✨ Add PENPOT_MCP_REPL_ENABLE env var for explicit REPL control

Allow the REPL server to be enabled independently of the devenv
setting via a new PENPOT_MCP_REPL_ENABLE environment variable.
When set to "true", the REPL server starts regardless of
PENPOT_MCP_DEVENV; when set to any other value, it is disabled.
When unset, the previous isDevEnv fallback applies.

Addresses review feedback on PR #11282.

AI-assisted-by: mimo-v2.5

mcp/README.md

@@ -265,6 +265,7 @@ The Penpot MCP server can be configured using environment variables.
 | `PENPOT_MCP_SERVER_PORT`                         | Port for the HTTP/SSE server                                               | `4401`         |
 | `PENPOT_MCP_WEBSOCKET_PORT`                      | Port for the WebSocket server (plugin connection)                          | `4402`         |
 | `PENPOT_MCP_REPL_PORT`                           | Port for the REPL server (development/debugging)                           | `4403`         |
+| `PENPOT_MCP_REPL_ENABLE`                         | Explicitly enable/disable the REPL server. Set to `true` to enable. When unset, defaults to the value of `PENPOT_MCP_DEVENV`. | (unset)        |
 | `PENPOT_MCP_REMOTE_MODE`                         | Enable remote mode (disables file system access). Set to `true` to enable. | `false`        |
 | `PENPOT_MCP_DEVENV`                              | Enable Penpot development environment tools. Set to `true` to enable.      | `false`        |
 | `PENPOT_MCP_TOOL_TIMEOUT_S`                      | Timeout, in seconds, for tool calls dispatched to the Penpot plugin        | `120`          |

mcp/packages/server/src/PenpotMcpServer.test.ts

@@ -16,6 +16,28 @@ test("isDevEnvEnabled returns true when PENPOT_MCP_DEVENV is 'true'", () => {
     assert.equal(PenpotMcpServer.isDevEnvEnabled({ PENPOT_MCP_DEVENV: "true" }), true);
 });
 
+// ── Pure function tests: isReplEnabled ──────────────────────────
+
+test("isReplEnabled returns false when neither env var is set", () => {
+    assert.equal(PenpotMcpServer.isReplEnabled({}), false);
+});
+
+test("isReplEnabled returns true when PENPOT_MCP_DEVENV is 'true' (fallback)", () => {
+    assert.equal(PenpotMcpServer.isReplEnabled({ PENPOT_MCP_DEVENV: "true" }), true);
+});
+
+test("isReplEnabled returns true when PENPOT_MCP_REPL_ENABLE is 'true'", () => {
+    assert.equal(PenpotMcpServer.isReplEnabled({ PENPOT_MCP_REPL_ENABLE: "true" }), true);
+});
+
+test("isReplEnabled returns false when PENPOT_MCP_REPL_ENABLE is 'false' even if DEVENV is true", () => {
+    assert.equal(PenpotMcpServer.isReplEnabled({ PENPOT_MCP_REPL_ENABLE: "false", PENPOT_MCP_DEVENV: "true" }), false);
+});
+
+test("isReplEnabled returns true when PENPOT_MCP_REPL_ENABLE is 'true' regardless of DEVENV", () => {
+    assert.equal(PenpotMcpServer.isReplEnabled({ PENPOT_MCP_REPL_ENABLE: "true" }), true);
+});
+
 // ── Integration tests: constructor gating ──────────────────────
 //
 // Each test uses unique ports to avoid conflicts when tests run
@@ -57,6 +79,40 @@ test("constructor creates ReplServer when PENPOT_MCP_DEVENV is 'true'", async ()
     }
 });
 
