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AI · alternatives · 2026

24 alternatives to A lightweight, stateless database for agent memory

I've been working on Polign and built a small prototype around something I've been thinking about with agent memory. I have built a lightweight/stateless vector db + BM25 search which works really well with typed facts and structured queries. It uses your own S3, or GCS bucket as primary storage, and restarting a node is fairly quick. Demo + writeup: https://polign.com/blog-edge-agent-memory Live search demo: https://demo.polign.com Docs: https://polign.com

Polign is a lightweight, stateless vector database designed for agent memory that combines vector search and BM25 search for typed facts and structured queries. It stores data in users' own S3 or GCS buckets as primary… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.

  1. 1

    Persistent memory for Claude Code, Codex & coding agents

    May 2026 · agent-memory.dev · its alternatives →

  2. 2
    Memori▲168

    Persistent memory from agent trace, not just conversation

    May 2026 · memorilabs.ai · its alternatives →

  3. 3

    Hey HN! I built a proof-of-concept for AI memory using Git instead of vector databases. The insight: Git already solved versioned document management. Why are we building complex vector stores when we could just use markdown files with Git's built-in diff/blame/history? How it works: Memories stored as markdown files in a Git repo Each conversation = one commit git diff shows how understanding evolves over time BM25 for search (no embeddings needed) LLMs generate search queries from conversation context Example: Ask "how has my project evolved?" and it uses git diff to show actual…

    2025 · github.com · its alternatives →

  4. 4
    pumaDB▲159

    a small hosted memory layer for AI agents

    Jun 2026 · pumadb.ai · its alternatives →

  5. 5

    Local persistent memory store for LLM applications including claude desktop, github copilot, codex, antigravity, etc. - CaviraOSS/LongMemory

    Dec 2025 · github.com · its alternatives →

  6. 6

    Repo-native memory for coding agents

    Jul 2026 · github.com · its alternatives →

  7. 7

    This is a project that I have been building for a while now, YourMemory is a solution to agentic memory which focuses on pruning of noise rather than hoarding of data. In the current state of agentic memory most of the context is stored in the form of a MD file or is derived through a RAG model where you store each and everything. Both of the solution leads to bloated context which does not optimize the usage of any tokens. In this system we only keep relevant data in our memory and prune all the unnecessary data. The relevance of a data is derived through multiple factors such as recall…

    Apr 2026 · yourmemoryai.vercel.app · its alternatives →

  8. 8

    An OKF-backed Model Context Protocol (MCP) server delivering persistent long-term memory and SQLite FTS5 search for AI agents. - fellowgeek/mcp-memory

    Aug 2026 · github.com · its alternatives →

  9. 9

    Vector databases store memories. They don't manage them. After 10k memories, recall quality degrades because there's no consolidation, no forgetting, no conflict resolution. Your AI agent just gets noisier. YantrikDB is a cognitive memory engine — embed it, run it as a server, or connect via MCP. It thinks about what it stores: consolidation collapses duplicate memories, contradiction detection flags incompatible facts, temporal decay with configurable half-life lets unimportant memories fade like human memory does. Single Rust binary. HTTP + binary wire protocol. 2-voter + 1-witness HA…

    Apr 2026 · github.com · its alternatives →

  10. 10

    Most AI agents forget everything between sessions. We built DeltaMemory to fix that. It's a cognitive memory layer that gives agents persistent recall, automatic fact extraction, and temporal reasoning — via a single SDK call. Key numbers: - 89% accuracy on LoCoMo long-term conversation benchmark - 50ms p50 retrieval latency - 97% cost reduction vs raw token re-processing Open source SDKs, works with any LLM stack. Currently in early access. Happy to answer questions about the architecture, benchmark methodology, or how we handle knowledge graphs.

    Feb 2026 · deltamemory.com · its alternatives →

  11. 11

    Tell MemorySync a fact, reload the page, then ask for it back in your own words. No signup. Every API call shown in cURL, Python and Node.js.

    9d ago · memorysync.io · its alternatives →

  12. 12

    Polygres turns the Postgres you already run into internal search for AI agents. Rows, relationships, and embeddings: one hybrid query, one ranked answer.

