diff --git a/docs/pi-extensions-design-appendix-zh.md b/docs/pi-extensions-design-appendix-zh.md
new file mode 100644
index 000000000..58fc8ea6b
--- /dev/null
+++ b/docs/pi-extensions-design-appendix-zh.md
@@ -0,0 +1,85 @@
+# Pi Extensions 一等支持设计附录
+
+> 状态：仅设计，不含实现。主工程不实现 extensions；themes 明确不在范围内。
+> authority：任何上游路径、加载顺序、启用规则或 tool 组合语义，在实施前都必须
+> 由 pin `ab366ebe94cacd419d986be454f12b1b9913aaca` 的 oracle 或
+> `scripts/pi-transport-capture.mjs` 实际执行确认，本文不以源码阅读代替证据。
+
+## 目标
+
+未来让用户在 cc-switch 中观察、导入、启用和停用 Pi extensions，同时满足：
+
+1. 原生文件/目录是真相，`exists = active`，不制造与 Pi 分叉的 enabled 影子状态；
+2. 只接管 cc-switch 明确拥有或用户显式、可验证采用的内容；
+3. extension 提供的 tools 与 pinned core tools 分开展示，不伪装为 MCP server；
+4. 所有写操作可并发检测、可补偿，portable import 不覆盖目标设备的未知资产；
+5. 复用前置 C inspection 与当前 Skill/Prompt 的共享文件、fingerprint、ownership
+   和协调器原语。
+
+## 模块边界
+
+```text
+PiExtensionInspector (只读、oracle 驱动)
+        │
+        ├── NativeExtensionObservation
+        │      path / fingerprint / manifest / contributed tools
+        │      validity / reasons / ownership
+        │
+        └── PiExtensionCoordinator (唯一写入口)
+               ├── exact-content adoption
+               ├── CAS + atomic replace
+               ├── ownership ledger transaction
+               ├── catalog epoch / UI invalidation
+               └── compensation on partial failure
+```
+
+- `PiExtensionInspector` 只负责原生观察和结构化诊断；不得写数据库或文件。
+- `PiExtensionCoordinator` 是唯一写入口；命令、deeplink、portable reconcile 与
+  UI mutation 都调用它，禁止各自复制目录。
+- 通用 `shared_file`、Skill tree fingerprint 与 ownership ledger 可复用；
+  extension-specific manifest/加载规则必须先新增捕获向量，不能借 Skill 规则猜测。
+- gateway 只消费 coordinator 发布后的 immutable runtime snapshot；extension
+  不能在请求中途直接改 candidate/header 计划。
+
+## 状态模型
+
+建议公开三个正交维度：
+
+- `discovery`: `absent | active | invalid | unknown`，只来自 native observation；
+- `ownership`: `external | adoptable_exact | managed | conflict`；
+- `capability`: `inspectable | manageable | unsupported | unknown`。
+
+不得增加独立 `enabled` 布尔值。用户点击“停用”时，语义是对受管原生资产执行可逆
+移除；外部资产只能显式采用后再管理。内容变化导致 fingerprint 不匹配时进入
+`conflict`，不得覆盖。
+
+## Tools 与 MCP
+
+- capture 已确认 pinned core tool inventory 为
+  `bash/edit/find/grep/ls/read/write`；未来 capture 应分别记录每个 extension
+  注入前后的 tool inventory 与来源。
+- UI 将 tools 按 `core` / `extension:<id>` 分组，并展示冲突与覆盖次序的实测结果。
+- MCP 页面仍不为 Pi 建虚假 registry。即使某个 extension 通过自身机制连接外部
+  tool，也属于 extension capability，除非未来 pinned Pi 真正提供 MCP registry
+  且由新证据和契约明确升级。
+
+## Portable 与冲突策略
+
+- 备份只携带 cc-switch 拥有的 extension 描述、内容 hash 和期望状态，不携带绝对
+  目录、设备 token 或未知外部目录。
+- 导入先观察目标设备；missing 可部署，exact 可采用，different 必须 conflict，
+  绝不“最后写入者获胜”。
+- 多 extension 贡献同名 tool、command 或资源时 fail-closed；只有 oracle/capture
+  证明 Pi 的确定 precedence 且产品明确展示该覆盖时，才允许自动解析。
+
+## 实施前验收
+
+1. 扩展 transport capture：发现路径、空/损坏 manifest、启停、重复 ID、资源覆盖、
+   tool inventory、相对路径和 symlink 负例。
+2. 冻结 schema/oracle provenance，建立 lossless raw observation；未知形状为
+   `unknown`，不得整目录连坐隐藏合法兄弟。
+3. 服务级测试覆盖显式采用、并发 CAS loser、写后补偿、portable reconcile、
+   外部冲突、目录越界与 UI 的 `exists = active`。
+4. 中英文 UI 与可访问性完成后，再进入独立实现与盲审。
+
+Themes 不与 extensions 共用该项目：其资源语义、预览与安全面另行立项。
