feat: /tidewave http paths

README.md

@@ -30,6 +30,32 @@ Available MCP options:
 
 - `--prefix path` - Specify the directory to find the `package.json` file
 
+### HTTP MCP via Vite Plugin
+
+Tidewave also provides HTTP-based MCP access through a Vite plugin for
+development environments. Add the plugin to your `vite.config.js`:
+
+```javascript
+import { defineConfig } from 'vite';
+import tidewave from 'tidewave/vite-plugin';
+
+export default defineConfig({
+  plugins: [tidewave()],
+});
+```
+
+This exposes MCP endpoints at `/tidewave/mcp` and `/tidewave/shell` during
+development.
+
+Configuration options:
+
+```javascript
+tidewave({
+  allowRemoteAccess: false, // Allow access from remote IPs
+  allowedOrigins: ['localhost'], // Allowed origins: defaults to the Vite's host+port
+});
+```
+
 ### CLI Usage
 
 Tidewave also provides the MCP features over a CLI tool. Use it directly via

eslint.config.js

@@ -53,7 +53,8 @@ export default [
       // Function style preferences
       'prefer-arrow-callback': 'error',
       'arrow-body-style': ['error', 'as-needed'],
-      'func-style': ['error', 'declaration'], // Prefer function declarations for better stack traces
+      // Prefer function declarations for better stack traces
+      'func-style': ['error', 'declaration', { allowArrowFunctions: true }],
     },
   },
   {

flake.nix

@@ -3,10 +3,7 @@
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05-small";
   };
 
-  outputs = {
-    nixpkgs,
-    ...
-  }: let
+  outputs = {nixpkgs, ...}: let
     inherit (nixpkgs.lib) genAttrs;
     inherit (nixpkgs.lib.systems) flakeExposed;
     forAllSystems = f:
@@ -20,12 +17,16 @@
     in {
       default = mkShell {
         name = "tidewave-javascript";
-        packages = with pkgs; [
-          bun
-          # nodejs_24
-          # nodePackages.npm
-          typescript
-        ] ++ lib.optional stdenv.isLinux [inotify-tools];
+        packages = with pkgs;
+          [
+            bun
+            # with homebrew
+            # nodejs_24
+            # nodePackages.npm
+            typescript
+            just
+          ]
+          ++ lib.optional stdenv.isLinux [inotify-tools];
       };
     });
 

justfile

@@ -0,0 +1,22 @@
+curl-mcp body='{}' port='5001':
+    curl -X POST \
+        -H 'accept: application/json,text/event-stream' \
+        -H 'content-type: application/json' \
+        -d '{{body}}' \
+        http://localhost:{{port}}/tidewave/mcp
+
+initialize-mcp:
+    @just curl-mcp '{"jsonrpc":"2.0","method":"initialize","params":{"protocolVersion":"2025-03-26","clientInfo":{"name":"curl-test","version":"1.0.0"},"capabilities":{}},"id":1}'
+
+list-tools-mcp port='5001':
+    @just curl-mcp '{"jsonrpc":"2.0","method":"tools/list","params":{},"id":2}' {{port}}
+
+curl-shell command port='5001':
+    curl -X POST http://localhost:{{port}}/tidewave/shell \
+        -H 'content-type: application/json' \
+        -H 'accept: text/event-stream,application/json' \
+        -d '{"command": "{{command}}"}' \
+        --output -
+
+default:
+    @just --choose

package.json

@@ -29,7 +29,7 @@
     "CHANGELOG.md"
   ],
   "scripts": {
-    "dist": "bun build --outdir dist --root src --external commander --external chalk --external typescript src/**/*.ts --target node",
+    "dist": "bun build --outdir dist --root src --external commander --external chalk --external typescript src/**/*.ts src/*.ts --target node",
     "dev": "bun run src/cli/index.ts",
     "test": "bun test",
     "lint": "eslint src/ --ext .ts,.js",
@@ -41,14 +41,18 @@
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.17.4",
+    "body-parser": "^2.2.0",
     "chalk": "^5.3.0",
     "commander": "^12.1.0",
+    "connect": "^3.7.0",
     "typescript": "^5",
     "zod": "3.25.76"
   },
   "devDependencies": {
     "@eslint/js": "^9.16.0",
+    "@types/body-parser": "^1.19.6",
     "@types/bun": "latest",
+    "@types/connect": "^3.4.38",
     "@types/node": "^22.10.1",
     "@typescript-eslint/eslint-plugin": "^8.18.0",
     "@typescript-eslint/parser": "^8.18.0",
@@ -57,6 +61,7 @@
     "eslint": "^9.16.0",
     "globals": "^15.14.0",
     "prettier": "^3.4.2",
+    "vite": "^7.1.5",
     "vitest": "^3.2.4"
   },
   "peerDependencies": {

src/cli/index.ts

@@ -60,9 +60,15 @@ async function handleGetSourcePath(
   console.log(sourceResult.path);
 }
 
-async function handleMcp(options: { prefix?: string }): Promise<void> {
+interface McpOptions {
+  prefix?: string;
+}
+
+async function handleMcp(options: McpOptions): Promise<void> {
   if (options.prefix) chdir(options.prefix);
-  console.error('Starting tidewave MCP server using stdio');
+
+  console.log('[Tidewave] Starting MCP server');
+
   const transport = new StdioServerTransport(process.stdin, process.stdout);
   await serveMcp(transport);
 }

src/evaluation/eval_worker.ts

@@ -2,7 +2,7 @@ import type { EvaluationRequest } from '../core';
 
 process.on('message', async ({ code, args }: EvaluationRequest) => {
   if (!process.send) {
-    console.error('Unable to establish communication channel with code-executor.');
+    console.error('[Tidewave] Unable to establish communication channel with code-executor.');
     process.exit(1);
   }
 

src/http/handlers/mcp.ts

@@ -0,0 +1,52 @@
+import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
+import { methodNotAllowed, type Request, type Response, type NextFn } from '..';
+import { serveMcp } from '../../mcp';
+
+export async function handleMcp(req: Request, res: Response, next: NextFn): Promise<void> {
+  try {
+    if (req.method !== 'POST') {
+      methodNotAllowed(res);
+      return;
+    }
+
+    console.debug(`[Tidewave] Received ${req.method} message`);
+
+    // stateless mode, no session managament
+    const transport = new StreamableHTTPServerTransport({
+      sessionIdGenerator: undefined,
+      enableJsonResponse: true,
+    });
+
+    if (!(req.body || res.headersSent)) {
+      mcpErrorResponse(res, 'Request body was not parsed');
+      return;
+    }
+
+    await serveMcp(transport);
+    await transport.handleRequest(req, res, req.body);
+  } catch (e) {
+    console.error(`[Tidewave] Failed to serve MCP with ${e}`);
+
+    if (!res.headersSent) {
+      mcpErrorResponse(res, e);
+    }
+
+    next(e);
+  }
+}
+
+function mcpErrorResponse(res: Response, err: Error | unknown): void {
+  res.statusCode = 500;
+  res.setHeader('content-type', 'application/json');
+  res.end(
+    JSON.stringify({
+      jsonrpc: 2.0,
+      id: null,
+      error: {
+        code: -32603,
+        message: 'Internal server error',
+        data: err instanceof Error ? err.message : String(err),
+      },
+    }),
+  );
+}