feat(server): upgrade the ACP runtime and bridge T3 MCP to ACP agents

apps/server/.gitignore

@@ -0,0 +1 @@
+tmp/

apps/server/scripts/acp-thread-spawn-helper.c

@@ -0,0 +1,37 @@
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+static const char *pid_path;
+
+static void *spawn_child(void *unused) {
+    (void)unused;
+    pid_t child = fork();
+    if (child == 0) {
+        execlp("sleep", "sleep", "120", NULL);
+        _exit(127);
+    }
+    if (child < 0) return NULL;
+    FILE *file = fopen(pid_path, "w");
+    if (file != NULL) {
+        fprintf(file, "%ld %d\n", syscall(SYS_gettid), child);
+        fclose(file);
+    }
+    waitpid(child, NULL, 0);
+    return NULL;
+}
+
+int main(int argc, char **argv) {
+    if (argc != 2) return 2;
+    pid_path = argv[1];
+    pthread_t worker;
+    if (pthread_create(&worker, NULL, spawn_child, NULL) != 0) return 3;
+    if (pthread_join(worker, NULL) != 0) return 4;
+    return 0;
+}

apps/server/scripts/acpMockCancellationState.ts

@@ -0,0 +1,3 @@
+export function beginAcpMockPrompt(cancelledSessions: Set<string>, sessionId: string): void {
+  cancelledSessions.delete(sessionId);
+}

apps/server/src/bin.test.ts

@@ -29,7 +29,7 @@ import * as CliError from "effect/unstable/cli/CliError";
 import * as TestConsole from "effect/testing/TestConsole";
 import { Command } from "effect/unstable/cli";
 
-import { cli, makeCli } from "./bin.ts";
+import { cli, makeCli } from "./binCli.ts";
 import * as ServiceLauncherClient from "./cloud/serviceLauncherClient.ts";
 import {
   SERVICE_LAUNCHER_CONTEXT_ENV,

apps/server/src/bin.ts

@@ -1,84 +1,13 @@
-import * as NodeRuntime from "@effect/platform-node/NodeRuntime";
-import * as NodeServices from "@effect/platform-node/NodeServices";
-import * as Effect from "effect/Effect";
-import * as Layer from "effect/Layer";
-import { Argument, Command } from "effect/unstable/cli";
-import * as CliError from "effect/unstable/cli/CliError";
-
-import * as NetService from "@t3tools/shared/Net";
-import packageJson from "../package.json" with { type: "json" };
-import { authCommand } from "./cli/auth.ts";
-import { appCommand } from "./cli/app.ts";
-import { connectCommand } from "./cli/connect.ts";
-import { pairCommand } from "./cli/pair.ts";
-import { hasCloudPublicConfig } from "./cloud/publicConfig.ts";
-import { sharedServerCommandFlags } from "./cli/config.ts";
+/**
+ * Thin CLI entry.
+ *
+ * Every ACP agent spawns `t3 acp-mcp-bridge` while opening its session, and
+ * terminal-fallback agents run `t3 acp-mcp-call` per tool call, so their
+ * startup sits on first-message latency. Both dispatch here before the full
+ * CLI module graph (seconds of evaluation) loads; everything else defers to
+ * the real CLI in ./binCli.ts.
+ */
 import { isEntrypoint } from "./entrypoint.ts";
-import { projectCommand } from "./cli/project.ts";
-import { runServerCommand, serveCommand, startCommand } from "./cli/server.ts";
-import { serviceCommand } from "./cli/service.ts";
-import { uninstallCommand } from "./cli/uninstall.ts";
-import { updateCommand } from "./cli/update.ts";
-import { claudeHistoryCommand } from "./cli/claudeHistory.ts";
-import { serviceLauncherCommand } from "./cli/serviceLauncher.ts";
-import { servicePreflightCommand } from "./cli/servicePreflight.ts";
-import { sshHelperCommand } from "./cli/sshHelper.ts";
-import { themeCommand } from "./cli/theme.ts";
-import { traceCommand } from "./cli/trace.ts";
-import { triageCommand } from "./cli/triage.ts";
-
-const CliRuntimeLayer = Layer.mergeAll(NodeServices.layer, NetService.layer);
-
-const connectPublicConfigMissingMessage =
-  "T3 Connect commands are unavailable: this build is missing T3 Connect public configuration.";
-
-class ConnectPublicConfigMissingError extends CliError.UserError {
-  override get message() {
-    return connectPublicConfigMissingMessage;
-  }
-}
-
-const connectUnavailableCommand = Command.make("connect", {
-  command: Argument.String("command").pipe(Argument.variadic),
-}).pipe(
-  Command.withDescription("T3 Connect is unavailable in builds without public configuration."),
-  Command.unlisted,
-  Command.withHandler(() =>
-    Effect.fail(
-      new CliError.ShowHelp({
-        commandPath: ["t3", "connect"],
-        errors: [new ConnectPublicConfigMissingError({ cause: connectPublicConfigMissingMessage })],
-      }),
-    ),
-  ),
-);
-
-export const makeCli = ({ cloudEnabled = hasCloudPublicConfig } = {}) =>
-  Command.make("t3", { ...sharedServerCommandFlags }).pipe(
-    Command.withDescription("Run the T3 Code server."),
-    Command.withHandler((flags) => runServerCommand(flags)),
-    Command.withSubcommands([
-      startCommand,
-      serveCommand,
-      appCommand,
-      pairCommand,
-      authCommand,
-      projectCommand,
-      serviceCommand,
-      updateCommand,
-      uninstallCommand,
-      serviceLauncherCommand,
-      claudeHistoryCommand,
-      servicePreflightCommand,
-      sshHelperCommand,
-      themeCommand,
-      traceCommand,
-      triageCommand,
-      cloudEnabled ? connectCommand : connectUnavailableCommand,
-    ]),
-  );
-
-export const cli = makeCli();
 
