fix(mobile): polyfill

- polyfill crypto.getRandomValues (uuid/LangChain not supported）) - polyfill AbortSignal.prototype.throwIfAborted (throwIfAborted is not a function）")
fix: resolve ReadableStream in simulator so LangGraph runs on RN
2026-02-04 16:48:00 -08:00 · 2026-02-04 15:24:14 -08:00 · 2026-02-03 21:37:41 -08:00
11 changed files with 659 additions and 5 deletions
--- a/App.tsx
+++ b/App.tsx
@@ -4,6 +4,7 @@
 * Main application component with authentication routing.
 * Shows loading screen while restoring auth state.
 */
+import './src/polyfills';

 import React from 'react';
 import { Buffer } from 'buffer';
--- a/assets/images/icon.png
+++ b/assets/images/icon.png
--- a/metro.config.js
+++ b/metro.config.js
@@ -6,8 +6,10 @@ const config = getDefaultConfig(__dirname);
 config.resolver.extraNodeModules = {
    ...config.resolver.extraNodeModules,
    crypto: path.resolve(__dirname, 'src/utils/crypto_polyfill.ts'),
-    stream: require.resolve('readable-stream'), // Just in case
+    stream: require.resolve('readable-stream'),
    vm: require.resolve('vm-browserify'),
+    async_hooks: path.resolve(__dirname, 'src/utils/async_hooks_mock.ts'),
+    'node:async_hooks': path.resolve(__dirname, 'src/utils/async_hooks_mock.ts'),
 };

 module.exports = config;
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,6 +10,8 @@
      "dependencies": {
        "@expo/metro-runtime": "~4.0.1",
        "@expo/vector-icons": "~14.0.4",
+        "@langchain/core": "^1.1.18",
+        "@langchain/langgraph": "^1.1.3",
        "@noble/ciphers": "^1.3.0",
        "@noble/hashes": "^1.8.0",
        "@react-native-async-storage/async-storage": "^2.2.0",
@@ -2203,6 +2205,12 @@
        "node": ">=6.9.0"
      }
    },
+    "node_modules/@cfworker/json-schema": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmmirror.com/@cfworker/json-schema/-/json-schema-4.1.1.tgz",
+      "integrity": "sha512-gAmrUZSGtKc3AiBL71iNWxDsyUC5uMaKKGdvzYsBoTW/xi42JQHl7eKV2OYzCUqvc+D2RCcf7EXY2iCyFIk6og==",
+      "license": "MIT"
+    },
    "node_modules/@egjs/hammerjs": {
      "version": "2.0.17",
      "resolved": "https://registry.npmjs.org/@egjs/hammerjs/-/hammerjs-2.0.17.tgz",
@@ -3216,6 +3224,204 @@
        "@jridgewell/sourcemap-codec": "^1.4.14"
      }
    },
+    "node_modules/@langchain/core": {
+      "version": "1.1.18",
+      "resolved": "https://registry.npmmirror.com/@langchain/core/-/core-1.1.18.tgz",
+      "integrity": "sha512-vwzbtHUSZaJONBA1n9uQedZPfyFFZ6XzTggTpR28n8tiIg7e1NC/5dvGW/lGtR1Du1VwV9DvDHA5/bOrLe6cVg==",
+      "license": "MIT",
+      "dependencies": {
+        "@cfworker/json-schema": "^4.0.2",
+        "ansi-styles": "^5.0.0",
+        "camelcase": "6",
+        "decamelize": "1.2.0",
+        "js-tiktoken": "^1.0.12",
+        "langsmith": ">=0.4.0 <1.0.0",
+        "mustache": "^4.2.0",
+        "p-queue": "^6.6.2",
+        "uuid": "^10.0.0",
+        "zod": "^3.25.76 || ^4"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/@langchain/core/node_modules/ansi-styles": {
+      "version": "5.2.0",
+      "resolved": "https://registry.npmmirror.com/ansi-styles/-/ansi-styles-5.2.0.tgz",
+      "integrity": "sha512-Cxwpt2SfTzTtXcfOlzGEee8O+c+MmUgGrNiBcXnuWxuFJHe6a5Hz7qwhwe5OgaSYI0IJvkLqWX1ASG+cJOkEiA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/ansi-styles?sponsor=1"
+      }
+    },
+    "node_modules/@langchain/core/node_modules/camelcase": {
+      "version": "6.3.0",
+      "resolved": "https://registry.npmmirror.com/camelcase/-/camelcase-6.3.0.tgz",