diff --git a/docs/pi-main-project-zh.md b/docs/pi-main-project-zh.md
index a86a6b2df..d4b2c3f97 100644
--- a/docs/pi-main-project-zh.md
+++ b/docs/pi-main-project-zh.md
@@ -46,3 +46,99 @@
 不必对齐红绿账本,不必按固定轮次做盲审,偏离不必硬停上报。
 遇到本文与既有契约冲突、或需要用户拍板的产品取舍(功能取舍、范围增删),
 才上报;其余自行裁量,完成后报终态 SHA。
+
+## 实现 authority 与可复现实证
+
+- 唯一 Pi implementation pin:
+  `ab366ebe94cacd419d986be454f12b1b9913aaca`。主工程没有沿用历史文档中的
+  旧 pin，也没有从远端观察值推导行为。
+- `scripts/generate-pi-native-oracle.mjs` 负责 schema/composer 的冻结 oracle；
+  `scripts/pi-transport-capture.mjs` 负责需要真实执行 Pi 才能确认的 transport、
+  compat、原生资源与 CLI 行为。两者都先校验上述 commit，pin 不符即拒绝运行。
+- 主工程捕获命令：
+  `PI_CHECKOUT=<pinned-Pi-checkout> node scripts/pi-transport-capture.mjs`。
+  捕获直接执行 Pi，而非阅读上游源码推断。
+- 捕获的发行元数据来自 `packages/coding-agent/package.json`，该文件在 pin 上的
+  SHA-256 为
+  `e02deae1cec07035807436c1864c88342e2f7d49050d03b858a3719f0c7aedbf`：
+  包名 `@earendil-works/pi-coding-agent`、可执行文件 `pi`、配置目录 `.pi`；
+  `parseArgs(["--version"])` 与带空格绝对路径的
+  `parseArgs(["--session", path])` 均由捕获实际执行。
+- 同一捕获实际发出了四族请求并记录最终 URL/headers。Anthropic OAuth 凭证
+  (`sk-ant-oat` 子串)最终为 `Authorization: Bearer <credential>`，
+  `anthropic-beta` 含 `claude-code-20250219,oauth-2025-04-20`，且主工程策略
+  强制不并发 `x-api-key`。OpenAI Responses/Completions、Google 与普通
+  Anthropic key 的头部矩阵也在同一输出中。
+
+## Hermes 先例逐项对照账本
+
+| 通路 | Pi 终态 | Hermes 差异或不适用理由 |
+|---|---|---|
+| App 注册、切换器、图标、可见性 | `AppType::Pi` 贯穿 Rust/IPC/TS，旧设置缺字段时默认可见，可独立隐藏 | 无差异 |
+| 供应商与模型 | 独立 Pi 表单无损保留 provider/model 的未知 JSON；支持 provider/model 级 `api`、`baseUrl`、headers、`authHeader`、credential、cost/compat 等 pinned 字段；原生 catalog 使用已认证 inspection 导入 | Hermes 的 Web UI overlay/只读 provider 是 Hermes 自身所有权模型，Pi 使用共享 `models.json`，不套用 overlay |
+| 新用户首用 | 创建第一位 Pi provider 时，在数据库、完整初始 endpoints 与原生 catalog 同一协调边界内发布，并把其第一模型设为 native default；随后可直接切换/代理 | 无需先手工导入或另开 native 文件 |
+| 原生 catalog 与当前状态 | 复用前置 C 的三层 inspection；展示 raw/managed/composer/gateway 状态；可用 fingerprint CAS 导入；当前 provider/model 直接读 native defaults | 不以数据库 current 字段制造第二份“当前”状态 |
+| 端点 | provider 主端点与多个 typed custom endpoints 均可增删、测速；membership 与 provider hydration 一致；网关按主端点及有序候选展开 | Hermes 的 additive provider 不具备该网关数据面 |
+| 切换、代理与故障转移 | Pi 有独立 loopback route/token、catalog epoch、健康状态、重试/熔断和 failover 队列；候选必须保持 wire family 与协议身份兼容；不可预测协议表达式只允许单次 direct attempt，不重放 | Hermes 当前没有 cc-switch gateway handler；Pi 对照的是已有完整代理 app 的安全边界 |
+| OAuth 数据面 | 完整实现 Anthropic OAuth 的 Bearer + oauth beta，强制删除 `x-api-key`；deferred credential 在物化后分类 | 由 request-capture 实证；不再停留在前置 C 的 DirectOnly |
+| Skills | Pi 进入统一 Skills UI；期望状态、原生发现、受管 ownership 分离；显式 native import 只在内容完全相同时接管；部署、删除、导入及 portable sync 有锁、CAS、事务补偿 | Pi 的原生目录是部署目标，不能复用其他 app 的“复制后即视为拥有”假设 |
+| Prompts | Prompt 库投影 `AGENTS.md`；同时原生管理 `SYSTEM.md`、`APPEND_SYSTEM.md` 与 `prompts/*.md`；文件存在即 active，直接编辑空白值会拒绝并要求显式删除 | Hermes 的 prompt 通路仍可复用；Pi 额外公开 pinned 原生资源，不制造 enabled 影子字段 |
+| Sessions | 扫描 pinned v1–v3 JSONL tree、只显示 active branch，支持详情、删除、终端恢复；遵守环境/设置/default sessionDir；相对 sessionDir 明示需要项目 cwd，不伪装为空列表 | Pi 的 tree/branch 与 Hermes session 格式不同，使用独立 parser 但复用统一 Session UI/安全入口 |