 if (
   isEntrypoint({
@@ -87,9 +16,12 @@ if (
     runtimeMain: import.meta.main,
   })
 ) {
-  Command.run(cli, { version: packageJson.version }).pipe(
-    Effect.scoped,
-    Effect.provide(CliRuntimeLayer),
-    NodeRuntime.runMain,
-  );
+  const command = process.argv[2];
+  if (command === "acp-mcp-bridge" || command === "acp-mcp-call") {
+    const { runAcpMcpCliFastPath } = await import("./mcp/AcpMcpStdioBridge.ts");
+    await runAcpMcpCliFastPath(command, process.argv.slice(3));
+  } else {
+    const { runCli } = await import("./binCli.ts");
+    runCli();
+  }
 }

apps/server/src/binCli.ts

@@ -0,0 +1,91 @@
+import * as NodeRuntime from "@effect/platform-node/NodeRuntime";
+import * as NodeServices from "@effect/platform-node/NodeServices";
+import * as Effect from "effect/Effect";
+import * as Layer from "effect/Layer";
+import { Argument, Command } from "effect/unstable/cli";
+import * as CliError from "effect/unstable/cli/CliError";
+
+import * as NetService from "@t3tools/shared/Net";
+import packageJson from "../package.json" with { type: "json" };
+import { acpMcpBridgeCommand, acpMcpCallCommand } from "./cli/acpMcpBridge.ts";
+import { authCommand } from "./cli/auth.ts";
+import { appCommand } from "./cli/app.ts";
+import { connectCommand } from "./cli/connect.ts";
+import { pairCommand } from "./cli/pair.ts";
+import { hasCloudPublicConfig } from "./cloud/publicConfig.ts";
+import { sharedServerCommandFlags } from "./cli/config.ts";
+import { projectCommand } from "./cli/project.ts";
+import { runServerCommand, serveCommand, startCommand } from "./cli/server.ts";
+import { serviceCommand } from "./cli/service.ts";
+import { uninstallCommand } from "./cli/uninstall.ts";
+import { updateCommand } from "./cli/update.ts";
+import { claudeHistoryCommand } from "./cli/claudeHistory.ts";
+import { serviceLauncherCommand } from "./cli/serviceLauncher.ts";
+import { servicePreflightCommand } from "./cli/servicePreflight.ts";
+import { sshHelperCommand } from "./cli/sshHelper.ts";
+import { themeCommand } from "./cli/theme.ts";
+import { traceCommand } from "./cli/trace.ts";
+import { triageCommand } from "./cli/triage.ts";
+
+const CliRuntimeLayer = Layer.mergeAll(NodeServices.layer, NetService.layer);
+
+const connectPublicConfigMissingMessage =
+  "T3 Connect commands are unavailable: this build is missing T3 Connect public configuration.";
+
+class ConnectPublicConfigMissingError extends CliError.UserError {
+  override get message() {
+    return connectPublicConfigMissingMessage;
+  }
+}
+
+const connectUnavailableCommand = Command.make("connect", {
+  command: Argument.String("command").pipe(Argument.variadic),
+}).pipe(
+  Command.withDescription("T3 Connect is unavailable in builds without public configuration."),
+  Command.unlisted,
+  Command.withHandler(() =>
+    Effect.fail(
+      new CliError.ShowHelp({
+        commandPath: ["t3", "connect"],
+        errors: [new ConnectPublicConfigMissingError({ cause: connectPublicConfigMissingMessage })],
+      }),
+    ),
+  ),
+);
+
+export const makeCli = ({ cloudEnabled = hasCloudPublicConfig } = {}) =>
+  Command.make("t3", { ...sharedServerCommandFlags }).pipe(
+    Command.withDescription("Run the T3 Code server."),
+    Command.withHandler((flags) => runServerCommand(flags)),
+    Command.withSubcommands([
+      acpMcpBridgeCommand,
+      acpMcpCallCommand,
+      startCommand,
+      serveCommand,
+      appCommand,
+      pairCommand,
+      authCommand,
+      projectCommand,
+      serviceCommand,
+      updateCommand,
+      uninstallCommand,
+      serviceLauncherCommand,
+      claudeHistoryCommand,
+      servicePreflightCommand,
+      sshHelperCommand,
+      themeCommand,
+      traceCommand,
+      triageCommand,
+      cloudEnabled ? connectCommand : connectUnavailableCommand,
+    ]),
+  );
+
+export const cli = makeCli();
+
+export function runCli() {
+  Command.run(cli, { version: packageJson.version }).pipe(
+    Effect.scoped,
+    Effect.provide(CliRuntimeLayer),
+    NodeRuntime.runMain,
+  );
+}

