diff --git a/server/utils/docs/client.ts b/server/utils/docs/client.ts
index ff3d56d863..f6a277d17f 100644
--- a/server/utils/docs/client.ts
+++ b/server/utils/docs/client.ts
@@ -18,6 +18,8 @@ import { isBuiltin } from 'node:module'
 /** Timeout for fetching modules in milliseconds */
 const FETCH_TIMEOUT_MS = 30 * 1000
 
+const IS_SOURCE_MAP = /\.(?:js|mjs|cjs|d\.[mc]?ts)\.map(?:[?#].*)?$/
+
 // =============================================================================
 // Main Export
 // =============================================================================
@@ -70,7 +72,7 @@ interface LoadResponse {
  *
  * Fetches modules from URLs using fetch(), with proper timeout handling.
  */
-function createLoader(): (
+export function createLoader(): (
   specifier: string,
   isDynamic?: boolean,
   cacheSetting?: string,
@@ -82,6 +84,10 @@ function createLoader(): (
     _cacheSetting?: string,
     _checksum?: string,
   ) => {
+    if (IS_SOURCE_MAP.test(specifier)) {
+      return undefined
+    }
+
     const url = URL.parse(specifier)
 
     if (url === null) {
@@ -130,8 +136,14 @@ function createLoader(): (
  *
  * Handles resolving relative imports and esm.sh redirects.
  */
-function createResolver(): (specifier: string, referrer: string) => string {
+export function createResolver(): (specifier: string, referrer: string) => string {
   return (specifier: string, referrer: string) => {
+    // Source map references are not modules. Resolving bare source map
+    // filenames can incorrectly treat them as package specifiers
+    if (IS_SOURCE_MAP.test(specifier)) {
+      return specifier
+    }
+
     // Handle relative imports
     if (specifier.startsWith('.') || specifier.startsWith('/')) {
       return new URL(specifier, referrer).toString()
diff --git a/test/unit/server/utils/docs/client.spec.ts b/test/unit/server/utils/docs/client.spec.ts
new file mode 100644
index 0000000000..96c0e9bc39
--- /dev/null
+++ b/test/unit/server/utils/docs/client.spec.ts
@@ -0,0 +1,89 @@
+import { describe, expect, it, vi, afterEach } from 'vitest'
+import { createResolver, createLoader } from '#server/utils/docs/client'
+
+describe('createResolver', () => {
+  const resolve = createResolver()
+  const referrer = 'https://esm.sh/effect-web-midi@0.2.1/dist-types/index.d.ts'
+
+  it('resolves relative imports', () => {
+    expect(resolve('./src/index.d.ts', referrer)).toBe(
+      'https://esm.sh/effect-web-midi@0.2.1/dist-types/src/index.d.ts',
+    )
+  })
+
+  it('resolves absolute paths', () => {
+    expect(resolve('/foo.d.ts', referrer)).toBe('https://esm.sh/foo.d.ts')
+  })
+
+  it('resolves bare specifiers', () => {
+    expect(resolve('effect', referrer)).toBe('https://esm.sh/effect')
+  })
+
+  it('leaves absolute URLs unchanged', () => {
+    expect(resolve('https://esm.sh/effect', referrer)).toBe('https://esm.sh/effect')
+  })
+
+  it('leaves node builtins unchanged', () => {
+    expect(resolve('node:fs', referrer)).toBe('node:fs')
+  })
+
+  // Issue #2739: Prevent sourceMappingURL specifiers from being resolved as package names
+  // https://github.com/npmx-dev/npmx.dev/issues/2739
+  it('does not resolve source map references', () => {
+    expect(resolve('index.d.ts.map', referrer)).toBe('index.d.ts.map')
+    expect(resolve('./index.d.ts.map', referrer)).toBe('./index.d.ts.map')
+  })
+
+  it('does not falsely flag packages containing the word map', () => {
+    expect(resolve('source-map', referrer)).toBe('https://esm.sh/source-map')
+    expect(resolve('my.package.map', referrer)).toBe('https://esm.sh/my.package.map')
+  })
+})
+
+describe('createLoader', () => {
+  const load = createLoader()
+
+  afterEach(() => {
+    vi.unstubAllGlobals()
+  })
+
+  it('returns undefined for source map files', async () => {
+    expect(await load('index.d.ts.map')).toBeUndefined()
+    expect(await load('https://esm.sh/foo.js.map')).toBeUndefined()
+    expect(await load('index.d.ts.map?v=123')).toBeUndefined()
+    expect(await load('https://esm.sh/foo.js.map#hash')).toBeUndefined()
+  })
+
+  it('returns undefined for invalid or non-HTTP URLs', async () => {
+    expect(await load('not-a-valid-url')).toBeUndefined()
+    expect(await load('node:fs')).toBeUndefined()
+    expect(await load('file:///etc/passwd')).toBeUndefined()
+  })
+
+  it('fetches and returns module content for valid URLs', async () => {
+    const mockFetch = vi.fn().mockResolvedValue({
+      status: 200,
+      url: 'https://esm.sh/foo@1.0.0/index.d.ts',
+      headers: new Headers({ 'content-type': 'application/typescript' }),
+      _data: { text: async () => 'export const foo = 1;' },
+    })
+    vi.stubGlobal('$fetch', { raw: mockFetch })
+
+    const result = await load('https://esm.sh/foo@1.0.0/index.d.ts')
+
+    expect(result).toEqual({
+      kind: 'module',
+      specifier: 'https://esm.sh/foo@1.0.0/index.d.ts',
+      headers: { 'content-type': 'application/typescript' },
+      content: 'export const foo = 1;',
+    })
+    expect(mockFetch).toHaveBeenCalledTimes(1)
+  })
+
+  it('returns undefined if the fetch fails (non-200 status)', async () => {
+    const mockFetch = vi.fn().mockResolvedValue({ status: 404 })
+    vi.stubGlobal('$fetch', { raw: mockFetch })
+
+    expect(await load('https://esm.sh/foo@1.0.0/missing.d.ts')).toBeUndefined()
+  })
+})