Respan Review (2026): Pricing, Features & Honest Verdict

TLDR

Respan, formerly Keywords AI, is an AI gateway and LLM observability platform. One OpenAI-compatible endpoint routes calls to 500+ models, with tracing, caching, spend controls, and evaluations layered on top. It is a solid all-in-one, though open-source rivals route for free if you self-host. Best for: AI engineers scaling LLM apps. Price: free, Team $199/mo. Rating: 6.9/10.

What is Respan?

Respan is an LLM engineering platform that lets developers route, observe, and evaluate every model call from one place. The gateway sits in front of your providers: you send OpenAI-style API calls to a single endpoint, and Respan forwards them to any of 500+ models with fallback logic, load balancing, prompt caching, and per-key spend limits. On top of that it captures detailed traces of each call, with latency, logs, and usage dashboards you can slice by model, user, or API key. A third layer handles evaluations, combining rule checks, LLM judges, and human review across both production traffic and test datasets.

The product was previously called Keywords AI and rebranded to Respan. It is aimed at AI engineers, product teams, and founders who have moved past a prototype and now need cost control, debugging, and quality assurance for LLM features in production. Named customers include Retell AI, Mem0, and Lovable, which span voice agents, memory systems, and AI dev tools. The pitch is that you get gateway, observability, and evals in one platform instead of stitching three separate tools together.

What Are Respan’s Key Features?

Unified gateway to 500+ models

The headline feature is the gateway. You point your OpenAI-format calls at a single Respan endpoint and reach 500+ models behind it, across providers like OpenAI, Anthropic, Google, and the open-source field. It handles automatic fallbacks when a model errors or hits a rate limit, so a provider outage does not take your app down. It load balances across providers and caches prompts to cut repeated costs on identical requests. This is the piece that removes the busywork of managing many provider SDKs, keys, and rate limits yourself, and it is the reason most teams adopt a gateway in the first place.

Observability and tracing

Respan captures a trace of every LLM interaction, with latency metrics, full request and response logs, token usage dashboards, and real-time monitoring. You can session-thread related calls so a multi-step agent run reads as one connected trace rather than scattered logs, and filter everything by model, user, or API key. For debugging a flaky agent or tracking which feature is burning tokens and money, this is the most useful part of the platform day to day, and it is the half that the bare open-source gateways tend not to give you out of the box.

Evaluations

The evals layer lets you compose workflows that mix deterministic rule checks, LLM-as-judge scoring, and human review. You can run these online against a sample of live production traffic, so quality regressions surface as they happen, or offline against experimental datasets before you ship a prompt change. That covers both pre-launch quality testing and ongoing monitoring of how a deployed model behaves, which most pure gateways do not include and which teams otherwise build themselves with a pile of scripts.

Spend controls and compliance

You set per-API-key spend limits with alerts, which is a practical guard against a runaway loop or a leaked key draining your budget overnight. Because keys are virtualized through the gateway, you can also rotate or revoke them without touching application code. On compliance, Respan holds SOC 2, GDPR, HIPAA, and ISO 27001, with a HIPAA BAA available on request. That is a stronger posture than most early-stage tools in this space and genuinely matters if you are shipping into healthcare, finance, or other regulated industries where the certifications gate procurement.

How Much Does Respan Cost?

Respan starts free. The Pro tier costs $0/mo with no credit card and includes 100k logs, 1k scores, 5 datasets, 2 evaluators, 5 prompts, and full gateway access. That is generous enough to run a small app in production, not just kick the tires. The Team plan is $199/mo, with a 17% discount billed yearly, and unlocks unlimited datasets, evaluators, and prompts, plus a private Slack channel and access to the SOC 2 report. Enterprise is custom-priced and adds volume discounts, custom SLAs, a dedicated support engineer, and the HIPAA BAA.

Compared with the field, Respan’s free tier is a genuine strength. Portkey, a managed gateway with guardrails, starts at $49/mo, so there is no free middle ground there. OpenRouter takes a 5% markup on every request instead of a subscription. The open-source options change the math entirely: LiteLLM is free to self-host, and Helicone is open-source too, though its cloud is now in maintenance mode after being acquired. So Respan’s paid value is the bundled observability and managed convenience, not the routing alone.

Watch the overages. Once you pass the free limits, extra usage costs $8 per additional 100k logs and $1 per additional 1k scores, and HIPAA on the lower tiers is a $249/mo add-on. At scale those line items add up, so model your real volume before committing. A high-traffic app can blow through 100k logs quickly, and the per-log charge means your bill tracks usage rather than sitting flat, which is worth a forecast against your expected request volume.

The honest way to frame the value is by what you would otherwise build. Respan’s $199/mo Team plan replaces a self-built stack of a gateway, a logging pipeline, and an evals harness, plus the engineering hours to maintain all three. For a small team that is a clear win. For a team with a platform engineer who can stand up LiteLLM and a logging tool in a week, the math flips, and the subscription buys convenience rather than capability you could not get otherwise.

Who is Respan Best For?

Use Respan if you are an AI engineer or small product team that wants one endpoint to route across many models, plus tracing and evals, without building that plumbing yourself. The free Pro tier makes it easy to start, and the all-in-one design saves you from wiring up a separate gateway, logger, and eval tool. The compliance certifications also make it a reasonable pick for teams shipping into regulated spaces.

Skip Respan if you have the engineering capacity to self-host and want to avoid per-log pricing. LiteLLM gives you the same multi-model routing for free if you run it yourself, and you can pair it with your own logging stack. The catch is that self-hosting means you own the uptime, scaling, and upkeep, so the real question is whether your team’s time is better spent there or on your product. Also skip Respan if your needs are tiny and stable: if you call one model through one provider and rarely change, a single SDK is all you need, and a gateway adds a hop and a bill for no benefit.

Best Respan Alternatives

LiteLLM

LiteLLM is the open-source default. It translates OpenAI-format calls to 100+ providers and is free to self-host, with spend tracking, rate limiting, and team management built in. It is the strongest choice if you have the technical capacity to run your own gateway and want zero subscription cost. The tradeoff is setup and maintenance, where Respan’s managed service does the work for you.

Helicone

Helicone is an open-source LLM observability and proxy tool that adds logging, cost tracking, caching, and analytics with a single line of code. It overlaps heavily with Respan’s observability layer. The caveat in 2026 is that its cloud service moved to maintenance mode after an acquisition, so active feature development has slowed, though self-hosting remains an option.

Portkey

Portkey is a managed gateway closest in spirit to Respan, with observability, guardrails, access controls, and virtual keys for managing usage across teams. It starts at $49/mo, so it is cheaper to enter at a paid tier than Respan’s $199/mo Team plan, but it lacks Respan’s free tier. It is worth comparing directly if guardrails and team key management are your priority.

Final Verdict: Is Respan Worth It?

Respan does a real job well: it combines an LLM gateway, observability, and evaluations into one platform with a free tier that is actually usable in production. For an AI team that wants to stop juggling provider SDKs and bolt-on logging, that bundling has clear value, and the compliance certifications are a bonus most small tools lack. The 6.9 rating reflects a capable, well-built product.

It lands at 6.9 rather than higher because the space is crowded and the economics are not always in Respan’s favor. LiteLLM does the routing for free if you can self-host, the leap from free to a $199/mo Team plan is large, and per-log overages add up at scale. We would recommend Respan to teams that value managed convenience and the integrated evals, and steer self-sufficient engineering teams toward the open-source path first.