Add OTEL gen-ai message format for auto-instrumented message tracing (#231)

* Add OTEL gen-ai message format support for auto-instrumented input/output message tracing

- OpenAI extension: Auto-record structured InputMessages/OutputMessages on response, generation,
  and function spans via OpenAIAgentsTraceProcessor with isContentRecordingEnabled option
- LangChain extension: Auto-record structured InputMessages/OutputMessages on chat, invoke_agent,
  and execute_tool spans via LangChainTracer with isContentRecordingEnabled option
- LangChain v1 support: Fix setToolAttributes to handle plain string tool results (v1 format),
  fix tool_call_id extraction from inputs, fix setSystemInstructionsAttribute to use getMessageType()
  for all message formats, fix setTokenAttributes to check last message for usage_metadata,
  fix getModel to check v1 direct response_metadata path
- Add message-schema-validator test helper for validating OTEL gen-ai message contract
- Add LangChainMessageContract and OpenAIMessageContract test suites

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address code review findings (CRM-001 through CRM-013)

- CRM-001: Move GEN_AI_TOOL_TYPE_KEY setAttribute outside forEach loop
- CRM-002: Wrap string output/input fallbacks in versioned OTEL message envelope
- CRM-003: Support tokenUsage shape (promptTokens/completionTokens) in setTokenAttributes
- CRM-009: Remove unused getAttributesFromInput export
- CRM-010: Replace dead extractMessageContent with extractStringContent delegating to extractRawContent
- CRM-011: Fix self-referential comment
- CRM-006: Add direct v1 constructor format tests for input/output messages
- CRM-007: Add response span content-gating suppression test
- CRM-008: Add empty array and null entry edge case tests
- CRM-013: Add function_call, input_file, malformed JSON, and unknown block type tests
- Fix getMessageType to skip v1 'constructor' type and check id array for message class

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Remove isContentRecordingEnabled gating, remove truncateValue from extensions, align tool serialization

- Remove isContentRecordingEnabled toggle: content recording is now ON by default
  (aligned with Python/.NET SDKs). suppressInvokeAgentInput remains.
- Remove truncateValue from both extensions: truncation now happens at the
  span/exporter level in core, not pre-truncated in extensions.
- Use safeSerializeToJson for tool arguments/results in both extensions,
  matching the core ExecuteToolScope pattern from PR #228.
- Export safeSerializeToJson from core index.ts.
- Add tool argument validation tests for both OpenAI and LangChain extensions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address PR review: fix output fallback, input_image part type, stale JSDoc

- processResponseSpanData: add else fallback for non-array output via
  wrapRawContentAsOutputMessages (handles object output)
- mapInputContentBlock: map input_image to type 'blob' (matches BlobPart
  contract) instead of non-standard 'image'
- Remove stale @param options JSDoc from LangChainTraceInstrumentor.instrument

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Use MAX_SPAN_SIZE_BYTES constant for truncation, export from observability, add missing expect import

- Replace hardcoded 1024 with MAX_SPAN_SIZE_BYTES in OpenAI extensions Utils
- Export MAX_SPAN_SIZE_BYTES from observability package
- Add missing `import { expect } from '@jest/globals'` to test helper

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Peng Fan <pefan@microsoft.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people

packages/agents-a365-observability-extensions-langchain/src/LangChainTraceInstrumentor.ts

@@ -20,9 +20,8 @@ class LangChainTraceInstrumentorImpl extends InstrumentationBase<Instrumentation
   private _hasBeenEnabled = false;
   private _isPatched = false;
   protected otelTracer: Tracer;
-  private isContentRecordingEnabled: boolean;
 
-  private constructor(options?: { isContentRecordingEnabled?: boolean }) {
+  private constructor() {
     if (LangChainTraceInstrumentorImpl._instance !== null) {
       throw new Error("LangChainTraceInstrumentor can only be instantiated once.");
     }
@@ -42,15 +41,14 @@ class LangChainTraceInstrumentorImpl extends InstrumentationBase<Instrumentation
       "agent365-langchain",
       "1.0.0"
     );
-    this.isContentRecordingEnabled = options?.isContentRecordingEnabled ?? false;
 
     LangChainTraceInstrumentorImpl._instance = this;
     logger.info("[LangChainTraceInstrumentor] Initialized and automatically enabled");
   }
 
-  static getInstance(options?: { isContentRecordingEnabled?: boolean }): LangChainTraceInstrumentorImpl {
+  static getInstance(): LangChainTraceInstrumentorImpl {
     if (!LangChainTraceInstrumentorImpl._instance) {
-      LangChainTraceInstrumentorImpl._instance = new LangChainTraceInstrumentorImpl(options);
+      LangChainTraceInstrumentorImpl._instance = new LangChainTraceInstrumentorImpl();
     }
     return LangChainTraceInstrumentorImpl._instance;
   }
@@ -104,7 +102,7 @@ class LangChainTraceInstrumentorImpl extends InstrumentationBase<Instrumentation
         this: CallbackManagerModuleType,
         ...args: Parameters<typeof CallbackManager["_configureSync"]>
       ) {
-        args[0] = addTracerToHandlers(instrumentor.otelTracer, args[0], { isContentRecordingEnabled: instrumentor.isContentRecordingEnabled });
+        args[0] = addTracerToHandlers(instrumentor.otelTracer, args[0]);
         logger.info("[LangChainTraceInstrumentor] _configureSync wrapped to add LangChainTracer");
         return original.apply(this, args);
       };
@@ -154,10 +152,9 @@ export class LangChainTraceInstrumentor {
   /**
    * Initialize and auto-instrument for LangChain
    * @param module The CallbackManager module to instrument
-   * @param options Optional configuration options
    */
-  static instrument(module: CallbackManagerModuleType, options?: { isContentRecordingEnabled?: boolean }): void {
-    LangChainTraceInstrumentorImpl.getInstance(options).manuallyInstrumentImpl(module);
+  static instrument(module: CallbackManagerModuleType): void {
+    LangChainTraceInstrumentorImpl.getInstance().manuallyInstrumentImpl(module);
   }
 
   /**
@@ -191,21 +188,20 @@ export class LangChainTraceInstrumentor {
 export function addTracerToHandlers(
   tracer: Tracer,
   handlers: CallbackManagerModule.Callbacks | undefined,
-  options?: { isContentRecordingEnabled?: boolean }
 ): CallbackManagerModule.Callbacks {
   if (handlers == null) {
-    return [new LangChainTracer(tracer, options)];
+    return [new LangChainTracer(tracer)];
   }
 
   if (Array.isArray(handlers)) {
     if (!handlers.some((h) => h instanceof LangChainTracer)) {
-      handlers.push(new LangChainTracer(tracer, options));
+      handlers.push(new LangChainTracer(tracer));
     }
     return handlers;
   }
 
   if (!handlers.inheritableHandlers.some((h) => h instanceof LangChainTracer)) {
-    handlers.addHandler(new LangChainTracer(tracer, options), true);
+    handlers.addHandler(new LangChainTracer(tracer), true);
   }
   return handlers;
 }