Respan

LLM engineering platform with routing, observability and automated evals

About Respan

Respan, formerly Keywords AI, is an LLM engineering platform for developers and product teams building AI applications. It routes every model call through one API to more than a thousand models with fallbacks, caching and spend limits, traces each request, tool run and agent turn with cost and latency, monitors production traffic with alerts, and scores outputs with automated evaluators so quality regressions surface before users notice them.

Respan website preview

Live preview of respan.ai via the WordPress mShots service — it can take a few seconds to generate on a first visit.

Respan: strengths & things to check

Strengths

Free tier available — you can start without paying (freemium model).
Covers llm ops, observability, ai gateway, evals — see the focus areas listed in its key facts.
Has 6 close alternatives in the same category on this page, so switching or comparing is easy.

Things to check

The full feature set sits behind a paid plan — check which limits the free tier carries on the official site before committing.
Current plan prices are not listed here (they change too often to print reliably) — confirm the exact price on the official site.
It is one of 1164 tools in the Developer Tools category here — compare it against the alternatives below before you commit.

Derived from this listing's own data (pricing model, focus areas and category) — not a hands-on review score.

Respan pricing

Pricing model	Freemium — a free tier lets you start, and paid plans are available if you need more.
Free access	Yes — free tier, paid upgrades available
Current plan prices	Listed on the official site — prices change, so this directory links out instead of printing a number that may already be stale.
Official site	respan.ai

Respan key facts

Category: Developer Tools
Pricing: Freemium — a free tier lets you start, and paid plans are available if you need more.
Focus areas: llm ops, observability, ai gateway, evals
Official site: respan.ai

Respan FAQ

How much does Respan cost?

Freemium — a free tier lets you start, and paid plans are available if you need more. Current plans and prices are listed on the official site (respan.ai).

What is Respan used for?

LLM engineering platform with routing, observability and automated evals Its focus areas in the Developer Tools category: llm ops, observability, ai gateway, evals.

Where can I try Respan?

On its official site, respan.ai — the Visit Official Site button above goes straight there.

Respan vs alternatives

	Respan	Confident AI	Datadog	Ferron
Pricing	Freemium — a free tier lets you start, and paid plans are available if you need more.	Freemium — a free tier lets you start, and paid plans are available if you need more.	Freemium — a free tier lets you start, and paid plans are available if you need more.	Free — listed in this directory as a free tool, with no paid plan required to use it.
Focus areas	llm ops, observability, ai gateway, evals	llm evaluation, observability, testing, ai quality	monitoring, observability, apm, logging	web server, rust, observability, open source
Official site	respan.ai	confident-ai.com	datadoghq.com	ferron.sh
Directory status	Listed	Listed	Listed	Listed

Side-by-side from each listing's own directory data. Full alternative cards are below.

About the Developer Tools category

Editors, platforms, and services developers rely on to build and ship software. The Developer Tools category on Tools Hub currently lists 1164 tools. Alongside Respan, it includes REDAXO, Code to Flow, GitProxy, Rosebud AI.

FreemiumDeveloper Toolsllm-opsobservabilityai-gatewayevals

Alternatives to Respan

Tools in the same Developer Tools category that share focus areas with Respan — worth comparing before you commit:

Developer Tools

Confident AI

LLM evaluation and observability platform behind the DeepEval framework

Freemiumllm-evaluationobservabilitytestingai-quality

Developer Tools

Datadog

Full-stack observability and security monitoring platform

Freemiummonitoringobservabilityapmlogging

Developer Tools

Ferron

A fast, memory-safe web server in Rust, built for production debugging.

Freeweb-serverrustobservabilityopen-source

Developer Tools

GoModel

Open-Source AI Gateway with Workflows, Aliases, and Usage Tracking

Freeai-gatewayllmopen-sourceself-hosted

Developer Tools

Grafana

Open dashboards and visualization for observability

Freemiumdashboardsobservabilityvisualizationopen-source

Developer Tools

Kiln AI

Build, evaluate, and optimize AI systems with evals and fine-tuning.

Freemiumllmevalsfine-tuningopen-source

More in Developer Tools

Comparing tools in the Developer Tools category? These related listings are worth a look: REDAXO — Simple, flexible, open-source content management system in PHP; Code to Flow — Turn code into interactive flowcharts with AI-powered analysis; GitProxy — Deploy custom push protections and policies on top of Git.