Comparison
Nexus vs Helicone
Helicone is an AI gateway that captures LLM calls automatically by routing requests through a proxy. Here's an honest look at when Nexus makes more sense — and when Helicone is the better fit.
TL;DR
Choose Nexus if you…
- ✓ Build multi-step agents with custom logic between LLM calls
- ✓ Need full trace/span visibility into agent workflows
- ✓ Use TypeScript agents or non-OpenAI/Anthropic models
- ✓ Don't want to route production traffic through a third-party proxy
- ✓ Want $9/mo flat rate (not $120/mo for team features)
Choose Helicone if you…
- ✓ Want zero-instrumentation LLM call logging via proxy
- ✓ Need built-in caching, rate limiting, or prompt management
- ✓ Are primarily making direct OpenAI/Anthropic API calls
- ✓ Need team collaboration features at scale
- ✓ Want LLM cost tracking per user or request
The fundamental difference: proxy vs instrumentation
Helicone works as a proxy: you change your OpenAI base URL from
api.openai.com to
oai.helicone.ai and every LLM call
is automatically captured. No SDK, no code changes beyond a one-line config edit.
Nexus works via instrumentation: you wrap your agent logic with the Nexus SDK to capture traces (entire agent runs) and spans (individual steps — LLM calls, tool use, retrieval). This means more setup, but you get visibility into the full agent workflow — not just raw LLM calls.
If your "agent" is mostly a single LLM call with a system prompt, Helicone's proxy model is simpler. If you're building multi-step agents where you need to understand what happened between calls, Nexus's trace/span model gives you the full picture.
Pricing
| Plan | Nexus | Helicone |
|---|---|---|
| Free | $0 · 1K traces/mo · 1 agent | $0 · 10K requests/mo |
| Pro / Growth | $9/mo · 50K traces · unlimited agents | $120/mo · 2M requests/mo |
| Enterprise | — | Custom pricing |
Helicone pricing as of 2026. Nexus counts agent traces (full runs); Helicone counts individual LLM API requests — these are not equivalent units.
Feature comparison
| Feature | Nexus | Helicone |
|---|---|---|
| Agent trace & span model | ✓ | — |
| Zero-code LLM call capture | — | ✓ (proxy) |
| TypeScript SDK | ✓ open-source | ✓ (proxy wrapper) |
| Python SDK | ✓ open-source | ✓ (proxy wrapper) |
| Multi-step agent visibility | ✓ full waterfall | Partial (per-request) |
| LLM cost tracking | — | ✓ |
| Request caching | — | ✓ |
| Rate limiting | — | ✓ |
| Prompt management | — | ✓ |
| Email alerts on failure | ✓ (Pro) | ✓ |
| Self-hosted option | — | ✓ (open-source) |
| Cloudflare edge (global CDN) | ✓ | — |
| Open-source server | — | ✓ |
| Multi-agent dashboard | ✓ | Partial |
| Setup time | < 2 min | < 1 min (proxy change) |
The honest take
Helicone is genuinely excellent for its use case: if you're building applications that make direct OpenAI or Anthropic API calls and you want logging, caching, and rate limiting without touching your application code, the proxy model is hard to beat. One line change to your base URL and you have full request/response logging.
The proxy model has real tradeoffs. Your production LLM traffic routes through Helicone's servers — that's an extra network hop and a dependency on their availability. For most teams this is fine, but it's worth considering. There's also a mental model gap: Helicone shows you individual requests, not agent runs. When a complex agent makes 12 LLM calls, you see 12 separate entries rather than one trace with 12 spans.
Nexus is built for the agent workflow problem specifically. If you're debugging "why did my agent fail on step 3?" you want traces with spans in waterfall order, not a list of raw API calls. The instrumentation overhead is 3–5 lines of SDK code, but you get the full agent timeline in return.
The pricing difference is significant for indie developers: $9/mo vs $120/mo at the first paid tier. Helicone's free tier is generous (10K requests/mo) but the paid jump is steep for individual developers.
Related
- All AI agent monitoring alternatives — compare every tool side by side
- LangChain observability guide — instrument chains with Nexus
- Nexus pricing — free plan or $9/mo Pro
Try Nexus free — no credit card needed
1,000 traces/month free. Drop in 3 lines of code and see your first trace in under a minute.