diff --git a/docs/contracts/Host-v1契约.md b/docs/contracts/Host-v1契约.md
index d8d27fd..8f457d1 100644
--- a/docs/contracts/Host-v1契约.md
+++ b/docs/contracts/Host-v1契约.md
@@ -8,7 +8,8 @@
 
 | 命令 | 参数 / 返回 |
 | --- | --- |
-| `host_capabilities` | protocol=1，workspace=true；core/sync/credentials/extensions=false |
+| `host_capabilities` | protocol=1，workspace/core=true；sync/credentials/extensions=false |
+| `core_request` | 仅代理固定的 `http://127.0.0.1:8000/health` 与 `/api/*` JSON 请求；路径、方法和超时由 Host 限制 |
 | `workspace_choose` | 原生选择，取消返回 null；成功返回 vault_id/path/name |
 | `workspace_open` | 只允许重开应用数据目录中已持久化授权的规范化路径 |
 | `workspace_recent` | 最近 20 个用户主动选择的 Vault；只保存身份、名称和路径 |
@@ -34,6 +35,6 @@ OS 文件锁配合 Rust Mutex 维持单实例 Vault 写入。Web `serialized_vau
 
 ## 前端与发布
 
-Web 模式沿用现有服务。Tauri Workspace Service 调用原生命令；AI Core 未接通时明确返回 CORE_UNAVAILABLE。桌面窗口关闭系统装饰，统一由应用标题栏提供拖动、最小化、最大化/还原及关闭；窗口命令只授予本地 `main` WebView。关闭请求先尝试保存，冲突或保存失败时保持窗口。原生菜单事件和标题栏可见的“段落”菜单复用 `editor.import-note-properties`；仅在源码模式、已打开笔记且无冲突时启用，转换作为单次编辑器历史事务执行。
+Web 模式沿用现有服务。Tauri Workspace Service 调用原生命令；当前预览版通过 Host 连接已在 `127.0.0.1:8000` 启动的 AI Core，连接失败时返回 CORE_UNAVAILABLE。随机端口、临时令牌和自动管理进程仍属于后续 Sidecar 交付。桌面窗口关闭系统装饰，统一由应用标题栏提供拖动、最小化、最大化/还原及关闭；窗口命令只授予本地 `main` WebView。关闭请求先尝试保存，冲突或保存失败时保持窗口。原生菜单事件和标题栏可见的“段落”菜单复用 `editor.import-note-properties`；仅在源码模式、已打开笔记且无冲突时启用，转换作为单次编辑器历史事务执行。
 
 `bundle.active=false`，无自动更新、无签名安装包。开发命令为前端 `pnpm dev` 与 `cargo run --features desktop`；生产 EXE 必须在 `frontend` 目录执行 `pnpm desktop:build`，由 Tauri CLI 先构建并嵌入前端资源。不要用普通 `cargo build --release` 代替该命令，否则 Rust Host 会更新但 WebView 仍可能携带旧资源。需要对应平台 C++ 工具链和 WebView；本次 Windows 已使用系统 `x86_64-pc-windows-gnu` 工具链构建，仍不替代 MSVC 或其他平台验证。
diff --git a/frontend/src-tauri/Cargo.lock b/frontend/src-tauri/Cargo.lock
index 3e14754..0ce041d 100644
--- a/frontend/src-tauri/Cargo.lock
+++ b/frontend/src-tauri/Cargo.lock
@@ -70,7 +70,7 @@ dependencies = [
  "enumflags2",
  "futures-channel",
  "futures-util",
- "rand",
+ "rand 0.9.5",
  "raw-window-handle",
  "serde",
  "serde_repr",
@@ -515,6 +515,23 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
+
+[[package]]
+name = "chacha20"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65c35e4b699c7e15ccbe7ee35c005e4fc0a278d22238a2857e6ce2dadeda1b06"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.1",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.45"
@@ -605,6 +622,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "cpufeatures"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca28b0ae3115b884660db4118d803791fd6756b6e88f39c0f3f7859060d7566"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crc32fast"
 version = "1.5.1"
@@ -1348,8 +1374,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
 dependencies = [
  "cfg-if",
+ "js-sys",
  "libc",
  "wasi",
+ "wasm-bindgen",
 ]
 
