diff --git a/src/bw/client.ts b/src/bw/client.ts
index 1972b05..03aecb0 100644
--- a/src/bw/client.ts
+++ b/src/bw/client.ts
@@ -1,5 +1,6 @@
 import { Readable } from "node:stream";
 import { TokenManager } from "./token.js";
+import { USER_AGENT } from "./user-agent.js";
 
 /**
  * Validate an identifier before interpolating it into a Bandwidth API URL path.
@@ -111,7 +112,7 @@ export function createBwClient(cfg: {
     async createCall({ to, from, answerUrl }) {
       const res = await fetchImpl(`${base}/accounts/${cfg.accountId}/calls`, {
         method: "POST",
-        headers: { "Content-Type": "application/json", Authorization: await authHeader() },
+        headers: { "Content-Type": "application/json", Authorization: await authHeader(), "User-Agent": USER_AGENT },
         body: JSON.stringify({ to, from, answerUrl, applicationId: cfg.applicationId }),
       });
       if (!res.ok)
@@ -122,7 +123,7 @@ export function createBwClient(cfg: {
     async modifyCall(callId, opts) {
       const res = await fetchImpl(`${base}/accounts/${cfg.accountId}/calls/${safeId(callId)}`, {
         method: "POST",
-        headers: { "Content-Type": "application/json", Authorization: await authHeader() },
+        headers: { "Content-Type": "application/json", Authorization: await authHeader(), "User-Agent": USER_AGENT },
         body: JSON.stringify(opts),
       });
       if (!res.ok)
@@ -130,7 +131,7 @@ export function createBwClient(cfg: {
     },
     async getCall(callId) {
       const res = await fetchImpl(`${base}/accounts/${cfg.accountId}/calls/${safeId(callId)}`, {
-        headers: { Accept: "application/json", Authorization: await authHeader() },
+        headers: { Accept: "application/json", Authorization: await authHeader(), "User-Agent": USER_AGENT },
       });
       if (!res.ok)
         throw new Error(`Bandwidth getCall failed: ${res.status} ${await res.text()}`);
@@ -140,7 +141,7 @@ export function createBwClient(cfg: {
     },
     async listRecordings(callId) {
       const res = await fetchImpl(`${base}/accounts/${cfg.accountId}/calls/${safeId(callId)}/recordings`, {
-        headers: { Accept: "application/json", Authorization: await authHeader() },
+        headers: { Accept: "application/json", Authorization: await authHeader(), "User-Agent": USER_AGENT },
       });
       if (!res.ok)
         throw new Error(`Bandwidth listRecordings failed: ${res.status} ${await res.text()}`);
@@ -150,7 +151,7 @@ export function createBwClient(cfg: {
     async getRecording(callId, recordingId) {
       const res = await fetchImpl(
         `${base}/accounts/${cfg.accountId}/calls/${safeId(callId)}/recordings/${safeId(recordingId)}`,
-        { headers: { Accept: "application/json", Authorization: await authHeader() } },
+        { headers: { Accept: "application/json", Authorization: await authHeader(), "User-Agent": USER_AGENT } },
       );
       if (!res.ok)
         throw new Error(`Bandwidth getRecording failed: ${res.status} ${await res.text()}`);
@@ -160,7 +161,7 @@ export function createBwClient(cfg: {
     async getRecordingMedia(callId, recordingId) {
       const res = await fetchImpl(
         `${base}/accounts/${cfg.accountId}/calls/${safeId(callId)}/recordings/${safeId(recordingId)}/media`,
-        { headers: { Authorization: await authHeader() } },
+        { headers: { Authorization: await authHeader(), "User-Agent": USER_AGENT } },
       );
       if (!res.ok || !res.body)
         throw new Error(`Bandwidth getRecordingMedia failed: ${res.status} ${await res.text()}`);
@@ -173,7 +174,7 @@ export function createBwClient(cfg: {
     async updateRecording(callId, state) {
       const res = await fetchImpl(`${base}/accounts/${cfg.accountId}/calls/${safeId(callId)}/recording`, {
         method: "PUT",
-        headers: { "Content-Type": "application/json", Authorization: await authHeader() },
+        headers: { "Content-Type": "application/json", Authorization: await authHeader(), "User-Agent": USER_AGENT },
         body: JSON.stringify({ state }),
       });
       if (!res.ok)
diff --git a/src/bw/token.ts b/src/bw/token.ts
index 0478287..980a0fc 100644
--- a/src/bw/token.ts
+++ b/src/bw/token.ts
@@ -1,3 +1,5 @@
+import { USER_AGENT } from "./user-agent.js";
+
 export interface TokenManagerOpts {
   clientId: string;
   clientSecret: string;
@@ -40,7 +42,11 @@ export class TokenManager {
     const basic = "Basic " + Buffer.from(`${this.opts.clientId}:${this.opts.clientSecret}`).toString("base64");
     const res = await this.fetchImpl(`${this.opts.apiHost}/api/v1/oauth2/token`, {
       method: "POST",
-      headers: { Authorization: basic, "Content-Type": "application/x-www-form-urlencoded" },
+      headers: {
+        Authorization: basic,
+        "Content-Type": "application/x-www-form-urlencoded",
+        "User-Agent": USER_AGENT,
+      },
       body: "grant_type=client_credentials",
     });
     if (!res.ok)
diff --git a/src/bw/user-agent.ts b/src/bw/user-agent.ts
new file mode 100644
index 0000000..5fd963d
--- /dev/null
+++ b/src/bw/user-agent.ts
@@ -0,0 +1,7 @@
+import pkg from "../../package.json" with { type: "json" };
+
+/**
+ * Client identifier sent on every outbound Bandwidth request so BW can
+ * attribute traffic to this adapter and version. Format: `bw-voice-adapter/<version>`.
+ */
+export const USER_AGENT = `bw-voice-adapter/${pkg.version}`;