+| MCP | **不适用**：pinned Pi core 没有原生 MCP registry，UI 不展示虚假 MCP 状态，服务入口结构化拒绝；capture 的 core tool inventory 为 `bash/edit/find/grep/ls/read/write` | Hermes 有原生 MCP registry；Pi extensions 可贡献 tools，但不等同 MCP。未来方案见 `docs/pi-extensions-design-appendix-zh.md` |
+| 深链 | provider 深链支持 Pi provider key、模型、api、端点及 credential，走真实 `ProviderService::add`；prompt 深链走统一库与 Pi 文件所有权链 | 未识别 Pi API 保持 opaque，不用名称猜协议 |
+| 设置与目录 | 设置页可发现/选择 Pi 配置目录，支持 `PI_CODING_AGENT_DIR`、WSL 路径展示、安装检测、网关/故障转移参数与凭证轮换；本地 gateway token 不下发前端 | 配置目录和 token 是 device-local，不写进 portable DB |
+| 使用统计 | 四族 response/SSE 使用量进入统一日志、价格、筛选与 dashboard；每请求携带 input-token semantics，不能用 `app_type` 猜；Pi 混合协议的 cache-write 总数标为“部分可得” | Hermes 无 gateway usage；Pi 的单一 app 桶可能混合四族，不能显示误导性的确定 0 |
+| 导入导出与远端同步 | DB provider/prompt/skill 期望状态可 portable；恢复后通过 catalog/prompt/skill reconciliation 与本机原生状态对齐；设备目录、native defaults、token、session 不跨机复制 | 原生资产属于设备/外部事实，不能塞进 SQL/binary 备份制造影子副本 |
+| Profile 切换器 | **不适用**：现有项目 Profile 仅定义 Claude 组与 Codex 组，Hermes 本身也不属于任何 Profile scope；Pi 页面同样不展示 | 若未来产品定义新的跨 app Profile scope，应单独设计原生文件事务，不能暗自归入 Claude/Codex |
+| Hermes Memory/Web UI | **不适用**：这是 Hermes 独有 daemon/API；Pi 的长期上下文入口是 `AGENTS.md` 与原生 instruction files，已在 Prompts 面公开 | 不伪造不存在的 Pi daemon 或 Web UI |
+| 原生“一键导入”按钮 | Pi 不调用 generic `import_default`；改为 certified native catalog 中逐 entry inspection + fingerprint CAS 导入 | 这是更严格的等价通路，不是功能缺失 |
+| Extensions / Themes | extensions 本工程只交设计附录；themes 明确排除 | 用户已裁定范围 |
+
+## 原生状态与 portable 状态边界
+
+1. `models.json` 的读取、composition 与 gateway capability 只走前置 C 已认证链。
+   写入统一经 Pi catalog coordinator，协调 DB aggregate、typed endpoints、
+   native document、default provider/model、epoch 与失败补偿；legacy live-sync
+   不得旁路写它。
+2. `AGENTS.md`、`SYSTEM.md`、`APPEND_SYSTEM.md`、prompt templates、Skills
+   与 Sessions 直接观察真实文件；所有 UI active 判断均来自 `exists` 或实际发现。
+   revision/fingerprint 只用于并发保护，不是第二套 enabled 状态。
+3. portable import 恢复的是 cc-switch 拥有的 provider、prompt 与 Skill 期望状态，
+   随后与本机 native 事实 reconcile；不会跨设备覆盖目录、凭证 token、native
+   defaults 或会话。
+4. Pi provider card 的“切换”选择该 provider 的第一模型；多模型的明确选择在
+   native catalog panel 完成，并写回同一 native default，不维护每 provider 的
+   隐藏 last-model 状态。
+
+## 完成审查约束
+
+- 主工程盲审最多七轮；每轮冻结精确 SHA/range，两位 fresh、互相独立、只读
+  reviewer。已审 clean SHA 作为下一轮增量基线；契约新增条款的作用域另做定向
+  全域调用点扫描。
+- P0/P1 finding 必须修复；P2 由主审按可达性、影响面、数据/安全后果与发生概率
+  独立裁决，只有低影响且极少触发的边界才可保留，并在最终报告列出理由。
+- 完成前做一次完整组件通读；零 validated P0/P1、相关验证全绿后才可交付。
+
+## Scope audit（主工程预审检查点）
+
+以主工程基线 `26a95aeb059235612c665d6b6bcd92fde9c3572e` 计，预审工作树为
+137 个文件、约 +13.7k 净行，触发历史 90 文件/12k 净行审计线。审计结论为
+**范围大但未越界**：
+
+- Rust 70 文件：Pi catalog/typed endpoints、共享文件与 ownership、gateway/runtime/
+  usage、prompts/skills/sessions，以及把 `AppType::Pi` 接进现有 command/service/
+  startup/sync 通路；其中新增的大文件按 catalog、transport、runtime、session、
+  deployment 分开，避免一个全知模块。
+- 前端 52 文件：3 个 Pi 专用 panel/form、typed IPC/query、既有导航/设置/代理/
+  使用统计接线和中英文 i18n；没有复制第二套 app shell。
+- 前端测试 12 文件：专用表单/prompt/usage 测试及既有跨 app matrix 增量。
+- 证据与文档 3 文件：transport capture、本文账本、extensions 设计附录。
+- `schema.rs`、`migration.rs`、`backup.rs`、三份认证套件及七个 pinned fixtures