 [[package]]
@@ -1371,8 +1399,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "300e883d756b2e4ec94e02791f39b04b522276138852cfc41d9fb7e904106099"
 dependencies = [
  "cfg-if",
+ "js-sys",
  "libc",
  "r-efi 6.0.0",
+ "rand_core 0.10.1",
+ "wasm-bindgen",
 ]
 
 [[package]]
@@ -1646,6 +1677,22 @@ dependencies = [
  "want",
 ]
 
+[[package]]
+name = "hyper-rustls"
+version = "0.27.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33ca68d021ef39cf6463ab54c1d0f5daf03377b70561305bb89a8f83aab66e0f"
+dependencies = [
+ "http",
+ "hyper",
+ "hyper-util",
+ "rustls",
+ "tokio",
+ "tokio-rustls",
+ "tower-service",
+ "webpki-roots",
+]
+
 [[package]]
 name = "hyper-util"
 version = "0.1.20"
@@ -2127,6 +2174,12 @@ version = "0.4.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f9f8bd3e56ce4dfc153cf470fffbfa98c7620958b312ca5c3a4b8d5181fd13c6"
 
+[[package]]
+name = "lru-slab"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "112b39cec0b298b6c1999fee3e31427f74f676e4cb9879ed1a121b43661a4154"
+
 [[package]]
 name = "markup5ever"
 version = "0.38.0"
@@ -2246,6 +2299,7 @@ name = "notesagent-desktop"
 version = "0.3.0-alpha.1"
 dependencies = [
  "fs2",
+ "reqwest 0.12.28",
  "rfd",
  "rusqlite",
  "serde",
@@ -2831,6 +2885,62 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "quinn"
+version = "0.11.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c1a41e437b6bbd489372cd4971de128e85c855f56c57f283d20ff016cf7c0a8"
+dependencies = [
+ "bytes",
+ "cfg_aliases",
+ "pin-project-lite",
+ "quinn-proto",
+ "quinn-udp",
+ "rustc-hash",
+ "rustls",
+ "socket2",
+ "thiserror 2.0.20",
+ "tokio",
+ "tracing",
+ "web-time",
+]
+
+[[package]]
+name = "quinn-proto"
+version = "0.11.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04759210543be93709136e28212294a659ef5001836ff4eab4d663e4529bba83"
+dependencies = [
+ "bytes",
+ "getrandom 0.4.3",
+ "lru-slab",
+ "rand 0.10.2",
+ "rand_pcg",
+ "ring",
+ "rustc-hash",
+ "rustls",
+ "rustls-pki-types",
+ "slab",
+ "thiserror 2.0.20",
+ "tinyvec",
+ "tracing",
+ "web-time",
+]
+
+[[package]]
+name = "quinn-udp"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35a133f956daabe89a61a685c2649f13d82d5aa4bd5d12d1277e1072a21c0694"
+dependencies = [
+ "cfg_aliases",
+ "libc",
+ "once_cell",
+ "socket2",
+ "tracing",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.47"
@@ -2859,7 +2969,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9ef1d0d795eb7d84685bca4f72f3649f064e6641543d3a8c415898726a57b41"
 dependencies = [
  "rand_chacha",
- "rand_core",
+ "rand_core 0.9.5",
+]
+
+[[package]]
+name = "rand"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7f5fa3a058cd35567ef9bfa5e75732bee0f9e4c55fa90477bef2dfcdbc4be80"
+dependencies = [
+ "chacha20",
+ "getrandom 0.4.3",
+ "rand_core 0.10.1",
 ]
 
 [[package]]
@@ -2869,7 +2990,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.9.5",
 ]
 
 [[package]]
@@ -2881,6 +3002,21 @@ dependencies = [
  "getrandom 0.3.4",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
+[[package]]
+name = "rand_pcg"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "caa0f4137e1c0a72f4c651489402276c8e8e1cf081f3b0ba156d2cbeef09e86a"
+dependencies = [
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "raw-window-handle"
 version = "0.6.2"
@@ -2956,6 +3092,44 @@ version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6f6ff9a378485b298a5286656da665ba74413d36db0979633275d2e708145d4"
 
