Comparison
Nexus vs Sentry for AI Agent Observability
Sentry is a powerful general-purpose APM and error tracking platform that added LLM monitoring features in 2024. Nexus is purpose-built for AI agent observability. Here's when each tool is the right fit.
TL;DR
Choose Nexus if you…
- ✓ Your product IS an AI agent — not just a feature
- ✓ Need per-agent health cards, handoff tracing, and cost tracking
- ✓ Want webhook and email alerts when agent error rates spike
- ✓ Need a simple $9/mo flat price with no per-event charges
Choose Sentry if you…
- ✓ Need general APM, error tracking, and session replay
- ✓ Already use Sentry for your web/mobile app
- ✓ Want LLM monitoring alongside broader application monitoring
- ✓ Need wide language and framework support beyond Python
Feature Comparison
| Feature | Nexus | Sentry |
|---|---|---|
| Primary focus | AI agent runtime observability | General APM + error tracking |
| LLM / AI agent tracing | ✓ Agent-first — span waterfall, handoff tracing | Add-on — LLM monitoring module, not native |
| Per-agent health dashboard | ✓ Error rates, 7d trends, per-agent view | No agent-level health cards |
| Error monitoring (non-AI) | ✗ Not built-in | ✓ Core feature — stack traces, issue grouping |
| Session replay | ✗ Not supported | ✓ Full session replay for web apps |
| Token cost tracking | ✓ Per-trace and per-agent cost visibility | Limited — not a first-class feature |
| Webhook / email alerts | ✓ Included on Pro plan | ✓ Available — alerting is a Sentry strength |
| Multi-framework AI support | ✓ LangChain, CrewAI, AG2, LangGraph, more | OpenAI, Anthropic focused via AI module |
| Pricing | Free tier + $9/mo flat (Pro) | Free tier + $26/mo+ (event-volume based) |
| Setup for agent tracing | 5 min — one API call to start tracing | Longer — requires Sentry SDK + AI module setup |
The honest take
Sentry is genuinely excellent at what it was built for: capturing exceptions, grouping issues, replaying sessions, and alerting on error spikes. If you're building a traditional web or mobile application that also happens to call an LLM, Sentry's AI monitoring add-on is a reasonable choice — you get LLM traces alongside the rest of your application observability in one place.
Nexus is built for a different scenario: when the AI agent IS the product. Multi-agent pipelines with handoffs, tool calls, retry loops, and cost tracking require a data model that starts with agents, not exceptions. Sentry's LLM monitoring is a module bolted onto a general APM foundation — the UI and mental model are optimized for traditional software errors, not agent spans.
On pricing: Sentry's free tier is generous but their paid plans scale by event volume, which can surprise teams with high-throughput agent pipelines. Nexus is $9/mo flat with no per-event charges — a predictable cost for teams instrumenting production agents.
The right call: if you're already a Sentry shop and want to add lightweight LLM visibility, stick with Sentry. If observability for your AI agents is a core requirement — not an afterthought — Nexus gives you an agent-first data model from day one.
Try Nexus free
Agent-first observability. Free tier, no credit card required. Works with LangChain, CrewAI, LangGraph, AG2, and more.