JayDB

JayDB is a JSON document store with per-user sign-in for apps that need data without an app-owned backend. It suits static and AI-built apps whose data fits individual user, session, or tenant documents. Its straightforward REST model and self-hosting option are useful, but its missing query tools and cross-document transactions are firm boundaries.

Overview

JayDB pairs tenant-specific OIDC authentication with JSON documents addressed by slash-separated paths. The first write creates a namespace automatically, so apps can start storing data without a separate namespace setup. That structure works best when the app already knows which document path it needs; it is not designed for searching and relating records flexibly.

Documents can be JSON, MsgPack, or raw data, up to 5 MB each. The database has no secondary indexes, joins, foreign-key constraints, full-text search, aggregation, or transactions. That makes it a poor choice when the app needs flexible discovery, relational integrity, or a change spanning multiple documents to succeed atomically. Vector search is also absent.

Key features

REST access and concurrency

The data plane uses standard REST HTTP for GET, PUT, DELETE, and prefix listing. ETag-based compare-and-swap can reject a write with HTTP 412 if the document changed since it was read, helping clients avoid silently overwriting one another. It does not solve contention: sustained concurrent writes to one hot key can cause retries to pile up.

Authentication and SDK

Each tenant gets an OIDC issuer, and browser apps can use Authorization Code with PKCE without embedding a client secret. Identity integrations include Google, GitHub, Microsoft, generic OIDC, and custom OAuth2 providers. The official zero-dependency @jaydb/cloud SDK adds OIDC and PKCE authentication, token refresh, typed document access, and compare-and-swap operations. This is a focused package for apps that want those paths in one SDK, rather than a broader database toolkit.

Managed or self-hosted

JayDB is available as a managed cloud service, and its Go engine is MIT-licensed for embedding or standalone deployment. The engine can use S3, Cloudflare R2, MinIO, or local disk; the documentation describes AWS S3 or compatible storage for durability. Self-hosting gives teams control over deployment, but also means taking responsibility for running the engine and its storage.

Pricing

The Free plan costs nothing, billed free every month forever. It includes 1 GB of storage, 100,000 reads per month, and 10,000 writes per month. Usage hard-stops at those allowances, so it is a genuine no-cost starting point but not a forgiving overage buffer for a growing app. There is no free trial.

Paid usage is metered at $0.05 per GB-month of storage, $0.20 per million reads, and $0.50 per million writes. Deletes are free, and egress has no per-GB line item under fair use. Paid from $0.05/mo reflects usage-based billing, not a fixed monthly plan; teams should account for read and write volume as well as stored data.

The $5 prepaid pack costs $5, paid once and prepays $6.50 of metered usage, a 1.3× discount. The $10 prepaid pack costs $10, paid once and prepays $15 of metered usage, a 1.5× discount. Both use the same metered rates; the larger pack suits buyers able to commit more upfront in exchange for the stronger discount.

Platforms

JayDB supports Android, iOS, Linux, macOS, Windows, web, and API use, with both managed and self-hosted deployment. That range accommodates browser and device apps as well as teams running the Go engine themselves.

Who it's for

Choose JayDB for static or AI-built apps that need per-user sign-in and shared document state organized around a user, session, or tenant. It is also relevant when multiple users or workers need to coordinate around individual documents and compare-and-swap is sufficient to guard updates. Look elsewhere if the workload depends on indexing, search, aggregation, relational constraints, vector retrieval, or atomic multi-document changes.

Pros and cons

• Useful identity-and-storage pairing: tenant OIDC, PKCE browser sign-in, and named identity providers serve apps that need authentication alongside document storage.
• Simple HTTP and document operations: REST access, prefix listing, and compare-and-swap suit clients organized around known document paths.
• Flexible deployment: a managed cloud service and an MIT-licensed Go engine support teams that want a hosted service or control over their own deployment.
• Hard free-plan stops: storage, read, and write caps can halt usage at the allowance, making the free tier risky for workloads that cannot tolerate interruption.
• Narrow data model: absent indexes, search, joins, aggregation, transactions, and vector search limit JayDB to workloads that can live without them.
• Hot-key contention: sustained concurrent writes to one key can accumulate retries, which is a concern for heavily shared documents.

Alternatives

Document Databases is the category directory for comparing options. Choose PouchDB instead if a free and open-source option across mobile, desktop, web, and self-hosted platforms fits better. RavenDB is another freemium alternative with Developer and Community plans. Consider eXist-db for a free option available for academic, non-commercial, and commercial applications, or MarkLogic for a freemium option with a free trial. Apache CouchDB is a free, open-source database that can be self-hosted on servers or VMs in single-node or clustered deployments. Azure DocumentDB offers a free tier with 32 GB of storage and one free database server per subscription. BaseX is a completely open-source option that requires Java 17 or higher. Firestore offers a free trial and free daily read and write allowances.

Verdict

JayDB is a strong fit for apps that need tenant-aware sign-in and simple, path-addressed document storage, especially when a team values REST access or the option to self-host. Its hard free-tier caps, usage-based costs, and missing query and transaction features make it the wrong choice for applications that need flexible search, relational behavior, or dependable high contention on a single document.