Statelet is a Fair Source agent runtime data layer for production AI systems, written in Rust. It unifies durable memory, runtime state, declarative memory queries, DiskHNSW/SPFresh vector recall, temporal graph traversal, CDC, Raft consensus, Redis compatibility, and a management UI in one engine.

What memory accuracy does Statelet reach?

Statelet's server-side memory engine was evaluated on LongMemEval-S and reached 91.6% full-pipeline accuracy over 500 questions, with 99.0% hit@5 retrieval recall. Search uses local embeddings and vector plus graph retrieval; the LLM is only used during ingestion when enabled.

What is temporal graph recall in Statelet?

Statelet stores memories as graph nodes and temporal edges with validity windows. You can query what was true at a specific time with AS OF, expand semantic vector hits through graph relationships, and follow supersedes chains for updated or conflicting memories.

What languages and protocols does Statelet support?

Statelet provides gRPC SDKs for Python (3.9+), Node.js/TypeScript (18+), Go (1.21+), Rust (1.70+), Java (17+), and C++ (17+), plus an npm memory plugin for coding agents. It also natively supports the Redis RESP2 protocol, so existing Redis clients can connect directly on port 6379.

How does Statelet isolate enterprise tenants?

Statelet isolates tenants with a namespace to database hierarchy. The selected scope is baked into physical key, vector index, and graph names before shard routing, so agents or end users can own identical logical names without sharing a physical key space.

What vector search capabilities does Statelet have?

Statelet includes DiskHNSW and SPFresh vector search backends with L2, cosine, and inner-product distance metrics. It supports Product Quantization and Scalar Quantization for memory-efficient search, sparse hybrid retrieval, graph-RAG expansion, and distributed fan-out search across cluster nodes.

How is Statelet deployed?

Statelet installs from pip, Homebrew, apt, dnf, a Windows MSI, or platform tarballs, and statelet-cluster start brings up all three services at once. The Debian and RPM packages register a systemd unit. It can also be built from source and ships Kubernetes manifests. The topology consists of stateless gateways, a metadata Raft plane, and sharded data nodes.

What interfaces does Statelet expose?

Statelet exposes the Statelet gRPC service, a Redis RESP2-compatible TCP server, REST management APIs on the gateway, a React management UI, and a durable SubscribeCommitted CDC feed for catch-up and live-tail integrations.

Is Statelet open source?

Statelet is Fair Source: the engine ships under the Functional Source License (FSL-1.1-ALv2) — free to use, modify and self-host, with each release converting to Apache-2.0 two years after it ships. The source release is coming soon; the client SDKs are Apache-2.0, and the LongMemEval benchmark suite is already public on GitHub at github.com/stateletlab/statelet-longmemeval.

Statelet - Agent Runtime Data Layer

Name: Statelet
Availability: InStock
Author: stateletlab

Statelet - Agent Runtime Data LayerStatelet is a Fair Source distributed database written in Rust. It gives AI agents durable memory, context versions, runtime state snapshots, an openCypher-style memory query language, DiskHNSW/SPFresh vector recall, temporal graph recall, CDC, Raft consensus, Redis compatibility, and local ONNX embeddings.Statelet Features

Unified Runtime Data Engine - Memory, context, state snapshots, vector recall, temporal graph, and triple-store rows share one Rust engine and transaction model.

Memory Query Language - Query agent memory declaratively with openCypher-style syntax, including vector search, graph expansion, and AS OF time travel.

LSM-Tree Storage Engine - Concurrent skip-list MemTable, prefix-compressed SST files, bloom filters, sharded LRU block cache, leveled compaction.

DiskHNSW / SPFresh Vector Search - Dense, sparse hybrid, graph-RAG, and quantized vector retrieval with local ONNX embeddings.

Temporal Graph Recall - Time-aware edges, AS OF queries, supersedes chains, and graph expansion for explainable memory.

Multi-Tenancy - Namespace and database scoping physically isolates keys, indexes, and graphs for every tenant or agent.

CDC Feed - Durable SubscribeCommitted stream keyed on Raft log offsets for catch-up and live-tail integrations.

Raft Distributed Consensus - Separate metadata and per-shard data Raft groups for production topology.

Redis Protocol Compatible - RESP2-compatible TCP server. Any Redis client can connect directly.

Multi-Language SDKs - Official gRPC clients for Python 3.9+, Node.js 18+, Go 1.21+, Rust 1.70+, Java 17+, and C++ 17+.

Management Web Console - Namespaces, databases, graph queries, KV operations, user management, and Prometheus metrics.

ArchitectureThree-tier distributed architecture: stateless Gateway (gRPC :9379, HTTP :9380, Redis :6379) routing to a Metadata Plane (Raft consensus for namespace/database registry, shard map, column families, and node registry) and Data Plane (ShardEngine per node with LSM-tree, DiskHNSW/SPFresh vector search, temporal GraphSST, and per-shard Raft).PerformanceLongMemEval-S memory evaluation

Full-pipeline accuracy: 91.6% over 500 questions

Retrieval-only hit@5: 99.0%; recall@5: 93.7%; MRR: 93.8%

span_hit@5: 90.0%; span_recall@5: 78.9%; top-1 similarity: 99.4%

End-to-end overall: 458 / 500 correct; strongest categories are single-session-assistant at 98.2% and single-session-user at 97.1%

Search is pure vector plus graph retrieval; LLM extraction is ingestion-time only when enabled

Fair Source (FSL-1.1-ALv2) — free to use, modify and self-host; each release converts to Apache-2.0 two years after it ships. Source release coming soon.Agent MemoryStatelet's gateway extracts structured facts from conversations, detects conflicts through vector similarity, resolves updates with temporal supersedes edges, and stores each fact with temporal metadata. Agents can recall memories with vector search, hybrid dense+sparse search, graph-RAG expansion, Personalized PageRank, and AS OF time travel.SDKs & ProtocolsOfficial gRPC clients: Python 3.9+ (pip install statelet-sdk), Node.js 18+ (npm install statelet-sdk), Go 1.21+, Rust 1.70+, Java 17+, C++ 17+. Redis RESP2 protocol compatible — connect with redis-cli or any Redis client library.Installation & DeploymentInstall the server with pip install statelet, brew install stateletlab/statelet/statelet, apt-get install statelet, dnf install statelet, a Windows MSI, or a platform tarball. Start everything with statelet-cluster start, or let the systemd unit from the Debian and RPM packages handle it. Also deployable via Docker (multi-stage build) and Kubernetes (StatefulSets with 3+ data nodes).Fair Source (FSL-1.1-ALv2) — the engine source release is coming soon. View the public benchmark on GitHub.