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Introduction to XMTP

XMTP (Extensible Message Transport Protocol) is an open protocol, network, and standards for secure, private web3 messaging.

XMTP's extensible design enables a diverse set of use cases for sending message data between web3 identities. For example, building with an XMTP client SDK, developers can enhance their apps with:

  • User-to-user direct messages
  • App-to-user notifications
  • Creator-to-community announcements

Because the XMTP network persists messages, and those messages are tied to web3 identities as opposed to a specific client app, each web3 identity has an interoperable inbox that it can access using any client app built with XMTP.

Developers can also build tools for decentralized apps (dapps), decentralized autonomous organizations (DAOs), creators, and protocols to re-engage users with web3 messaging.

XMTP has been implemented to work with Ethereum Virtual Machine (EVM)-compatible wallet apps and blockchain accounts (wallets), though XMTP itself does not use EVMs. XMTP also works with other web3 identities that apps built with XMTP can derive from Ethereum accounts, such as ENS names and Lens profiles.

To learn more, see Works with XMTP.

XMTP’s primary contributor, XMTP Labs, is funded by some of the industry’s top venture capital funds, including a16z Crypto and Coinbase Ventures.

XMTP at a glance

Here are some key considerations as you explore building with XMTP for secure web3 messaging:

Message directionBidirectional
Participant identitiesAny EVM blockchain EOA (externally owned account) can send a message to any other EVM blockchain EOA that has advertised its XMTP identity on the network.
Chain focusChain-agnostic, but currently requires an EVM blockchain account.

To learn more, see Chains.
Wallet app compatibilityEVM-compatible wallets capable of signing with private keys, such as MetaMask, Coinbase Wallet, and Rainbow Wallet.

To learn more, see Wallet apps.
AuthenticationAn XMTP-specific key bundle derived from a blockchain account address signature is used to authenticate a user identity.

To learn more about these key bundles, see Key generation and usage.
Message encryptionMessages are encrypted individually by default and are readable by message participants only.

To learn more about message encryption, see Invitation and message encryption.
Message deliveryMessages are immediately relayed by XMTP nodes, using the Waku protocol.

To learn more, see Network layer.
Message storageMessages are stored off-chain in the XMTP network, with all nodes currently hosted by XMTP Labs.

XMTP Labs is working toward a phased decentralization of the network. To learn more see, XMTP: The journey to decentalization.
Supported content typesPlaintext messages as a standard content type, but custom content types are supported as well.

To learn more, see Content types.
Adoption of standard content typesOpen, extensible, and community-governed via XIP-5 (XMTP Improvement Proposal-5).

To learn more, see XIP-5 Message Content Types.
ImplementationAny app built with the XMTP client SDK can send or receive messages.

To learn more, see XMTP SDKs and developer tools.
Receiving messagesAny frontend built with the XMTP client SDK can receive messages.

To learn more, see XMTP SDKs and developer tools.
EnvironmentsXMTP client SDKs are available for JavaScript and React, Kotlin (Android), Swift (iOS), and Dart (Flutter).

To learn about other SDKs in the works, see the Roadmap.
Message costMost messaging incurs no fee. As XMTP decentralizes, messaging between participants that opt-in will remain free, while unsolicited messages will often incur fees or see token staking requirements.
DecentralizationXMTP network nodes are run by XMTP Labs at this time. In the future, network node software will be open sourced and anyone will be welcome to operate a node.

Client implementation is permissionless, nor is permission required to access and develop with the SDK. Permission isn't required to connect to the XMTP network to send/receive messages on behalf of users.

XMTP Labs is working toward a phased decentralization of the network. To learn more see, XMTP: The journey to decentalization.

Protocol overview

A user can send and receive encrypted XMTP messages using an app with an embedded XMTP client, authenticating using a wallet signature. XMTP network nodes persist the user's messages

Clients and nodes are implemented as Waku2 peers but with XMTP-specific functions and capabilities.

To learn more about clients, see Client layer.

To learn more about nodes, see Network layer.

Example apps

Check out these app repos you can use for guidance and inspiration when building with XMTP:

  • The xmtp-quickstart-react repo provides the XMTP Quickstart React chat app, which demonstrates core capabilities of the XMTP client SDK. You can use the code in this repo to learn to build a basic messaging app.

  • The xmtp-inbox-web repo provides the XMTP Inbox chat app, which demonstrates core and advanced capabilities of the XMTP client SDK and showcases innovative ways of building with XMTP.

For even more examples of apps built with XMTP, see:

Learn more

Have more questions? See FAQ about XMTP

Join and learn with the XMTP Discord community

Ready to build with XMTP? Start here

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