Respan Review 2026: LLM Gateway, Observability, Evals, and Pricing

Route, trace, evaluate, and monitor model and agent traffic through one engineering platform

Checked this monthResearch BasedFreemiumCodeData AnalysisAutomation
Recently Updated

Who should use this?

Teams operating multiple model providers and Developers debugging production AI agents.

Who should avoid it?

Workloads that cannot send traces through a third party, Teams needing an evaluator to act as ground truth

What problem does it solve?

Respan, formerly Keywords AI, combines a multi-model gateway with tracing, cost monitoring, prompt management, datasets, evaluations, alerts, and production controls.

Would I recommend it?

Respan earns a pilot for teams whose model traffic, evaluations, and prompts have outgrown separate dashboards and scripts. Use the free tier to prove trace quality and incident-time savings, keep a tested provider bypass, exclude sensitive fields by default, and grant production evaluators authority only after measuring false positives and false negatives.

Advisor score

8.2/10

Premium review framework

Visit Respan

Respan, formerly Keywords AI, combines a multi-model gateway with tracing, cost monitoring, prompt management, datasets, evaluations, alerts, and production controls.

Direct verdict

Respan earns a pilot for teams whose model traffic, evaluations, and prompts have outgrown separate dashboards and scripts. Use the free tier to prove trace quality and incident-time savings, keep a tested provider bypass, exclude sensitive fields by default, and grant production evaluators authority only after measuring false positives and false negatives.

What to verify

Mirror five percent of sanitized production traffic for two weeks, then route a reversible workload through Respan with direct-provider bypass available. Compare trace completeness, evaluator agreement with 300 expert labels, fallback correctness, cache safety, p50 and p95 latency, gateway and provider errors, cost attribution, PII masking, export quality, and recovery during an injected outage. Calculate platform cost per investigated failure and per accepted output.

Personal Recommendation

Respan earns a pilot for teams whose model traffic, evaluations, and prompts have outgrown separate dashboards and scripts. Use the free tier to prove trace quality and incident-time savings, keep a tested provider bypass, exclude sensitive fields by default, and grant production evaluators authority only after measuring false positives and false negatives.

Try the recommendation

See whether Respan belongs in your stack

Gateway, traces, evaluations, and prompts in one platform

Overall Score

8.2/10
Research Based
Last reviewed
Sep 9, 2026
Last updated
Sep 9, 2026

Editorial Review Framework

How Respan scores

Recently Updated

Who should use this?

Teams operating multiple model providers, Developers debugging production AI agents, Organizations unifying gateway, prompts, evals, and spend.

Who should avoid it?

Workloads that cannot send traces through a third party, Teams needing an evaluator to act as ground truth

What problem does it solve?

Respan, formerly Keywords AI, combines a multi-model gateway with tracing, cost monitoring, prompt management, datasets, evaluations, alerts, and production controls.

Would I recommend it?

Respan earns a pilot for teams whose model traffic, evaluations, and prompts have outgrown separate dashboards and scripts. Use the free tier to prove trace quality and incident-time savings, keep a tested provider bypass, exclude sensitive fields by default, and grant production evaluators authority only after measuring false positives and false negatives.

Overall Score

8.2

Ease of Use

8.0

AI Quality

8.2

Features

8.6

Speed

8.0

Integrations

8.4

Value for Money

8.0

Customer Support

7.6

Learning Curve

7.4

Recommended For

  • Teams operating multiple model providers
  • Developers debugging production AI agents
  • Organizations unifying gateway, prompts, evals, and spend

Not Recommended For

  • Workloads that cannot send traces through a third party
  • Teams needing an evaluator to act as ground truth
  • Simple low-volume prototypes with no operations burden

Recommended Because…

Gateway, traces, evaluations, and prompts in one platform

Scores use a 0-10 editorial scale. The source data is maintained as 5-point review dimensions, then normalized for reader-friendly comparison.

Reusable trial worksheet

Test Respan before you commit

Turn this review’s buyer test into evidence. Your entries autosave only in this browser and are never added to shared shortlist links.

0/7 checks complete
  1. Confirm the tool meets every must-have workflow and stakeholder requirement.

    Review starting point: Teams operating multiple model providers; Developers debugging production AI agents; Organizations unifying gateway, prompts, evals, and spend

  2. Run the same representative work you would use in production; do not score a polished demo.

    Review starting point: Complete three to five representative tasks with known acceptable outcomes and compare them with your current process.

  3. Calculate the effective cost per accepted result, including usage, review, corrections, and required add-ons.

    Review starting point: Respan lists a $0 Free plan with 100,000 logs, 1,000 scores, five datasets, two evaluators, five prompts, seven-day retention, and one workspace. Team is $199 per month when billed annually and adds unlimited datasets, evaluators, and prompts, 30-day retention, five members, and private Slack support. Extra usage is listed at $8 per 100,000 logs and $1 per…

  4. Define an acceptance threshold, test known answers and edge cases, and record every correction.

    Review starting point: Editorial quality signals: features 4.3/5; AI quality 4.1/5. Validate these signals in your own work.

