diff --git a/tools/ai-cli-dispatch/src/config.ts b/tools/ai-cli-dispatch/src/config.ts
new file mode 100644
index 0000000..73adf86
--- /dev/null
+++ b/tools/ai-cli-dispatch/src/config.ts
@@ -0,0 +1,92 @@
+import { homedir } from "node:os";
+import {
+  readFileSync as realReadFileSync,
+  existsSync as realExistsSync,
+} from "node:fs";
+import { spawnSync } from "node:child_process";
+import type { ClientName } from "./types.js";
+
+const CLIENT_NAMES: ClientName[] = ["codex", "claude", "opencode"];
+
+export interface ResolvedConfig {
+  paths: Partial<Record<ClientName, string>>;
+  defaultClient?: ClientName;
+}
+
+export interface ResolveConfigOptions {
+  flags?: Record<string, string | boolean | undefined>;
+  env?: NodeJS.ProcessEnv;
+  homeDir?: string;
+  readFileSync?: (path: string, encoding: BufferEncoding) => string;
+  existsSync?: (path: string) => boolean;
+  whichSync?: (cmd: string) => string | undefined;
+}
+
+function defaultWhichSync(cmd: string): string | undefined {
+  const isWin = process.platform === "win32";
+  const result = spawnSync(isWin ? "where" : "which", [cmd], {
+    encoding: "utf-8",
+  });
+  if (result.status === 0) {
+    return result.stdout.trim().split("\n")[0];
+  }
+  return undefined;
+}
+
+export function resolveConfig(
+  options: ResolveConfigOptions = {}
+): ResolvedConfig {
+  const {
+    flags = {},
+    env = process.env,
+    homeDir = homedir(),
+    readFileSync = realReadFileSync,
+    existsSync = realExistsSync,
+    whichSync = defaultWhichSync,
+  } = options;
+
+  const configPath = `${homeDir}/.openclaw/ai-cli-dispatch.json`;
+
+  let fileConfig: Record<string, unknown> = {};
+  if (existsSync(configPath)) {
+    try {
+      fileConfig = JSON.parse(readFileSync(configPath, "utf-8"));
+    } catch {
+      fileConfig = {};
+    }
+  }
+
+  const filePaths = (fileConfig.paths ?? {}) as Partial<
+    Record<ClientName, string>
+  >;
+  const fileDefault = fileConfig.defaultClient as ClientName | undefined;
+
+  const paths: Partial<Record<ClientName, string>> = {};
+  for (const name of CLIENT_NAMES) {
+    const flagKey = `${name}-path`;
+    const envKey = `AI_CLI_${name.toUpperCase()}_PATH`;
+    const resolved =
+      (typeof flags[flagKey] === "string"
+        ? (flags[flagKey] as string)
+        : undefined) ??
+      env[envKey] ??
+      filePaths[name] ??
+      whichSync(name);
+    if (resolved !== undefined) {
+      paths[name] = resolved;
+    }
+  }
+
+  const defaultClient =
+    (typeof flags["default-client"] === "string"
+      ? (flags["default-client"] as string)
+      : undefined) ??
+    env.AI_CLI_DEFAULT_CLIENT ??
