diff --git a/tools/ai-cli-dispatch/src/dispatch.ts b/tools/ai-cli-dispatch/src/dispatch.ts
new file mode 100644
index 0000000..9bc2a4c
--- /dev/null
+++ b/tools/ai-cli-dispatch/src/dispatch.ts
@@ -0,0 +1,39 @@
+import type { ClientName } from "./types.js";
+
+export interface DispatchConfig {
+  defaultClient?: ClientName;
+  client?: ClientName;
+}
+
+const CLIENT_NAMES: ClientName[] = ["codex", "claude", "opencode"];
+
+export function resolveClient(
+  prompt: string,
+  config?: DispatchConfig
+): ClientName | null {
+  // Explicit --client flag takes highest precedence
+  if (config?.client && CLIENT_NAMES.includes(config.client)) {
+    return config.client;
+  }
+
+  const lower = prompt.toLowerCase();
+
+  // Check for "open code" before "opencode" to handle the spaced variant
+  if (lower.includes("open code")) {
+    return "opencode";
+  }
+
+  if (lower.includes("claude")) {
+    return "claude";
+  }
+
+  if (lower.includes("codex")) {
+    return "codex";
+  }
+
+  if (lower.includes("opencode")) {
+    return "opencode";
+  }
+
+  return config?.defaultClient ?? null;
+}
diff --git a/tools/ai-cli-dispatch/tests/dispatch.test.ts b/tools/ai-cli-dispatch/tests/dispatch.test.ts
new file mode 100644
index 0000000..663e91c
--- /dev/null
+++ b/tools/ai-cli-dispatch/tests/dispatch.test.ts
@@ -0,0 +1,83 @@
+import { describe, it } from "node:test";
+import assert from "node:assert";
+import { resolveClient } from "../src/dispatch.js";
+import type { ClientName } from "../src/types.js";
+
+describe("resolveClient", () => {
+  it('returns "codex" when prompt contains "use codex"', () => {
+    const result = resolveClient("use codex to refactor this");
+    assert.strictEqual(result, "codex");
+  });
+
+  it('returns "claude" when prompt contains "tell claude to..."', () => {
+    const result = resolveClient("tell claude to review my code");
+    assert.strictEqual(result, "claude");
+  });
+
+  it('returns "opencode" when prompt contains "run with opencode"', () => {
+    const result = resolveClient("run with opencode");
+    assert.strictEqual(result, "opencode");
+  });
+
+  it('returns "opencode" when prompt contains "open code"', () => {
+    const result = resolveClient("open code this file");
+    assert.strictEqual(result, "opencode");
+  });
+
+  it("returns null when no keyword matches and no default is configured", () => {
+    const result = resolveClient("hello world");
+    assert.strictEqual(result, null);
+  });
+
+  it("returns defaultClient when no keyword matches", () => {
+    const result = resolveClient("hello world", { defaultClient: "claude" });
+    assert.strictEqual(result, "claude");
+  });
+
+  it("prefers --client flag over keyword parsing", () => {
+    const result = resolveClient("use codex for this", { client: "claude" });
+    assert.strictEqual(result, "claude");
+  });
+
+  it("prefers --client flag over defaultClient", () => {
+    const result = resolveClient("hello world", {
+      client: "opencode",
+      defaultClient: "codex",
+    });
+    assert.strictEqual(result, "opencode");
+  });
+
+  it("handles uppercase CODEX", () => {
+    const result = resolveClient("Use CODEX please");
+    assert.strictEqual(result, "codex");
+  });
+
+  it("handles mixed-case Claude", () => {
+    const result = resolveClient("Tell Claude to fix this");
+    assert.strictEqual(result, "claude");
+  });
+
+  it("returns first match when multiple clients are mentioned", () => {
+    const result = resolveClient("ask claude or codex to help");
+    assert.strictEqual(result, "claude");
+  });
+
+  it("returns null for empty prompt with no default", () => {
+    const result = resolveClient("");
+    assert.strictEqual(result, null);
+  });
+
+  it("returns defaultClient for empty prompt", () => {
+    const result = resolveClient("", { defaultClient: "codex" });
+    assert.strictEqual(result, "codex");
+  });
+
+  it("validates --client flag value", () => {
+    // Invalid client flag should fall back to keyword/default behavior
+    const result = resolveClient("use codex", {
+      client: "invalid" as ClientName,
+    });
+    // If client flag is invalid, we should fall back to keyword matching
+    assert.strictEqual(result, "codex");
+  });
+});