Add delete file tool call (#47)

* Add file delete tool

* Update instructions for local dev setup

* Add tests

* Prettier

Author: courtney-sims

apps/sandbox-container/.dev.vars.example

@@ -0,0 +1,2 @@
+CLOUDFLARE_CLIENT_ID=
+CLOUDFLARE_CLIENT_SECRET=

apps/sandbox-container/README.md

@@ -4,9 +4,17 @@ This is a simple MCP-based interface for a sandboxed development environment.
 
 ## Local dev
 
-Currently a work in progress. Cloudchamber local dev isn't implemented yet, so we are doing a bit of a hack to just run the server in your local environment.
+Cloudchamber local dev isn't implemented yet, so we are doing a bit of a hack to just run the server in your local environment. Because of this, testing the container(s) and container manager locally is not possible at this time.
 
-TODO: replace locally running server with the real docker container.
+Do the following from within the sandbox-container app:
+
+1. Copy the `.dev.vars.example` file to a new `.dev.vars` file.
+2. Get the Cloudflare client id and secret from a team member and add them to the `.dev.vars` file.
+3. Run `pnpm i` then `pnpm dev` to start the MCP server.
+4. Run `pnpx @modelcontextprotocol/inspector` to start the MCP inspector client.
+5. Open the inspector client in your browser and connect to the server via `http://localhost:8976/workers/sandbox/sse`.
+
+Note: Temporary files created through files tool calls are stored in the workdir folder of this app.
 
 ## Deploying
 

apps/sandbox-container/container/fileUtils.spec.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from 'vitest'
+
+import { get_file_name_from_path } from './fileUtils'
+
+describe('get_file_name_from_path', () => {
+	it('strips files/contents', async () => {
+		const path = await get_file_name_from_path('/files/contents/cats')
+		expect(path).toBe('/cats')
+	}),
+		it('works if files/contents is not present', async () => {
+			const path = await get_file_name_from_path('/dogs')
+			expect(path).toBe('/dogs')
+		}),
+		it('strips a trailing slash', async () => {
+			const path = await get_file_name_from_path('/files/contents/birds/')
+			expect(path).toBe('/birds')
+		})
+})

apps/sandbox-container/container/fileUtils.ts

@@ -0,0 +1,6 @@
+export async function get_file_name_from_path(path: string): Promise<string> {
+	path = path.replace('/files/contents', '')
+	path = path.endsWith('/') ? path.substring(0, path.length - 1) : path
+
+	return path
+}

apps/sandbox-container/container/index.ts

@@ -7,7 +7,10 @@ import { Hono } from 'hono'
 import { streamText } from 'hono/streaming'
 import mime from 'mime'
 
-import { ExecParams, FileList, FilesWrite } from '../shared/schema.ts'
+import { ExecParams, FilesWrite } from '../shared/schema.ts'
+import { get_file_name_from_path } from './fileUtils.ts'
+
+import type { FileList } from '../shared/schema.ts'
 
 process.chdir('workdir')
 
@@ -60,8 +63,7 @@ app.get('/files/ls', async (c) => {
  * Get the contents of a file or directory
  */
 app.get('/files/contents/*', async (c) => {
-	let reqPath = c.req.path.replace('/files/contents', '')
-	reqPath = reqPath.endsWith('/') ? reqPath.substring(0, reqPath.length - 1) : reqPath
+	const reqPath = await get_file_name_from_path(c.req.path)
 	try {
 		const mimeType = mime.getType(reqPath)
 		const headers = mimeType ? { 'Content-Type': mimeType } : undefined
@@ -105,7 +107,8 @@ app.get('/files/contents/*', async (c) => {
  */
 app.post('/files/contents', zValidator('json', FilesWrite), async (c) => {
 	const file = c.req.valid('json')
-	const reqPath = file.path.endsWith('/') ? file.path.substring(0, file.path.length - 1) : file.path
+	const reqPath = await get_file_name_from_path(file.path)
+
 	try {
 		await fs.writeFile(reqPath, file.text)
 		return c.newResponse(null, 200)
@@ -114,6 +117,28 @@ app.post('/files/contents', zValidator('json', FilesWrite), async (c) => {
 	}
 })
 