+  均零改动；restore、themes 与 extensions 实现零文件。
+
+压缩方案也做过评估：把 Pi 强塞进 legacy live-sync、通用 additive provider、
+固定 app-type usage 语义或无 ledger Skill 复制可以减少文件，却会重新引入已经
+认证过的 ownership/原生真实/协议分类错误；把 UI 与领域代码揉成少数巨型文件只
+会减少文件数而增加审查风险。当前拆分复用了 provider write、proxy server、
+Prompt/Skill/Session UI、同步锁和统计基础设施，新增代码只承载 Pi 不同的原生语义。
+因此不为满足计数机械缩并，也不扩展到契约外功能。
diff --git a/scripts/pi-transport-capture.mjs b/scripts/pi-transport-capture.mjs
index cda83ec91..3ab5d5806 100644
--- a/scripts/pi-transport-capture.mjs
+++ b/scripts/pi-transport-capture.mjs
@@ -21,9 +21,16 @@
 
 import { createServer } from "node:http";
 import { execFileSync } from "node:child_process";
+import { createHash } from "node:crypto";
 import { createRequire } from "node:module";
-import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
-import { join } from "node:path";
+import {
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  rmSync,
+  writeFileSync,
+} from "node:fs";
+import { join, resolve } from "node:path";
 import { pathToFileURL } from "node:url";
 
 const PI = process.env.PI_CHECKOUT;
@@ -45,6 +52,17 @@ if (piCommit !== EXPECTED_PI_COMMIT) {
 
 const requireFromPi = createRequire(join(PI, "package.json"));
 const { buildSync, version: esbuildVersion } = requireFromPi("esbuild");
+const codingAgentPackagePath = join(PI, "packages/coding-agent/package.json");
+const codingAgentPackageBytes = readFileSync(codingAgentPackagePath);
+const codingAgentPackage = JSON.parse(codingAgentPackageBytes.toString("utf8"));
+const distributionMetadata = {
+  source: "packages/coding-agent/package.json",
+  sha256: createHash("sha256").update(codingAgentPackageBytes).digest("hex"),
+  name: codingAgentPackage.name,
+  version: codingAgentPackage.version,
+  bin: codingAgentPackage.bin,
+  piConfig: codingAgentPackage.piConfig,
+};
 
 const ANTHROPIC_SSE =
   'event: message_start\ndata: {"type":"message_start","message":{"id":"m","type":"message","role":"assistant","model":"m","content":[],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"output_tokens":1}}}\n\n' +
@@ -77,11 +95,40 @@ const aiShimPath = join(harnessDirectory, "pi-ai-shim.mjs");
 const compatShimPath = join(harnessDirectory, "pi-ai-compat-shim.mjs");
 writeFileSync(
   aiShimPath,
-  'export function lazyStream() { throw new Error("transport shim must not execute during compat capture"); }\n',
+  [
+    'export function lazyStream() { throw new Error("transport shim must not execute during compat capture"); }',
+    "let uuidSequence = 0;",
+    'export function uuidv7() { uuidSequence += 1; return `00000000-0000-7000-8000-${String(uuidSequence).padStart(12, "0")}`; }',
+    "export class EventStream {}",
+    "export class ModelsError extends Error {}",
+    "export function validateToolArguments() { return undefined; }",
+    'export function contentText(value) { return typeof value === "string" ? value : ""; }',
+    'export function retryAssistantCall() { throw new Error("resource capture must not call AI"); }',
+    "export function parseStreamingJson() { return undefined; }",
