Respan

Respan is an LLM engineering platform that pulls four jobs into one place: observability, evaluation, prompt optimisation, and a unified LLM gateway. The tracing layer records what each agent does, capturing every prompt, tool call, and response along with context from real production traffic, so you can search, filter, and sort instead of guessing. Evaluation is treated as a process rather than a one off, combining manual review, code checks, and LLM judgement in a single workflow. Optimisation runs iteratively over prompts, tools, and routing, with version control on every change so you can compare versions and roll back. Deployment happens through one gateway, and monitoring dashboards watch production in real time.

- Trace an agent run end to end, including prompts, tool calls, and responses.

- Build an evaluation workflow that mixes manual, code, and LLM based checks.

- Iterate on prompts, tools, and routing with version control on every change.

- Promote prompts, models, and workflows to production from the interface.

- Engineers building and debugging LLM features in production.

- Product teams that need to measure and improve output quality.

- Founders running products with large API call volumes.

- Teams that want one control plane for prompts, models, and routing.

A free trial is offered, but continued use needs a paid plan, and the pricing structure is not detailed on the page, so ask for it during the demo. The platform is aimed at teams with genuine production traffic, and a small side project may not generate enough value to justify the setup and the instrumentation work. Connecting your stack takes real effort, and the quality of what you see depends on what you send. The customer stories quoted on the site are the vendor's own accounts rather than independent measurements, so treat the scaling numbers as examples of what customers report, not as a guarantee of what you will get.