nowfound

Dev tools · May 19, 2026

Lexem | Version, Eval & Deploy Prompts

Git for prompts. Version, test & deploy AI safely.

What it does

Lexem is the version control and testing platform for AI prompts. Commit, diff, branch, rollback, run evals, and deploy LLM prompts safely with eval-gated promotions, regression detection, and a TypeScript/Python SDK.

Does the same job

all alternatives →
  • Latitude2024 · latitude.so · ▲685

    The open-source prompt engineering platform

  • Langfuse Prompt Experiments2024 · ▲467

    Open Source LLM Engineering Platform

  • PO
    PromptTools – open-source tools for evaluating LLMs and vector DBs2023 · github.com · ▲211

    Hey HN! We’re Kevin and Steve. We’re building PromptTools (https://github.com/hegelai/prompttools): open-source, self-hostable tools for experimenting with, testing, and evaluating LLMs, vector databases, and prompts. Evaluating prompts, LLMs, and vector databases is a painful, time-consuming but necessary part of the product engineering process. Our tools allow engineers to do this in a lot less time. By “evaluating” we mean checking the quality of a model's response for a given use case, which is a combination of testing and benchmarking. As examples: - For generated…

  • Flapico2025 · ▲149

    Prompt versioning, testing, and evaluation

  • PromptCompose - BetaOct 2025 · ▲153

    The command center for your AI prompts.

  • PE
    Prompt Engine – Auto pick LLMs based on your prompts2024 · jigsawstack.com · ▲93

    Nowadays, a common AI tech stack has hundreds of different prompts running across different LLMs. Three key problems: - Choices, picking from 100s of LLMs the best LLM for that 1 prompt is gonna be challenging, you're probably not picking the most optimized LLM for a prompt you wrote. - Scaling/Upgrading, similar to choices but you want to keep consistency of your output even when models depreciate or configurations change. - Prompt management is scary, if something works, you'll never want to touch it but you should be able to without fear of everything breaking. So we launched Prompt…

More dev tools this month

the category →
  • Dograh592

    The open source VAPI alternative

    Dev tools · 25d ago · dograh.com

  • Meridian530

    Don't let your work go unnoticed. Get promoted!

    Dev tools · 20d ago · meridiona.com

  • x1516

    Lovable for iPhone apps go from idea to App Store

    Dev tools · 11d ago · x1.new

  • The first open-source price index for GPU compute

    Dev tools · 10d ago · getcomputable.com

  • OpenTrailPaper is open-source bike computer firmware for the LilyGO T5S3 4.7" E-Paper PRO. It supports offline maps, GPX routes, FIT recording and Bluetooth sensors.

    Dev tools · 2d ago · opentrailpaper.com

  • Open-source GTM skills for technical founders

    Dev tools · 29d ago · gtmcofounder.com

Launched alongside, May 2026

the whole month →
  • Brew 905

    Like Claude design for email marketing

    AI · May 2026 · brew.new

  • Parallel agents, diff reviewer, and multi-model comparisons

    Dev tools · May 2026 · kilo.ai

  • StoreClaw805

    Grow your store profits with agents that know how to sell

    AI · May 2026 · storeclaw.ai

  • Give your agent a real number and voice to make calls.

    AI · May 2026 · pollyreach.ai

  • NW

    Hey HN, Henry here from Cactus. We open-sourced Needle, a 26M parameter function-calling (tool use) model. It runs at 6000 tok/s prefill and 1200 tok/s decode on consumer devices. We were always frustrated by the little effort made towards building agentic models that run on budget phones, so we conducted investigations that led to an observation: agentic experiences are built upon tool calling, and massive models are overkill for it. Tool calling is fundamentally retrieval-and-assembly (match query to tool name, extract argument values, emit JSON), not reasoning. Cross-attention…

    Life & fun · May 2026 · github.com

  • FM

    Dev tools · May 2026 · github.com