  5. Verify what data enters the product, who can access it, how long it is retained, and whether it trains models.

    Review starting point: Use approved low-risk data first. Check roles, consent, deletion, subprocessors, model-training settings, and the contract—not only the marketing page.

  6. Test the real handoffs, permissions, failure states, and export path your team depends on.

    Review starting point: OpenAI SDK, Vercel AI SDK, LangChain, LlamaIndex, Mastra, OpenTelemetry

  7. Record training, governance, reliability, accessibility, ownership, and change-management risks before rollout.

    Review starting point: Creates a central traffic and telemetry dependency; Team price requires annual billing; Judges and fallbacks need independent validation

Open Decision Workspace

Loading saved worksheet… · private to this device or your optional account

Product interface evidence

Visual evidence statusWhat we verified without a screenshot

Evaluation

Research-based

Price posture

From $0/month

Reviewed

2026-09-09

No authentic product screenshot is published for this review. DiscoverAI does not use generated interface images as product evidence.

Pricing

Freemium

Respan lists a $0 Free plan with 100,000 logs, 1,000 scores, five datasets, two evaluators, five prompts, seven-day retention, and one workspace. Team is $199 per month when billed annually and adds unlimited datasets, evaluators, and prompts, 30-day retention, five members, and private Slack support. Extra usage is listed at $8 per 100,000 logs and $1 per 1,000 scores; additional Team seats are $15 per member. Enterprise and model-provider charges are separate or custom. Reviewed September 9, 2026.

Free plan: Yes. The Free plan includes the full platform within published log, score, prompt, evaluator, dataset, retention, and throughput limits.

Editorial freshness

Checked this month

Pricing and material product claims were checked September 9, 2026.

Pros & Cons

Pros

  • Gateway, traces, evaluations, and prompts in one platform
  • Useful free limits for a production-shaped pilot
  • Published overage and retention boundaries

Cons

  • Creates a central traffic and telemetry dependency
  • Team price requires annual billing
  • Judges and fallbacks need independent validation

Best For

Teams operating multiple model providersDevelopers debugging production AI agentsOrganizations unifying gateway, prompts, evals, and spend

Community evidence

How verified users put Respan to work

Structured, editor-moderated experience—not star ratings. This complements our independent review and never changes its score.

No approved community evidence yet. Be the first verified user to contribute.

Key Features

  • Multi-model gateway
  • Agent tracing
  • Evaluations
  • Prompt management
  • Cost monitoring
  • Operational alerts

Integrations

  • OpenAI SDK
  • Vercel AI SDK
  • LangChain
  • LlamaIndex
  • Mastra
  • OpenTelemetry

FAQs

What is Respan?

Respan is the new name for Keywords AI's LLM engineering platform, combining a model gateway, observability, evaluations, prompt management, and monitoring.

How much does Respan cost?

Respan lists a free plan, Team at $199 per month billed annually, metered log and score overages, and custom Enterprise pricing; model-provider usage is separate.

Can Respan route between AI models?

Yes. Its gateway supports a unified endpoint, provider fallbacks, retries, caching, load balancing, budgets, and rate limits.

Does Respan replace human evaluation?

No. Its automated and LLM-judge evaluations should be calibrated against expert labels before they block traffic or approve a release.

Keep Deciding

Where to go next

Material changes only

Follow Respan

Get an occasional email when something decision-relevant changes. This is separate from the weekly newsletter.

Alert me about

Confirm by email · unsubscribe from any alert · no newsletter enrollment

Compare alternatives

See how similar tools stack up

Langfuse

Open-source tracing, evaluation, prompt management, and metrics for LLM applications

4.0

Langfuse unifies traces, costs, prompts, datasets, and evaluation with cloud and self-hosted options, but telemetry sensitivity, retention, operational load, and fast-rising plan costs demand a scoped pilot.

FreemiumCodeAnalytics

Helicone

An open-source AI gateway with request monitoring, cost tracking, caching, fallbacks, prompts, and evaluations

4.0

Helicone combines multi-provider routing and observability behind a familiar API, but proxy trust, logged payloads, retention, usage-based costs, and gateway dependency need careful architecture review.

FreemiumCodeAnalytics

Patronus AI

Evaluate, debug, and guard AI systems with managed judges, benchmarks, traces, and an investigation agent

4.1

Patronus AI combines offline evaluation, production guardrails, tracing, prompt management, curated benchmarks, and Percival for investigating agent failures.

FreemiumCodeSecurity