Identity model

XMTP’s identity model includes an inbox ID and its associated identities and installations.

Term	Meaning
Inbox ID	Stable destination for messages
Identity	Addressable account linked to an inbox
Recovery identity	First identity; can manage other identities and installations
Installation	One app instance with its own cryptographic keys

An inbox can contain several account identifiers. Messages to any linked identifier reach the same inbox. Supported identifiers include Ethereum EOAs, smart contract wallets, and passkeys.

Each installation has independent keys and local state. An inbox supports up to 10 installations. The recovery identity can revoke installations.

Inbox ID (stable destination for messages)
├── Identity 1 (recovery identity, first identity added to an inbox)
├── Identity 2 (EOA wallet)
├── Identity 3 (SCW wallet)
└── Any identity that can produce a verifiable cryptographic signature

Each identity can authenticate new installations:
├── Installation A (phone app)
├── Installation B (web app)
├── Installation C (desktop app)
└── Up to 10 installations

See inboxes and installations for the SDK operations and limits.