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Show HN: Reticle – Postman for AI Agents

TL;DR

Reticle is a local desktop tool (Tauri + React + SQLite) that consolidates the full LLM agent testing loop into one interface.

Key Points

  • You define scenarios with prompts, variables, and tools, run them against multiple models, and see prompts, responses, tool calls, and results in one view.
  • An eval mode checks whether a prompt or model change silently breaks existing behavior – essentially regression testing for AI agents.
  • All data stays local: prompts, API keys, and run history are stored in SQLite on your own machine.
  • A step-by-step view for agent runs shows exactly why a model made a specific decision.

Nauti's Take

The Postman analogy is well-chosen and hits a real nerve – tooling for agent development is still lagging far behind the pace at which people are actually building agents. The fact that everything runs locally is not a limitation but a hard requirement for many companies.

The interesting question is whether Reticle can evolve from a useful solo tool into something teams share – collaborative eval sets and shared scenarios would be the logical next step. For now: a solid approach worth watching.

Context

Anyone building agents today mostly debugs in the dark: add logs, run code, manually compare prompts. Reticle targets this pain point directly, positioning itself as 'Postman for AI agents' – an analogy that highlights how badly a standardized testing tool is needed in this space. The eval mode is especially relevant: prompt changes have side effects that often only surface in production.

A local, privacy-friendly tool also lowers the barrier for teams unwilling to send sensitive data to cloud services.

Sources