diff --git a/.changeset/warm-islands-fetch.md b/.changeset/warm-islands-fetch.md
new file mode 100644
index 00000000..a845151c
--- /dev/null
+++ b/.changeset/warm-islands-fetch.md
@@ -0,0 +1,2 @@
+---
+---
diff --git a/apps/base/package.json b/apps/base/package.json
index abbe1a85..2265b796 100644
--- a/apps/base/package.json
+++ b/apps/base/package.json
@@ -32,12 +32,10 @@
     "@modelcontextprotocol/sdk": "^1.26.0",
     "@perstack/core": "workspace:*",
     "commander": "^14.0.3",
-    "mime-types": "^3.0.2",
     "zod": "^4.3.6"
   },
   "devDependencies": {
     "@tsconfig/node22": "^22.0.5",
-    "@types/mime-types": "^3.0.1",
     "@types/node": "^25.2.3",
     "tsup": "^8.5.1",
     "typescript": "^5.9.3",
diff --git a/apps/base/src/lib/mime.ts b/apps/base/src/lib/mime.ts
new file mode 100644
index 00000000..4b0f754b
--- /dev/null
+++ b/apps/base/src/lib/mime.ts
@@ -0,0 +1,14 @@
+import { extname } from "node:path"
+
+const MIME_TYPES: Record<string, string> = {
+  ".png": "image/png",
+  ".jpg": "image/jpeg",
+  ".jpeg": "image/jpeg",
+  ".gif": "image/gif",
+  ".webp": "image/webp",
+  ".pdf": "application/pdf",
+}
+
+export function lookupMimeType(filePath: string): string | undefined {
+  return MIME_TYPES[extname(filePath).toLowerCase()]
+}
diff --git a/apps/base/src/tools/read-image-file.ts b/apps/base/src/tools/read-image-file.ts
index b51bd147..c9e53310 100644
--- a/apps/base/src/tools/read-image-file.ts
+++ b/apps/base/src/tools/read-image-file.ts
@@ -1,8 +1,8 @@
 import { existsSync } from "node:fs"
 import { stat } from "node:fs/promises"
 import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"
-import mime from "mime-types"
 import { z } from "zod/v4"
+import { lookupMimeType } from "../lib/mime.js"
 import { validatePath } from "../lib/path.js"
 import { errorToolResult, successToolResult } from "../lib/tool-result.js"
 
@@ -14,7 +14,7 @@ export async function readImageFile(input: { path: string }) {
   if (!isFile) {
     throw new Error(`File ${path} does not exist.`)
   }
-  const mimeType = mime.lookup(validatedPath)
+  const mimeType = lookupMimeType(validatedPath)
   if (!mimeType || !["image/png", "image/jpeg", "image/gif", "image/webp"].includes(mimeType)) {
     throw new Error(`File ${path} is not supported.`)
   }
diff --git a/apps/base/src/tools/read-pdf-file.ts b/apps/base/src/tools/read-pdf-file.ts
index add2a4a2..14eb8a3a 100644
--- a/apps/base/src/tools/read-pdf-file.ts
+++ b/apps/base/src/tools/read-pdf-file.ts
@@ -1,8 +1,8 @@
 import { existsSync } from "node:fs"
 import { stat } from "node:fs/promises"
 import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"
-import mime from "mime-types"
 import { z } from "zod/v4"
+import { lookupMimeType } from "../lib/mime.js"
 import { validatePath } from "../lib/path.js"
 import { errorToolResult, successToolResult } from "../lib/tool-result.js"
 
@@ -14,7 +14,7 @@ export async function readPdfFile(input: { path: string }) {
   if (!isFile) {
     throw new Error(`File ${path} does not exist.`)
   }
-  const mimeType = mime.lookup(validatedPath)
+  const mimeType = lookupMimeType(validatedPath)
   if (mimeType !== "application/pdf") {
     throw new Error(`File ${path} is not a PDF file.`)
   }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5db2a352..0f25aa1d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -65,9 +65,6 @@ importers:
       commander:
         specifier: ^14.0.3
         version: 14.0.3
-      mime-types:
-        specifier: ^3.0.2
-        version: 3.0.2
       zod:
         specifier: ^4.3.6
         version: 4.3.6
@@ -75,9 +72,6 @@ importers:
       '@tsconfig/node22':
         specifier: ^22.0.5
         version: 22.0.5
-      '@types/mime-types':
-        specifier: ^3.0.1
-        version: 3.0.1
       '@types/node':
         specifier: ^25.2.3
         version: 25.2.3
@@ -1832,9 +1826,6 @@ packages:
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
-  '@types/mime-types@3.0.1':
-    resolution: {integrity: sha512-xRMsfuQbnRq1Ef+C+RKaENOxXX87Ygl38W1vDfPHRku02TgQr+Qd8iivLtAMcR0KF5/29xlnFihkTlbqFrGOVQ==}
-
   '@types/node@12.20.55':
     resolution: {integrity: sha512-J8xLz7q2OFulZ2cyGTLE1TbbZcjpno7FaN6zdJNrgAdrJ+DZzh/uFR6YrTb4C+nXakvud8Q4+rbhoIWlYQbUFQ==}
 
@@ -4628,8 +4619,6 @@ snapshots:
 
   '@types/estree@1.0.8': {}
 
-  '@types/mime-types@3.0.1': {}
-
   '@types/node@12.20.55': {}
 
   '@types/node@25.2.3':