSeedsFor = (owner) => engagementSeeds.get(owner) || null
+
 // `specFile` is CORE-ONLY and is not on the module-facing signature. A slot's
 // router reaches the app through declareSlot(), which no static parse of app.js
 // can follow, so swagger-autogen would silently drop every route in it — the
@@ -757,6 +979,7 @@ function stage(owner) {
     slashCommands: [],
     triggers: [],
     audiences: [],
+    engagementSeeds: [],
   }
   return {
     staged,
@@ -788,6 +1011,9 @@ function stage(owner) {
       if (!Array.isArray(entries)) throw new Error('registerAudiences: expected an array')
       for (const e of entries) staged.audiences.push(checkAudienceShape(e))
     },
+    registerEngagementSeeds(entry) {
+      staged.engagementSeeds.push(checkEngagementSeeds(owner, entry))
+    },
   }
 }
 
@@ -810,6 +1036,7 @@ function apply({
   slashCommands: newSlashCommands = [],
   triggers: newTriggers = [],
   audiences: newAudiences = [],
+  engagementSeeds: newSeeds = [],
 }) {
   // ── validate ──
   const seenStreams = new Set()
@@ -886,6 +1113,14 @@ function apply({
     seenSlots.add(x.slot)
   }
 
+  // One call per registrant, like the post hook and the team provider above it.
+  // A second call is a module that wrote its seeds in two places, and merging
+  // them silently would make "which group is this rule in" unanswerable.
+  if (newSeeds.length > 1) throw new Error(`"${owner}" registered engagement seeds more than once`)
+  if (newSeeds.length && engagementSeeds.has(owner)) {
+    throw new Error(`"${owner}" already registered engagement seeds`)
+  }
+
   if (newPostHooks.length > 1) throw new Error(`"${owner}" registered more than one post hook`)
   if (newPostHooks.length && postHooks.has(owner)) {
     throw new Error(`"${owner}" already registered a post hook`)
@@ -921,6 +1156,7 @@ function apply({
   for (const c of newSlashCommands) slashCommands.set(c.name, { owner, ...c })
   for (const t of newTriggers) triggers.set(t.id, { owner, ...t })
   for (const a of newAudiences) audiences.set(a.id, { owner, ...a })
+  for (const seeds of newSeeds) engagementSeeds.set(owner, seeds)
 }
 
 // ── Core's own registrations ───────────────────────────────────────────────
@@ -996,6 +1232,7 @@ function _reset() {
   slashCommands.clear()
   triggers.clear()
   audiences.clear()
+  engagementSeeds.clear()
   coreRegistered = false
 }
 
@@ -1023,6 +1260,9 @@ module.exports = {
   allAudiences,
   audience,
   resolveAudience,
+  allEngagementSeeds,
+  engagementSeedsFor,
+  SEEDABLE_CHANNELS,
   VARIABLE_TYPES,
   TRIGGER_KINDS,
   stage,
diff --git a/server/src/modules/version.js b/server/src/modules/version.js
index 157b28e..2aa6743 100644
--- a/server/src/modules/version.js
+++ b/server/src/modules/version.js
@@ -9,6 +9,39 @@
 // Deliberately separate from PROTOCOL_VERSION (which versions the shard wire and
 // has nothing to say about a website module) and from any module's own version.
 
