NeDB
Embeddable persistent document store for Node.js and browser with a MongoDB-compatible API. Stores data in a file-based append-only format (or in-memory for tests). No external server required — the DB runs in-process. @seald-io/nedb is the actively maintained fork of the original archived nedb project.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Local embedded database. No network exposure. Data stored in plaintext — encrypt at rest if sensitive data. Original package abandoned; use @seald-io fork for security patches.
⚡ Reliability
Best When
You need a zero-dependency embedded document database for a single-process Node.js agent, CLI tool, or Electron app.
Avoid When
You need horizontal scaling, replication, or the full MongoDB aggregation pipeline — use MongoDB Atlas or a proper embedded option like SQLite.
Use Cases
- • Store agent state, task queues, or conversation history in a persistent file-based document store without running a database server
- • Prototype agent backends with MongoDB-compatible query syntax before migrating to a real MongoDB instance
- • Build lightweight desktop or CLI agents that need persistent document storage without Docker or system dependencies
- • Cache LLM responses or agent results locally with document-oriented storage and indexes
- • Run integration tests against an in-memory NeDB instance as a MongoDB-compatible stub
Not For
- • Production workloads at scale — NeDB is single-process and not designed for high-concurrency or large datasets
- • Applications needing full MongoDB feature set (aggregation pipeline, $lookup joins, change streams)
- • Multi-process or clustered applications — NeDB does not support concurrent file access from multiple processes
Interface
Authentication
Local library — filesystem permissions control access. No built-in authentication.
Pricing
MIT license. Original project archived; @seald-io/nedb is the active fork.
Agent Metadata
Known Gotchas
- ⚠ NeDB's append-only format grows indefinitely — must call db.persistence.compactDatafile() periodically or on startup to prevent unbounded disk growth
- ⚠ The original nedb npm package is abandoned (last release 2016) — always use @seald-io/nedb for active maintenance and Node.js 18+ compatibility
- ⚠ No schema validation — documents can have any shape; agents must validate before insert to avoid data corruption
- ⚠ Queries use MongoDB-style selectors ($gt, $in, $regex) but lack $lookup and aggregation pipeline — complex joins require application-level code
- ⚠ In-memory mode (no filename) loses all data on process exit — only use for tests or ephemeral caches
- ⚠ Single-file storage means file corruption (power loss during write) can corrupt the entire database — use WAL-based SQLite for higher durability requirements
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for NeDB.
Scores are editorial opinions as of 2026-03-06.