diff --git a/docs/concepts.md b/docs/concepts.md
index 94d8742..8aaca8e 100644
--- a/docs/concepts.md
+++ b/docs/concepts.md
@@ -184,7 +184,7 @@ cr/normalize/extract/...     ← normalize extraction
 cr/normalize/reuse/...       ← source patching
 ```
 
-Branches are auto-merged or held for review depending on your workflow config.
+Branches are auto-merged or held for review depending on your workflow config. When a review branch is merged or rejected, its remote copy is deleted too, so merged branches don't linger as phantom pending reviews — run `contentrain prune` to drain any existing backlog, or set `remoteBranchCleanup: false` to opt out.
 
 ## How It Compares
 
diff --git a/docs/packages/cli.md b/docs/packages/cli.md
index 4e73540..d3ee6fc 100644
--- a/docs/packages/cli.md
+++ b/docs/packages/cli.md
@@ -60,14 +60,15 @@ Example: `contentrain --debug status` or `CONTENTRAIN_DEBUG=1 contentrain status
 |---------|--------|
 | `contentrain init` | Initialize `.contentrain/`, git workflow, templates, and IDE rules |
 | `contentrain status` | Show project overview, models, branch pressure, and validation summary |
-| `contentrain doctor` | Check setup health, SDK freshness, orphan content, and branch limits |
+| `contentrain doctor` | Check setup health, SDK freshness, orphan content, local branch limits, and remote `cr/*` count |
 | `contentrain validate` | Validate content against schemas, optionally create review-branch fixes |
 | `contentrain generate` | Generate `.contentrain/client/` and `#contentrain` package imports |
 | `contentrain describe` | Display full model schema and sample data |
 | `contentrain describe-format` | Show file format specification and storage conventions |
 | `contentrain scaffold` | Apply starter templates (blog, landing, docs, SaaS, ...) |
-| `contentrain diff` | Review and merge or reject pending `cr/*` branches interactively |
-| `contentrain merge <branch>` | Merge one pending `cr/*` branch non-interactively |
+| `contentrain diff` | Review and merge or reject pending `cr/*` branches interactively (deletes the remote copy on merge/reject) |
+| `contentrain merge <branch>` | Merge one pending `cr/*` branch non-interactively (deletes the remote copy) |
+| `contentrain prune` | Delete merged `cr/*` branches locally and on the remote (drain the backlog) |
 | `contentrain setup` | Configure MCP server and AI rules for your IDE |
 | `contentrain skills` | Install, update, or list AI skills and rules for your IDE |
 | `contentrain serve` | Start the local review UI, the MCP stdio server, or the MCP HTTP server |
@@ -238,7 +239,20 @@ contentrain merge cr/content/faq/1234-abcd
 contentrain merge cr/content/faq/1234-abcd --yes  # Skip confirm (CI)
 ```
 
-Non-interactive single-branch sibling of `contentrain diff`. Delegates to MCP's `mergeBranch` so dirty-file protections + selective sync warnings behave identically.
+Non-interactive single-branch sibling of `contentrain diff`. Delegates to MCP's `mergeBranch` so dirty-file protections + selective sync warnings behave identically. After a successful merge it also deletes the branch's copy on the remote — best-effort, so an offline or permission failure only prints a warning. Opt out with `remoteBranchCleanup: false` in `config.json`.
+
+---
+
+### `contentrain prune`
+
+```bash
+contentrain prune --dry-run   # Preview merged cr/* branches (local + remote)
+contentrain prune             # Confirm, then delete them
+contentrain prune --yes       # Skip confirm (CI)
+contentrain prune --json      # Machine-readable output (mutates only with --yes)
+```
+
+Drains already-merged `cr/*` branches: local ones past their retention period plus every merged copy left on the remote. This is the operator-facing cleanup for backlogs the per-merge deletion could not remove — e.g. branches merged before remote cleanup shipped, or after an offline/permission failure. Merged detection uses the same ancestry + patch-id classification as the rest of the toolchain, so branches orphaned by a base-history rewrite are still recognised. Governed by `remoteBranchCleanup` in `config.json`; exits non-zero if any remote deletion fails.
 
