Plurai vs Stash

Plurai launched today as Product Hunt's #1 product with a deceptively simple pitch: describe how you want your AI agent to behave, and the platform automatically generates training data, validates it, and deploys a custom evaluation model — no labeled datasets, no annotation pipelines, no prompt engineering. They call it "vibe coding, but for evals and guardrails." Under the hood, Plurai builds on published BARRED methodology research, running small language models fine-tuned for your specific use case rather than calling GPT-4 for every eval check. This delivers sub-100ms latency at 8x lower cost than GPT-based evaluation approaches. The company claims a 43% reduction in agent failure rates across early customers, and the always-on monitoring goes beyond sampling to evaluate every single interaction. This hits a real and growing problem: as AI agents proliferate in production, the gap between "it works in the demo" and "it works reliably for real users" is where most teams are bleeding. Traditional eval approaches either require expensive human labeling or depend on another LLM to judge the first one — both brittle. Plurai's approach of training lightweight specialized models from natural language descriptions could be a genuine step change for teams that aren't ML experts.

Stash is an open-source persistent memory infrastructure for AI agents built on PostgreSQL and pgvector. Unlike retrieval-augmented generation, which searches static documents, Stash actively learns from agent experience — consolidating raw observations into facts, relationships, causal links, and higher-order patterns over time. The system exposes 28 MCP tools covering the full cognitive stack: episode storage, fact synthesis, entity graph management, goal tracking, failure pattern recognition, and self-correction when contradictions emerge. It deploys via Docker Compose in three steps and works with any OpenAI-compatible API — Claude, GPT, local models via Ollama. Hierarchical namespaces let agents keep user facts separate from project facts separate from self-knowledge. This fills a real gap in the agent ecosystem. Most agent frameworks treat each session as stateless, which means agents repeat the same mistakes and lose hard-won context. Stash gives agents a persistent cognitive layer that compounds. It surfaced on Hacker News this week to notable developer interest and is worth watching as MCP adoption accelerates.