diff --git a/docs/architecture/migration-progress.md b/docs/architecture/migration-progress.md
index ab1ff1547..ec726a9b0 100644
--- a/docs/architecture/migration-progress.md
+++ b/docs/architecture/migration-progress.md
@@ -1086,6 +1086,25 @@ Status values: `[ ]` not started, `[~]` in progress, `[x]` complete, `[!]` block
   - Verification: migration and layer guards, formatting check, diff hygiene,
     risk scan, full pre-commit, and required three-expert review passed.
 
+- [x] `API-041` Lock ECStore compatibility passthrough allowlists.
+  - Current branch: `overtrue/arch-compat-passthrough-guards`.
+  - Current slice: add a migration rule that snapshots every
+    `rustfs_ecstore` module/function passthrough exposed from local
+    `storage_compat.rs` boundaries across RustFS, scanner, heal, Swift,
+    S3 Select, IAM, notify, observability, e2e, and fuzz harnesses.
+  - Acceptance: compatibility boundaries cannot silently add or remove ECStore
+    passthrough items; future cleanup PRs must update the explicit allowlist
+    when they intentionally shrink or reshape a boundary.
+  - Must preserve: all existing local compatibility paths, ECStore concrete
+    type ownership, storage behavior, startup behavior, scanner/heal behavior,
+    Swift/S3 Select/IAM/notify behavior, observability reads, and test/fuzz
+    harness behavior.
+  - Risk defense: this is a loss-prevention guard only; it does not change
+    runtime code, storage APIs, object metadata shape, reader behavior, or
+    worker lifecycle.
+  - Verification: migration guard, formatting check, diff hygiene, risk scan,
+    focused script check, and full pre-commit required before push.
+
 ## Phase 8 Background Controller Tasks
 
 - [x] `BGC-001` Inventory background services.
@@ -1362,14 +1381,23 @@ Status values: `[ ]` not started, `[~]` in progress, `[x]` complete, `[!]` block
 
 | Expert | Status | Notes |
 |---|---|---|
-| Quality/architecture | passed | Delete-object DTO ownership lives in storage-api; ECStore internal consumers use storage-api directly while public aliases remain, and store_api compatibility boundaries now expose only direct explicit contract aliases guarded by a whitelist. |
-| Migration preservation | passed | Field shape, helper semantics, delete behavior, replication scheduling, MRF delete replay, object info/options aliases, reader aliases, and old ECStore concrete type compatibility are preserved. |
-| Testing/verification | passed | Multi-crate compile, guards, formatting, diff hygiene, risk scan, and full `make pre-commit` passed. |
+| Quality/architecture | passed | API-041 is guard-only and snapshots local ECStore compatibility passthroughs without changing runtime boundaries. |
+| Migration preservation | passed | Existing local `storage_compat.rs` paths and ECStore concrete ownership remain unchanged; the guard only reports passthrough drift. |
+| Testing/verification | passed | Script syntax, guards, formatting, diff hygiene, risk scan, and full `make pre-commit` passed. |
 
 ## Verification Notes
 
 Passed before push:
 
+- API-041 current slice:
+  - `bash -n scripts/check_architecture_migration_rules.sh`: passed.
+  - `./scripts/check_architecture_migration_rules.sh`: passed.
+  - `./scripts/check_layer_dependencies.sh`: passed.
+  - `cargo fmt --all --check`: passed.
+  - `git diff --check`: passed.
+  - Rust risk scan: passed; no Rust code changed.
+  - `make pre-commit`: passed.
+
 - API-040 current slice:
   - `./scripts/check_architecture_migration_rules.sh`: passed.
   - `./scripts/check_layer_dependencies.sh`: passed.
diff --git a/scripts/check_architecture_migration_rules.sh b/scripts/check_architecture_migration_rules.sh
index 67e2859db..6de9dc167 100755
--- a/scripts/check_architecture_migration_rules.sh
+++ b/scripts/check_architecture_migration_rules.sh
@@ -67,6 +67,9 @@ PRODUCTION_UNUSED_COMPAT_ALLOW_HITS_FILE="${TMP_DIR}/production_unused_compat_al
 BROAD_STORE_API_COMPAT_REEXPORT_HITS_FILE="${TMP_DIR}/broad_store_api_compat_reexport_hits.txt"
 NESTED_STORE_API_COMPAT_MODULE_HITS_FILE="${TMP_DIR}/nested_store_api_compat_module_hits.txt"
 UNAPPROVED_STORE_API_COMPAT_ALIAS_HITS_FILE="${TMP_DIR}/unapproved_store_api_compat_alias_hits.txt"
+ECSTORE_COMPAT_PASSTHROUGH_EXPECTED_FILE="${TMP_DIR}/ecstore_compat_passthrough_expected.txt"
+ECSTORE_COMPAT_PASSTHROUGH_ACTUAL_FILE="${TMP_DIR}/ecstore_compat_passthrough_actual.txt"
+ECSTORE_COMPAT_PASSTHROUGH_DIFF_FILE="${TMP_DIR}/ecstore_compat_passthrough_diff.txt"
 
 awk '
   /^## PR Types$/ {
@@ -420,6 +423,148 @@ if [[ -s "$UNAPPROVED_STORE_API_COMPAT_ALIAS_HITS_FILE" ]]; then
   report_failure "storage compatibility boundaries may only keep explicit ECStore-owned store_api type aliases: $(paste -sd '; ' "$UNAPPROVED_STORE_API_COMPAT_ALIAS_HITS_FILE")"
 fi
 