+      "integrity": "sha512-Gmy6FhYlCY7uOElZUSbxo2UCDH8owEk996gkbrpsgGtrJLM3J7jGxl9Ic7Qwwj4ivOE5AWZWRMecDdF7hqGjFA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/@langchain/core/node_modules/uuid": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmmirror.com/uuid/-/uuid-10.0.0.tgz",
+      "integrity": "sha512-8XkAphELsDnEGrDxUOHB3RGvXz6TeuYSGEZBOjtTtPm2lwhGBjLgOzLHB63IUWfBpNucQjND6d3AOudO+H3RWQ==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist/bin/uuid"
+      }
+    },
+    "node_modules/@langchain/langgraph": {
+      "version": "1.1.3",
+      "resolved": "https://registry.npmmirror.com/@langchain/langgraph/-/langgraph-1.1.3.tgz",
+      "integrity": "sha512-o/cEWeocDDSpyBI2MfX07LkNG4LzdRKxwcgUcbR4PyRzhxxCkeIZRCCYkXVQoDbdKqAczJa0D7+yjU9rmA5iHQ==",
+      "license": "MIT",
+      "dependencies": {
+        "@langchain/langgraph-checkpoint": "^1.0.0",
+        "@langchain/langgraph-sdk": "~1.5.5",
+        "@standard-schema/spec": "1.1.0",
+        "uuid": "^10.0.0"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "peerDependencies": {
+        "@langchain/core": "^1.0.1",
+        "zod": "^3.25.32 || ^4.2.0",
+        "zod-to-json-schema": "^3.x"
+      },
+      "peerDependenciesMeta": {
+        "zod-to-json-schema": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@langchain/langgraph-checkpoint": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmmirror.com/@langchain/langgraph-checkpoint/-/langgraph-checkpoint-1.0.0.tgz",
+      "integrity": "sha512-xrclBGvNCXDmi0Nz28t3vjpxSH6UYx6w5XAXSiiB1WEdc2xD2iY/a913I3x3a31XpInUW/GGfXXfePfaghV54A==",
+      "license": "MIT",
+      "dependencies": {
+        "uuid": "^10.0.0"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "peerDependencies": {
+        "@langchain/core": "^1.0.1"
+      }
+    },
+    "node_modules/@langchain/langgraph-checkpoint/node_modules/uuid": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmmirror.com/uuid/-/uuid-10.0.0.tgz",
+      "integrity": "sha512-8XkAphELsDnEGrDxUOHB3RGvXz6TeuYSGEZBOjtTtPm2lwhGBjLgOzLHB63IUWfBpNucQjND6d3AOudO+H3RWQ==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist/bin/uuid"
+      }
+    },
+    "node_modules/@langchain/langgraph-sdk": {
+      "version": "1.5.5",
+      "resolved": "https://registry.npmmirror.com/@langchain/langgraph-sdk/-/langgraph-sdk-1.5.5.tgz",
+      "integrity": "sha512-SyiAs6TVXPWlt/8cI9pj/43nbIvclY3ytKqUFbL5MplCUnItetEyqvH87EncxyVF5D7iJKRZRfSVYBMmOZbjbQ==",
+      "license": "MIT",
+      "dependencies": {
+        "p-queue": "^9.0.1",
+        "p-retry": "^7.1.1",
+        "uuid": "^13.0.0"
+      },
+      "peerDependencies": {
+        "@langchain/core": "^1.1.15",
+        "react": "^18 || ^19",
+        "react-dom": "^18 || ^19"
+      },
+      "peerDependenciesMeta": {
+        "@langchain/core": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@langchain/langgraph-sdk/node_modules/eventemitter3": {
+      "version": "5.0.4",
+      "resolved": "https://registry.npmmirror.com/eventemitter3/-/eventemitter3-5.0.4.tgz",
+      "integrity": "sha512-mlsTRyGaPBjPedk6Bvw+aqbsXDtoAyAzm5MO7JgU+yVRyMQ5O8bD4Kcci7BS85f93veegeCPkL8R4GLClnjLFw==",
+      "license": "MIT"
+    },
+    "node_modules/@langchain/langgraph-sdk/node_modules/p-queue": {
+      "version": "9.1.0",
+      "resolved": "https://registry.npmmirror.com/p-queue/-/p-queue-9.1.0.tgz",
+      "integrity": "sha512-O/ZPaXuQV29uSLbxWBGGZO1mCQXV2BLIwUr59JUU9SoH76mnYvtms7aafH/isNSNGwuEfP6W/4xD0/TJXxrizw==",
+      "license": "MIT",