+    "export function modelsAreEqual(left, right) { return left === right; }",
+    "export function createModels() { return {}; }",
+    "export function getBuiltinModelDataGeneratedAt() { return undefined; }",
+    "export function builtinProviders() { return []; }",
+    "export function radiusProvider() { return undefined; }",
+    "",
+  ].join("\n"),
 );
 writeFileSync(
   compatShimPath,
-  'export function getApiProvider() { throw new Error("transport shim must not execute during compat capture"); }\n',
+  [
+    'export function getApiProvider() { throw new Error("transport shim must not execute during compat capture"); }',
+    "export function clampThinkingLevel(value) { return value; }",
+    "export async function cleanupSessionResources() {}",
+    "export function getSupportedThinkingLevels() { return []; }",
+    "export function isContextOverflow() { return false; }",
+    "export function isRetryableAssistantError() { return false; }",
+    "export function modelsAreEqual(left, right) { return left === right; }",
+    "export function resetApiProviders() {}",
+    'export function streamSimple() { throw new Error("resource capture must not call AI"); }',
+    'export function stream() { throw new Error("resource capture must not call AI"); }',
+    'export function completeSimple() { throw new Error("resource capture must not call AI"); }',
+    "",
+  ].join("\n"),
 );
 const entryPoint = join(harnessDirectory, "entry.mjs");
 writeFileSync(
@@ -90,8 +137,14 @@ writeFileSync(
     `export { streamSimple as anthropicMessages } from "${PI}/packages/ai/src/api/anthropic-messages.ts";`,
     `export { streamSimple as openaiResponses } from "${PI}/packages/ai/src/api/openai-responses.ts";`,
     `export { streamSimple as openaiCompletions } from "${PI}/packages/ai/src/api/openai-completions.ts";`,
+    `export { streamSimple as googleGenerativeAi } from "${PI}/packages/ai/src/api/google-generative-ai.ts";`,
     `export { composeModelProvider } from "${PI}/packages/coding-agent/src/core/provider-composer.ts";`,
     `export { resolveConfigValueOrThrow } from "${PI}/packages/coding-agent/src/core/resolve-config-value.ts";`,
+    `export { loadSkills } from "${PI}/packages/coding-agent/src/core/skills.ts";`,
+    `export { loadPromptTemplates } from "${PI}/packages/coding-agent/src/core/prompt-templates.ts";`,
+    `export { SessionManager } from "${PI}/packages/coding-agent/src/core/session-manager.ts";`,
+    `export { parseArgs } from "${PI}/packages/coding-agent/src/cli/args.ts";`,
+    `export { createAllToolDefinitions } from "${PI}/packages/coding-agent/src/core/tools/index.ts";`,
   ].join("\n"),
 );
 const bundlePath = join(harnessDirectory, "bundle.mjs");
@@ -111,16 +164,57 @@ buildSync({
 });
 const adapters = await import(pathToFileURL(bundlePath).href);
 
+// ResourceLoader pulls the complete coding-agent resource graph. Bundle the
+// real pinned ResourceLoader separately with broad AI stubs; the captured
+// instruction behavior remains real while unrelated generated model data is
+// kept outside this resource-only probe.