+// 1.9.0 - a sixth registration call: `api.registerEngagementSeeds({ templates,
+// ruleGroups })` (docs/website/ENGAGEMENT.md Phase 11b, decision 7). A module
+// could declare a trigger from 1.7.0 and could never say what the mail should
+// READ like: `templateSeeds.js` and `coreRules.js` are core files with core
+// arrays in them, so a module's notification was core's generic body or nothing.
+// Additions only, so minor: every module written against 1.8.0 keeps working and
+// simply seeds nothing.
+//
+// **What a module has to know about it beyond the new name**, because the two
+// halves behave differently on purpose:
+//
+//   - **Templates are re-ensured on every boot**, under `seed_key` /
+//     `seed_version` / `customized` - so bumping a body's `seedVersion` reaches
+//     every deployment except the ones where an operator edited that row, and a
+//     template added in a later module version reaches everyone.
+//   - **Rules are one-shot, per named GROUP.** Re-ensuring one would resurrect a
+//     rule an operator deleted and reset one they enabled, so each group carries
+//     its own settings guard. A rule appended to an existing group therefore
+//     reaches FRESH INSTALLS ONLY; one that must reach deployments already
+//     stamped takes a new group key. That is 11a's seed-key finding as an API
+//     rather than as a warning, and the module makes the choice knowingly.
+//
+// Two things it deliberately does not permit. A seeded rule is always
+// `enabled = 0` - it is not a parameter - which is Q3's invariant surviving
+// contact with the largest seed set in the workstream. And a module may not mark
+// a template `protected`: that flag means "the system breaks without this body",
+// which is true of a password reset and of nothing a module ships, and a module
+// setting it would take an operator's delete button away.
+//
+// It runs from `modules/lifecycle.js` `boot()` rather than `seedDefaults()`, and
+// that is forced rather than chosen: core seeds before `app.js` is required, and
+// requiring `app.js` is what runs the loader.
+
 // 1.8.0 - a seventh value in the audience ceiling lattice: `admin`, a child of
 // `staff` (docs/website/ENGAGEMENT.md Phase 11, decision 1). A module may now
 // declare `ceiling: 'admin'` on a trigger or an audience, so the set of values
@@ -101,6 +134,6 @@
 // an admin action a module performs belongs in core's one audit log, the
 // extension slot needs the user its prefix names, and §2.7 forbids a module
 // reading core's `APP_BASE_URL` for itself. Additions only, so minor.
-const MODULE_API_VERSION = '1.8.0'
+const MODULE_API_VERSION = '1.9.0'
 
 module.exports = { MODULE_API_VERSION }
diff --git a/server/test/emailTemplates.test.js b/server/test/emailTemplates.test.js
index 9ef94af..1c4cfe8 100644
--- a/server/test/emailTemplates.test.js
+++ b/server/test/emailTemplates.test.js
@@ -19,6 +19,7 @@ const { SEEDS, AMBIENT_VARIABLES, seedByKey } = require('../src/engagement/templ
 const templatesDb = require('../src/model/engagement/engagementTemplates.db')
 const settings = require('../src/model/settings/settings.model')
 const templates = require('../src/engagement/templates')
+const registries = require('../src/modules/registries')
 
 const SITE = 'Runic Gateway'
 const BASE = 'https://shard.example.com'
@@ -400,6 +401,30 @@ test('variablesFor answers from the seed for a template with no trigger, plus th
   assert.deepEqual(templates.variablesFor({}).map((v) => v.name), ['siteName', 'siteUrl', 'logoUrl', 'year'])
 })
 
+test('a TRIGGER-bound template also gets the per-delivery variables', () => {
+  // Phase 11b. `emailChannel.deliver` computes an unsubscribe token per recipient
+  // and merges it last, so `{{unsubscribeUrl}}` has always RENDERED — but a
+  // trigger-bound template takes its variable list from the trigger, and a
+  // trigger has no business declaring a fact about how the mail was sent. Without
+  // this, a body carrying an unsubscribe line rendered correctly and then the
+  // save-time undeclared-variable check refused the first operator who edited it.
+  //
+  // Nothing had taken this path before: core's `notify.event` declares the
+  // variable in its own seed and is bound to no trigger.
+  registries.registerCore()
+  const names = templates.variablesFor({ trigger_id: 'news.post' }).map((v) => v.name)
+  assert.ok(names.includes('unsubscribeUrl'), 'a trigger-bound body may reference it')
+  assert.ok(names.includes('title'), 'and still gets the trigger\'s own')
+  assert.ok(names.includes('siteName'), 'and the ambient set')
+
+  // A SEEDLESS, triggerless template gets neither — there is no delivery to
+  // describe, and an unsubscribe link on a password reset is meaningless.
+  assert.equal(
+    templates.variablesFor({}).map((v) => v.name).includes('unsubscribeUrl'),
+    false,
+  )
+})
+
 // ── The seeder and the render entrypoint ────────────────────────────────────
 
