Event store database built for event sourcing.
AllSource records application state as ordered, immutable event streams. Rebuild projections, replay production history, query point-in-time state, and expose same durable record to AI agents through Prime.
Hosted plans from £18.99/month after trial · Apache-2.0 Core available to self-host
What did the user do yesterday at 3pm?
At 15:00 they checked out a $49 cart, then the agent decided to upsell.
published Core read benchmark: 11.9μs p99
What breaks without an event store
Current state hides its history
A row shows what is true now, not which accepted facts produced it. Debugging and audit work then depend on scattered logs and application-specific fixes.
Every read model becomes permanent
When current-state tables become source of truth, changing a projection means risky migrations. Durable events let teams rebuild new views beside old ones.
Historical queries become projects
Reconstructing state at a past timestamp usually means joining logs, snapshots, and database records. An ordered event history makes that query explicit.
From event write to queryable state
One ordered history supports application state, operational analysis, and higher-level uses such as agent memory.
- 01
Write events
Send structured events through HTTP, WebSocket, an SDK, or MCP. AllSource appends accepted writes to an immutable stream.
- 02
Build useful views
Query Service folds ordered Core events into tenant-scoped current-state projections and separates HTTP, realtime, and analytics reads.
- 03
Query and replay history
Serve request-response queries, push live channel updates, run analytics, or rebuild a read model from the same source history.
Full event-store capabilities
Immutable streams, concurrency, replay, projections, snapshots, schemas, and durable consumers share one source of truth.
Immutable event streams
Read an entity's complete history in order, inspect each payload, and trace which event caused a state change.
Read guide →Point-in-time reconstruction
Ask what a stream contained at a sequence or timestamp and reconstruct the matching state.
Read guide →Schema governance
Register versioned event schemas and reject incompatible payloads before they become permanent history.
Read guide →Stream processing
Filter, map, reduce, window, or branch accepted events inline while preserving source history.
Read guide →Rebuildable projections
Fold existing events into tenant-scoped read models for HTTP, realtime, and analytics consumers.
Read guide →Durable subscriptions
Resume named consumers from acknowledged WAL positions, replay missed events, and continue into live delivery.
Read guide →Claims you can inspect
Numbers link back to reproducible commands and source code. Architecture pages explain which service owns each part of the data path.
11.9μs
Core indexed-read p99
Published in-memory reference benchmark
469K
events/sec
Published batch-ingestion benchmark
WAL + Parquet
durable storage
Write-ahead log with columnar persistence
Apache-2.0
core licence
Inspect, run, and modify the event-store core
Pricing
Indie
£18.99/mo
Billed monthly
Includes 50K x402 calls. $0.0001/call after.
- 500K events/month
- 14-day retention
- 3 streams
- Hosted MCP: read
- Email support (48h)
Studio
—
Live catalog could not be reached
Includes 500K x402 calls. $0.0001/call after.
- 5M events/month
- 90-day retention
- Unlimited streams
- Hosted MCP: read + write
- Email support (24h) + Discord
Scale
—
Live catalog could not be reached
Includes 5M x402 calls. $0.0001/call after.
- 50M events/month
- 365-day retention
- Unlimited streams
- Hosted MCP: read + write + dedicated
- Priority support + Slack
Enterprise
Regulated / SLA workloads. Dedicated MCP cluster. Negotiated volume, unlimited retention, 24/7 + dedicated SE.
FAQ
Recent product and engineering notes
Agent memory security: prevent poisoning and cross-tenant recall
A concrete threat model for durable agent memory: scoped writers, provenance, tenant isolation, correction events, bounded recall, and audit evidence.
MCP memory server guide: durable tools for cross-session agents
Separate event-store tools from Prime memory tools, choose local or hosted transport, scope credentials, and verify provenance before an agent relies on recalled context.
Reconstructing Agent Memory in Rust: Events, Provenance, and Point-in-Time State
Build durable AI-agent memory as an append-only event stream in Rust, derive current state without destroying history, and reconstruct exactly what an agent knew before a decision.
Write → inspect → query
Store one real event, then query it back.
Start with hosted AllSource, or run the Apache-2.0 core on your own infrastructure. Both use the same event model and APIs.