Software Architecture
The 21 Travel Rule software solution consists of containerised microservices. The container images are available as a “FROM scratch”-image (referred to as the “micro image”). With the micro image, the executables run in an empty container, which includes nothing but the absolute minimum for the program to work and, with that, isolates the execution environment of a process. Even if an attacker successfully hacks our software, they find themselves in an empty container with no further exploitable software.
Container Images
21travel (Backend Services)
This image contains the microservices for trpd, aopd, and autod.
21-travel-web-ui (Back Office GUI)
This image serves the optional internal Compliance Dashboard web application.
virtualcounter (Front Office GUI)
This image serves the optional Virtual Counter web application which automates interactions with your customers. For more information see 21analytics.ch/virtual-counter.
quickproof (Front Office GUI)
This image serves the optional Quickproof web application which automates interactions with your customers without the need for authentication by relying on unique URLs instead.
sunrise (Front Office GUI)
This image serves the optional Sunrise web application which automates interactions with counterparty VASPs. For more information see 21analytics.ch/sunrise/.
Microservices and Network Overview
Microservices
trpd (TRP)
trpd is the processing engine for exchanging travel rule data through Travel Rule Protocol (TRP). It handles communication with all counterparty VASPs using TRP. It's possible to run multiple instances of trpd for HA, failover and zero-downtime updates.
aopd (AOPP)
aopd is the processing engine for registering ownership proofs through Address Ownership Proof Protocol (AOPP; Digital Signatures), Visual Proofs and Satoshi Tests. It handles communication with non-custodial (self-hosted) wallets. It's possible to run multiple instances of aopd for HA, failover and zero-downtime updates.
autod (Internal API)
autod is the internal API that provides unified access to all databases and services of 21 Travel Rule. Its GraphQL API is used by the Web User Interface and custom integrated services from the VASP.
Databases
The SQL databases are handled by PostgreSQL, a free and open-source (OSI-approved license) relational database management system. PostgreSQL can be run as a container, standalone application, or is also available as a fully managed service from various cloud providers.
TRP
The TRP database contains all data related to transfers through the Travel Rule Protocol, as well as additional data for those transfers sourced from Blockchain Analytics, Screening and Exchange Rate services.
The Email database contains all data related to transfers sent out via email, as well as additional data for those transfers sourced from Blockchain Analytics, Screening and Exchange Rate services.
AOPP
The AOPP database contains all data related to transfers with self-hosted wallets, as well as additional data for those transfers sourced from Blockchain Analytics and Exchange Rate services.
Offline
The Offline database contains all data related to incoming-transfers registered manually by receiving VASP through the Compliance Dashboard or the API.
Compliance Dashboard
The Compliance Dashboard is served from a container of the 21-travel-web-ui image. It runs a HTTP file server. The Compliance Dashboard is only accessible to users (typically compliance officers) from within the VASP and should never be exposed to the outside world. It only accesses autod, the internal API.
It's possible to run multiple instances of the Compliance Dashboard.
SeaweedFS
SeaweedFS is an open-source fast distributed storage system for blobs, objects, files, and data lake, for billions of files. In the 21 Travel Rule software solution it's used to store and access of visual proofs.
Keycloak
Keycloak is an open source identity and access management software. It provides the account management and single-sign on functionality. Keycloak has built-in support to connect to existing LDAP or Active Directory servers.
Physical Architecture
21 Travel Rule can be run on a single machine, as demonstrated in our Reference Deployment Reference Deployment, which is based on Docker Compose.
Our container-based architecture also effortlessly enables more advanced setups, such as deploying a cluster of machines on OpenShift to provide HA and automatic failover.