A private messaging app and network that protects metadata as well as content. Messages are end-to-end encrypted with libsodium and routed through a decentralised onion-routing network the project calls onion requests, so that no single server knows both the origin and the destination of a message; identities are anonymous and messages are stored in swarms of network nodes until collected. The app runs on mobile and desktop, supports one-to-one and group messages, and the project says contributors are working on Session Protocol V2, which plans post-quantum cryptography. It is stewarded by the Session Technology Foundation, a Swiss foundation without shareholders, and the site lists a Session token .
LicenseCopyleft (GPL-3.0 for the Android app). https://github.com/session-foundation/session-android and sibling repositories for other platforms
Dev Status 🟢 Active
OwnerSession Technology Foundation (a Swiss foundation, per its own site), which stewards the Session ecosystem; the app code is under the session-foundation GitHub organisation
Governing BodySession Technology Foundation, a Swiss foundation bound to its purpose and with no shareholders
CountrySwitzerland (the Session Technology Foundation is a Swiss foundation)
Start Year 2018
StackLibsodium cryptography; Session Protocol with onion requests over a network of nodes holding message swarms; Kotlin and Java Android client
FundingDonations and the Session token ecosystem, per the foundation's site navigation
Last Investigated Oct 29, 2026
Topology view
This tool in the centre and the things it is directly related to. Each line names the kind of relationship.
OriginsMessaging that keeps the identities of the communicating people private, by removing phone numbers and central servers and routing messages through an onion network
DatabaseLocal encrypted database on the device; swarms of network nodes hold messages until delivered
Query Language N/A
Data FormatsSession Protocol messages, with libsodium-based encryption; onion request format between client and nodes
Collaborative Live Editing N/A
Rich Text Editing Not stated by the project.
Mobile SupportYes: Android and iOS clients, per the project's FAQ, and an Android repository under the foundation's organisation
Web SupportNo web client was described in the cited sources
Native AppsAndroid, iOS and desktop clients, per the project's FAQ
TermsFree to use; open-source code; donations are invited
Funds Not stated by the project.
Based OnLibsodium for cryptography; the project describes its onion routing as similar to Tor with a few key differences
Use Case CategoryPrivate, anonymous messaging and group chat
User Interface TypeMobile and desktop apps
Offline CapabilitiesMessages are held in node swarms until collected; no offline or local-network mode was described
Collaboration FeaturesOne-to-one and group messages, with attachments
Data Portability Not stated by the project.
Integration EcosystemAn open protocol and several client implementations; the foundation awards grants to community implementations
Web2 Data Export Not stated by the project.
Prosocial Coherence Not stated by the project.
Economic FlowsToken-based: the Session token ($SESH) is the native cryptocurrency of the Session ecosystem and underpins the node network, per the project's FAQ
Governance & Decision MakingStewarded by the Session Technology Foundation, which publishes transparency reports and funds community work
Media / Publishing N/A
Knowledge Management N/A
Sensemaking N/A
Project Management N/A
Communication ModelMessages are sent through onion requests to a swarm of nodes and collected by polling; push notifications are an optional 'fast mode'
Network ResilienceDecentralised network of nodes; the app can use push notifications through a provider in 'fast mode', which the project says exposes less than it appears
Discovery MechanismContacts are added by their account ID or QR code; no central directory
Max Participants Not stated by the project.
Data SovereigntyMedium to high: content is end-to-end encrypted and identities are anonymous, but messages pass through a network of nodes the user does not run
Relationships
How this tool connects to other tools and organizations, from relationships reviewed by the OpenHaven data steward. They describe how projects connect, not how good they are.