Core Concepts
Understanding the building blocks of the RCAN protocol.
Robot Registration Number (RRN)
An RRN is a permanent, globally unique identifier assigned to each robot in the registry.
RRN-00000001 Format
- Prefix:
RRN- - 8-digit zero-padded number
- Assigned sequentially
- Never reused, even if robot is retired
Properties
| Permanent | Once assigned, an RRN never changes |
|---|---|
| Unique | No two robots share an RRN |
| Sequential | Assigned in order of registration |
| Verifiable | Can be looked up in the registry |
Robot URI (RURI)
A RURI is an addressable identifier that locates a specific robot instance on a network.
rcan://continuon.cloud/acme/bot-x1/12345678 Components
| Part | Example | Description |
|---|---|---|
scheme | rcan:// | Protocol identifier |
registry | continuon.cloud | Registry domain |
manufacturer | acme | Manufacturer namespace |
model | bot-x1 | Robot model |
device-id | 12345678 | Unique device identifier |
port | :8080 | Optional port |
capability | /arm | Optional sub-endpoint |
RRN vs RURI
RRN
Registry identity - "who is this robot?"
Static, permanent, for documentation
RURI
Network address - "where is this robot?"
Dynamic, can change, for communication
Registry
A registry is a database of robot records that stores specifications, metadata, and ownership information.
Types of Registries
- Public - Like rcan.dev, open to all
- Private - Corporate or organizational
- Local - Self-hosted for private networks
Federation
Registries are federated like email servers. A robot registered at one registry can communicate with robots at another. Owners can migrate robots between registries.
Role-Based Access Control
RCAN defines five permission levels:
CREATOR
Full hardware/software control, OTA updates, safety overrides
OWNER
Configuration, skill installation, user management
LEASEE
Time-bound operational control
USER
Operational control within allowed modes
GUEST
Limited interaction, status viewing
Rule: Higher roles inherit all permissions of lower roles.
Discovery
Robots can be discovered via:
mDNS (Local Network)
_rcan._tcp.local.Works without internet. Broadcasts robot presence with TXT records containing RURI, capabilities, and status.
Registry Lookup
Query a registry's API to find robots by manufacturer, model, or capabilities.