+      "dependencies": {
+        "eventemitter3": "^5.0.1",
+        "p-timeout": "^7.0.0"
+      },
+      "engines": {
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/@langchain/langgraph-sdk/node_modules/p-timeout": {
+      "version": "7.0.1",
+      "resolved": "https://registry.npmmirror.com/p-timeout/-/p-timeout-7.0.1.tgz",
+      "integrity": "sha512-AxTM2wDGORHGEkPCt8yqxOTMgpfbEHqF51f/5fJCmwFC3C/zNcGT63SymH2ttOAaiIws2zVg4+izQCjrakcwHg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/@langchain/langgraph-sdk/node_modules/uuid": {
+      "version": "13.0.0",
+      "resolved": "https://registry.npmmirror.com/uuid/-/uuid-13.0.0.tgz",
+      "integrity": "sha512-XQegIaBTVUjSHliKqcnFqYypAd4S+WCYt5NIeRs6w/UAry7z8Y9j5ZwRRL4kzq9U3sD6v+85er9FvkEaBpji2w==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist-node/bin/uuid"
+      }
+    },
+    "node_modules/@langchain/langgraph/node_modules/uuid": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmmirror.com/uuid/-/uuid-10.0.0.tgz",
+      "integrity": "sha512-8XkAphELsDnEGrDxUOHB3RGvXz6TeuYSGEZBOjtTtPm2lwhGBjLgOzLHB63IUWfBpNucQjND6d3AOudO+H3RWQ==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist/bin/uuid"
+      }
+    },
    "node_modules/@noble/ciphers": {
      "version": "1.3.0",
      "resolved": "https://registry.npmmirror.com/@noble/ciphers/-/ciphers-1.3.0.tgz",
@@ -3818,6 +4024,12 @@
        "@sinonjs/commons": "^3.0.0"
      }
    },
+    "node_modules/@standard-schema/spec": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmmirror.com/@standard-schema/spec/-/spec-1.1.0.tgz",
+      "integrity": "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==",
+      "license": "MIT"
+    },
    "node_modules/@types/babel__core": {
      "version": "7.20.5",
      "resolved": "https://registry.npmjs.org/@types/babel__core/-/babel__core-7.20.5.tgz",
@@ -3940,6 +4152,12 @@
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      "license": "MIT"
    },
+    "node_modules/@types/uuid": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmmirror.com/@types/uuid/-/uuid-10.0.0.tgz",
+      "integrity": "sha512-7gqG38EyHgyP1S+7+xomFtL+ZNHcKv6DwNaCZmJmo1vgMugyF3TCnXVg4t1uk89mLNwnLtnY3TpOpCOyp1/xHQ==",
+      "license": "MIT"
+    },
    "node_modules/@types/yargs": {
      "version": "17.0.35",
      "resolved": "https://registry.npmjs.org/@types/yargs/-/yargs-17.0.35.tgz",
@@ -5099,6 +5317,15 @@
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      "license": "MIT"
    },
+    "node_modules/console-table-printer": {
+      "version": "2.15.0",
+      "resolved": "https://registry.npmmirror.com/console-table-printer/-/console-table-printer-2.15.0.tgz",
+      "integrity": "sha512-SrhBq4hYVjLCkBVOWaTzceJalvn5K1Zq5aQA6wXC/cYjI3frKWNPEMK3sZsJfNNQApvCQmgBcc13ZKmFj8qExw==",
+      "license": "MIT",
+      "dependencies": {
+        "simple-wcswidth": "^1.1.2"
+      }
+    },
    "node_modules/convert-source-map": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
@@ -5238,6 +5465,15 @@
        }
      }
    },
+    "node_modules/decamelize": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmmirror.com/decamelize/-/decamelize-1.2.0.tgz",
+      "integrity": "sha512-z2S+W9X73hAUUki+N+9Za2lBlun89zigOyGrsax+KUQ6wKW4ZoWpEYBkGhQjwAjjDCkWxhY0VKEhk8wzY7F5cA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
    "node_modules/decode-uri-component": {
      "version": "0.2.2",
      "resolved": "https://registry.npmjs.org/decode-uri-component/-/decode-uri-component-0.2.2.tgz",