 ---
 
diff --git a/docs/packages/mcp.md b/docs/packages/mcp.md
index e05622f..16fb14a 100644
--- a/docs/packages/mcp.md
+++ b/docs/packages/mcp.md
@@ -76,7 +76,7 @@ The MCP server exposes **19 tools** organized by function. Each tool includes [M
 | `contentrain_status` | Project overview | Config, models, branch health, context, validation summary |
 | `contentrain_describe` | Model deep-dive | Full schema, sample data, field types for any model |
 | `contentrain_describe_format` | Format reference | File structure, JSON formats, markdown conventions, locale strategies |
-| `contentrain_doctor` | Health diagnostics | Setup validation, SDK freshness, orphan content, branch limits, unused keys, missing translations |
+| `contentrain_doctor` | Health diagnostics | Setup validation, SDK freshness, orphan content, local branch limits, remote `cr/*` count, unused keys, missing translations |
 | `contentrain_content_list` | Read content | List and filter content entries with optional relation resolution |
 
 ### Write Tools (Git-Backed, Branch-Isolated)
@@ -90,10 +90,10 @@ The MCP server exposes **19 tools** organized by function. Each tool includes [M
 | `contentrain_content_save` | Write content | Save entries for any model kind (collection, singleton, dictionary, document) |
 | `contentrain_content_delete` | Remove content | Delete specific content entries |
 | `contentrain_validate` | Check & fix | Validate content against schemas, optionally auto-fix structural issues |
-| `contentrain_submit` | Push branches | Push `cr/*` review branches to remote |
-| `contentrain_merge` | Merge branches | Merge a review-mode branch into contentrain locally (by exact branch or model; no external platform needed) |
-| `contentrain_branch_list` | Inspect branches | List pending `cr/*` branches with merge status and branch-health pressure |
-| `contentrain_branch_delete` | Clean up branches | Delete a stale/failed `cr/*` branch (the contentrain branch is protected) |
+| `contentrain_submit` | Push branches | Push `cr/*` review branches to remote, then lazily prune merged local + remote leftovers |
+| `contentrain_merge` | Merge branches | Merge a review-mode branch into contentrain locally (by exact branch or model; no external platform needed); deletes the branch's remote copy |
+| `contentrain_branch_list` | Inspect branches | List pending `cr/*` branches with merge status and branch-health pressure (`remote: true` adds a remote view + remote-only leftovers) |
+| `contentrain_branch_delete` | Clean up branches | Delete a stale/failed `cr/*` branch locally and on the remote (the contentrain branch is protected; supports remote-only deletion) |
 
 ### Normalize Tools (Scan + Apply)
 
@@ -133,7 +133,9 @@ All write operations create or update `cr/*` branches:
 - Content changes go to isolated branches (`cr/{scope}/{target}[/{locale}]/{timestamp}-{suffix}`)
 - Humans review via `contentrain diff` or the serve UI
 - Approved changes merge into the `contentrain` branch, baseBranch is advanced via update-ref
-- Branch health is tracked and surfaced via `contentrain_status` (warning at 50, blocked at 80 active branches)
+- Merging (or deleting) a branch also removes its copy on the remote, so merged branches don't pile up as phantom pending reviews — best-effort, opt out with `remoteBranchCleanup: false` in `config.json`. Drain an existing backlog with `contentrain prune`
+- Merged-branch detection survives base-history rewrites (ancestry check with a patch-id fallback)
+- Branch health is tracked and surfaced via `contentrain_status` (warning at 50, blocked at 80 active branches); `contentrain_doctor` adds a remote `cr/*` count
 - Legacy `contentrain/*` branches are auto-migrated on first init
 
 ### 4. Local-First by Default, Remote Providers Opt-In