From ab04e7a80b3aa7d669786d469ba256d009a195e6 Mon Sep 17 00:00:00 2001
From: James Sumners <jsumners@newrelic.com>
Date: Wed, 31 Jan 2024 14:21:10 -0500
Subject: [PATCH] feat: Add feature flag for LangChain instrumentation (#1990)

---
 documentation/feature-flags.md | 6 ++++++
 lib/feature_flags.js           | 3 ++-
 test/unit/feature_flag.test.js | 3 ++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/documentation/feature-flags.md b/documentation/feature-flags.md
index 099b36bcd..c5b6f99f7 100644
--- a/documentation/feature-flags.md
+++ b/documentation/feature-flags.md
@@ -44,3 +44,9 @@ Any prerelease flags can be enabled or disabled in your agent config by adding a
 * Configuration: `{ feature_flag: { aws_bedrock_instrumentation: true|false }}`
 * Environment Variable: `NEW_RELIC_FEATURE_FLAG_AWS_BEDROCK_INSTRUMENTATION`
 * Description: Enables instrumentation of AWS Bedrock in `aws-sdk@3`. 
+
+#### langchain_instrumentation
+* Enabled by default: `false`
+* Configuration: `{ feature_flag: { langchain_instrumentation: true|false }}`
+* Environment Variable: `NEW_RELIC_FEATURE_FLAG_LANGCHAIN_INSTRUMENTATION`
+* Description: Enables instrumentation of the LangChain LLM library.
diff --git a/lib/feature_flags.js b/lib/feature_flags.js
index 72446a233..ff72d7348 100644
--- a/lib/feature_flags.js
+++ b/lib/feature_flags.js
@@ -12,7 +12,8 @@ exports.prerelease = {
   reverse_naming_rules: false,
   undici_async_tracking: true,
   unresolved_promise_cleanup: true,
-  legacy_context_manager: false
+  legacy_context_manager: false,
+  langchain_instrumentation: false
 }
 
 // flags that are no longer used for released features
diff --git a/test/unit/feature_flag.test.js b/test/unit/feature_flag.test.js
index a73b9a674..890f1f076 100644
--- a/test/unit/feature_flag.test.js
+++ b/test/unit/feature_flag.test.js
@@ -35,7 +35,8 @@ const used = [
   'unresolved_promise_cleanup',
   'undici_instrumentation',
   'undici_async_tracking',
-  'aws_bedrock_instrumentation'
+  'aws_bedrock_instrumentation',
+  'langchain_instrumentation'
 ]
 
 tap.test('feature flags', (t) => {