diff --git a/src/client.ts b/src/client.ts
index 41eba54..4c8bebb 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -1,7 +1,12 @@
+import { createRequire } from "node:module"
 import type { OpenSeaClientConfig } from "./types/index.js"
 
+const require = createRequire(import.meta.url)
+const { version } = require("../package.json") as { version: string }
+
 const DEFAULT_BASE_URL = "https://api.opensea.io"
 const DEFAULT_TIMEOUT_MS = 30_000
+const USER_AGENT = `opensea-cli/${version}`
 
 export class OpenSeaClient {
   private apiKey: string
@@ -37,6 +42,7 @@ export class OpenSeaClient {
       method: "GET",
       headers: {
         Accept: "application/json",
+        "User-Agent": USER_AGENT,
         "x-api-key": this.apiKey,
       },
       signal: AbortSignal.timeout(this.timeoutMs),
@@ -71,6 +77,7 @@ export class OpenSeaClient {
 
     const headers: Record<string, string> = {
       Accept: "application/json",
+      "User-Agent": USER_AGENT,
       "x-api-key": this.apiKey,
     }
 
diff --git a/test/client.test.ts b/test/client.test.ts
index d068dde..5fb3912 100644
--- a/test/client.test.ts
+++ b/test/client.test.ts
@@ -39,10 +39,11 @@ describe("OpenSeaClient", () => {
         "https://api.opensea.io/api/v2/test",
         expect.objectContaining({
           method: "GET",
-          headers: {
+          headers: expect.objectContaining({
             Accept: "application/json",
+            "User-Agent": expect.stringMatching(/^opensea-cli\/\d+\.\d+\.\d+/),
             "x-api-key": "test-key",
-          },
+          }),
         }),
       )
       expect(result).toEqual(mockResponse)
@@ -93,10 +94,11 @@ describe("OpenSeaClient", () => {
         "https://api.opensea.io/api/v2/refresh",
         expect.objectContaining({
           method: "POST",
-          headers: {
+          headers: expect.objectContaining({
             Accept: "application/json",
+            "User-Agent": expect.stringMatching(/^opensea-cli\/\d+\.\d+\.\d+/),
             "x-api-key": "test-key",
-          },
+          }),
         }),
       )
       expect(result).toEqual(mockResponse)
@@ -111,11 +113,12 @@ describe("OpenSeaClient", () => {
         "https://api.opensea.io/api/v2/create",
         expect.objectContaining({
           method: "POST",
-          headers: {
+          headers: expect.objectContaining({
             Accept: "application/json",
             "Content-Type": "application/json",
+            "User-Agent": expect.stringMatching(/^opensea-cli\/\d+\.\d+\.\d+/),
             "x-api-key": "test-key",
-          },
+          }),
           body: JSON.stringify({ name: "test" }),
         }),
       )