feat(ai-providers): add Antigravity and Cursor OAuth providers

.github/workflows/ci.yml

@@ -59,6 +59,7 @@ jobs:
             --no-extensions \
             --extension "$package/extensions/file-search/index.ts" \
             --extension "$package/extensions/git-info/index.ts" \
+            --extension "$package/extensions/ai-providers/index.ts" \
             </dev/null
 
   windows-background-terminals:

README.md

@@ -130,6 +130,7 @@ OpenPI 把成熟 Coding Agent 的工作习惯做成 Pi-native 能力，但不复
 | 快捷工作流   | `/btw` 旁路提问（TUI）、`/lg` 浏览 Diff（TUI）、`/pr` 查 PR、`/copy-all`、`fd`、`rg`、只读 Git 工具       |
 | 人类决策     | `ask_user` 草稿与最终复核、parent-only `human_handoff`、Plan Ready 实施门禁                               |
 | 统一配置     | `/openpi-setup` 管理 OpenPI 自有模型、并发、Footer、输出密度与 Post-edit 偏好                             |
+| 模型授权     | `/login google-antigravity`；实验性的 `/login cursor`（仅聊天，不执行 Cursor 原生工具）                   |
 
 OpenPI 采用 [MIT License](LICENSE)；第三方来源与保留声明见 [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md)。
 