+cat >"$ECSTORE_COMPAT_PASSTHROUGH_EXPECTED_FILE" <<'EOF'
+crates/e2e_test/src/storage_compat.rs:bucket
+crates/e2e_test/src/storage_compat.rs:disk
+crates/e2e_test/src/storage_compat.rs:rpc
+crates/heal/src/heal/storage_compat.rs:data_usage
+crates/heal/src/heal/storage_compat.rs:disk
+crates/heal/src/heal/storage_compat.rs:error
+crates/heal/src/heal/storage_compat.rs:global
+crates/heal/src/heal/storage_compat.rs:store
+crates/heal/tests/common/storage_compat.rs:bucket
+crates/heal/tests/common/storage_compat.rs:disk
+crates/heal/tests/common/storage_compat.rs:endpoints
+crates/heal/tests/common/storage_compat.rs:store
+crates/iam/src/storage_compat.rs:config
+crates/iam/src/storage_compat.rs:error
+crates/iam/src/storage_compat.rs:global
+crates/iam/src/storage_compat.rs:notification_sys
+crates/iam/src/storage_compat.rs:store
+crates/notify/src/storage_compat.rs:config
+crates/notify/src/storage_compat.rs:global
+crates/obs/src/storage_compat.rs:bucket
+crates/obs/src/storage_compat.rs:data_usage
+crates/obs/src/storage_compat.rs:global
+crates/obs/src/storage_compat.rs:pools
+crates/obs/src/storage_compat.rs:resolve_object_store_handle
+crates/protocols/src/swift/storage_compat.rs:bucket
+crates/protocols/src/swift/storage_compat.rs:error
+crates/protocols/src/swift/storage_compat.rs:resolve_object_store_handle
+crates/protocols/src/swift/storage_compat.rs:store
+crates/s3select-api/src/storage_compat.rs:error
+crates/s3select-api/src/storage_compat.rs:resolve_object_store_handle
+crates/s3select-api/src/storage_compat.rs:set_disk
+crates/s3select-api/src/storage_compat.rs:store
+crates/scanner/src/storage_compat.rs:bucket
+crates/scanner/src/storage_compat.rs:cache_value
+crates/scanner/src/storage_compat.rs:config
+crates/scanner/src/storage_compat.rs:data_usage
+crates/scanner/src/storage_compat.rs:disk
+crates/scanner/src/storage_compat.rs:error
+crates/scanner/src/storage_compat.rs:global
+crates/scanner/src/storage_compat.rs:pools
+crates/scanner/src/storage_compat.rs:resolve_object_store_handle
+crates/scanner/src/storage_compat.rs:set_disk
+crates/scanner/src/storage_compat.rs:store
+crates/scanner/src/storage_compat.rs:store_utils
+crates/scanner/tests/common/storage_compat.rs:bucket
+crates/scanner/tests/common/storage_compat.rs:client
+crates/scanner/tests/common/storage_compat.rs:disk
+crates/scanner/tests/common/storage_compat.rs:endpoints
+crates/scanner/tests/common/storage_compat.rs:global
+crates/scanner/tests/common/storage_compat.rs:pools
+crates/scanner/tests/common/storage_compat.rs:store
+crates/scanner/tests/common/storage_compat.rs:tier
+fuzz/fuzz_targets/storage_compat.rs:bucket
+rustfs/src/admin/storage_compat.rs:bucket
+rustfs/src/admin/storage_compat.rs:client
+rustfs/src/admin/storage_compat.rs:config
+rustfs/src/admin/storage_compat.rs:data_usage
+rustfs/src/admin/storage_compat.rs:disk
+rustfs/src/admin/storage_compat.rs:endpoints
+rustfs/src/admin/storage_compat.rs:error
+rustfs/src/admin/storage_compat.rs:global
+rustfs/src/admin/storage_compat.rs:metrics_realtime
+rustfs/src/admin/storage_compat.rs:notification_sys
+rustfs/src/admin/storage_compat.rs:rebalance
+rustfs/src/admin/storage_compat.rs:rpc
+rustfs/src/admin/storage_compat.rs:store
+rustfs/src/admin/storage_compat.rs:store_utils
+rustfs/src/admin/storage_compat.rs:tier
+rustfs/src/app/storage_compat.rs:admin_server_info
+rustfs/src/app/storage_compat.rs:bucket
+rustfs/src/app/storage_compat.rs:client
+rustfs/src/app/storage_compat.rs:compress