@@ -5596,6 +5832,12 @@
        "node": ">=6"
      }
    },
+    "node_modules/eventemitter3": {
+      "version": "4.0.7",
+      "resolved": "https://registry.npmmirror.com/eventemitter3/-/eventemitter3-4.0.7.tgz",
+      "integrity": "sha512-8guHBZCwKnFhYdHr2ysuRWErTwhoN2X8XELRlrRwpmfeY2jjuUN4taQMsULKUVo1K4DvZl+0pgfyoysHxvmvEw==",
+      "license": "MIT"
+    },
    "node_modules/events": {
      "version": "3.3.0",
      "resolved": "https://registry.npmmirror.com/events/-/events-3.3.0.tgz",
@@ -6813,6 +7055,18 @@
        "node": ">=0.10.0"
      }
    },
+    "node_modules/is-network-error": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmmirror.com/is-network-error/-/is-network-error-1.3.0.tgz",
+      "integrity": "sha512-6oIwpsgRfnDiyEDLMay/GqCl3HoAtH5+RUKW29gYkL0QA+ipzpDLA16yQs7/RHCSu+BwgbJaOUqa4A99qNVQVw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=16"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
    "node_modules/is-number": {
      "version": "7.0.0",
      "resolved": "https://registry.npmjs.org/is-number/-/is-number-7.0.0.tgz",
@@ -7131,6 +7385,15 @@
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      "license": "MIT"
    },
+    "node_modules/js-tiktoken": {
+      "version": "1.0.21",
+      "resolved": "https://registry.npmmirror.com/js-tiktoken/-/js-tiktoken-1.0.21.tgz",
+      "integrity": "sha512-biOj/6M5qdgx5TKjDnFT1ymSpM5tbd3ylwDtrQvFQSu0Z7bBYko2dF+W/aUkXUPuk6IVpRxk/3Q2sHOzGlS36g==",
+      "license": "MIT",
+      "dependencies": {
+        "base64-js": "^1.5.1"
+      }
+    },
    "node_modules/js-tokens": {
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",
@@ -7251,6 +7514,65 @@
        "node": ">=6"
      }
    },
+    "node_modules/langsmith": {
+      "version": "0.4.12",
+      "resolved": "https://registry.npmmirror.com/langsmith/-/langsmith-0.4.12.tgz",
+      "integrity": "sha512-YWt0jcGvKqjUgIvd78rd4QcdMss0lUkeUaqp0UpVRq7H2yNDx8H5jOUO/laWUmaPtWGgcip0qturykXe1g9Gqw==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/uuid": "^10.0.0",
+        "chalk": "^4.1.2",
+        "console-table-printer": "^2.12.1",
+        "p-queue": "^6.6.2",
+        "semver": "^7.6.3",
+        "uuid": "^10.0.0"
+      },
+      "peerDependencies": {
+        "@opentelemetry/api": "*",
+        "@opentelemetry/exporter-trace-otlp-proto": "*",
+        "@opentelemetry/sdk-trace-base": "*",
+        "openai": "*"
+      },
+      "peerDependenciesMeta": {
+        "@opentelemetry/api": {
+          "optional": true
+        },
+        "@opentelemetry/exporter-trace-otlp-proto": {
+          "optional": true
+        },
+        "@opentelemetry/sdk-trace-base": {
+          "optional": true
+        },
+        "openai": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/langsmith/node_modules/semver": {
+      "version": "7.7.3",
+      "resolved": "https://registry.npmmirror.com/semver/-/semver-7.7.3.tgz",
+      "integrity": "sha512-SdsKMrI9TdgjdweUSR9MweHA4EJ8YxHn8DFaDisvhVlUOe4BF1tLD7GAj0lIqWVl+dPb/rExr0Btby5loQm20Q==",
+      "license": "ISC",
+      "bin": {
+        "semver": "bin/semver.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/langsmith/node_modules/uuid": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmmirror.com/uuid/-/uuid-10.0.0.tgz",
+      "integrity": "sha512-8XkAphELsDnEGrDxUOHB3RGvXz6TeuYSGEZBOjtTtPm2lwhGBjLgOzLHB63IUWfBpNucQjND6d3AOudO+H3RWQ==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist/bin/uuid"
+      }
+    },
    "node_modules/leven": {
      "version": "3.1.0",