@@ -622,6 +623,7 @@ Plan Mode 不猜“任意 Shell 是否只读”，只放行由已知安全零件
 
 ```text
 extensions/
+├── ai-providers/          # Antigravity 与实验性 Cursor OAuth 模型 Provider
 ├── setup/                 # /openpi-setup 与受限配置工具
 ├── capabilities/          # 最小能力发现入口与 Session 工具面加载
 ├── background-terminals/  # 长进程、日志、/ps
@@ -663,6 +665,6 @@ npm 仍用于发布包的 `pack` / clean-install 验证，因为用户通过 npm
 
 本项目最初基于 [davis7dotsh/my-pi-setup](https://github.com/davis7dotsh/my-pi-setup) 演进，现作为独立发行版维护。感谢原作者提供起点。
 
-`extensions/sessions/` 改编自 [jayshah5696/pi-agent-extensions](https://github.com/jayshah5696/pi-agent-extensions)。独立可选的顶层 Session 通信 package 见 [pi-intercom](https://github.com/nicobailon/pi-intercom)。完整第三方说明见 [`THIRD_PARTY_NOTICES.md`](THIRD_PARTY_NOTICES.md)。
+`extensions/ai-providers/` 的部分协议实现改编自 [oh-my-pi](https://github.com/can1357/oh-my-pi)；`extensions/sessions/` 改编自 [jayshah5696/pi-agent-extensions](https://github.com/jayshah5696/pi-agent-extensions)。独立可选的顶层 Session 通信 package 见 [pi-intercom](https://github.com/nicobailon/pi-intercom)。完整第三方说明见 [`THIRD_PARTY_NOTICES.md`](THIRD_PARTY_NOTICES.md)。
 
 本项目以 MIT 许可证发布（见 [`LICENSE`](LICENSE)）；`THIRD_PARTY_NOTICES.md` 记录第三方来源与各自许可。

THIRD_PARTY_NOTICES.md

@@ -1,5 +1,21 @@
 # Third-Party Notices
 
+## OAuth model providers
+
+`extensions/ai-providers/` adapts protocol and OAuth details from
+[`oh-my-pi`](https://github.com/can1357/oh-my-pi) (Antigravity Cloud Code
+Assist and Cursor AgentService). The upstream project is distributed under the
+MIT License. Its copyright notice states `Copyright (c) 2025 Mario Zechner`,
+`Copyright (c) 2025-2026 Can Bölük`, and `Copyright (c) 2026 Stencil Labs, Inc.`;
+the complete license text is included at
+[`extensions/ai-providers/LICENSE.upstream`](extensions/ai-providers/LICENSE.upstream).
+The local Antigravity message conversion is adapted from the same project's
+pi-ai 0.84.1 Google conversion implementation so the installed extension does
+not depend on a non-public Pi runtime module.
+
+Cursor support in this package is chat-only: it does not copy or execute
+Cursor-native coding tools.
+
 ## Sessions extension
 
 `extensions/sessions/` is adapted from

extensions/ai-providers/LICENSE.upstream

@@ -0,0 +1,23 @@
+MIT License
+
+Copyright (c) 2025 Mario Zechner
+Copyright (c) 2025-2026 Can Bölük
+Copyright (c) 2026 Stencil Labs, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

extensions/ai-providers/README.md

@@ -0,0 +1,51 @@
+# OAuth model providers
+
+This extension registers two opt-in model providers backed by account OAuth:
+
+- `google-antigravity` uses Google Cloud Code Assist and supports ordinary Pi
+  tool calls.
+- `cursor` uses Cursor AgentService and is experimental, chat-only support.
+  It does not advertise or execute Cursor-native coding tools. If the server
+  requests one, the request fails explicitly instead of bypassing Pi's tool and
+  permission lifecycle.
+
+After installing OpenPI, restart Pi or run `/reload`, then authenticate and
+select a model:
+
+```text
+/login google-antigravity
+/login cursor
+/model
+```
+
+For source-checkout testing without changing the installed OpenPI package, load
+this extension explicitly:
+
+```sh
+pi --approve -e ./extensions/ai-providers/index.ts
+```
+
+The model catalog is refreshed from the authenticated account and persisted by
+Pi. A failed refresh retains the last successful account catalog; Antigravity
+also has a validated static baseline, while Cursor keeps the server-side `Auto`
+route as its baseline. No provider is contacted until it is selected.
+
+Pi's interactive clipboard flow inserts an image's local path into the editor.
+When Cursor is selected, a supported PNG/JPEG/GIF/WebP path at the start of an
+interactive prompt is converted into an actual image attachment (up to 10 MiB)
+before the request is sent. The absolute path is not exposed to the model.
+
+The provider also adds an explicit chat-only rule so the normal Pi coding
+system prompt cannot cause Cursor to attempt unavailable read or shell tools.
+
+Cursor's token delta describes generated output only, so the provider does not
+publish it as complete context usage. Pi 0.84.3+ can estimate an all-Cursor
+history and trigger threshold compaction without provider usage. Older Pi hosts
+retain the correct unknown-usage state but cannot automatically threshold-
+compact a session with no usage-backed response. Project-wide Pi baseline
+tracking is kept in [#328](https://github.com/openpi-dev/openpi/issues/328).
+
+Cursor model discovery and chat use HTTP/2. They honor `PI_PROXY_CURSOR`, then
+`PI_PROXY`, the standard `HTTPS_PROXY`/`HTTP_PROXY` variables, and `ALL_PROXY`;
+`NO_PROXY` bypass rules apply. The proxy must support HTTP CONNECT and preserve
+HTTP/2 ALPN negotiation to Cursor.

extensions/ai-providers/antigravity/credentials.ts

@@ -0,0 +1,52 @@
+/**
+ * Credential codec for the Antigravity provider.
+ *
+ * pi persists whatever object `login` returns into auth.json and hands it back
+ * to `refreshToken`/`getApiKey` verbatim, so the Antigravity-specific extras
+ * (projectId, email) ride along as additional fields. `getApiKey` then packs
+ * everything the stream needs into the single `apiKey` string pi threads into
+ * `SimpleStreamOptions.apiKey`.
+ */
+
+import type { OAuthCredentials } from "@earendil-works/pi-ai/compat";
+
+/** Stored credential shape: pi's OAuth fields plus Antigravity extras. */
+export interface AntigravityCredentials extends OAuthCredentials {
+  /** Cloud Code Assist project resolved during login provisioning. */
+  projectId?: string;