+[[package]]
+name = "reqwest"
+version = "0.12.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eddd3ca559203180a307f12d114c268abf583f59b03cb906fd0b3ff8646c1147"
+dependencies = [
+ "base64 0.22.1",
+ "bytes",
+ "futures-core",
+ "http",
+ "http-body",
+ "http-body-util",
+ "hyper",
+ "hyper-rustls",
+ "hyper-util",
+ "js-sys",
+ "log",
+ "percent-encoding",
+ "pin-project-lite",
+ "quinn",
+ "rustls",
+ "rustls-pki-types",
+ "serde",
+ "serde_json",
+ "serde_urlencoded",
+ "sync_wrapper",
+ "tokio",
+ "tokio-rustls",
+ "tower",
+ "tower-http",
+ "tower-service",
+ "url",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "web-sys",
+ "webpki-roots",
+]
+
 [[package]]
 name = "reqwest"
 version = "0.13.4"
@@ -3014,6 +3188,20 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "ring"
+version = "0.17.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4689e6c2294d81e88dc6261c768b63bc4fcdb852be6d1352498b114f61383b7"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "getrandom 0.2.17",
+ "libc",
+ "untrusted",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "rusqlite"
 version = "0.32.1"
@@ -3056,12 +3244,53 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "rustls"
+version = "0.23.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6725596c3f2c3a0aef021139e145d4eafe314a6623e4680ca83852b2c67ab2ba"
+dependencies = [
+ "once_cell",
+ "ring",
+ "rustls-pki-types",
+ "rustls-webpki",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-pki-types"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2f4925028c7eb5d1fcdaf196971378ed9d2c1c4efc7dc5d011256f76c99c0a96"
+dependencies = [
+ "web-time",
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-webpki"
+version = "0.103.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3c3cf1d8b1e7d4927e2d154c3fcb02979afb9939629c62cd9048d4f07b60ac2"
+dependencies = [
+ "ring",
+ "rustls-pki-types",
+ "untrusted",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf54715a573b99ac80df0bc206da022bcd442c974952c7b9720069370852e21f"
 
+[[package]]
+name = "ryu"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9774ba4a74de5f7b1c1451ed6cd5285a32eddb5cccb8cc655a4e50009e06477f"
+
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -3258,6 +3487,18 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "serde_urlencoded"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3491c14715ca2294c4d6a88f15e84739788c1d030eed8c110436aafdaa2f3fd"
+dependencies = [
+ "form_urlencoded",
+ "itoa",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "serde_with"
 version = "3.22.0"
@@ -3329,7 +3570,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
 dependencies = [
  "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.17",
  "digest",
 ]
 
@@ -3467,6 +3708,12 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
+[[package]]
+name = "subtle"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+
 [[package]]
 name = "swift-rs"
 version = "1.0.8"
@@ -3630,7 +3877,7 @@ dependencies = [
  "percent-encoding",
  "plist",
  "raw-window-handle",
- "reqwest",
+ "reqwest 0.13.4",
  "serde",
  "serde_json",
  "serde_repr",
@@ -3944,6 +4191,16 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "tokio-rustls"
+version = "0.26.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0c85f2c3ef0b1cd58b36682f4b17aaa995f0e5db534d85692b4903abce21f67"
+dependencies = [
+ "rustls",
+ "tokio",
+]
+
 [[package]]
 name = "tokio-util"
 version = "0.7.19"
@@ -4257,6 +4514,12 @@ version = "1.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"
 
+[[package]]
+name = "untrusted"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
+
 [[package]]
 name = "url"
 version = "2.5.8"
@@ -4516,6 +4779,16 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "web-time"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a6580f308b1fad9207618087a65c04e7a10bc77e02c8e84e9b00dd4b12fa0bb"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "web_atoms"
 version = "0.2.6"
@@ -4572,6 +4845,15 @@ dependencies = [
  "system-deps",
 ]
 