      "resolved": "https://registry.npmjs.org/leven/-/leven-3.1.0.tgz",
@@ -8337,6 +8659,15 @@
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      "license": "MIT"
    },
+    "node_modules/mustache": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmmirror.com/mustache/-/mustache-4.2.0.tgz",
+      "integrity": "sha512-71ippSywq5Yb7/tVYyGbkBggbU8H3u5Rz56fH60jGFgr8uHwxs+aSKeqmluIVzM0m0kB7xQjKS6qPfd0b2ZoqQ==",
+      "license": "MIT",
+      "bin": {
+        "mustache": "bin/mustache"
+      }
+    },
    "node_modules/mz": {
      "version": "2.7.0",
      "resolved": "https://registry.npmjs.org/mz/-/mz-2.7.0.tgz",
@@ -8751,6 +9082,49 @@
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
+    "node_modules/p-queue": {
+      "version": "6.6.2",
+      "resolved": "https://registry.npmmirror.com/p-queue/-/p-queue-6.6.2.tgz",
+      "integrity": "sha512-RwFpb72c/BhQLEXIZ5K2e+AhgNVmIejGlTgiB9MzZ0e93GRvqZ7uSi0dvRF7/XIXDeNkra2fNHBxTyPDGySpjQ==",
+      "license": "MIT",
+      "dependencies": {
+        "eventemitter3": "^4.0.4",
+        "p-timeout": "^3.2.0"
+      },
+      "engines": {
+        "node": ">=8"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/p-retry": {
+      "version": "7.1.1",
+      "resolved": "https://registry.npmmirror.com/p-retry/-/p-retry-7.1.1.tgz",
+      "integrity": "sha512-J5ApzjyRkkf601HpEeykoiCvzHQjWxPAHhyjFcEUP2SWq0+35NKh8TLhpLw+Dkq5TZBFvUM6UigdE9hIVYTl5w==",
+      "license": "MIT",
+      "dependencies": {
+        "is-network-error": "^1.1.0"
+      },
+      "engines": {
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/p-timeout": {
+      "version": "3.2.0",
+      "resolved": "https://registry.npmmirror.com/p-timeout/-/p-timeout-3.2.0.tgz",
+      "integrity": "sha512-rhIwUycgwwKcP9yTOOFK/AKsAopjjCakVqLHePO3CC6Mir1Z99xT+R63jZxAT5lFZLa2inS5h+ZS2GvR99/FBg==",
+      "license": "MIT",
+      "dependencies": {
+        "p-finally": "^1.0.0"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
    "node_modules/p-try": {
      "version": "2.2.0",
      "resolved": "https://registry.npmjs.org/p-try/-/p-try-2.2.0.tgz",
@@ -10143,6 +10517,12 @@
      "integrity": "sha512-m6UrgzFVUYawGBh1dUsWR5M2Clqic9RVXC/9f8ceNlv2IcO9j9J/z8UoCLPqtsPBFNzEpfR3xftohbfqDx8EQA==",
      "license": "MIT"
    },
+    "node_modules/simple-wcswidth": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmmirror.com/simple-wcswidth/-/simple-wcswidth-1.1.2.tgz",
+      "integrity": "sha512-j7piyCjAeTDSjzTSQ7DokZtMNwNlEAyxqSZeCS+CXH7fJ4jx3FuJ/mTW3mE+6JLs4VJBbcll0Kjn+KXI5t21Iw==",
+      "license": "MIT"
+    },
    "node_modules/sisteransi": {
      "version": "1.0.5",
      "resolved": "https://registry.npmjs.org/sisteransi/-/sisteransi-1.0.5.tgz",
@@ -11493,6 +11873,15 @@
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
+    },
+    "node_modules/zod": {
+      "version": "4.3.6",
+      "resolved": "https://registry.npmmirror.com/zod/-/zod-4.3.6.tgz",
+      "integrity": "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
    }
  }
 }
--- a/package.json
+++ b/package.json
@@ -11,6 +11,8 @@
  "dependencies": {
    "@expo/metro-runtime": "~4.0.1",
    "@expo/vector-icons": "~14.0.4",
+    "@langchain/core": "^1.1.18",
+    "@langchain/langgraph": "^1.1.3",
    "@noble/ciphers": "^1.3.0",
    "@noble/hashes": "^1.8.0",
    "@react-native-async-storage/async-storage": "^2.2.0",
--- a/src/polyfills.ts
+++ b/src/polyfills.ts
@@ -0,0 +1,45 @@
+/**
+ * Polyfills that must run before any other app code (including LangChain/LangGraph).