    Jul 2026 · polygres.com · its alternatives →

  13. 13

    Coding agents don't have long-term memory. But you do have months of full-fidelity agent transcripts stored on your machine. A simple solution that goes a long way: ingest those transcripts and logs into a structured SQLite database, then search them with ranked text match. Everything is fully local and doesn't require anything fancy like a graph database or hosted memory service. This is the idea behind ctx, a Rust CLI that handles the ingestion and searching. We give our agents a skill that tells them to reference past sessions before working in an area. Usually we do this through an…

    Jul 2026 · github.com · its alternatives →

  14. 14

    This is a small library for giving an agent persistent memory without running any infrastructure. The whole store is one SQLite file, and the default install has no dependencies. I built it because whenever I wanted an agent to remember a handful of facts across sessions, the options were a hosted API, a vector database, or a framework, and that felt like too much for what is usually a few thousand short strings. The part I find most useful is that recall is deterministic, so you can write unit tests that assert what your agent remembers and run them in CI. I haven't seen that elsewhere and…

    Aug 2026 · github.com · its alternatives →

  15. 15

    Hey HN, I built MemoClaw, a simple memory service for AI agents. Store and recall memories with semantic search. No registration, no API keys, your wallet address is your identity. How it works: - POST /v1/store → save a memory ($0.001) - POST /v1/recall → semantic search ($0.001) - Payment via x402 protocol (USDC on Base) Why I built this: Every agent framework has its own memory solution, but they're all local or require complex setup. I wanted something like S3 for memories – just call an API and pay for what you use. CLI: `npm install -g memoclaw` Docs:…

    Feb 2026 · memoclaw.com · its alternatives →

  16. 16

    Hi HN, we're Kiran and Vijay! Over the past two years, we have built a columnar storage engine for observability: logs, metrics, and traces. Today, it's exciting for us to show what we've built on top of that foundation: LLM Agent Observability. Given how non-deterministic agents are, storing all traces without sampling was critical for us. But these traces tend to be in the MBs, sometimes GBs - we needed to store them inexpensively. We also needed the queries and analyses to be fast. To meet both these goals, we store them in S3 in our own parquet-like file format, and query them using AWS…

    Jul 2026 · oodle.ai · its alternatives →

  17. 17

    The TLS for autonomous agent state.

    Jul 2026 · memora.optitransfer.ch · its alternatives →

  18. 18

    How it works: - Storage uses one SQLite database file, plus a local LanceDB index of vectors. No need for a server, cloud services, or any API keys. - Retrieval is a hybrid approach using BM25 (rank-bm25) and vector-based search (sentence-transformers) combined with a co-occurrence graph of entities, using reciprocal rank fusion. The idea is to find the right memory, not the closest one. - It plugs into the agent's lifecycle via MCP: before the agent responds, relevant memories are added to its input; after each turn, decisions and new learnings are automatically recorded. No need to…

    Jun 2026 · github.com · its alternatives →

  19. 19

    An agent that remembers across sessions can keep its memory as curated markdown files, as an auto-mined structured store, or as trained experience.

    Aug 2026 · pinglin.tw · its alternatives →

  20. 20

    Extremely memory-efficient vector database. Contribute to D-Star-AI/minDB development by creating an account on GitHub.

    2024 · github.com · its alternatives →

  21. 21

    Hey HN! I'm Arindam, part of the team behind Memori (https://memori.gibsonai.com/). Memori adds a stateful memory engine to AI agents, enabling them to stay consistent, recall past work, and improve over time. With Memori, agents don’t lose track of multi-step workflows, repeat tool calls, or forget user preferences. Instead, they build up human-like memory that makes them more reliable and efficient across sessions. We’ve also put together demo apps (a personal diary assistant, a research agent, and a travel planner) so you can see memory in action. Current LLMs are stateless…

    2025 · github.com · its alternatives →

  22. 22

    Markdown based AI agent memory with semantic search, hybrid retrieval, and offline-first sync between agents. - sqliteai/sqlite-memory

    Apr 2026 · github.com · its alternatives →

  23. 23

    AgentState to solve a problem I kept running into: managing state for multi-agent AI systems is surprisingly hard. When you have multiple AI agents that need to coordinate, persist their state, and query each other's status, you typically end up with a mess of Redis/Postgres setups, custom queuing, and manual synchronization code. The whole thing is ~3MB, written in Rust for performance and safety, runs in Docker, and handles 1000+ ops/sec. I've been running it in production for AI workflows and it's been rock solid.

    2025 · github.com · its alternatives →

  24. 24

    Tired of AI coding tools that forget everything between sessions? Every time I open a new chat with Claude or fire up Copilot, I'm back to square one explaining my codebase structure. So I built something to fix this. It's called In Memoria. Its an MCP server that gives AI tools persistent memory. Instead of starting fresh every conversation, the AI remembers your coding patterns, architectural decisions, and all the context you've built up. The setup is dead simple: `npx in-memoria server` then connect your AI tool. No accounts, no data leaves your machine. Under the hood it's TypeScript +…

    2025 · github.com · its alternatives →

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