include addresses, subject

packages/otel-resend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kubiks/otel-resend",
-  "version": "1.0.0",
+  "version": "1.0.2",
   "private": false,
   "publishConfig": {
     "access": "public"

packages/otel-resend/src/index.test.ts

@@ -16,6 +16,11 @@ import {
   SEMATTRS_RESEND_RESOURCE_ID,
   SEMATTRS_RESEND_TARGET,
   SEMATTRS_RESEND_TEMPLATE_ID,
+  SEMATTRS_RESEND_TO_ADDRESSES,
+  SEMATTRS_RESEND_CC_ADDRESSES,
+  SEMATTRS_RESEND_BCC_ADDRESSES,
+  SEMATTRS_RESEND_FROM,
+  SEMATTRS_RESEND_SUBJECT,
 } from "./index";
 
 describe("instrumentResend", () => {
@@ -72,7 +77,7 @@ describe("instrumentResend", () => {
     instrumentResend(resend);
 
     const payload = {
-      to: ["user@example.com", { email: "second@example.com" }],
+      to: ["user@example.com", "second@example.com"],
       template_id: "tmpl_123",
     };
 
@@ -96,6 +101,7 @@ describe("instrumentResend", () => {
     expect(span.attributes[SEMATTRS_RESEND_MESSAGE_COUNT]).toBe(1);
     expect(span.attributes[SEMATTRS_RESEND_RECIPIENT_COUNT]).toBe(2);
     expect(span.attributes[SEMATTRS_RESEND_TEMPLATE_ID]).toBe("tmpl_123");
+    expect(span.attributes[SEMATTRS_RESEND_TO_ADDRESSES]).toBe("user@example.com, second@example.com");
     expect(span.status.code).toBe(SpanStatusCode.OK);
   });
 
@@ -187,4 +193,90 @@ describe("instrumentResend", () => {
     const spans = exporter.getFinishedSpans();
     expect(spans).toHaveLength(0);
   });
+
+  it("captures email addresses from all recipient fields", async () => {
+    const resend = createMockResend();
+    instrumentResend(resend);
+
+    const payload = {
+      to: ["to1@example.com", "to2@example.com", "to3@example.com"],
+      cc: ["cc1@example.com", "cc2@example.com"],
+      bcc: "bcc@example.com",
+      subject: "Test Email",
+      from: "sender@example.com",
+      text: "Test content",
+    };
+
+    await resend.emails.send(payload);
+
+    const spans = exporter.getFinishedSpans();
+    expect(spans).toHaveLength(1);
+
+    const span = spans[0];
+    if (!span) {
+      throw new Error("Expected a span to be recorded");
+    }
+
+    expect(span.attributes[SEMATTRS_RESEND_RECIPIENT_COUNT]).toBe(6);
+    expect(span.attributes[SEMATTRS_RESEND_TO_ADDRESSES]).toBe("to1@example.com, to2@example.com, to3@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_CC_ADDRESSES]).toBe("cc1@example.com, cc2@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_BCC_ADDRESSES]).toBe("bcc@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_SUBJECT]).toBe("Test Email");
+    expect(span.attributes[SEMATTRS_RESEND_FROM]).toBe("sender@example.com");
+  });
+
+  it("handles missing recipient fields gracefully", async () => {
+    const resend = createMockResend();
+    instrumentResend(resend);
+
+    const payload = {
+      to: "single@example.com",
+    };
+
+    await resend.emails.send(payload);
+
+    const spans = exporter.getFinishedSpans();
+    expect(spans).toHaveLength(1);
+
+    const span = spans[0];
+    if (!span) {
+      throw new Error("Expected a span to be recorded");
+    }
+
+    expect(span.attributes[SEMATTRS_RESEND_RECIPIENT_COUNT]).toBe(1);
+    expect(span.attributes[SEMATTRS_RESEND_TO_ADDRESSES]).toBe("single@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_CC_ADDRESSES]).toBeUndefined();
+    expect(span.attributes[SEMATTRS_RESEND_BCC_ADDRESSES]).toBeUndefined();
+  });
+
+  it("handles mixed string and array formats correctly", async () => {
+    const resend = createMockResend();
+    instrumentResend(resend);
+
+    const payload = {
+      to: "single@example.com",
+      cc: ["cc1@example.com", "cc2@example.com"],
+      bcc: ["bcc1@example.com"],
+      from: "noreply@example.com",
+      subject: "Mixed Format Test",
+      text: "Test",
+    };
+
+    await resend.emails.send(payload);
+
+    const spans = exporter.getFinishedSpans();
+    expect(spans).toHaveLength(1);
+
+    const span = spans[0];
+    if (!span) {
+      throw new Error("Expected a span to be recorded");
+    }
+
+    expect(span.attributes[SEMATTRS_RESEND_TO_ADDRESSES]).toBe("single@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_CC_ADDRESSES]).toBe("cc1@example.com, cc2@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_BCC_ADDRESSES]).toBe("bcc1@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_RECIPIENT_COUNT]).toBe(4);
+    expect(span.attributes[SEMATTRS_RESEND_FROM]).toBe("noreply@example.com");
+    expect(span.attributes[SEMATTRS_RESEND_SUBJECT]).toBe("Mixed Format Test");
+  });
 });

packages/otel-resend/src/index.ts

@@ -6,6 +6,7 @@ import {
   type Span,
   type Tracer,
 } from "@opentelemetry/api";
+import type { CreateEmailOptions } from "resend";
 
