Route, observe, and evaluate
every LLM callevaluate
every LLM call

One API for every model

Send every request to one endpoint, reach 1,000+ models across every major provider, and switch between them by changing a single word.

One model fails, the next takes over

List the models to fall back to, and Respan moves to the next the moment one errors or rate-limits, so an outage never takes you down.

Repeat requests served from cache

Cache a request and its response, then serve the same call again instantly, cutting the cost and latency of every repeat to nothing.

Budgets and limits at every scope

Set budgets and rate limits per key, per customer, or org-wide, get warned as you near them, and block requests before spend runs away.

Every way to grade an output, in one evaluator

An LLM judge, a deterministic code check, or a human reviewer, composed into one evaluator that turns any output into a single score.

Test cases sampled straight from production

Pull real requests from your logs by filter and sampling rate, or upload a CSV, so every case is one your users actually sent.

See which version scores better, before you ship

Run a prompt or model against the dataset, then compare their score distributions side by side, so you ship the change that measurably wins.

The same evaluator, now scoring live traffic

Deploy an evaluator on production spans, filtered by status, customer, or thread and sampled to control cost, so regressions surface in real time.

An alert the instant a metric crosses its limit

Watch cost, errors, latency, or tokens over any window, and the alert reaches Slack, email, or a webhook the moment it breaches.

Every metric on one dashboard

Requests, errors, cost, latency, and tokens across all your traffic, sliced by model, key, or user, so a spike is easy to spot.

Every step of a request, in one trace

LLM calls, tool runs, retrievals, and agent turns each become a span in one trace, showing exactly where a run's time and cost go.

Any span, down to the last field

Model, latency, cost, tokens, and the exact input and output sit on every span, showing precisely what each step ran and returned.