City Chains
City Chains are geographic Layer 3 app-chains that provide communities with their own attestation and verifiable compute infrastructure. Each City Chain consists of an Attestor node (L{CORE}) and a Cartesi rollup for deterministic compute—all settling to Locale Network (L2) for payment finality.
What is a City Chain?
A City Chain is a dedicated app-chain for a specific geographic region—typically a city or metropolitan area. Unlike traditional L3 rollups that handle asset transfers, City Chains focus on data attestation and verifiable computation. All payments and asset transfers settle on Locale Network (L2).
City Chains are app-chains for attestation and compute—they do not hold or transfer assets. All payments settle on Locale Network (L2), which inherits Ethereum security.
Why City Chains?
Local Data Sovereignty
Communities control their own:
- Data Attestation: Verify local IoT data, identity, and credentials
- Compute: Run deterministic calculations in Cartesi VMs
- Governance: Local stakeholders shape protocol parameters
- Privacy: Sensitive local data remains under local control
Optimized for Local Use Cases
City Chains can be configured for local needs:
- Custom attestors: Add city-specific data verification
- Compute templates: Pre-built Cartesi apps for local applications
- Validator sets: Include local institutions as operators
- Privacy levels: Configure anonymization and disclosure rules
Interoperability
While sovereign, City Chains remain connected:
- Cross-chain messaging: Send attestations to other City Chains
- Shared standards: Compatible attestation schemas and APIs
- Network effects: Benefit from the broader ecosystem
- Payment routing: All settlements flow through Locale Network (L2)
Architecture
Core Components
| Component | Description |
|---|---|
| Attestor Node | L{CORE} instance for data verification and TEE attestation |
| Cartesi VM | Deterministic Linux-based compute for complex logic |
| State Manager | Maintains canonical attestation state |
| Message Relay | Posts attestations and proofs to Locale Network (L2) |
Governance Framework
City Chains can adopt a templated governance framework with these capabilities:
| Function | Description |
|---|---|
| propose | Create a new governance proposal with targets and calldata |
| castVote | Vote on an active proposal (for/against/abstain) |
| execute | Execute a passed proposal after timelock |
| cancel | Cancel a proposal before execution |
Civic DAO Integration
City Chains can integrate with Civic DAOs for local stablecoin governance:
| Capability | Description |
|---|---|
| Stablecoin Parameters | Civic DAO governs local stablecoin policies |
| Treasury Management | Community-controlled treasury on L2 |
| Merchant Programs | Governance over merchant incentive programs |
| Data Policies | Community decisions on data sharing and privacy |
Deployment Models
Municipal Deployment
City government operates the City Chain:
- Pros: Official backing, regulatory clarity
- Cons: Slower decision-making, political risks
- Best for: Large cities with technical capacity
Community Deployment
Community organization operates the City Chain:
- Pros: Faster iteration, community-driven
- Cons: Less official recognition
- Best for: Neighborhoods, districts, or regions without municipal support
Hybrid Deployment
Partnership between city and community:
- Pros: Official backing with community agility
- Cons: Requires coordination
- Best for: Most deployments
Status
City Chain infrastructure is currently in development. No live City Chains are deployed yet. Follow our roadmap for launch updates.