+test("constructor creates ReplServer when PENPOT_MCP_REPL_ENABLE is 'true' without DEVENV", async () => {
+    const prevDevEnv = process.env.PENPOT_MCP_DEVENV;
+    const prevReplEnable = process.env.PENPOT_MCP_REPL_ENABLE;
+    const prevPorts = setUniqueEnv();
+    delete process.env.PENPOT_MCP_DEVENV;
+    process.env.PENPOT_MCP_REPL_ENABLE = "true";
+    let server: PenpotMcpServer | undefined;
+    try {
+        server = new PenpotMcpServer(false);
+        assert.equal(server.hasReplServer(), true);
+    } finally {
+        await server?.stop();
+        restoreEnv(prevDevEnv, prevPorts);
+        restoreOrDelete("PENPOT_MCP_REPL_ENABLE", prevReplEnable);
+    }
+});
+
+test("constructor does not create ReplServer when PENPOT_MCP_REPL_ENABLE is 'false' even with DEVENV", async () => {
+    const prevDevEnv = process.env.PENPOT_MCP_DEVENV;
+    const prevReplEnable = process.env.PENPOT_MCP_REPL_ENABLE;
+    const prevPorts = setUniqueEnv();
+    process.env.PENPOT_MCP_DEVENV = "true";
+    process.env.PENPOT_MCP_REPL_ENABLE = "false";
+    let server: PenpotMcpServer | undefined;
+    try {
+        server = new PenpotMcpServer(false);
+        assert.equal(server.hasReplServer(), false);
+    } finally {
+        await server?.stop();
+        restoreEnv(prevDevEnv, prevPorts);
+        restoreOrDelete("PENPOT_MCP_REPL_ENABLE", prevReplEnable);
+    }
+});
+
 // ── Helpers ────────────────────────────────────────────────────
 
 function setUniqueEnv() {

mcp/packages/server/src/PenpotMcpServer.ts

@@ -66,6 +66,20 @@ export class PenpotMcpServer {
         return env.PENPOT_MCP_DEVENV === "true";
     }
 
+    /**
+     * Determines whether the REPL server should be enabled.
+     *
+     * If ``PENPOT_MCP_REPL_ENABLE`` is set, its value controls the result
+     * (``"true"`` enables, any other value disables). When the variable is
+     * not set, the result falls back to {@link isDevEnvEnabled}.
+     */
+    public static isReplEnabled(env: Record<string, string | undefined>): boolean {
+        if (env.PENPOT_MCP_REPL_ENABLE !== undefined) {
+            return env.PENPOT_MCP_REPL_ENABLE === "true";
+        }
+        return PenpotMcpServer.isDevEnvEnabled(env);
+    }
+
     /**
      * Returns a short, non-reversible fingerprint of a user token, suitable for
      * correlating log lines without exposing the full credential.
@@ -160,7 +174,7 @@ export class PenpotMcpServer {
 
         this.pluginBridge = new PluginBridge(this, this.webSocketPort, toolTimeoutSecs, this.redisBridge);
 
-        if (PenpotMcpServer.isDevEnvEnabled(process.env)) {
+        if (PenpotMcpServer.isReplEnabled(process.env)) {
             this.replServer = new ReplServer(this.pluginBridge, this.replPort, this.host);
         } else {
             this.replServer = null;
@@ -211,7 +225,9 @@ export class PenpotMcpServer {
     /**
      * Indicates whether the REPL server was created.
      *
-     * The REPL server is created only in development environment mode.
+     * The REPL server is created when {@link isReplEnabled} returns true,
+     * which means either ``PENPOT_MCP_REPL_ENABLE=true`` or, when that
+     * variable is unset, ``PENPOT_MCP_DEVENV=true``.
      */
     public hasReplServer(): boolean {
         return this.replServer !== null;
@@ -449,7 +465,9 @@ export class PenpotMcpServer {
                 if (this.replServer) {
                     await this.replServer.start();
                 } else {
-                    this.logger.info("REPL server disabled (set PENPOT_MCP_DEVENV=true to enable)");
+                    this.logger.info(
+                        "REPL server disabled (set PENPOT_MCP_REPL_ENABLE=true or PENPOT_MCP_DEVENV=true to enable)"
+                    );
                 }
                 this.startSessionTimeoutChecker();