+ * This file is imported as the very first line in App.tsx so that ReadableStream
+ * and crypto.getRandomValues exist before @langchain/core / uuid are loaded.
+ */
+import 'web-streams-polyfill';
+
+// Ensure globalThis has ReadableStream (main polyfill may not patch in RN/Metro)
+const g = typeof globalThis !== 'undefined' ? globalThis : (typeof global !== 'undefined' ? global : (typeof self !== 'undefined' ? self : {}));
+if (typeof (g as any).ReadableStream === 'undefined') {
+  const ponyfill = require('web-streams-polyfill/dist/ponyfill.js');
+  (g as any).ReadableStream = ponyfill.ReadableStream;
+  (g as any).WritableStream = ponyfill.WritableStream;
+  (g as any).TransformStream = ponyfill.TransformStream;
+}
+
+// Polyfill crypto.getRandomValues for React Native/Expo (required by uuid, LangChain, etc.)
+if (typeof g !== 'undefined') {
+  const cryptoObj = (g as any).crypto;
+  if (!cryptoObj || typeof (cryptoObj.getRandomValues) !== 'function') {
+    try {
+      const ExpoCrypto = require('expo-crypto');
+      const getRandomValues = (array: ArrayBufferView): ArrayBufferView => {
+        ExpoCrypto.getRandomValues(array);
+        return array;
+      };
+      if (!(g as any).crypto) (g as any).crypto = {};
+      (g as any).crypto.getRandomValues = getRandomValues;
+    } catch (e) {
+      console.warn('[polyfills] crypto.getRandomValues polyfill failed:', e);
+    }
+  }
+}
+
+// Polyfill AbortSignal.prototype.throwIfAborted (required by fetch/LangChain in RN; not present in older runtimes)
+const AbortSignalGlobal = (g as any).AbortSignal;
+if (typeof AbortSignalGlobal === 'function' && AbortSignalGlobal.prototype && typeof AbortSignalGlobal.prototype.throwIfAborted !== 'function') {
+  AbortSignalGlobal.prototype.throwIfAborted = function (this: AbortSignal) {
+    if (this.aborted) {
+      const e = new Error('Aborted');
+      e.name = 'AbortError';
+      throw e;
+    }
+  };
+}
--- a/src/screens/FlowScreen.tsx
+++ b/src/screens/FlowScreen.tsx
@@ -31,6 +31,8 @@ import * as ImagePicker from 'expo-image-picker';
 import { AIRole } from '../types';
 import { colors, typography, spacing, borderRadius, shadows } from '../theme/colors';
 import { aiService, AIMessage } from '../services/ai.service';
+import { langGraphService } from '../services/langgraph.service';
+import { HumanMessage, AIMessage as LangChainAIMessage, SystemMessage } from "@langchain/core/messages";
 import { assetsService } from '../services/assets.service';
 import { useAuth } from '../context/AuthContext';
 import { AI_CONFIG, getVaultStorageKeys } from '../config';
@@ -280,8 +282,23 @@ export default function FlowScreen() {
    setMessages(prev => [...prev, userMsg]);

    try {
-      // Call AI proxy with selected role's system prompt
-      const aiResponse = await aiService.sendMessage(userMessage, token, selectedRole?.systemPrompt || '');
+      // 1. Convert current messages history to LangChain format
+      const history: (HumanMessage | LangChainAIMessage | SystemMessage)[] = messages.map(msg => {
+        if (msg.role === 'user') return new HumanMessage(msg.content);
+        return new LangChainAIMessage(msg.content);
+      });
+
+      // 2. Add system prompt
+      const systemPrompt = new SystemMessage(selectedRole?.systemPrompt || '');
+
+      // 3. Add current new message
+      const currentMsg = new HumanMessage(userMessage);
+
+      // 4. Combine all messages for LangGraph processing
+      const fullMessages = [systemPrompt, ...history, currentMsg];
+
+      // 5. Execute via LangGraph service (handles token limits and context)
+      const aiResponse = await langGraphService.execute(fullMessages, token);

      // Add AI response
      const aiMsg: ChatMessage = {
--- a/src/services/ai.service.ts
+++ b/src/services/ai.service.ts