 test('the shipped default is used when the row is missing, and when it is unusable', async () => {
diff --git a/server/test/moduleEngagementSeeds.test.js b/server/test/moduleEngagementSeeds.test.js
new file mode 100644
index 0000000..5ac2674
--- /dev/null
+++ b/server/test/moduleEngagementSeeds.test.js
@@ -0,0 +1,294 @@
+// ── registerEngagementSeeds + the module seeder ────────────────────────────
+//
+// ENGAGEMENT.md Phase 11b, decision 7. Two halves, tested apart because they
+// fail differently: the REGISTRY refuses a bad declaration at boot with the key
+// named, and the SEEDER decides what reaches the database and — much more
+// importantly — what does not reach it a second time.
+//
+// The properties worth a test are the ones no hand run would catch:
+//
+//   • a module cannot ship an ENABLED rule, or a `protected` template, or a body
+//     for someone else's trigger, or a rule pointing at a template that does not
+//     exist. Each of those is a shipped mistake that only shows up as mail.
+//   • templates are re-ensured and rules are NOT — the asymmetry the whole
+//     design rests on, and the one an implementer would most plausibly "tidy".
+//   • a disabled module is skipped, which is the operator's switch meaning what
+//     it says even for content that is only rows in a table.
+
+process.env.DB_HOST = '127.0.0.1'
+process.env.DB_PORT = '59999'
+
+const { test, beforeEach, after } = require('node:test')
+const assert = require('node:assert/strict')
+
+const registries = require('../src/modules/registries')
+const db = require('../src/utils/db')
+
+after(() => db.close())
+beforeEach(() => registries._reset())
+
+const blocks = [{ id: 'p1', type: 'email.text', props: { text: 'Hail, {{siteName}}.' } }]
+
+const tpl = (over = {}) => ({
+  key: 'demo.house.warning',
+  name: 'A warning',
+  channel: 'email',
+  subject: 'A warning',
+  seedVersion: 1,
+  blocks,
+  ...over,
+})
+
+const rule = (over = {}) => ({
+  trigger_id: 'demo.house.warning',
+  name: 'House warning',
+  audience: 'owner',
+  channels: ['email'],
+  template_keys: { email: 'demo.house.warning' },
+  cooldown_seconds: 3600,
+  max_sends_per_hour: 200,
+  ...over,
+})
+
+/** Register a seed batch as `owner`; returns the error message or null. */
+function trySeeds(owner, seeds) {
+  const api = registries.stage(owner)
+  try {
+    api.registerEngagementSeeds(seeds)
+    registries.apply(api.staged)
+    return null
+  } catch (err) {
+    return err.message
+  }
+}
+
+// ── The registry: what a module may and may not ship ───────────────────────
+
+test('a well-formed batch registers and reads back under its owner', () => {
+  assert.equal(trySeeds('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', note: 'the first set', rules: [rule()] }],
+  }), null)
+
+  const all = registries.allEngagementSeeds()
+  assert.equal(all.length, 1)
+  assert.equal(all[0].owner, 'demo')
+  assert.equal(all[0].templates.length, 1)
+  assert.equal(all[0].ruleGroups[0].key, 'v1')
+  assert.deepEqual(registries.engagementSeedsFor('demo').templates[0].key, 'demo.house.warning')
+  assert.equal(registries.engagementSeedsFor('nobody'), null)
+})
+
+test('a seeded rule is always disabled, whatever the module said', () => {
+  // Q3's invariant, and the one place in the workstream where a module could
+  // have overridden it. `enabled: 1` is not refused — it is IGNORED — because
+  // refusing would let a typo take a deployment's whole module offline at boot.
+  assert.equal(trySeeds('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule({ enabled: 1 })] }],
+  }), null)
+  assert.equal(registries.engagementSeedsFor('demo').ruleGroups[0].rules[0].enabled, 0)
+})
+
+test('a template key must be namespaced to its owner', () => {
+  // `engagement_templates.key` is UNIQUE across the table, so an unprefixed
