diff --git a/index.ts b/index.ts
index 249c968..ac782a3 100644
--- a/index.ts
+++ b/index.ts
@@ -9,6 +9,7 @@ export * as nip05 from './nip05'
 export * as nip06 from './nip06'
 export * as nip19 from './nip19'
 export * as nip26 from './nip26'
+export * as nip39 from './nip39'
 export * as nip57 from './nip57'
 
 export * as fj from './fakejson'
diff --git a/nip39.test.js b/nip39.test.js
new file mode 100644
index 0000000..dbd4b8b
--- /dev/null
+++ b/nip39.test.js
@@ -0,0 +1,15 @@
+/* eslint-env jest */
+
+const fetch = require('node-fetch')
+const {nip39} = require('./lib/nostr.cjs.js')
+
+test('validate github claim', async () => {
+  nip39.useFetchImplementation(fetch)
+
+  let result = await nip39.validateGithub(
+    'npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z',
+    'vitorpamplona',
+    'cf19e2d1d7f8dac6348ad37b35ec8421'
+  )
+  expect(result).toBe(true)
+})
diff --git a/nip39.ts b/nip39.ts
new file mode 100644
index 0000000..9a94af7
--- /dev/null
+++ b/nip39.ts
@@ -0,0 +1,27 @@
+var _fetch: any
+
+try {
+  _fetch = fetch
+} catch {}
+
+export function useFetchImplementation(fetchImplementation: any) {
+  _fetch = fetchImplementation
+}
+
+export async function validateGithub(
+  pubkey: string,
+  username: string,
+  proof: string
+): Promise<boolean> {
+  try {
+    let res = await (
+      await _fetch(`https://gist.github.com/${username}/${proof}/raw`)
+    ).text()
+    return (
+      res ===
+      `Verifying that I control the following Nostr public key: ${pubkey}`
+    )
+  } catch (_) {
+    return false
+  }
+}