diff --git a/ahbg/android/app/build.gradle.kts b/ahbg/android/app/build.gradle.kts
index 5ba1b15..fed909c 100644
--- a/ahbg/android/app/build.gradle.kts
+++ b/ahbg/android/app/build.gradle.kts
@@ -61,5 +61,9 @@ android {
 
 dependencies {
     implementation("androidx.webkit:webkit:1.12.1")
-    implementation("com.revenuecat.purchases:purchases:8.10.1")
+    // RevenueCat 10.x core plus the Samsung Galaxy Store billing backend.
+    // Native Galaxy IAP support requires the purchases-store-galaxy module
+    // (RevenueCat >= 10.7.0). Store selection is auto-detected at runtime.
+    implementation("com.revenuecat.purchases:purchases:10.19.1")
+    implementation("com.revenuecat.purchases:purchases-store-galaxy:10.19.1")
 }
diff --git a/ahbg/android/app/src/main/java/org/interdependency/ahbg/Entitlements.kt b/ahbg/android/app/src/main/java/org/interdependency/ahbg/Entitlements.kt
index b5b7c5e..99906c9 100644
--- a/ahbg/android/app/src/main/java/org/interdependency/ahbg/Entitlements.kt
+++ b/ahbg/android/app/src/main/java/org/interdependency/ahbg/Entitlements.kt
@@ -15,6 +15,10 @@ import com.revenuecat.purchases.interfaces.ReceiveCustomerInfoCallback
  * unlocks only when RevenueCat reports the `benchmark_lab` entitlement as
  * active for the current app user.
  *
+ * RevenueCat 10.x with the `purchases-store-galaxy` billing backend: the
+ * store (Galaxy, or a later Play build with its module added) is auto-detected
+ * at runtime, so this file never hard-codes a store.
+ *
  * When the RevenueCat key is not provisioned (free/dev builds), the store
  * degrades to the free tier rather than crashing or faking premium.
  */
diff --git a/ahbg/submission/GALAXY_STORE_RUNBOOK.md b/ahbg/submission/GALAXY_STORE_RUNBOOK.md
new file mode 100644
index 0000000..b3567c6
--- /dev/null
+++ b/ahbg/submission/GALAXY_STORE_RUNBOOK.md
@@ -0,0 +1,80 @@
+# Samsung Galaxy Store publication runbook
+
+Shipaton accepts a fully published Galaxy Store URL. This runbook follows the
+Galaxy-first order: Seller Portal approval first, code/RevenueCat in parallel,
+then register, IAP, closed-beta purchase verification, review, publish.
+
+## 0. Code (done in this PR)
+
+- RevenueCat upgraded `8.10.1 → 10.19.1` with the `purchases-store-galaxy`
+  billing backend (native Galaxy IAP requires RevenueCat >= 10.7.0 + that
+  module). Store is auto-detected at runtime.
+- Package stays `org.interdependency.ahbg`; target API 35 (Galaxy does not
+  currently impose Play's API-36 rule).
+
+## 1. Samsung Seller Portal (start immediately — longest lead time)
+
+1. Register a Samsung account at the Seller Portal.
+2. Request **Commercial Seller Status** (required even for free distribution).
+   - Provide identity/business documentation and financial information.
+   - PayPal is the supported/easiest payout path.
+   - D-U-N-S or international-bank verification can take up to 10 business
+     days; Samsung also documents applying without D-U-N-S using business
+     documentation.
+3. Record approval here when granted: `SELLER_PORTAL_APPROVED=<date>`.
+
+## 2. Register AHBG
+
+1. Seller Portal → Add Application.
+2. Package name: `org.interdependency.ahbg`.
+3. Upload the signed release binary (APK or AAB) built with:
+   ```bash
+   gradle assembleRelease \
+     -PruntimeUrl=https://ahbg.interdependentway.org \
+     -PrevenueCatApiKey=<rc_public_key> \
+     -PahbgStoreFile=/secure/ahbg-release.jks -PahbgStorePassword=... \
+     -PahbgKeyAlias=... -PahbgKeyPassword=...
+   ```
+4. Fill listing with `STORE_LISTING.md`, privacy policy `PRIVACY_POLICY.md`,
+   icon, and screenshots (see `DEMO_STORYBOARD.md`).
+
+## 3. Samsung IAP
+
+1. Seller Portal → In-App Purchase → create item `ahbg_benchmark_lab`
+   (one-time, non-consumable), matching the RevenueCat product id.
+2. Keep the free core playable without IAP; `benchmark_lab` gates only
+   Benchmark Lab.
+
+## 4. Connect Galaxy to RevenueCat
+
+1. RevenueCat dashboard → add a **Galaxy Store** app with package
+   `org.interdependency.ahbg`.
+2. Create a Galaxy Seller Portal **service account**; give those credentials
+   to RevenueCat so it can validate Samsung purchases.
+3. Create the `benchmark_lab` entitlement and the `ahbg_benchmark_lab`
+   product/offering (see `REVENUECAT_PROVISIONING.md`).
+
+## 5. Closed beta + purchase verification
+
+1. Samsung **Closed Beta** supports in-app purchases and has no fixed
+   14-day/12-person production gate.
+2. Verify the full path on-device:
+   install → observe/plan/act/build → persist/reload →
+   purchase `benchmark_lab` → entitlement unlocks → restore → repeat.
+
+## 6. Review → publish → Devpost
+
+1. Submit for Galaxy review.
+2. Once live, use the public Galaxy Store listing URL as the Devpost entry
+   URL (a beta link does not count; the app must be publicly downloadable in
+   the US).
+3. Galaxy optimization notes (Best App for Galaxy category, 20% of score):
+   foldable/multi-window support and Samsung-specific features are the
+   highest-value follow-ups; exclusivity is a bonus, not required.
+
+## hmmm
+
+- Commercial Seller Status approval time is the schedule risk; it is external
+  and started first for that reason.
+- The live Galaxy listing URL, Seller Portal service-account credentials, and
+  RevenueCat Galaxy app id cannot be produced from this repository.
diff --git a/ahbg/submission/README.md b/ahbg/submission/README.md
index 066f86d..86abb5f 100644
--- a/ahbg/submission/README.md
+++ b/ahbg/submission/README.md
@@ -6,6 +6,7 @@ everything that requires a live external account is listed in
 