 const DEFAULT_TRACER_NAME = "@kubiks/otel-resend";
 const INSTRUMENTED_FLAG = "__kubiksOtelResendInstrumented" as const;
@@ -22,6 +23,11 @@ export const SEMATTRS_RESEND_SEGMENT_ID = "resend.segment_id" as const;
 export const SEMATTRS_RESEND_AUDIENCE_ID = "resend.audience_id" as const;
 export const SEMATTRS_RESEND_RECIPIENT_COUNT = "resend.recipient_count" as const;
 export const SEMATTRS_RESEND_RESOURCE_ID = "resend.resource_id" as const;
+export const SEMATTRS_RESEND_TO_ADDRESSES = "resend.to_addresses" as const;
+export const SEMATTRS_RESEND_CC_ADDRESSES = "resend.cc_addresses" as const;
+export const SEMATTRS_RESEND_BCC_ADDRESSES = "resend.bcc_addresses" as const;
+export const SEMATTRS_RESEND_FROM = "resend.from" as const;
+export const SEMATTRS_RESEND_SUBJECT = "resend.subject" as const;
 
 export interface InstrumentResendConfig {
   tracerName?: string;
@@ -86,7 +92,7 @@ function buildBaseAttributes(
   return attributes;
 }
 
-function countRecipients(value: unknown): number {
+function countRecipients(value: string | string[] | undefined): number {
   if (!value) {
     return 0;
   }
@@ -94,30 +100,25 @@ function countRecipients(value: unknown): number {
     return value.trim() ? 1 : 0;
   }
   if (Array.isArray(value)) {
-    return value.reduce((count, item) => count + countRecipients(item), 0);
-  }
-  if (typeof value === "object") {
-    // Array-like or iterable structures
-    if (typeof (value as { length?: number }).length === "number") {
-      return (value as { length: number }).length;
-    }
-    if (Symbol.iterator in (value as object)) {
-      let count = 0;
-      for (const item of value as Iterable<unknown>) {
-        count += countRecipients(item);
-      }
-      return count;
-    }
-    if (
-      typeof (value as { email?: unknown }).email === "string" ||
-      typeof (value as { address?: unknown }).address === "string"
-    ) {
-      return 1;
-    }
+    return value.filter(email => typeof email === "string" && email.trim()).length;
   }
   return 0;
 }
 
+function extractEmailAddresses(value: string | string[] | undefined): string[] {
+  if (!value) {
+    return [];
+  }
+  if (typeof value === "string") {
+    const trimmed = value.trim();
+    return trimmed ? [trimmed] : [];
+  }
+  if (Array.isArray(value)) {
+    return value.filter(email => typeof email === "string" && email.trim()).map(email => email.trim());
+  }
+  return [];
+}
+
 function annotateRequest(
   span: Span,
   path: readonly string[],
@@ -133,14 +134,64 @@ function annotateRequest(
     return;
   }
 
-  const data = payload as Record<string, unknown>;
+  // Check if this is an email send operation
+  if (path[0] === "emails" || path[0] === "batch") {
+    // Try to cast to CreateEmailOptions for better type safety
+    const data = payload as Partial<CreateEmailOptions>;
 
-  const recipientCount =
-    countRecipients(data.to) + countRecipients(data.cc) + countRecipients(data.bcc);
-  if (recipientCount > 0) {
-    span.setAttribute(SEMATTRS_RESEND_RECIPIENT_COUNT, recipientCount);
+    // Extract and set email addresses using proper types
+    const toAddresses = extractEmailAddresses(data.to);
+    if (toAddresses.length > 0) {
+      span.setAttribute(SEMATTRS_RESEND_TO_ADDRESSES, toAddresses.join(", "));
+    }
+
+    const ccAddresses = extractEmailAddresses(data.cc);
+    if (ccAddresses.length > 0) {
+      span.setAttribute(SEMATTRS_RESEND_CC_ADDRESSES, ccAddresses.join(", "));
+    }
+
+    const bccAddresses = extractEmailAddresses(data.bcc);
+    if (bccAddresses.length > 0) {
+      span.setAttribute(SEMATTRS_RESEND_BCC_ADDRESSES, bccAddresses.join(", "));
+    }
+
+    // Count recipients
+    const recipientCount = toAddresses.length + ccAddresses.length + bccAddresses.length;
+    if (recipientCount > 0) {
+      span.setAttribute(SEMATTRS_RESEND_RECIPIENT_COUNT, recipientCount);
+    }
+
+    // Handle other email-specific attributes
+    if (data.subject) {
+      span.setAttribute(SEMATTRS_RESEND_SUBJECT, data.subject);
+    }
+
+    if (data.from) {
+      span.setAttribute(SEMATTRS_RESEND_FROM, data.from);
+    }
+  } else {
+    // For non-email operations, use generic handling
+    const data = payload as Record<string, unknown>;
+    
+    // Only count if the fields exist and are the right type
+    let recipientCount = 0;
+    if (typeof data.to === "string" || Array.isArray(data.to)) {
+      recipientCount += countRecipients(data.to as string | string[]);
+    }
+    if (typeof data.cc === "string" || Array.isArray(data.cc)) {
+      recipientCount += countRecipients(data.cc as string | string[]);
+    }
+    if (typeof data.bcc === "string" || Array.isArray(data.bcc)) {
+      recipientCount += countRecipients(data.bcc as string | string[]);
+    }
+    if (recipientCount > 0) {
+      span.setAttribute(SEMATTRS_RESEND_RECIPIENT_COUNT, recipientCount);
+    }
   }
 
+  // Handle generic attributes that apply to all operations
+  const data = payload as Record<string, unknown>;
+  
   const templateId =
     (typeof data.template_id === "string" && data.template_id) ||
     (typeof data.templateId === "string" && data.templateId) ||