From f575fb12adfacad5937389d381ede98b4909e4f8 Mon Sep 17 00:00:00 2001
From: Julian Boilen <julianboilen@gmail.com>
Date: Mon, 11 May 2026 17:28:39 -0400
Subject: [PATCH 1/2] Setup datadog llm observability to trace llm calls

---
 backend/appHandler.ts                |  2 ++
 backend/serverless.yml               |  1 +
 backend/src/business/ai/AiService.ts | 14 ++++++++++----
 backend/src/tracer.ts                | 10 ++++++++++
 backend/withSetup.ts                 |  1 +
 frontend/package-lock.json           |  3 +--
 6 files changed, 25 insertions(+), 6 deletions(-)
 create mode 100644 backend/src/tracer.ts

diff --git a/backend/appHandler.ts b/backend/appHandler.ts
index b23e4c6b6..b178b9cb3 100644
--- a/backend/appHandler.ts
+++ b/backend/appHandler.ts
@@ -1,3 +1,5 @@
+import './src/tracer';
+
 import 'reflect-metadata';
 import serverlessHttp from 'serverless-http';
 import 'source-map-support/register';
diff --git a/backend/serverless.yml b/backend/serverless.yml
index 2af722651..69353aadb 100644
--- a/backend/serverless.yml
+++ b/backend/serverless.yml
@@ -47,6 +47,7 @@ provider:
     OPENAI_SK: ${ssm:/${self:service}-${sls:stage}-openai-sk}
     RAPIDAPI_API_KEY: ${ssm:/${self:service}-${sls:stage}-rapidapi-api-key}
     PRINTFUL_SK: ${ssm:/${self:service}-${sls:stage}-printful-sk}
+    DD_LLMOBS_ML_APP: fourtiesnyc
 plugins:
   - serverless-plugin-conditional-functions
   - serverless-webpack
diff --git a/backend/src/business/ai/AiService.ts b/backend/src/business/ai/AiService.ts
index d2ee44c83..de16ec50c 100644
--- a/backend/src/business/ai/AiService.ts
+++ b/backend/src/business/ai/AiService.ts
@@ -1,3 +1,4 @@
+import tracer from 'dd-trace';
 import OpenAI from 'openai';
 import createStoryTitlePrompt from './createStoryTitlePrompt';
 
@@ -7,9 +8,14 @@ const openai = new OpenAI({
 });
 
 export async function suggestStoryTitle(storyContent: string): Promise<string> {
-  const response = await openai.chat.completions.create(
-    createStoryTitlePrompt(storyContent)
-  );
+  return tracer.llmobs.trace(
+    { kind: 'task', name: 'story-title-generation' },
+    async () => {
+      const response = await openai.chat.completions.create(
+        createStoryTitlePrompt(storyContent)
+      );
 
-  return response.choices[0].message.content?.trim() ?? '';
+      return response.choices[0].message.content?.trim() ?? '';
+    }
+  );
 }
diff --git a/backend/src/tracer.ts b/backend/src/tracer.ts
new file mode 100644
index 000000000..dafc4b057
--- /dev/null
+++ b/backend/src/tracer.ts
@@ -0,0 +1,10 @@
+import tracer from 'dd-trace';
+
+tracer.init({
+  llmobs: {
+    mlApp: process.env.DD_LLMOBS_ML_APP,
+    agentlessEnabled: true,
+  },
+});
+
+export default tracer;
diff --git a/backend/withSetup.ts b/backend/withSetup.ts
index 27df84238..866444c6b 100644
--- a/backend/withSetup.ts
+++ b/backend/withSetup.ts
@@ -1,3 +1,4 @@
+import './src/tracer';
 import 'reflect-metadata';
 
 import 'source-map-support/register';
diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index 29755b48e..f1a923ab8 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -15018,8 +15018,7 @@
     },
     "node_modules/tslib": {
       "version": "2.8.1",
-      "license": "0BSD",
-      "peer": true
+      "license": "0BSD"
     },
     "node_modules/tsyringe": {
       "version": "4.10.0",

From b759184409b546bb43cfbe25dee7e9d51326bc3d Mon Sep 17 00:00:00 2001
From: Julian Boilen <julianboilen@gmail.com>
Date: Mon, 11 May 2026 19:02:42 -0400
Subject: [PATCH 2/2] Limit dd-trace init to functions that have the Datadog
 layer

Putting the tracer import in withSetup caused functions excluded from the
Datadog plugin (like renderMerchPrintfiles) to fail with "Cannot find
module 'dd-trace'" on cold start.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---
 backend/generateStoryTitles.ts | 1 +
 backend/withSetup.ts           | 1 -
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/generateStoryTitles.ts b/backend/generateStoryTitles.ts
index c14466a93..3f525175d 100644
--- a/backend/generateStoryTitles.ts
+++ b/backend/generateStoryTitles.ts
@@ -1,3 +1,4 @@
+import './src/tracer';
 import generateStoryTitlesImpl from './src/cron/generateStoryTitles';
 
 import withSetup from './withSetup';
diff --git a/backend/withSetup.ts b/backend/withSetup.ts
index 866444c6b..27df84238 100644
--- a/backend/withSetup.ts
+++ b/backend/withSetup.ts
@@ -1,4 +1,3 @@
-import './src/tracer';
 import 'reflect-metadata';
 
 import 'source-map-support/register';