+  // `notify.event` from a module would collide with core's and win or lose on
+  // boot order.
+  const err = trySeeds('demo', { templates: [tpl({ key: 'notify.event' })] })
+  assert.match(err, /not namespaced "demo\."/)
+})
+
+test('a module may not ship a rule for a trigger it does not own', () => {
+  const err = trySeeds('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule({ trigger_id: 'news.post' })] }],
+  })
+  assert.match(err, /not namespaced "demo\."/)
+})
+
+test('a module may not mark a template protected', () => {
+  const err = trySeeds('demo', { templates: [tpl({ protected: true })] })
+  assert.match(err, /may not be protected/)
+})
+
+test('a rule must name a template that exists — its own or core\'s', () => {
+  const missing = trySeeds('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule({ template_keys: { email: 'demo.nope' } })] }],
+  })
+  assert.match(missing, /neither one of its own seeds nor core's/)
+
+  // Core's generic bodies ARE permitted — that is §4.6.1 property 1 in force,
+  // and the nine plain bodies of decision 9 are exactly this case.
+  registries._reset()
+  assert.equal(trySeeds('demo', {
+    ruleGroups: [{
+      key: 'v1',
+      rules: [rule({ template_keys: { email: 'notify.event', inapp: 'inapp.event', digest: 'notify.digest' } })],
+    }],
+  }), null)
+})
+
+test('an email body needs a subject and an in-app body may not have one', () => {
+  assert.match(trySeeds('demo', { templates: [tpl({ subject: null })] }), /no subject/)
+  registries._reset()
+  assert.match(
+    trySeeds('demo', { templates: [tpl({ channel: 'inapp' })] }),
+    /cannot carry a subject/,
+  )
+  registries._reset()
+  assert.equal(trySeeds('demo', { templates: [tpl({ channel: 'inapp', subject: null })] }), null)
+})
+
+test('a rule must carry a per-hour ceiling', () => {
+  // Q3: the module chooses the number and may not decline to have one.
+  const err = trySeeds('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule({ max_sends_per_hour: 0 })] }],
+  })
+  assert.match(err, /max_sends_per_hour/)
+})
+
+test('registering twice is a collision, not an addition', () => {
+  assert.equal(trySeeds('demo', { templates: [tpl()] }), null)
+  assert.match(trySeeds('demo', { templates: [tpl({ key: 'demo.other' })] }), /already registered/)
+})
+
+test('a bad template leaves nothing behind — validate-then-commit', () => {
+  const err = trySeeds('demo', {
+    templates: [tpl(), tpl({ key: 'demo.bad', channel: 'sms' })],
+    ruleGroups: [{ key: 'v1', rules: [rule()] }],
+  })
+  assert.match(err, /unknown channel "sms"/)
+  assert.equal(registries.engagementSeedsFor('demo'), null)
+  assert.deepEqual(registries.allEngagementSeeds(), [])
+})
+
+// ── The seeder ─────────────────────────────────────────────────────────────
+
+const moduleSeeds = require('../src/engagement/moduleSeeds')
+
+/** A registered batch, shaped the way `allEngagementSeeds()` returns it. */
+function registered(owner, seeds) {
+  assert.equal(trySeeds(owner, seeds), null)
+  return () => registries.allEngagementSeeds()
+}
+
+test('guardKey names both the owner and the group', () => {
+  // Two modules may use the same group name, and one module may add a second
+  // group later without disturbing the first.
+  assert.equal(moduleSeeds.guardKey('uo', 'triggers-v1'), 'engagement_module_rules_seeded:uo:triggers-v1')
+  assert.notEqual(moduleSeeds.guardKey('uo', 'a'), moduleSeeds.guardKey('other', 'a'))
+})
+
+test('templates are re-ensured every run and rule groups are seeded once', async () => {
+  // The asymmetry the design rests on. A second run must re-offer every template
+  // (so a bumped seedVersion reaches an existing deployment) and must offer no
+  // rule at all (so a rule an operator deleted stays deleted).
+  const seeds = registered('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule()] }],