 | Asset | File |
 |---|---|
+| **Galaxy Store publication runbook** | `GALAXY_STORE_RUNBOOK.md` |
 | Store listing copy | `STORE_LISTING.md` |
 | Privacy declaration | `PRIVACY_POLICY.md` |
 | ≤2-minute device demo | `DEMO_STORYBOARD.md` |
@@ -13,11 +14,17 @@ everything that requires a live external account is listed in
 | RevenueCat production provisioning | `REVENUECAT_PROVISIONING.md` |
 | Remaining external blockers | `SUBMISSION_BLOCKERS.md` |
 
+## Shipping path
+
+**Galaxy first** (Shipaton accepts a published Galaxy Store URL; no Samsung
+publishing fee and no Play 12-tester/14-day gate). RevenueCat is upgraded to
+`10.19.1` with the `purchases-store-galaxy` backend in this line.
+
 ## Current release identity
 
 - App id: `org.interdependency.ahbg`
 - versionCode `2`, versionName `0.2.0`
 - Production runtime endpoint: `https://ahbg.interdependentway.org`
-- Entitlement: `benchmark_lab` (RevenueCat)
+- Entitlement: `benchmark_lab` (RevenueCat `10.19.1` + Galaxy backend)
 - Construction authority: `ucns.mobius-seed-construction@0.1.0`
   (The-Interdependency/ucns, merged `828c0b8`)
diff --git a/ahbg/submission/REVENUECAT_PROVISIONING.md b/ahbg/submission/REVENUECAT_PROVISIONING.md
index 0aeeb21..6135eaa 100644
--- a/ahbg/submission/REVENUECAT_PROVISIONING.md
+++ b/ahbg/submission/REVENUECAT_PROVISIONING.md
@@ -8,10 +8,15 @@ store consoles; the following steps are the exact remaining external work.
 
