diff --git a/.cursor/rules/unomi-3-dev-backport.mdc b/.cursor/rules/unomi-3-dev-backport.mdc
index 9027fc379..5cc1ac861 100644
--- a/.cursor/rules/unomi-3-dev-backport.mdc
+++ b/.cursor/rules/unomi-3-dev-backport.mdc
@@ -5,37 +5,43 @@ alwaysApply: true
 
 # unomi-3-dev → master (UNOMI-875)
 
-**Status:** Backport phase **complete** (Phase 2 + [#791](https://github.com/apache/unomi/pull/791)). **Active tracker:** `.local-notes/unomi-3.1-remaining-work-plan.md`.
+**Status:** Backport phase **complete** (Phase 2 + [#791](https://github.com/apache/unomi/pull/791) + [#819](https://github.com/apache/unomi/pull/819) 3-dev closure, July 2026). **Active tracker:** `.local-notes/unomi-3.1-remaining-work-plan.md`.
+
+**Branch archive (2026-07-11):** Remote `unomi-3-dev` **deleted**. Tip preserved as tag `unomi-3-dev-archive-2026-07` (`eca005fd8`). Do **not** expect `origin/unomi-3-dev` to exist.
 
 **Historical plans:** `.local-notes/archive/unomi-3-dev-backport-plan-phase2.md` (§1 exclusion register, §2 playbook).
 
 **Generic workflow first:** `.cursor/rules/branch-backport.mdc` (history audit, diff audit, ADD/MODIFY/MERGE).
 
-For any future cherry-pick from `unomi-3-dev`, set:
+For any future cherry-pick from the archived 3-dev line, use the tag — not a branch:
 
 ```bash
-SOURCE=unomi-3-dev
+SOURCE=unomi-3-dev-archive-2026-07   # tag, not branch
 TARGET=master
+git fetch origin tag unomi-3-dev-archive-2026-07
 ```
 
+In generic backport commands, substitute the tag ref wherever `origin/$SOURCE` appeared (e.g. `git diff origin/master unomi-3-dev-archive-2026-07 -- <path>`).
+
 ## Unomi-specific never
 
 - **Never** replace `master` review refactors with 3-dev monoliths (REST mappers, tracing lifecycle, test harness, shell CRUD fixes).
 - **Never** port items in archived plan §1 exclusion register: REST exception mappers (implement on master patterns), migration scripts (UNOMI-943), security WIP, wholesale 3-dev test harness.
 - **Never** wholesale-checkout `.github/workflows` (master ahead: #780, #957), `AGENTS.md` (#769), migration groovy, `.asf.yaml` rulesets.
 - **Never** blind-checkout `extensions/router/**` — master ahead (#756, #779, #780).
+- **Never** recreate or push a `unomi-3-dev` branch — use the archive tag for historical diffs only.
 
 ## Unomi-specific always
 
-- Check merged master PRs (#755–#791, etc.) before assuming master lacks a 3-dev feature.
+- Check merged master PRs (#755–#819, etc.) before assuming master lacks a 3-dev feature.
 - **MERGE surgically:** `build.sh`, root `pom.xml`, CI — keep master non-interactive CI, Javadoc, IT memory sampler (#780, #957).
 - **Docker compose:** additive only; align image pins with Track E in the remaining-work plan.
 
 ## Shell CRUD — learned 2026-06-10
 
-Shell polish from 3-dev is **mostly already on master** (#755, #763). Before any shell port:
+Shell polish from 3-dev is **on master** (#755, #763). Before any shell port from the archive tag:
 
-`git log origin/unomi-3-dev..origin/master -- tools/shell-dev-commands/`
+`git log unomi-3-dev-archive-2026-07..origin/master -- tools/shell-dev-commands/`
 
 ## Validation before PR (Unomi)
 
diff --git a/AGENTS.md b/AGENTS.md
index c1dedade2..9b8c18efb 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -51,16 +51,23 @@ Cursor rule: `.cursor/rules/branch-backport.mdc`
 
 ## Backporting `unomi-3-dev` → `master` (UNOMI-875)
 
-**Backport phase complete** (Phase 2 mega-PRs + [#791](https://github.com/apache/unomi/pull/791) final hygiene). **Apply generic rules above** for any future cherry-picks; see
+**Backport phase complete** (Phase 2 mega-PRs + [#791](https://github.com/apache/unomi/pull/791) final hygiene + [#819](https://github.com/apache/unomi/pull/819) 3-dev closure, July 2026). **Apply generic rules above** for any future cherry-picks; see
 `.cursor/rules/unomi-3-dev-backport.mdc` for standing exclusions.
 
 | | |
 |---|---|
-| Source | `unomi-3-dev` (archive/reference only) |
+| Source (archived) | Tag `unomi-3-dev-archive-2026-07` @ `eca005fd8` — remote branch **deleted** |
 | Target | `master` |
 | **Active local plan** | `.local-notes/unomi-3.1-remaining-work-plan.md` |
 | Archived backport plans | `.local-notes/archive/` (Phase 1, Phase 2, #757 stack tracker) |
 
+To inspect the archived tip:
+
+```bash
+git fetch origin tag unomi-3-dev-archive-2026-07
+git diff master...unomi-3-dev-archive-2026-07 -- <path>
+```
+
 Unomi-specific reminders:
 
 - Master is ahead on REST mappers, tracing, shell CRUD (#755, #763), CI
@@ -68,3 +75,4 @@ Unomi-specific reminders:
 - Safe wholesale adds: new scripts, Postman, docs, new Java classes.
 - Do not port: migration scripts (UNOMI-943), 3-dev REST mappers, security
   WIP, wholesale test harness from 3-dev.
+- Remaining 3.1 work: [UNOMI-960](https://issues.apache.org/jira/browse/UNOMI-960) (Javadoc / PR10) — not a 3-dev backport.