+[[package]]
+name = "webpki-roots"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7dcd9d09a39985f5344844e66b0c530a33843579125f23e21e9f0f220850f22a"
+dependencies = [
+ "rustls-pki-types",
+]
+
 [[package]]
 name = "webview2-com"
 version = "0.38.2"
@@ -4802,6 +5084,15 @@ dependencies = [
  "windows-targets 0.42.2",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
@@ -5204,6 +5495,12 @@ dependencies = [
  "synstructure",
 ]
 
+[[package]]
+name = "zeroize"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e13c156562582aa81c60cb29407084cdb54c4164760106ab78e6c5b0858cf64e"
+
 [[package]]
 name = "zerotrie"
 version = "0.2.5"
diff --git a/frontend/src-tauri/Cargo.toml b/frontend/src-tauri/Cargo.toml
index 11cdf86..3975553 100644
--- a/frontend/src-tauri/Cargo.toml
+++ b/frontend/src-tauri/Cargo.toml
@@ -14,7 +14,7 @@ required-features = ["desktop"]
 
 [features]
 default = []
-desktop = ["dep:tauri", "dep:tauri-build", "dep:rfd"]
+desktop = ["dep:tauri", "dep:tauri-build", "dep:rfd", "dep:reqwest"]
 
 [dependencies]
 serde = { version = "1", features = ["derive"] }
@@ -26,6 +26,7 @@ tempfile = "3"
 fs2 = "0.4"
 tauri = { version = "2", optional = true, features = ["tray-icon"] }
 rfd = { version = "0.15", optional = true }
+reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"], optional = true }
 
 [build-dependencies]
-tauri-build = { version = "2", optional = true }
+tauri-build = { version = "2", optional = true , features = [] }
diff --git a/frontend/src-tauri/build.rs b/frontend/src-tauri/build.rs
index d822f38..6758303 100644
--- a/frontend/src-tauri/build.rs
+++ b/frontend/src-tauri/build.rs
@@ -3,6 +3,7 @@ fn main() {
     tauri_build::try_build(tauri_build::Attributes::new().app_manifest(
         tauri_build::AppManifest::new().commands(&[
             "host_capabilities",
+            "core_request",
             "editor_capabilities",
             "workspace_choose",
             "workspace_open",
diff --git a/frontend/src-tauri/capabilities/main.json b/frontend/src-tauri/capabilities/main.json
index ba003a3..c50da85 100644
--- a/frontend/src-tauri/capabilities/main.json
+++ b/frontend/src-tauri/capabilities/main.json
@@ -8,6 +8,7 @@
   "permissions": [
     "core:default",
     "allow-host-capabilities",
+    "allow-core-request",
     "allow-workspace-choose",
     "allow-workspace-open",
     "allow-workspace-tree",
diff --git a/frontend/src-tauri/permissions/autogenerated/core_request.toml b/frontend/src-tauri/permissions/autogenerated/core_request.toml
new file mode 100644
index 0000000..5140356
--- /dev/null
+++ b/frontend/src-tauri/permissions/autogenerated/core_request.toml
@@ -0,0 +1,11 @@
+# Automatically generated - DO NOT EDIT!
+
+[[permission]]
+identifier = "allow-core-request"
+description = "Enables the core_request command without any pre-configured scope."
+commands.allow = ["core_request"]
+
+[[permission]]
+identifier = "deny-core-request"
+description = "Denies the core_request command without any pre-configured scope."
+commands.deny = ["core_request"]
diff --git a/frontend/src-tauri/src/main.rs b/frontend/src-tauri/src/main.rs
index d6bd922..ea6ef21 100644
--- a/frontend/src-tauri/src/main.rs
+++ b/frontend/src-tauri/src/main.rs
@@ -6,6 +6,7 @@ use notesagent_host::recent::{RecentVault, RecentVaultStore};
 use notesagent_host::workspace::{Document, Entry, Workspace};
 use std::path::Path;
 use std::sync::Mutex;
+use std::time::Duration;
 use tauri::{Emitter, Manager, State};
 