 1. Create the production project in RevenueCat.
    - Record the **project id** here once created: `rc_<TO_FILL>`.
-2. Add the Android app (`org.interdependency.ahbg`) with the Play public key.
+2. Add the Android app (`org.interdependency.ahbg`). For the Galaxy-first
+   path add a **Galaxy Store** app; add the Play app later if shipping Play.
+   - Galaxy: create a Galaxy Seller Portal **service account** and give those
+     credentials to RevenueCat so it can validate Samsung purchases.
+   - Play (later): attach the Play public key.
 3. Create the entitlement `benchmark_lab` (non-consumable).
 4. Create the product `ahbg_benchmark_lab` (one-time purchase, "Benchmark
-   Lab"), attach it to the entitlement.
+   Lab"), attach it to the entitlement, and mirror it as a Samsung IAP item
+   with the same id in Seller Portal.
 5. Create an offering (default) containing that product; optionally add a
    trial offering `ahbg_benchmark_lab_trial` if a trial is desired.
 6. Copy the **public SDK API key** (`appl_...` or `goog_...` public key) into
@@ -23,6 +28,8 @@ store consoles; the following steps are the exact remaining external work.
      -PahbgStoreFile=/secure/ahbg-release.jks \
      -PahbgStorePassword=... -PahbgKeyAlias=... -PahbgKeyPassword=...
    ```
+7. SDK: RevenueCat `10.19.1` + `purchases-store-galaxy` (this PR); Galaxy
+   IAP requires RevenueCat >= 10.7.0 and the store module.
 
 ## Verify (gate items)
 
diff --git a/ahbg/submission/SUBMISSION_BLOCKERS.md b/ahbg/submission/SUBMISSION_BLOCKERS.md
index 1d4b906..c88c02a 100644
--- a/ahbg/submission/SUBMISSION_BLOCKERS.md
+++ b/ahbg/submission/SUBMISSION_BLOCKERS.md
@@ -11,28 +11,33 @@ external accounts or hardware and cannot be completed from this repository.
   regression coverage proves external harness + A0 both build.
 - No remaining core-mechanics blocker.
 
-## 2. Android release signing and store upload — EXTERNAL
+## 2. Galaxy Store publication — EXTERNAL (now the primary path)
 
-- Signing config and versioning are in `ahbg/android/app/build.gradle.kts`
-  (keystore supplied via gradle properties; never committed).
-- Production HTTPS endpoint and network security config are in place.
-- **Blocker**: a Play Console account, a release keystore, the store listing
-  review, and the actual upload/publish step happen outside this repository.
+- RevenueCat upgraded to `10.19.1` + `purchases-store-galaxy` (this line);
+  signing config, versioning, HTTPS endpoint, network security config, and
+  submission assets are all in-repo.
+- **Blocker**: Samsung Seller Portal registration and **Commercial Seller
+  Status approval** (schedule risk — start first; PayPal is the documented
+  easiest payout path; D-U-N-S/international-bank verification can take up to
+  10 business days). Then app registration, Samsung IAP item, Galaxy review,
+  and publish. See `GALAXY_STORE_RUNBOOK.md`.
 
 ## 3. RevenueCat production provisioning — EXTERNAL
 
-- Client + runtime entitlement boundary complete.
-- **Blocker**: the live RevenueCat project, product, `benchmark_lab`
-  entitlement, offering, and public SDK key must be created in the dashboard.
+- Client + runtime entitlement boundary complete; Galaxy billing backend is
+  part of this line.
+- **Blocker**: the live RevenueCat project, Galaxy Store app, Seller Portal
+  service-account credentials, product, `benchmark_lab` entitlement, offering,
+  and public SDK key must be created in the dashboard.
   See `REVENUECAT_PROVISIONING.md`.
 
 ## 4. Publish + submission assets — EXTERNAL
 
-- Store listing, privacy policy, demo storyboard, and Devpost material are in
-  `ahbg/submission/`.
+- Store listing, privacy policy, demo storyboard, Galaxy runbook, and Devpost
+  material are in `ahbg/submission/`.
 - **Blocker**: recording the ≤2-minute device demo, capturing screenshots,
-  creating promo/trial codes, uploading assets, and obtaining the public store
-  URL require the published store listing.
+  creating promo/trial codes, uploading assets, obtaining the public Galaxy
+  Store URL, and submitting that URL to Devpost require the published listing.
 
 ## Gate status