+const resourceEntryPoint = join(harnessDirectory, "resource-entry.mjs");
+const resourceBundlePath = join(harnessDirectory, "resource-bundle.mjs");
+writeFileSync(
+  resourceEntryPoint,
+  `export { DefaultResourceLoader } from "${PI}/packages/coding-agent/src/core/resource-loader.ts";\n`,
+);
+buildSync({
+  entryPoints: [resourceEntryPoint],
+  bundle: true,
+  platform: "node",
+  format: "esm",
+  outfile: resourceBundlePath,
+  external: ["node:*"],
+  packages: "external",
+  alias: {
+    "@earendil-works/pi-ai/providers/all": aiShimPath,
+    "@earendil-works/pi-ai/oauth": aiShimPath,
+    "@earendil-works/pi-ai": aiShimPath,
+    "@earendil-works/pi-ai/compat": compatShimPath,
+  },
+  logLevel: "silent",
+});
+const resourceAdapters = await import(pathToFileURL(resourceBundlePath).href);
+
 const API_BY_ADAPTER = {
   anthropicMessages: "anthropic-messages",
   openaiResponses: "openai-responses",
   openaiCompletions: "openai-completions",
+  googleGenerativeAi: "google-generative-ai",
 };
 
 /** 每个用例只改变凭证与显式 header,其余保持最小合法模型。 */
 const CASES = [
   ["anthropicMessages", "plain-key", "sk-ant-api03-plain", {}],
   ["anthropicMessages", "oauth-token", "sk-ant-oat01-token", {}],
+  [
+    "anthropicMessages",
+    "oauth-with-explicit-x-api-key",
+    "sk-ant-oat01-token",
+    { "x-api-key": "explicit-secret" },
+  ],
+  [
+    "anthropicMessages",
+    "oauth-with-explicit-authorization",
+    "sk-ant-oat01-token",
+    { authorization: "Bearer configured" },
+  ],
   [
     "anthropicMessages",
     "explicit-x-api-key",
@@ -153,6 +247,13 @@ const CASES = [
     "synthesized-secret",
     { "x-api-key": "explicit-secret" },
   ],
+  ["googleGenerativeAi", "plain-key", "google-plain", {}],
+  [
+    "googleGenerativeAi",
+    "explicit-x-goog-api-key",
+    "google-synthesized",
+    { "x-goog-api-key": "google-explicit" },
+  ],
 ];
 
 const results = [];
@@ -193,6 +294,7 @@ for (const [adapter, label, apiKey, headers] of CASES) {
     adapter: API_BY_ADAPTER[adapter],
     case: label,
     requestSent: Boolean(request),
+    requestUrl: request?.url,
     error: request ? undefined : error,
     authHeaders: request
       ? Object.fromEntries(
@@ -243,6 +345,38 @@ const compatProvider = adapters.composeModelProvider(
 );
 const compatSpread = compatProvider.getModels()[0].compat;
 
+const minimalProvider = adapters.composeModelProvider(
+  "minimal-provider",
+  undefined,
+  {
+    getProvider(providerId) {
+      return providerId === "minimal-provider"
+        ? {
+            name: "Minimal provider",
+            api: "openai-responses",
+            baseUrl: "https://minimal.example/v1",
+            apiKey: "literal",
+            models: [{ id: "minimal-model", name: "Minimal model" }],
+          }
+        : undefined;
+    },
+  },
+  undefined,
+);
+const minimalModel = minimalProvider.getModels()[0];
+const minimalProviderComposition = {
+  id: minimalModel.id,
+  name: minimalModel.name,
+  provider: minimalModel.provider,
+  api: minimalModel.api,
+  baseUrl: minimalModel.baseUrl,
+  reasoning: minimalModel.reasoning,
+  input: minimalModel.input,
+  cost: minimalModel.cost,
+  contextWindow: minimalModel.contextWindow,
+  maxTokens: minimalModel.maxTokens,
+};
+
 function jsonSafeJavaScriptValue(value) {
   if (typeof value === "string") {
     const codeUnits = Array.from({ length: value.length }, (_, index) =>
@@ -357,6 +491,262 @@ const resolverCases = resolverInputs.map((input) => {
   }
 });
 
+// Execute Pi's real discovery entry point. The directories are deliberately
+// created in reverse order: a deterministic winner must come from Pi's
+// discovery ordering, not filesystem insertion order.