 #[derive(Default)]
@@ -38,7 +39,84 @@ fn with_workspace<T>(
 
 #[tauri::command]
 fn host_capabilities() -> serde_json::Value {
-    serde_json::json!({"protocol":1,"workspace":true,"core":false,"sync":false,"credentials":false,"extensions":false,"release":"preview"})
+    serde_json::json!({"protocol":1,"workspace":true,"core":true,"sync":false,"credentials":false,"extensions":false,"release":"preview"})
+}
+
+#[derive(serde::Serialize)]
+struct CoreResponse {
+    status: u16,
+    content_type: String,
+    body: String,
+}
+
+fn core_url(path: &str) -> Result<String, String> {
+    if (!path.starts_with("/api/") && path != "/api" && path != "/health")
+        || path.contains("..")
+        || path.contains(['\r', '\n'])
+    {
+        return Err("CORE_PATH_DENIED".into());
+    }
+    Ok(format!("http://127.0.0.1:8000{path}"))
+}
+
+#[cfg(test)]
+mod core_proxy_tests {
+    use super::core_url;
+
+    #[test]
+    fn only_allows_expected_loopback_paths() {
+        assert_eq!(core_url("/health").unwrap(), "http://127.0.0.1:8000/health");
+        assert!(core_url("/api/status?verbose=true").is_ok());
+        assert!(core_url("https://example.com/api/status").is_err());
+        assert!(core_url("/api/../secret").is_err());
+    }
+}
+
+/// 预览版只代理固定回环地址，避免 WebView CORS 与任意地址转发。
+#[tauri::command]
+async fn core_request(
+    method: String,
+    path: String,
+    body: Option<serde_json::Value>,
+    authorization: Option<String>,
+) -> Result<CoreResponse, String> {
+    let method =
+        reqwest::Method::from_bytes(method.as_bytes()).map_err(|_| "CORE_METHOD_DENIED")?;
+    if !matches!(
+        method,
+        reqwest::Method::GET
+            | reqwest::Method::POST
+            | reqwest::Method::PUT
+            | reqwest::Method::PATCH
+            | reqwest::Method::DELETE
+    ) {
+        return Err("CORE_METHOD_DENIED".into());
+    }
+    let client = reqwest::Client::builder()
+        .timeout(Duration::from_secs(30))
+        .build()
+        .map_err(|_| "CORE_CLIENT_ERROR")?;
+    let mut request = client.request(method, core_url(&path)?);
+    if let Some(value) = body {
+        request = request.json(&value);
+    }
+    if let Some(value) = authorization {
+        request = request.header(reqwest::header::AUTHORIZATION, value);
+    }
+    let response = request.send().await.map_err(|_| "CORE_UNAVAILABLE")?;
+    let status = response.status().as_u16();
+    let content_type = response
+        .headers()
+        .get(reqwest::header::CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .unwrap_or("")
+        .to_owned();
+    let body = response.text().await.map_err(|_| "CORE_RESPONSE_ERROR")?;
+    Ok(CoreResponse {
+        status,
+        content_type,
+        body,
+    })
 }
 
 #[tauri::command]
@@ -197,6 +275,7 @@ fn main() {
         })
         .invoke_handler(tauri::generate_handler![
             host_capabilities,
+            core_request,
             editor_capabilities,
             workspace_choose,
             workspace_open,
diff --git a/frontend/src-tauri/tauri.conf.json b/frontend/src-tauri/tauri.conf.json
index d5d2d23..bf4cdd1 100644
--- a/frontend/src-tauri/tauri.conf.json
+++ b/frontend/src-tauri/tauri.conf.json
@@ -12,7 +12,7 @@
   "app": {
     "windows": [{"label": "main", "title": "NotesAgent Preview", "width": 1200, "height": 800, "minWidth": 640, "minHeight": 480, "decorations": false}],
     "security": {
-      "csp": "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self' data:; connect-src ipc: http://ipc.localhost; frame-src 'self' blob:; object-src 'none'; base-uri 'self'",
+      "csp": "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob: http://127.0.0.1:8000; font-src 'self' data:; connect-src ipc: http://ipc.localhost http://127.0.0.1:8000; frame-src 'self' blob:; object-src 'none'; base-uri 'self'",
       "capabilities": ["main"]
     }
   },
diff --git a/frontend/src/features/vault/VaultEntry.vue b/frontend/src/features/vault/VaultEntry.vue
index bcb5d15..fd862c5 100644
--- a/frontend/src/features/vault/VaultEntry.vue
+++ b/frontend/src/features/vault/VaultEntry.vue
@@ -72,7 +72,7 @@ async function openFolderPicker() {
         <div v-if="openError" class="error-banner" role="alert">{{ openError }} <button class="btn" @click="initializeVault" :disabled="isLoading">{{ t('重试', 'Retry') }}</button></div>
         <p v-if="isLoading" role="status">{{ t('正在打开知识库…', 'Opening knowledge base…') }}</p>
         <h2 class="card-title">{{ t('选择知识库', 'Select Knowledge Base') }}</h2>
-        <p class="card-desc">{{ isDesktop() ? t('桌面预览：选择本地目录；AI 与同步尚未接通。', 'Desktop preview: choose a local folder. AI and sync are not connected yet.') : t('Web 联调模式连接 AI Core 当前配置的 Vault', 'Web development mode connects to the Vault configured in AI Core') }}</p>
+        <p class="card-desc">{{ isDesktop() ? t('桌面预览：选择本地目录；自动连接本机 AI Core。', 'Desktop preview: choose a local folder and connect to the local AI Core.') : t('Web 联调模式连接 AI Core 当前配置的 Vault', 'Web development mode connects to the Vault configured in AI Core') }}</p>
 
