@posthog/ai crashes without @opentelemetry/exporter-trace-otlp-http despite it being marked optional

[muhammadolim]

Bug description

@posthog/ai declares @opentelemetry/exporter-trace-otlp-http as an optional peer dependency in peerDependenciesMeta, but the main entry point unconditionally requires it:

CJS (dist/index.cjs, line 6):

var exporterTraceOtlpHttp = require('@opentelemetry/exporter-trace-otlp-http');

ESM (dist/index.mjs, line 5):

import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';

This causes a MODULE_NOT_FOUND crash at import time for any consumer that doesn't install the OpenTelemetry package — even if they only use withTracing or LangChainCallbackHandler, which have nothing to do with OpenTelemetry.

Steps to reproduce

1. Install @posthog/ai without @opentelemetry/exporter-trace-otlp-http
2. Import anything from the package:

   import { withTracing } from '@posthog/ai';

3. Application crashes:

   Error: Cannot find module '@opentelemetry/exporter-trace-otlp-http'
   

Root cause

PostHogTraceExporter (which extends OTLPTraceExporter) is bundled into the main dist/index.cjs and dist/index.mjs entry points. Because it extends the OTel base class, the import must resolve at module load time — making the "optional" declaration in peerDependenciesMeta ineffective at runtime.

The sub-entry point @posthog/ai/otel already exists and correctly isolates this dependency. The issue is that the main entry point re-exports it as well.

Suggested fix

Any of these would work:

1. Remove PostHogTraceExporter from the main entry point — keep it only in @posthog/ai/otel (least invasive)
2. Lazy-load the dependency inside PostHogTraceExporter's constructor via dynamic require()
3. Wrap the top-level require in try/catch and throw a descriptive error only when PostHogTraceExporter is actually instantiated

Environment

• @posthog/ai: 7.12.0
• Node.js: v22.22.0
• Package manager: Yarn 1.22.22

[rustammdev]

Can confirm this issue. We hit the same MODULE_NOT_FOUND crash in our NestJS backend after npm install resolved @posthog/ai to 7.12.0 via the ^7.11.2 range.

We only use withTracing and LangChainCallbackHandler from the main entry point — nothing related to OpenTelemetry. The unconditional top-level import of @opentelemetry/exporter-trace-otlp-http in dist/index.cjs broke our app at startup.

Workaround: We pinned @posthog/ai to 7.11.2 (removed the ^ caret) until this is fixed upstream.

Would be great to see option 1 from the suggested fixes — removing PostHogTraceExporter from the main entry point and keeping it only in @posthog/ai/otel.