Matrix Limits

A collection of various limits and related factoids about the Matrix specification and implementations.

Contents

• Specification
  • Events
  • Identifiers
• Servers
  • Synapse
  • Dendrite

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Specification

Events

The content has been adapted from the spec itself.

• Events must not be larger than 64 KiB when formatted as a PDU
• sender must not exceed 255 bytes (including domain)
• room_id must not exceed 255 bytes
• state_key must not exceed 255 bytes
• type must not exceed 255 bytes
• event_id must not exceed 255 bytes

Identifiers

• User ID localparts are limited to [a-z0-9-.=_/]+ in the spec, but historical user IDs can contain any printable ASCII except spaces and federation allows arbitrary unicode including unprintable ASCII

Servers

Synapse

• Events table used to use a 32-bit stream ordering ID, limiting a server to a total of 2^31 (2,147,483,648) events across all known rooms (develop has changed to bigint, so the limit will soon become 2^63)

Dendrite

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License

Creative Commons Attribution 4.0 International