Add passthrough MCP mode

.changeset/mcp-passthrough-mode.md

@@ -0,0 +1,10 @@
+---
+"@executor-js/sdk": minor
+"@executor-js/fumadb": minor
+"@executor-js/plugin-openapi": patch
+"@executor-js/plugin-graphql": patch
+"@executor-js/plugin-mcp": patch
+"executor": minor
+---
+
+Add a passthrough MCP mode (`?mode=passthrough`, `executor mcp --mode passthrough`) that serves every connected integration tool as its own MCP tool, with workspace policy folded into each tool's annotations so the client's native approval flow applies. Adds `executor.tools.describeAll()` and a `readOnly` tool annotation.

apps/cli/src/main.ts

@@ -1363,6 +1363,8 @@ const mcpUrlForActiveLocalServer = (input: {
   readonly elicitationMode: "browser" | "model";
   readonly artifacts: boolean;
   readonly searchTools: boolean;
+  readonly toolMode: "codemode" | "passthrough";
+  readonly integrations: readonly string[];
 }): URL => {
   const url = new URL("/mcp", input.connection.origin);
   if (input.elicitationMode === "browser") {
@@ -1378,6 +1380,14 @@ const mcpUrlForActiveLocalServer = (input: {
   if (input.searchTools) {
     url.searchParams.set("search_tools", "true");
   }
+  // Passthrough is the non-default surface; only it is spelled out, and the
+  // integration filter only means anything alongside it.
+  if (input.toolMode === "passthrough") {
+    url.searchParams.set("mode", "passthrough");
+    if (input.integrations.length > 0) {
+      url.searchParams.set("integrations", input.integrations.join(","));
+    }
+  }
   return url;
 };
 
@@ -1394,6 +1404,8 @@ const runMcpHttpBridge = async (input: {
   readonly elicitationMode: "browser" | "model";
   readonly artifacts: boolean;
   readonly searchTools: boolean;
+  readonly toolMode: "codemode" | "passthrough";
+  readonly integrations: readonly string[];
 }): Promise<void> => {
   const stdio = new StdioServerTransport();
   const authorization = getExecutorServerAuthorizationHeader(input.manifest.connection);
@@ -1403,6 +1415,8 @@ const runMcpHttpBridge = async (input: {
       elicitationMode: input.elicitationMode,
       artifacts: input.artifacts,
       searchTools: input.searchTools,
+      toolMode: input.toolMode,
+      integrations: input.integrations,
     }),
     authorization ? { requestInit: { headers: { Authorization: authorization } } } : undefined,
   );
@@ -1482,6 +1496,8 @@ const runStdioMcpSession = (input: {
   readonly elicitationMode: "browser" | "model";
   readonly artifacts: boolean;
   readonly searchTools: boolean;
+  readonly toolMode: "codemode" | "passthrough";
+  readonly integrations: readonly string[];
 }) =>
   Effect.gen(function* () {
     // `executor mcp` never owns the local database. If a local server is already
@@ -1499,6 +1515,8 @@ const runStdioMcpSession = (input: {
           elicitationMode: input.elicitationMode,
           artifacts: input.artifacts,
           searchTools: input.searchTools,
+          toolMode: input.toolMode,
+          integrations: input.integrations,
         }),
       );
       return;
@@ -1526,6 +1544,8 @@ const runStdioMcpSession = (input: {
         elicitationMode: input.elicitationMode,
         artifacts: input.artifacts,
         searchTools: input.searchTools,
+        toolMode: input.toolMode,
+        integrations: input.integrations,
       }),
     );
   });
@@ -2898,11 +2918,45 @@ const mcpCommand = Command.make(
           "Serve one search_<integration> tool per connected integration. Off by default; each routes through the same flow as tools.search inside execute.",
         ),
       ),
+    toolMode: Options.choice("mode", ["codemode", "passthrough"] as const)
+      .pipe(Options.withDefault("codemode"))
+      .pipe(
+        Options.withDescription(
+          "codemode (default) serves the execute tool; passthrough serves every connected integration tool directly, with policy folded into each tool's annotations and no execute, skills, or resume.",
+        ),
+      ),
+    integrations: Options.string("integrations")
+      .pipe(Options.optional)
+      .pipe(
+        Options.withDescription(
+          "Passthrough only: comma-separated integration slugs to serve. Omit for every connected integration.",
+        ),
+      ),
   },
-  ({ scope, elicitationMode, noArtifacts, searchTools }) =>
+  ({ scope, elicitationMode, noArtifacts, searchTools, toolMode, integrations }) =>
     Effect.gen(function* () {
       applyScope(scope);
-      yield* runStdioMcpSession({ elicitationMode, artifacts: !noArtifacts, searchTools });
+      if (toolMode === "passthrough" && searchTools) {
+        return yield* Effect.fail(
+          new Error(
+            "--search-tools is a codemode option; passthrough already lists every tool. Drop --search-tools or --mode passthrough.",
+          ),
+        );
+      }
+      yield* runStdioMcpSession({
+        elicitationMode,
+        artifacts: !noArtifacts,
+        searchTools,
+        toolMode,
+        integrations: Option.match(integrations, {
+          onNone: () => [],
+          onSome: (value) =>
+            value
+              .split(",")
+              .map((slug) => slug.trim())
+              .filter((slug) => slug.length > 0),
+        }),
+      });
     }),
 ).pipe(Command.withDescription("Start an MCP server over stdio"));
 

apps/cloud/drizzle/0018_tool_generation.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "definition" ADD COLUMN "generation" text;--> statement-breakpoint
+ALTER TABLE "tool" ADD COLUMN "generation" text;

apps/cloud/drizzle/0019_connection_tools_manifest.sql

@@ -0,0 +1 @@
+ALTER TABLE "connection" ADD COLUMN "tools_manifest" json;

apps/cloud/drizzle/0020_connection_tools_rebuild.sql

@@ -0,0 +1 @@
+ALTER TABLE "connection" ADD COLUMN "tools_rebuild" text;