+rustfs/src/app/storage_compat.rs:config
+rustfs/src/app/storage_compat.rs:data_usage
+rustfs/src/app/storage_compat.rs:disk
+rustfs/src/app/storage_compat.rs:endpoints
+rustfs/src/app/storage_compat.rs:error
+rustfs/src/app/storage_compat.rs:global
+rustfs/src/app/storage_compat.rs:new_object_layer_fn
+rustfs/src/app/storage_compat.rs:notification_sys
+rustfs/src/app/storage_compat.rs:pools
+rustfs/src/app/storage_compat.rs:rio
+rustfs/src/app/storage_compat.rs:set_disk
+rustfs/src/app/storage_compat.rs:set_object_store_resolver
+rustfs/src/app/storage_compat.rs:store
+rustfs/src/app/storage_compat.rs:tier
+rustfs/src/storage/storage_compat.rs:admin_server_info
+rustfs/src/storage/storage_compat.rs:bucket
+rustfs/src/storage/storage_compat.rs:client
+rustfs/src/storage/storage_compat.rs:config
+rustfs/src/storage/storage_compat.rs:disk
+rustfs/src/storage/storage_compat.rs:error
+rustfs/src/storage/storage_compat.rs:get_global_lock_client
+rustfs/src/storage/storage_compat.rs:global
+rustfs/src/storage/storage_compat.rs:metrics_realtime
+rustfs/src/storage/storage_compat.rs:resolve_object_store_handle
+rustfs/src/storage/storage_compat.rs:rio
+rustfs/src/storage/storage_compat.rs:rpc
+rustfs/src/storage/storage_compat.rs:set_disk
+rustfs/src/storage/storage_compat.rs:store
+rustfs/src/storage_compat.rs:bucket
+rustfs/src/storage_compat.rs:config
+rustfs/src/storage_compat.rs:disk
+rustfs/src/storage_compat.rs:disks_layout
+rustfs/src/storage_compat.rs:endpoints
+rustfs/src/storage_compat.rs:error
+rustfs/src/storage_compat.rs:event_notification
+rustfs/src/storage_compat.rs:global
+rustfs/src/storage_compat.rs:notification_sys
+rustfs/src/storage_compat.rs:resolve_object_store_handle
+rustfs/src/storage_compat.rs:rpc
+rustfs/src/storage_compat.rs:set_disk
+rustfs/src/storage_compat.rs:set_global_endpoints
+rustfs/src/storage_compat.rs:store
+rustfs/src/storage_compat.rs:update_erasure_type
+EOF
+sort -o "$ECSTORE_COMPAT_PASSTHROUGH_EXPECTED_FILE" "$ECSTORE_COMPAT_PASSTHROUGH_EXPECTED_FILE"
+
+(
+  cd "$ROOT_DIR"
+  find rustfs/src crates fuzz/fuzz_targets -type f -name 'storage_compat.rs' -print0 |
+    xargs -0 perl -0ne '
+      my $file = $ARGV;
+      while (/pub(?:\([^)]*\))?\s+use\s+rustfs_ecstore::\{([^}]*)\}\s*;/sg) {
+        my $items = $1;
+        for my $item (split /,/, $items) {
+          $item =~ s/^\s+|\s+$//g;
+          next if $item eq "";
+          print "$file:$item\n";
+        }
+      }
+      while (/pub(?:\([^)]*\))?\s+use\s+rustfs_ecstore::([A-Za-z_][A-Za-z0-9_]*)\s*;/g) {
+        print "$file:$1\n";
+      }
+    ' | sort
+) >"$ECSTORE_COMPAT_PASSTHROUGH_ACTUAL_FILE"
+
+if ! diff -u "$ECSTORE_COMPAT_PASSTHROUGH_EXPECTED_FILE" "$ECSTORE_COMPAT_PASSTHROUGH_ACTUAL_FILE" >"$ECSTORE_COMPAT_PASSTHROUGH_DIFF_FILE"; then
+  report_failure "ECStore compatibility passthrough allowlist drifted: $(tr '\n' '; ' <"$ECSTORE_COMPAT_PASSTHROUGH_DIFF_FILE")"
+fi
+
 (
   cd "$ROOT_DIR"
   rg -n --no-heading 'async fn (get_object_reader|put_object|get_object_info|verify_object_integrity|copy_object|delete_object_version|delete_object|delete_objects|put_object_metadata|get_object_tags|put_object_tags|delete_object_tags|add_partial|transition_object|restore_transitioned_object|list_multipart_uploads|new_multipart_upload|copy_object_part|put_object_part|get_multipart_info|list_object_parts|abort_multipart_upload|complete_multipart_upload|heal_format|heal_bucket|heal_object|get_pool_and_set|check_abandoned_parts|new_ns_lock)\b' \