@@ -13,6 +13,7 @@ import {
  logApiDebug,
 } from '../config';
 import { AIRole } from '../types';
+import { trimInternalMessages } from '../utils/token_utils';

 // =============================================================================
 // Type Definitions
@@ -259,14 +260,17 @@ export const aiService = {
      });
    }

-    const historicalMessages = messages.map(msg => ({
+    // Enforce token limit (10,000 tokens)
+    const trimmedMessages = trimInternalMessages(messages);
+
+    const historicalMessages = trimmedMessages.map(msg => ({
      role: msg.role,
      content: msg.content,
    }));

    const summaryPrompt: AIMessage = {
      role: 'user',
-      content: 'Please provide a concise summary of the conversation above in Chinese (since the user request was in Chinese). Focus on the main topics discussed and any key conclusions or actions mentioned.',
+      content: 'Please provide a concise summary of the conversation above in English. Focus on the main topics discussed and any key conclusions or actions mentioned.',
    };

    const response = await this.chat([...historicalMessages, summaryPrompt], token);
--- a/src/services/langgraph.service.ts
+++ b/src/services/langgraph.service.ts
@@ -0,0 +1,96 @@
+/**
+ * LangGraph Service
+ * 
+ * Implements AI chat logic using LangGraph.js for state management
+ * and context handling.
+ */
+
+import { StateGraph, START, END, Annotation } from "@langchain/langgraph";
+import { BaseMessage, HumanMessage, AIMessage, SystemMessage } from "@langchain/core/messages";
+import { aiService } from "./ai.service";
+import { trimLangChainMessages } from "../utils/token_utils";
+
+// =============================================================================
+// Settings
+// =============================================================================
+
+/**
+ * Define the State using Annotation (Standard for latest LangGraph.js)
+ */
+const GraphAnnotation = Annotation.Root({
+    messages: Annotation<BaseMessage[]>({
+        reducer: (x, y) => x.concat(y),
+        default: () => [],
+    }),
+});
+
+// =============================================================================
+// Graph Definition
+// =============================================================================
+
+/**
+ * The main node that calls our existing AI API
+ */
+async function callModel(state: typeof GraphAnnotation.State, config: any) {
+    const { messages } = state;
+    const { token } = config.configurable || {};
+
+    // 1. Trim messages to stay under token limit
+    const trimmedMessages = trimLangChainMessages(messages);
+
+    // 2. Convert LangChain messages to our internal AIMessage format for the API
+    const apiMessages = trimmedMessages.map(m => {
+        let role: 'system' | 'user' | 'assistant' = 'user';
+        const type = (m as any)._getType?.() || (m instanceof SystemMessage ? 'system' : m instanceof HumanMessage ? 'human' : m instanceof AIMessage ? 'ai' : 'user');
+
+        if (type === 'system') role = 'system';
+        else if (type === 'human') role = 'user';
+        else if (type === 'ai') role = 'assistant';
+
+        return {
+            role,
+            content: m.content.toString()
+        };
+    });
+
+    // 3. Call the proxy service
+    const response = await aiService.chat(apiMessages, token);
+    const content = response.choices[0]?.message?.content || "No response generated";
+
+    // 4. Return the new message to satisfy the Graph (it will be appended due to reducer)
+    return {
+        messages: [new AIMessage(content)]
+    };
+}
+
+// =============================================================================
+// Service Export
+// =============================================================================
+
+export const langGraphService = {
+    /**