         <div v-if="workspaceStore.recentVaults.length" class="recent-vaults">
           <div class="section-label">{{ t('最近打开', 'Recently opened') }}</div>
diff --git a/frontend/src/services/apiClient.ts b/frontend/src/services/apiClient.ts
index 19b85bc..7d97f61 100644
--- a/frontend/src/services/apiClient.ts
+++ b/frontend/src/services/apiClient.ts
@@ -1,8 +1,10 @@
 import type { ApiError, ErrorResponse } from '@/contracts'
-import { isDesktop } from './platform/desktop'
+import { hostInvoke, isDesktop } from './platform/desktop'
 
 // 所有 HTTP 请求都经过此边界，以统一地址、请求追踪和错误契约。
-const BASE_URL = import.meta.env.VITE_API_BASE_URL ?? import.meta.env.VITE_API_BASE ?? ''
+const BASE_URL = import.meta.env.VITE_API_BASE_URL ?? import.meta.env.VITE_API_BASE ?? (isDesktop() ? 'http://127.0.0.1:8000' : '')
+
+interface DesktopCoreResponse { status: number; content_type: string; body: string }
 
 export function resolveApiUrl(path: string): string {
   if (/^https?:\/\//i.test(path)) return path
@@ -28,7 +30,6 @@ export class ApiErrorClass extends Error {
 }
 
 async function request<T>(path: string, options: RequestOptions = {}): Promise<T> {
-  if (isDesktop()) throw new ApiErrorClass('CORE_UNAVAILABLE', '桌面 AI Core 尚未接通；本地编辑可继续。')
   const { params, token, headers, timeoutMs, ...rest } = options
   const controller = timeoutMs ? new AbortController() : null
   let timedOut = false
@@ -61,6 +62,22 @@ async function request<T>(path: string, options: RequestOptions = {}): Promise<T
   reqHeaders['X-Request-Id'] = reqId
 
   try {
+    if (isDesktop()) {
+      const parsed = new URL(url)
+      const response = await hostInvoke<DesktopCoreResponse>('core_request', {
+        method: rest.method ?? 'GET',
+        path: `${parsed.pathname}${parsed.search}`,
+        body: typeof rest.body === 'string' ? JSON.parse(rest.body) : undefined,
+        authorization: token ? `Bearer ${token}` : undefined,
+      })
+      if (response.status >= 200 && response.status < 300) {
+        if (response.status === 204) return undefined as T
+        return (response.content_type.includes('application/json') ? JSON.parse(response.body) : response.body) as T
+      }
+      let error: ErrorResponse | null = null
+      try { error = JSON.parse(response.body) as ErrorResponse } catch { /* 非 JSON 错误 */ }
+      throw new ApiErrorClass(error?.error?.code ?? `HTTP_${response.status}`, error?.error?.message ?? `Request failed with status ${response.status}`, error?.error?.details)
+    }
     const resp = await fetch(url, {
       ...rest,
       signal: controller?.signal ?? rest.signal,