feat(exec): add autoEnter option for tmux send-keys commands

Add optional `autoEnter` parameter to the exec tool that automatically
appends `Enter` to tmux send-keys commands when it's missing. This helps
agents reliably execute commands in tmux sessions without forgetting to
press Enter.

- Add `autoEnter?: boolean` to exec tool schema
- Auto-detect `tmux send-keys` pattern and append Enter if missing
- Default is false for safety (opt-in behavior)
- Add comprehensive tests for the feature

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/agents/bash-tools.exec.tmux-autoenter.test.ts

@@ -0,0 +1,101 @@
+import { afterEach, describe, expect, test } from "vitest";
+
+import { resetProcessRegistryForTests } from "./bash-process-registry";
+import { createExecTool } from "./bash-tools.exec";
+
+afterEach(() => {
+  resetProcessRegistryForTests();
+});
+
+describe("tmux send-keys autoEnter", () => {
+  test("regular exec commands unchanged when autoEnter is true", async () => {
+    const execTool = createExecTool();
+    const result = await execTool.execute("toolcall", {
+      command: "echo hello",
+      autoEnter: true,
+    });
+    // Should complete normally without modification
+    expect(result.details.status).toBe("completed");
+    expect((result.details as { aggregated?: string }).aggregated).toContain("hello");
+  });
+
+  test("tmux send-keys with Enter unchanged when autoEnter is true", async () => {
+    const execTool = createExecTool();
+    // This command already has Enter, so it shouldn't be added again
+    // We use echo to simulate the command (can't actually run tmux in test)
+    const result = await execTool.execute("toolcall", {
+      command: 'echo "tmux send-keys -t test echo hello Enter"',
+      autoEnter: true,
+    });
+    expect(result.details.status).toBe("completed");
+    // The echo should show the command unchanged (only one Enter)
+    const output = (result.details as { aggregated?: string }).aggregated ?? "";
+    expect(output).toContain("Enter");
+    // Should not have "Enter Enter" (double Enter)
+    expect(output).not.toMatch(/Enter\s+Enter/);
+  });
+
+  test("tmux send-keys without Enter gets Enter appended when autoEnter is true", async () => {
+    const execTool = createExecTool();
+    // We can verify the auto-enter logic by checking that the command runs with Enter appended.
+    // Since we can't run actual tmux in tests, we use a marker approach:
+    // The command will include 'send-keys' and we can verify via echo that Enter is appended.
+    const result = await execTool.execute("toolcall", {
+      command: 'sh -c \'echo "$0" "$@"\' tmux send-keys -t test "hello"',
+      autoEnter: true,
+    });
+    expect(result.details.status).toBe("completed");
+    const output = (result.details as { aggregated?: string }).aggregated ?? "";
+    // Since autoEnter is true and the command contains 'tmux send-keys' without Enter,
+    // Enter should be appended. The echo will show the arguments including Enter.
+    expect(output).toContain("Enter");
+  });
+
+  test("tmux send-keys unchanged when autoEnter is false", async () => {
+    const execTool = createExecTool();
+    const result = await execTool.execute("toolcall", {
+      command: 'sh -c \'echo "$0" "$@"\' tmux send-keys -t test "hello"',
+      autoEnter: false,
+    });
+    expect(result.details.status).toBe("completed");
+    const output = (result.details as { aggregated?: string }).aggregated ?? "";
+    // autoEnter is false, so Enter should NOT be appended
+    expect(output).not.toContain("Enter");
+  });
+
+  test("tmux send-keys unchanged when autoEnter is not set", async () => {
+    const execTool = createExecTool();
+    const result = await execTool.execute("toolcall", {
+      command: 'sh -c \'echo "$0" "$@"\' tmux send-keys -t test "hello"',
+    });
+    expect(result.details.status).toBe("completed");
+    const output = (result.details as { aggregated?: string }).aggregated ?? "";
+    // autoEnter defaults to undefined/false, so Enter should NOT be appended
+    expect(output).not.toContain("Enter");
+  });
+
+  test("tmux send-keys with trailing quote and Enter unchanged", async () => {
+    const execTool = createExecTool();
+    const result = await execTool.execute("toolcall", {
+      command: 'echo "tmux send-keys -t test hello Enter"',
+      autoEnter: true,
+    });
+    expect(result.details.status).toBe("completed");
+    const output = (result.details as { aggregated?: string }).aggregated ?? "";
+    // Should have exactly one Enter, not double
+    const enterCount = (output.match(/Enter/g) || []).length;
+    expect(enterCount).toBe(1);
+  });
+
+  test("handles tmux -S socket send-keys pattern", async () => {
+    const execTool = createExecTool();
+    const result = await execTool.execute("toolcall", {
+      command: 'sh -c \'echo "$0" "$@"\' tmux -S /tmp/socket send-keys -t test "cmd"',
+      autoEnter: true,
+    });
+    expect(result.details.status).toBe("completed");
+    const output = (result.details as { aggregated?: string }).aggregated ?? "";
+    // Should detect 'tmux ... send-keys' and append Enter
+    expect(output).toContain("Enter");
+  });
+});

src/agents/bash-tools.exec.ts

@@ -190,6 +190,12 @@ const execSchema = Type.Object({
       description: "Node id/name for host=node.",
     }),
   ),
+  autoEnter: Type.Optional(
+    Type.Boolean({
+      description:
+        "Auto-append Enter to tmux send-keys commands that are missing it. Default false.",
+    }),
+  ),
 });
 
 export type ExecToolDetails =
@@ -749,12 +755,21 @@ export function createExecTool(
         security?: string;
         ask?: string;
         node?: string;
+        autoEnter?: boolean;
       };
 
       if (!params.command) {
         throw new Error("Provide a command to start.");
       }
 
+      // Auto-append Enter to tmux send-keys commands if autoEnter is enabled and missing.
+      if (params.autoEnter && /tmux\s+.*send-keys/i.test(params.command)) {
+        // Check if the command already ends with Enter (possibly followed by whitespace or quotes).
+        if (!/\bEnter['"]?\s*$/.test(params.command)) {
+          params.command = `${params.command} Enter`;
+        }
+      }
+
       const maxOutput = DEFAULT_MAX_OUTPUT;
       const pendingMaxOutput = DEFAULT_PENDING_MAX_OUTPUT;
       const warnings: string[] = [];