diff --git a/.env.example b/.env.example
index ff1ecdc..c87290f 100644
--- a/.env.example
+++ b/.env.example
@@ -75,3 +75,23 @@
 # Directory for delegate-job audit logs (sits beside .mam/jobs/).
 #default: <cwd>/.mam/delegate_job_logs
 # DELEGATE_JOB_LOGS_DIR=/path/to/workspace/.mam/delegate_job_logs
+
+# ==============================================================================
+# deploy / distribution source (for forks/mirrors)
+# ==============================================================================
+# Note: These variables are read from the execution environment by deployment scripts.
+# Since deploy/install.sh runs before .env exists, you must pass them via export
+# or prepended variables (e.g. MAM_REPO_URL=... bash deploy/install.sh).
+# If you run a private mirror, we strongly recommend configuring all three variables.
+
+# Distribution repository URL (cloned during recovery steps).
+#default: https://git.godopu.com/tmpl/multi-agent-mux.git
+# MAM_REPO_URL=https://git.godopu.com/tmpl/multi-agent-mux.git
+
+# Distribution archive download URL (used for bootstrap extraction).
+#default: https://git.godopu.com/tmpl/multi-agent-mux/archive/main.tar.gz
+# MAM_ARCHIVE_URL=https://git.godopu.com/tmpl/multi-agent-mux/archive/main.tar.gz
+
+# Distribution update/installer script URL.
+#default: https://git.godopu.com/tmpl/multi-agent-mux/raw/branch/main/deploy/install.sh
+# MAM_INSTALLER_URL=https://git.godopu.com/tmpl/multi-agent-mux/raw/branch/main/deploy/install.sh
diff --git a/deploy/README.md b/deploy/README.md
index 1ac93a2..31d747c 100644
--- a/deploy/README.md
+++ b/deploy/README.md
@@ -26,6 +26,20 @@ Alternatively, if they have cloned the repository, they can execute:
 bash deploy/install.sh
 ```
 
+### 2. Custom Fork / Private Mirror Installations
+If you run a private mirror or fork, you can override the source URLs during installation using environment variables:
+
+```bash
+# Installing from a custom mirror (pipe prepends must be applied to the bash command)
+curl -fsSL https://my-mirror.example.com/.../install.sh \
+  | MAM_REPO_URL=https://my-mirror.example.com/me/multi-agent-mux.git \
+    MAM_ARCHIVE_URL=https://my-mirror.example.com/me/multi-agent-mux/archive/main.tar.gz \
+    bash
+
+# Updating an existing workspace against a mirror
+MAM_INSTALLER_URL=https://my-mirror.example.com/.../install.sh bash deploy/update.sh
+```
+
 ### 2. Registering as a Workspace Plugin
 To register these skills globally or for a specific workspace:
 *   **Workspace Level**: Copy the `.agents/` folder into your project root.
diff --git a/deploy/install.sh b/deploy/install.sh
index c22b170..294f14b 100644
--- a/deploy/install.sh
+++ b/deploy/install.sh
@@ -54,8 +54,8 @@ echo "✅ PyYAML (system dependency) detected."
 mkdir -p "$TARGET_DIR"
 cd "$TARGET_DIR"
 
-REPO_URL="https://git.godopu.com/tmpl/multi-agent-mux.git"
-ARCHIVE_URL="https://git.godopu.com/tmpl/multi-agent-mux/archive/main.tar.gz"
+REPO_URL="${MAM_REPO_URL:-https://git.godopu.com/tmpl/multi-agent-mux.git}"
+ARCHIVE_URL="${MAM_ARCHIVE_URL:-https://git.godopu.com/tmpl/multi-agent-mux/archive/main.tar.gz}"
 
 # Helper to verify presence of all core runtime files.
 # Keying off a set of core files helps detect and recover from partial/interrupted installations.
diff --git a/deploy/update.sh b/deploy/update.sh
index 199babb..2c3fd02 100644
--- a/deploy/update.sh
+++ b/deploy/update.sh
@@ -135,7 +135,8 @@ bash remove.sh --force
 
 # 4. Fetch and run the latest installer from Gitea
 echo "📥 Fetching and running the latest installer..."
-INSTALLER_URL="https://git.godopu.com/tmpl/multi-agent-mux/raw/branch/main/deploy/install.sh"
+# Note: MAM_*_URL environment variables are automatically inherited by the child installer bash process.
+INSTALLER_URL="${MAM_INSTALLER_URL:-https://git.godopu.com/tmpl/multi-agent-mux/raw/branch/main/deploy/install.sh}"
 if command -v curl &>/dev/null; then
   curl -fsSL "$INSTALLER_URL" | bash -s -- "$TARGET_DIR"
 elif command -v wget &>/dev/null; then