apps/server/src/cli/acpMcpBridge.ts

@@ -0,0 +1,34 @@
+import * as Effect from "effect/Effect";
+import { Argument, Command } from "effect/unstable/cli";
+
+import { runAcpMcpCliFastPath } from "../mcp/AcpMcpStdioBridge.ts";
+
+/**
+ * `t3 acp-mcp-bridge` — internal stdio MCP server that ACP agents spawn.
+ *
+ * The T3 server injects this command (with per-session endpoint and
+ * credential environment variables) into `session/new` so every ACP agent
+ * reaches the t3-code toolkit through ACP's required stdio MCP transport.
+ * The credential stays in the environment, never on the command line.
+ *
+ * Real invocations dispatch through the bin.ts fast path before the CLI
+ * graph loads; these definitions keep the commands wired for help and for
+ * anything that drives the full CLI programmatically.
+ */
+export const acpMcpBridgeCommand = Command.make("acp-mcp-bridge").pipe(
+  Command.withDescription("Bridge T3 Code's MCP endpoint to stdio for ACP agents."),
+  Command.unlisted,
+  Command.withHandler(() => Effect.promise(() => runAcpMcpCliFastPath("acp-mcp-bridge", []))),
+);
+
+/** Terminal fallback for ACP agents that do not expose injected MCP servers. */
+export const acpMcpCallCommand = Command.make("acp-mcp-call", {
+  tool: Argument.String("tool"),
+  argumentsJson: Argument.String("arguments-json"),
+}).pipe(
+  Command.withDescription("Call one T3 Code MCP tool from an ACP agent terminal."),
+  Command.unlisted,
+  Command.withHandler(({ tool, argumentsJson }) =>
+    Effect.promise(() => runAcpMcpCliFastPath("acp-mcp-call", [tool, argumentsJson])),
+  ),
+);

apps/server/src/cli/app.test.ts

@@ -20,7 +20,7 @@ import * as Layer from "effect/Layer";
 import { Command } from "effect/unstable/cli";
 import { afterEach, describe, expect, vi } from "vite-plus/test";
 
-import { makeCli } from "../bin.ts";
+import { makeCli } from "../binCli.ts";
 
 vi.mock("node:os", async (importOriginal) => {
   const os = await importOriginal<typeof import("node:os")>();

apps/server/src/cli/pair.test.ts

@@ -13,7 +13,7 @@ import * as Layer from "effect/Layer";
 import * as TestConsole from "effect/testing/TestConsole";
 import { Command } from "effect/unstable/cli";
 
-import { cli } from "../bin.ts";
+import { cli } from "../binCli.ts";
 import {
   SERVICE_LAUNCHER_CONTEXT_ENV,
   SERVICE_LAUNCHER_PROTOCOL,

apps/server/src/cli/theme.test.ts

@@ -12,7 +12,7 @@ import * as Layer from "effect/Layer";
 import * as TestConsole from "effect/testing/TestConsole";
 import { Command } from "effect/unstable/cli";
 
-import { cli } from "../bin.ts";
+import { cli } from "../binCli.ts";
 import { symlinksSupported } from "@t3tools/shared/testing/symlinks";
 import { HostProcessPlatform } from "@t3tools/shared/hostProcess";