+  /** Google account email, best-effort display metadata. */
+  email?: string;
+}
+
+/** What the stream function needs, packed into the apiKey string. */
+export interface AntigravityApiKeyPayload {
+  token: string;
+  projectId?: string;
+}
+
+export function encodeApiKey(credentials: AntigravityCredentials): string {
+  const payload: AntigravityApiKeyPayload = {
+    token: credentials.access,
+    projectId: credentials.projectId,
+  };
+  return JSON.stringify(payload);
+}
+
+export function decodeApiKey(raw: string): AntigravityApiKeyPayload {
+  try {
+    const parsed: unknown = JSON.parse(raw);
+    if (parsed !== null && typeof parsed === "object" && "token" in parsed) {
+      const token = parsed.token;
+      if (typeof token === "string") {
+        const projectId =
+          "projectId" in parsed && typeof parsed.projectId === "string"
+            ? parsed.projectId
+            : undefined;
+        return { token, projectId };
+      }
+    }
+  } catch {
+    // Not JSON: tolerate a bare access token (e.g. hand-written auth.json).
+  }
+  return { token: raw };
+}

extensions/ai-providers/antigravity/discovery.ts

@@ -0,0 +1,130 @@
+/**
+ * Antigravity model discovery.
+ *
+ * `POST /v1internal:fetchAvailableModels` returns a map of wire model id to
+ * metadata (reference: omp packages/catalog/src/discovery/antigravity.ts).
+ * Static models are the provider baseline. Network/protocol failures throw so
+ * createProvider can retain the last successfully persisted dynamic catalog.
+ */
+
+import type { RefreshModelsContext } from "@earendil-works/pi-ai";
+import { Type, type Static } from "typebox";
+import { Value } from "typebox/value";
+import { ensureAntigravityVersion, getAntigravityUserAgent } from "./oauth.ts";
+import {
+  ANTIGRAVITY_API_URL,
+  type AntigravityProviderModel,
+} from "./models.ts";
+import {
+  collapseAntigravityModels,
+  type AntigravityModelDefinition,
+} from "./routing.ts";
+
+const DISCOVERY_ENDPOINTS = [
+  "https://daily-cloudcode-pa.googleapis.com",
+  "https://daily-cloudcode-pa.sandbox.googleapis.com",
+] as const;
+const FETCH_AVAILABLE_MODELS_PATH = "/v1internal:fetchAvailableModels";
+
+// Reference: omp ANTIGRAVITY_DISCOVERY_DENYLIST.
+const DISCOVERY_DENYLIST: Record<string, true> = {
+  chat_20706: true,
+  chat_23310: true,
+  "gemini-2.5-pro": true,
+};
+
+const DEFAULT_CONTEXT_WINDOW = 200_000;
+const DEFAULT_MAX_TOKENS = 64_000;
+
+const DiscoveryModelSchema = Type.Object({
+  displayName: Type.Optional(Type.String()),
+  supportsImages: Type.Optional(Type.Boolean()),
+  supportsThinking: Type.Optional(Type.Boolean()),
+  maxTokens: Type.Optional(Type.Number()),
+  maxOutputTokens: Type.Optional(Type.Number()),
+  isInternal: Type.Optional(Type.Boolean()),
+});
+
+const DiscoveryResponseSchema = Type.Object({
+  models: Type.Optional(Type.Record(Type.String(), DiscoveryModelSchema)),
+});
+
+type DiscoveryResponse = Static<typeof DiscoveryResponseSchema>;
+
+type DiscoveredModel = AntigravityProviderModel & AntigravityModelDefinition;
+
+function positiveNumber(value: number | undefined, fallback: number): number {
+  return value !== undefined && Number.isFinite(value) && value > 0
+    ? value
+    : fallback;
+}
+
+function toModelDefinition(
+  id: string,
+  meta: Static<typeof DiscoveryModelSchema>,
+): DiscoveredModel {
+  const advertisedMaxTokens = positiveNumber(
+    meta.maxOutputTokens,
+    DEFAULT_MAX_TOKENS,
+  );
+  return {
+    id,
+    name: meta.displayName ?? id,
+    api: "antigravity-cloudcode",
+    provider: "google-antigravity",
+    baseUrl: ANTIGRAVITY_API_URL,
+    reasoning: meta.supportsThinking === true,
+    input: meta.supportsImages === true ? ["text", "image"] : ["text"],
+    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+    contextWindow: positiveNumber(meta.maxTokens, DEFAULT_CONTEXT_WINDOW),
+    maxTokens: id.toLowerCase().includes("claude")
+      ? Math.min(advertisedMaxTokens, DEFAULT_MAX_TOKENS)
+      : advertisedMaxTokens,
+  };
+}
+
+export async function fetchAntigravityModels(
+  context: RefreshModelsContext,
+): Promise<DiscoveredModel[]> {
+  if (!context.allowNetwork) return [];
+  context.signal.throwIfAborted();
+  const credential = context.credential;
+  if (!credential || credential.type !== "oauth") return [];
+  await ensureAntigravityVersion(context.signal);
+
+  for (const endpoint of DISCOVERY_ENDPOINTS) {
+    if (context.signal.aborted) break;
+    try {
+      const response = await fetch(
+        `${endpoint}${FETCH_AVAILABLE_MODELS_PATH}`,
+        {
+          method: "POST",
+          headers: {
+            Authorization: `Bearer ${credential.access}`,
+            "Content-Type": "application/json",
+            "User-Agent": getAntigravityUserAgent(),
+          },
+          body: "{}",
+          signal: context.signal,
+        },
+      );
+      if (!response.ok) continue;
+      const parsed = Value.Parse(
+        DiscoveryResponseSchema,
+        await response.json(),
+      ) as DiscoveryResponse;
+      if (!parsed.models) continue;
+      const discovered = Object.entries(parsed.models)
+        .filter(
+          ([id, meta]) =>
+            !Object.hasOwn(DISCOVERY_DENYLIST, id) && meta.isInternal !== true,
+        )
+        .map(([id, meta]) => toModelDefinition(id, meta));
+      return collapseAntigravityModels(discovered);
+    } catch {
+      // Try the next endpoint; total failure must preserve the stored catalog.
+    }
+  }
+  context.signal.throwIfAborted();
+  throw new Error("Antigravity model discovery failed on all endpoints");
+}