Reference

Limits and defaults

Every size limit, name rule, default window and timeout in one place.

Names#

Thing	Rule
Domain slug	3–40 characters: lowercase letters, digits and `-`, not starting or ending with `-`.
Topic	1–8 levels of `a-z A-Z 0-9 _ -`, joined by `:`; at most 128 characters.
Main Topic	One level: `a-z A-Z 0-9 _ -`, at most 128 characters.
Event type	1–64 characters of `a-z A-Z 0-9 _ . : -`.
State key	1–128 characters of `a-z A-Z 0-9 _ . : -`.
App Key	80 lowercase hex characters: a 16-character selector and a 64-character secret.

Sizes#

Limit	Value
Event `data`, as JSON	64 KiB (65 536 bytes); `null` not allowed
State `value`, as JSON	64 KiB (65 536 bytes); `null` not allowed
Ops per WebSocket message	100
WebSocket frame from a client	100 × (64 KiB + 1 KiB); larger closes with `1009`
REST listing `limit`	default 100, maximum 1000 (larger is capped)

Tokens#

Setting	Value
Token TTL of an App Key	1–86 400 seconds; default 30
Token type	Bearer (JWT), always expiring
Checked	every REST request; WebSocket handshake only

Retention defaults#

Applied to a Main Topic's family when it has no config of its own.

Broker	Count	Age
Event Broker	newest 1000 events	1 hour
State Broker	unbounded	never expire

Expired data is removed by a sweep that runs about once a minute; it never notifies subscribers. Configs are set per Main Topic: Event Broker, State Broker.

WebSocket timing#

Setting	Value
Server ping interval	30 seconds
Idle timeout	60 seconds without any frame from the client (pongs count)
Permissions	snapshot at connect, for the connection's life

Claims#

Field	Values
Domain Claim protocol flags	`0`, `1` (R), `4` (W), `5` (W R)
Broker claim `topic_flags`	`0`, `1`, `4`, `5`
Broker claim data flags	`0`–`15` (`P` 8, `W` 4, `S` 2, `R` 1)
Claims per key	at most one of each kind
Keys per claim	unlimited