+const skillProbeRoot = join(harnessDirectory, "skill-discovery");
+const skillAgentDir = join(skillProbeRoot, "agent");
+const skillProjectDir = join(skillProbeRoot, "project");
+for (const directory of [
+  skillProjectDir,
+  join(skillAgentDir, "skills", "b-second"),
+  join(skillAgentDir, "skills", "a-first"),
+]) {
+  mkdirSync(directory, { recursive: true });
+}
+writeFileSync(
+  join(skillAgentDir, "skills", "b-second", "SKILL.md"),
+  "---\nname: duplicate\ndescription: second\n---\nsecond\n",
+);
+writeFileSync(
+  join(skillAgentDir, "skills", "a-first", "SKILL.md"),
+  "---\nname: duplicate\ndescription: first\n---\nfirst\n",
+);
+const skillDiscovery = jsonSafeJavaScriptValue(
+  await adapters.loadSkills({
+    cwd: skillProjectDir,
+    agentDir: skillAgentDir,
+    skillPaths: [],
+    includeDefaults: true,
+  }),
+);
+
+const promptAgentDir = join(harnessDirectory, "prompt-agent");
+const promptProjectDir = join(harnessDirectory, "prompt-project");
+mkdirSync(join(promptAgentDir, "prompts", "nested"), { recursive: true });
+mkdirSync(promptProjectDir, { recursive: true });
+writeFileSync(
+  join(promptAgentDir, "prompts", "review.md"),
+  "---\ndescription: Review captured changes\nargument-hint: <range>\n---\nReview $1\n",
+);
+writeFileSync(join(promptAgentDir, "prompts", "empty.md"), "");
+writeFileSync(
+  join(promptAgentDir, "prompts", "nested", "ignored.md"),
+  "nested",
+);
+const promptTemplateDiscovery = jsonSafeJavaScriptValue(
+  adapters
+    .loadPromptTemplates({
+      cwd: promptProjectDir,
+      agentDir: promptAgentDir,
+      promptPaths: [],
+      includeDefaults: true,
+    })
+    .map((template) => ({
+      name: template.name,
+      description: template.description,
+      argumentHint: template.argumentHint,
+      content: template.content,
+      source: template.sourceInfo?.source,
+      scope: template.sourceInfo?.scope,
+      relativeFile:
+        template.filePath ===
+        join(promptAgentDir, "prompts", `${template.name}.md`)
+          ? `prompts/${template.name}.md`
+          : template.filePath,
+    })),
+);
+
+// File presence, including a zero-byte file, is the native activation state
+// for Pi's global instruction resources. Execute the real resource loader so
+// cc-switch does not infer that rule from a parser implementation.
+const instructionAgentDir = join(harnessDirectory, "instruction-agent");
+const instructionProjectDir = join(harnessDirectory, "instruction-project");
+mkdirSync(instructionAgentDir, { recursive: true });
+mkdirSync(instructionProjectDir, { recursive: true });
+for (const filename of ["AGENTS.md", "SYSTEM.md", "APPEND_SYSTEM.md"]) {
+  writeFileSync(join(instructionAgentDir, filename), "");
+}
+const instructionLoader = new resourceAdapters.DefaultResourceLoader({
+  cwd: instructionProjectDir,
+  agentDir: instructionAgentDir,
+  noExtensions: true,
+  noSkills: true,
+  noPromptTemplates: true,
+  noThemes: true,
+});
+await instructionLoader.reload();
+const emptyInstructionFiles = {
+  agentsFiles: instructionLoader.getAgentsFiles().agentsFiles.map((entry) => ({
+    relativeFile: entry.path.startsWith(instructionAgentDir)
+      ? entry.path.slice(instructionAgentDir.length + 1)
+      : entry.path,
+    content: entry.content,
+  })),
+  systemPrompt: instructionLoader.getSystemPrompt(),
+  systemPromptSource: instructionLoader.getSystemPromptSource()?.path,
+  appendSystemPrompt: instructionLoader.getAppendSystemPrompt(),
+  appendSystemPromptSources: instructionLoader
+    .getAppendSystemPromptSources()
+    .map((entry) => entry.path),
+};
+
+// Exercise Pi's real SessionManager instead of inferring sessionDir or JSONL
+// shape from its TypeScript source. Relative sessionDir is resolved against the
+// launching process cwd, while the header keeps the explicit project cwd.
+const sessionProjectDir = join(harnessDirectory, "session project");
+mkdirSync(sessionProjectDir, { recursive: true });
+const originalCwd = process.cwd();
+process.chdir(sessionProjectDir);
+const capturedSession = adapters.SessionManager.create(
+  sessionProjectDir,
+  ".pi/sessions",
+  { id: "cc-switch-capture-session" },
+);
+capturedSession.appendSessionInfo("Captured session");
+capturedSession.appendMessage({
+  role: "user",
+  content: [{ type: "text", text: "captured question" }],
+  timestamp: 1_700_000_000_000,
+});
+capturedSession.appendMessage({
+  role: "assistant",
+  content: [{ type: "text", text: "captured answer" }],
+  api: "openai-responses",
+  provider: "capture",
+  model: "capture-model",
+  usage: {
+    input: 1,
+    output: 1,
+    cacheRead: 0,
+    cacheWrite: 0,