+  })
+
+  const settings = new Map()
+  const seededTemplates = []
+  const insertedRules = []
+  const stub = {
+    templatesDb: {
+      seedOne: async (t) => { seededTemplates.push(t.key); return 'inserted' },
+      staleCustomized: async () => [],
+    },
+    rulesDb: { insert: async (r) => { insertedRules.push(r.trigger_id) } },
+    settingsDb: {
+      get: async (k) => settings.get(k) || null,
+      set: async (k, v) => { settings.set(k, v) },
+    },
+  }
+
+  await moduleSeeds.seedModuleEngagement({ seeds, ...stub })
+  await moduleSeeds.seedModuleEngagement({ seeds, ...stub })
+
+  assert.deepEqual(seededTemplates, ['demo.house.warning', 'demo.house.warning'])
+  assert.deepEqual(insertedRules, ['demo.house.warning'])
+  assert.ok(settings.has(moduleSeeds.guardKey('demo', 'v1')))
+})
+
+test('a partial rule group is still stamped', async () => {
+  // Re-running would duplicate the rules that DID insert, and a duplicate rule
+  // is two mails per event — worse than the one missing rule an operator can add
+  // from the Rules screen. `coreRules.seedGroup` made the same call.
+  const seeds = registered('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule(), rule({ trigger_id: 'demo.house.gone', name: 'Gone' })] }],
+  })
+
+  const settings = new Map()
+  let inserts = 0
+  await moduleSeeds.seedModuleEngagement({
+    seeds,
+    templatesDb: { seedOne: async () => 'inserted', staleCustomized: async () => [] },
+    rulesDb: {
+      insert: async () => {
+        inserts += 1
+        if (inserts === 2) throw new Error('duplicate')
+      },
+    },
+    settingsDb: {
+      get: async (k) => settings.get(k) || null,
+      set: async (k, v) => { settings.set(k, v) },
+    },
+  })
+
+  assert.equal(inserts, 2)
+  assert.ok(settings.has(moduleSeeds.guardKey('demo', 'v1')))
+})
+
+test('a skipped owner is seeded not at all', async () => {
+  // The operator's switch means what it says even for content that is only rows.
+  const seeds = registered('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule()] }],
+  })
+  let touched = 0
+  await moduleSeeds.seedModuleEngagement({
+    seeds,
+    skip: new Set(['demo']),
+    templatesDb: { seedOne: async () => { touched += 1; return 'inserted' }, staleCustomized: async () => [] },
+    rulesDb: { insert: async () => { touched += 1 } },
+    settingsDb: { get: async () => null, set: async () => {} },
+  })
+  assert.equal(touched, 0)
+})
+
+test('a database failure is logged, never thrown — this is the boot path', async () => {
+  const seeds = registered('demo', {
+    templates: [tpl()],
+    ruleGroups: [{ key: 'v1', rules: [rule()] }],
+  })
+  await moduleSeeds.seedModuleEngagement({
+    seeds,
+    templatesDb: {
+      seedOne: async () => { throw new Error('table is gone') },
+      staleCustomized: async () => { throw new Error('also gone') },
+    },
+    rulesDb: { insert: async () => { throw new Error('gone too') } },
+    settingsDb: { get: async () => { throw new Error('and gone') }, set: async () => {} },
+  })
+})
+
+test('an invalid block array is refused rather than stored', async () => {
+  // A shipped block array no renderer understands reads to an operator as their
+  // deployment being broken. Refusing leaves renderByKey's fallback in charge.
+  const seeds = registered('demo', {
+    templates: [tpl({ blocks: [{ id: 'x', type: 'email.nosuchblock', props: {} }] })],
+  })
+  let stored = 0
+  const totals = await moduleSeeds.seedModuleEngagement({
+    seeds,
+    templatesDb: { seedOne: async () => { stored += 1; return 'inserted' }, staleCustomized: async () => [] },
+    rulesDb: { insert: async () => {} },
+    settingsDb: { get: async () => null, set: async () => {} },
+  })
+  assert.equal(stored, 0)
+  assert.equal(totals.templates, 0)
+})