+     * Run the chat graph with history
+     */
+    async execute(
+        currentMessages: BaseMessage[],
+        userToken: string,
+    ): Promise<string> {
+        // Define the graph
+        const workflow = new StateGraph(GraphAnnotation)
+            .addNode("agent", callModel)
+            .addEdge(START, "agent")
+            .addEdge("agent", END);
+
+        const app = workflow.compile();
+
+        // Execute the graph
+        const result = await app.invoke(
+            { messages: currentMessages },
+            { configurable: { token: userToken } }
+        );
+
+        // Return the content of the last message (the AI response)
+        const lastMsg = result.messages[result.messages.length - 1];
+        return lastMsg.content.toString();
+    }
+};
--- a/src/utils/async_hooks_mock.ts
+++ b/src/utils/async_hooks_mock.ts
@@ -0,0 +1,22 @@
+/**
+ * Mock for Node.js async_hooks
+ * Used to fix LangGraph.js compatibility with React Native
+ */
+
+export class AsyncLocalStorage {
+    disable() { }
+    getStore() {
+        return undefined;
+    }
+    run(store: any, callback: (...args: any[]) => any, ...args: any[]) {
+        return callback(...args);
+    }
+    exit(callback: (...args: any[]) => any, ...args: any[]) {
+        return callback(...args);
+    }
+    enterWith(store: any) { }
+}
+
+export default {
+    AsyncLocalStorage,
+};
--- a/src/utils/token_utils.ts
+++ b/src/utils/token_utils.ts
@@ -0,0 +1,76 @@
+/**
+ * Token Utilities
+ * 
+ * Shared logic for trimming messages to stay within token limits.
+ */
+
+import { BaseMessage, SystemMessage } from "@langchain/core/messages";
+import { AIMessage as ServiceAIMessage } from "../services/ai.service";
+
+export const TOKEN_LIMIT = 10000;
+const CHARS_PER_TOKEN = 3; // Conservative estimate: 1 token ≈ 3 chars
+export const MAX_CHARS = TOKEN_LIMIT * CHARS_PER_TOKEN;
+
+/**
+ * Trims LangChain messages to fit within token limit
+ */
+export function trimLangChainMessages(messages: BaseMessage[]): BaseMessage[] {
+    let totalLength = 0;
+    const trimmed: BaseMessage[] = [];
+
+    // Always keep the system message if it's at the start
+    let systemMsg: BaseMessage | null = null;
+    if (messages.length > 0 && (messages[0] instanceof SystemMessage || (messages[0] as any)._getType?.() === 'system')) {
+        systemMsg = messages[0];
+        totalLength += systemMsg.content.toString().length;
+    }
+
+    // Iterate backwards and add messages until we hit the char limit
+    for (let i = messages.length - 1; i >= (systemMsg ? 1 : 0); i--) {
+        const msg = messages[i];
+        const len = msg.content.toString().length;
+
+        if (totalLength + len > MAX_CHARS) break;
+
+        trimmed.unshift(msg);
+        totalLength += len;
+    }
+
+    if (systemMsg) {
+        trimmed.unshift(systemMsg);
+    }
+
+    return trimmed;
+}
+
+/**
+ * Trims internal AIMessage format messages to fit within token limit
+ */
+export function trimInternalMessages(messages: ServiceAIMessage[]): ServiceAIMessage[] {
+    let totalLength = 0;
+    const trimmed: ServiceAIMessage[] = [];
+
+    // Always keep the system message if it's at the start
+    let systemMsg: ServiceAIMessage | null = null;
+    if (messages.length > 0 && messages[0].role === 'system') {
+        systemMsg = messages[0];
+        totalLength += systemMsg.content.length;
+    }
+
+    // Iterate backwards and add messages until we hit the char limit
+    for (let i = messages.length - 1; i >= (systemMsg ? 1 : 0); i--) {
+        const msg = messages[i];
+        const len = msg.content.length;
+
+        if (totalLength + len > MAX_CHARS) break;
+
+        trimmed.unshift(msg);
+        totalLength += len;
+    }
+
+    if (systemMsg) {
+        trimmed.unshift(systemMsg);
+    }
+
+    return trimmed;
+}