+    fileDefault;
+
+  const result: ResolvedConfig = { paths };
+  if (defaultClient !== undefined) {
+    result.defaultClient = defaultClient as ClientName;
+  }
+  return result;
+}
diff --git a/tools/ai-cli-dispatch/tests/config.test.ts b/tools/ai-cli-dispatch/tests/config.test.ts
new file mode 100644
index 0000000..89b74b9
--- /dev/null
+++ b/tools/ai-cli-dispatch/tests/config.test.ts
@@ -0,0 +1,111 @@
+import { describe, it } from "node:test";
+import assert from "node:assert";
+import { resolveConfig } from "../src/config.js";
+
+describe("resolveConfig", () => {
+  it("returns empty config when no sources are present", () => {
+    const config = resolveConfig({
+      existsSync: () => false,
+      whichSync: () => undefined,
+    });
+    assert.deepStrictEqual(config.paths, {});
+    assert.strictEqual(config.defaultClient, undefined);
+  });
+
+  it("loads config from file", () => {
+    const config = resolveConfig({
+      existsSync: () => true,
+      readFileSync: () =>
+        JSON.stringify({
+          paths: { codex: "/file/codex", claude: "/file/claude" },
+          defaultClient: "claude",
+        }),
+      whichSync: () => undefined,
+    });
+    assert.strictEqual(config.paths.codex, "/file/codex");
+    assert.strictEqual(config.paths.claude, "/file/claude");
+    assert.strictEqual(config.defaultClient, "claude");
+  });
+
+  it("overrides file config with env vars", () => {
+    const config = resolveConfig({
+      env: { AI_CLI_CODEX_PATH: "/env/codex" },
+      existsSync: () => true,
+      readFileSync: () => JSON.stringify({ paths: { codex: "/file/codex" } }),
+      whichSync: () => undefined,
+    });
+    assert.strictEqual(config.paths.codex, "/env/codex");
+  });
+
+  it("overrides env vars with CLI flags", () => {
+    const config = resolveConfig({
+      flags: { "codex-path": "/flag/codex" },
+      env: { AI_CLI_CODEX_PATH: "/env/codex" },
+      existsSync: () => true,
+      readFileSync: () => JSON.stringify({ paths: { codex: "/file/codex" } }),
+      whichSync: () => undefined,
+    });
+    assert.strictEqual(config.paths.codex, "/flag/codex");
+  });
+
+  it("falls back to PATH detection when config file is missing", () => {
+    const config = resolveConfig({
+      existsSync: () => false,
+      whichSync: (cmd) =>
+        cmd === "opencode" ? "/usr/bin/opencode" : undefined,
+    });
+    assert.strictEqual(config.paths.opencode, "/usr/bin/opencode");
+    assert.strictEqual(config.paths.codex, undefined);
+    assert.strictEqual(config.paths.claude, undefined);
+  });
+
+  it("respects full priority ordering: flag > env > file > PATH", () => {
+    const config = resolveConfig({
+      flags: {
+        "codex-path": "/flag/codex",
+        "claude-path": "/flag/claude",
+        "opencode-path": "/flag/opencode",
+        "default-client": "opencode",
+      },
+      env: {
+        AI_CLI_CODEX_PATH: "/env/codex",
+        AI_CLI_CLAUDE_PATH: "/env/claude",
+        AI_CLI_OPENCODE_PATH: "/env/opencode",
+        AI_CLI_DEFAULT_CLIENT: "claude",
+      },
+      existsSync: () => true,
+      readFileSync: () =>
+        JSON.stringify({
+          paths: {
+            codex: "/file/codex",
+            claude: "/file/claude",
+            opencode: "/file/opencode",
+          },
+          defaultClient: "codex",
+        }),
+      whichSync: (cmd) => `/path/${cmd}`,
+    });
+    assert.strictEqual(config.paths.codex, "/flag/codex");
+    assert.strictEqual(config.paths.claude, "/flag/claude");
+    assert.strictEqual(config.paths.opencode, "/flag/opencode");
+    assert.strictEqual(config.defaultClient, "opencode");
+  });
+
+  it("uses env var for default client when no flag is given", () => {
+    const config = resolveConfig({
+      env: { AI_CLI_DEFAULT_CLIENT: "claude" },
+      existsSync: () => false,
+      whichSync: () => undefined,
+    });
+    assert.strictEqual(config.defaultClient, "claude");
+  });
+
+  it("uses file default client when no env var is given", () => {
+    const config = resolveConfig({
+      existsSync: () => true,
+      readFileSync: () => JSON.stringify({ defaultClient: "codex" }),
+      whichSync: () => undefined,
+    });
+    assert.strictEqual(config.defaultClient, "codex");
+  });
+});