+/**
+ * DELETE /files/contents/{filepath}
+ *
+ * Delete a file or directory
+ */
+app.delete('/files/contents/*', async (c) => {
+	const reqPath = await get_file_name_from_path(c.req.path)
+
+	try {
+		await fs.rm(path.join(process.cwd(), reqPath), { recursive: true })
+		return c.newResponse('ok', 200)
+	} catch (e: any) {
+		if (e.code) {
+			if (e.code === 'ENOENT') {
+				return c.notFound()
+			}
+		}
+
+		throw e
+	}
+})
+
 /**
  * POST /exec
  *

apps/sandbox-container/package.json

@@ -11,6 +11,7 @@
 		"start": "wrangler dev",
 		"start:container": "tsx container/index.ts",
 		"postinstall": "mkdir -p workdir",
+		"test": "vitest",
 		"types": "wrangler types"
 	},
 	"dependencies": {

apps/sandbox-container/server/containerMcp.ts

@@ -3,12 +3,14 @@ import { McpAgent } from 'agents/mcp'
 import { z } from 'zod'
 
 import { OPEN_CONTAINER_PORT } from '../shared/consts'
-import { ExecParams, FileList, FilesWrite } from '../shared/schema'
+import { ExecParams, FilePathParam, FilesWrite } from '../shared/schema'
 import { MAX_CONTAINERS, proxyFetch, startAndWaitForPort } from './containerHelpers'
 import { getContainerManager } from './containerManager'
 import { BASE_INSTRUCTIONS } from './prompts'
 import { fileToBase64 } from './utils'
-import { Env, Props } from '.'
+
+import type { FileList } from '../shared/schema'
+import type { Env, Props } from '.'
 
 export class ContainerMcpAgent extends McpAgent<Env, Props> {
 	server = new McpServer(
@@ -70,6 +72,17 @@ export class ContainerMcpAgent extends McpAgent<Env, Props> {
 				}
 			}
 		)
+		this.server.tool(
+			'container_file_delete',
+			'Delete file and its contents',
+			{ args: FilePathParam },
+			async ({ args }) => {
+				const deleted = await this.container_file_delete(args)
+				return {
+					content: [{ type: 'text', text: `File deleted: ${deleted}.` }],
+				}
+			}
+		)
 		this.server.tool(
 			'container_files_write',
 			'Write file contents',
@@ -229,11 +242,20 @@ export class ContainerMcpAgent extends McpAgent<Env, Props> {
 		return json
 	}
 
+	async container_file_delete(filePath: string): Promise<boolean> {
+		const res = await proxyFetch(
+			this.env.ENVIRONMENT,
+			this.ctx.container,
+			new Request(`http://host:${OPEN_CONTAINER_PORT}/files/contents/${filePath}`, {
+				method: 'DELETE',
+			}),
+			OPEN_CONTAINER_PORT
+		)
+		return res.ok
+	}
 	async container_files_read(
 		filePath: string
 	): Promise<{ blob: Blob; mimeType: string | undefined }> {
-		console.log('reading')
-		console.log(filePath)
 		const res = await proxyFetch(
 			this.env.ENVIRONMENT,
 			this.ctx.container,
@@ -269,7 +291,6 @@ export class ContainerMcpAgent extends McpAgent<Env, Props> {
 		if (!res || !res.ok) {
 			throw new Error(`Request to container failed: ${await res.text()}`)
 		}
-		const txt = await res.text()
 		return `Wrote file: ${file.path}`
 	}
 }

apps/sandbox-container/shared/schema.ts

@@ -13,6 +13,9 @@ export const FilesWrite = z.object({
 	text: z.string().describe('Full text content of the file you want to write.'),
 })
 
+export type FilePathParam = z.infer<typeof FilePathParam>
+export const FilePathParam = z.string()
+
 export type FileList = z.infer<typeof FileList>
 export const FileList = z.object({
 	resources: z