+    totalTokens: 2,
+    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+  },
+  stopReason: "stop",
+  timestamp: 1_700_000_001_000,
+});
+const capturedSessionFile = capturedSession.getSessionFile();
+if (!capturedSessionFile) {
+  throw new Error("pinned SessionManager did not persist the capture session");
+}
+const capturedSessionPath = resolve(capturedSessionFile);
+const parsedSessionArgs = adapters.parseArgs([
+  "--session",
+  capturedSessionPath,
+]);
+const parsedVersionArgs = adapters.parseArgs(["--version"]);
+const sessionCliSemantics = {
+  argv: ["--session", capturedSessionPath],
+  parsedSession: parsedSessionArgs.session,
+  diagnostics: parsedSessionArgs.diagnostics,
+  versionArgv: ["--version"],
+  parsedVersion: parsedVersionArgs.version,
+  versionDiagnostics: parsedVersionArgs.diagnostics,
+};
+const capturedSessionLines = capturedSessionFile
+  ? readFileSync(capturedSessionFile, "utf8")
+      .trim()
+      .split("\n")
+      .map((line) => JSON.parse(line))
+  : [];
+const sessionDirectorySemantics = {
+  processCwd: sessionProjectDir,
+  suppliedProjectCwd: sessionProjectDir,
+  suppliedSessionDir: ".pi/sessions",
+  resolvedSessionDir: capturedSession.getSessionDir(),
+  headerKeys: Object.keys(capturedSession.getHeader() ?? {}).sort(),
+  entryShapes: capturedSession.getEntries().map((entry) => ({
+    type: entry.type,
+    keys: Object.keys(entry).sort(),
+    messageRole: entry.type === "message" ? entry.message.role : undefined,
+    messageKeys:
+      entry.type === "message" ? Object.keys(entry.message).sort() : undefined,
+  })),
+  persistedLineTypes: capturedSessionLines.map((entry) => entry.type),
+  listAllCount: (
+    await adapters.SessionManager.listAll(capturedSession.getSessionDir())
+  ).length,
+};
+
+const branchedSession = adapters.SessionManager.create(
+  sessionProjectDir,
+  ".pi/sessions",
+  { id: "cc-switch-capture-branch" },
+);
+const branchRootId = branchedSession.appendMessage({
+  role: "user",
+  content: [{ type: "text", text: "branch root" }],
+  timestamp: 1_700_000_002_000,
+});
+branchedSession.appendSessionInfo("Abandoned branch name");
+branchedSession.appendMessage({
+  role: "assistant",
+  content: [{ type: "text", text: "abandoned answer" }],
+  api: "openai-responses",
+  provider: "capture",
+  model: "capture-model",
+  usage: {
+    input: 1,
+    output: 1,
+    cacheRead: 0,
+    cacheWrite: 0,
+    totalTokens: 2,
+    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+  },
+  stopReason: "stop",
+  timestamp: 1_700_000_003_000,
+});
+branchedSession.branch(branchRootId);
+branchedSession.appendMessage({
+  role: "user",
+  content: [{ type: "text", text: "active branch" }],
+  timestamp: 1_700_000_004_000,
+});
+const sessionBranchSemantics = {
+  sessionName: branchedSession.getSessionName(),
+  activeEntryTypes: branchedSession.getBranch().map((entry) => entry.type),
+};
+
+const malformedSessionFile = join(
+  capturedSession.getSessionDir(),
+  "cc-switch-capture-malformed.jsonl",
+);
+writeFileSync(
+  malformedSessionFile,
+  [
+    JSON.stringify(capturedSession.getHeader()),
+    "{not valid json",
+    ...capturedSession
+      .getEntries()
+      .map((entry) => JSON.stringify(entry)),
+    "",
+  ].join("\n"),
+);
+let malformedSessionSemantics;
+try {
+  const malformedSession = adapters.SessionManager.open(malformedSessionFile);
+  malformedSessionSemantics = {
+    status: "accepted",
+    entryTypes: malformedSession.getEntries().map((entry) => entry.type),
+  };
+} catch (error) {
+  malformedSessionSemantics = {
+    status: "rejected",
+    error: error instanceof Error ? error.message : String(error),
+  };
+}
+process.chdir(originalCwd);
+
+// The executed built-in tool factory is the authoritative core inventory.
+// Extension-provided tools remain possible, but Pi exposes no native MCP
+// registry for cc-switch to mirror as an app toggle.
+const nativeToolInventory = Object.values(
+  adapters.createAllToolDefinitions(sessionProjectDir),
+)
+  .map((tool) => tool.name)
+  .sort();
+
 server.close();
 console.log(
   JSON.stringify(
@@ -364,11 +754,21 @@ console.log(
       bundler: `esbuild@${esbuildVersion}`,
       piCheckout: PI,
       piCommit,
+      distributionMetadata,
       baseUrl,
       results,
+      minimalProviderComposition,
       compatSpread,
       compatEdgeCases,
       resolverCases,
+      skillDiscovery,
+      promptTemplateDiscovery,
+      emptyInstructionFiles,
+      sessionDirectorySemantics,
+      sessionCliSemantics,
+      sessionBranchSemantics,
+      malformedSessionSemantics,
+      nativeToolInventory,
     },
     null,
     2,