Prune vs Helicone — when to use each
Great logging tells you what already happened. It doesn't stop the next request from leaking data or blowing the budget.
Quick answer
Helicone is an observability-first proxy: logs, traces, cost dashboards, and caching layered onto your LLM calls. Prune is a control plane — the same visibility, plus PII/injection enforcement and hard spend caps applied before the request reaches the provider, and a signed receipt as evidence, not just a chart.
Side-by-side
| Dimension | Helicone | Prune |
|---|---|---|
| Primary value | Logs, traces, cost dashboards | Enforcement before the call + unique-path savings |
| PII / secrets | Visible in logs unless you scrub upstream | Default-on tokenize/redact before the provider sees it |
| Prompt injection | Not a built-in gateway concern | Audit or enforce, per key |
| Spend | Dashboards + rate limiting | Hard stop — Spend caps enforced in under 10ms, before the provider call |
| Proof | Exportable logs | Ed25519-signed prune_metadata — verify at /verify |
Observability answers a different question
Helicone tells you what happened: which prompts ran, what they cost, how long they took. That's valuable for debugging and for building your own alerting on top. It does not, by default, stop a request that contains a customer's SSN or an injected instruction from reaching the model — it logs it afterward.
Prune answers is this request safe and affordable, before it leaves: PII is tokenized or redacted pre-flight, injection signatures are audited or blocked, and a spend cap can reject the call outright — all in the same request path, not a separate logging pipeline you build alerts on top of.
Cost visibility vs cost control
A cost dashboard shows you the bill after the fact. Prune's unique-path savings (routing, output caps, compression) act on every call — including ones that never repeat — and the same numbers land on a per-response, cryptographically signed receipt, so the “what did this cost” answer is provable, not just logged.
When Helicone is the right choice
- Your main need is request-level tracing and debugging
- You already have your own security/policy layer upstream
- You want an open-source-friendly logging proxy you can self-host
When Prune is the right choice
- You need PII/injection stopped before the provider, not logged after
- A budget alert isn't enough — you need a hard spend stop
- Most requests are unique, so cache-driven savings alone won't move the bill (≥25% median cost reduction on unique (non-cache) traffic in the published benchmark suite)
- Finance or an auditor needs a signed record, not a log export