Development Fund Proposal
Author: Erkan Efe (e***@gmail.com)
Status: Submitted
Created: 2026-04-03
Abstract
This proposal is based on direct observation of repeated interaction patterns and inconsistencies encountered while building multi-party workflows on Canton. Canton Interaction Primitives is a reusable Daml primitive kit for modeling multi-party interaction lifecycles on Canton. The project addresses a recurring ecosystem gap: teams repeatedly re-implement the same approval and lifecycle patterns from scratch. This proposal requests funding to deliver a staged, production-oriented primitive layer across 5 milestones: core intent/consent primitives, negative path and resolution semantics, multi-party approval patterns, stabilization, and documentation/release.
Specification
1. Objective
Establish a reusable application-layer interaction standard for Canton that reduces duplicated workflow logic and improves consistency across projects.
Target outcome:
- a minimal but composable primitive set for interaction lifecycle modeling
- explicit and verifiable state transitions
- reusable reference flows that teams can adopt directly
Core lifecycle model:
Intent -> Consent -> Resolution
2. Implementation Mechanics
The solution is implemented as modular Daml primitives plus reference flows and validation scripts.
Scope by capability:
- Interaction initiation and authorization
Intent primitive for structured interaction requestsConsent primitive for approval formation
- Interaction resolution
- explicit execution boundary
- reject/cancel/expiry semantics for stalled or failed interactions
- Composition and validation
- reference flows for single-party and multi-party approval models
- script-based validation for allowed and forbidden transitions
Implementation principles:
- minimal abstractions
- explicit transitions over hidden mutable state
- composability over framework-style orchestration
3. Architectural Alignment
This work aligns with Canton ecosystem priorities by improving application-layer developer ergonomics without changing protocol behavior.
Alignment points:
- uses native Daml authorization and visibility semantics (signatories/controllers/choices)
- complements existing infrastructure/tooling rather than replacing it
- provides reusable patterns that can be applied across domains (payments, asset flows, coordination workflows)
- reduces friction in onboarding and prototyping for multi-party app teams
4. Backward Compatibility
No backward compatibility impact.
This project introduces reusable application-layer primitives and examples. It does not require protocol changes or breaking migrations to existing Canton infrastructure.
5. Risks and Mitigation
- Risk: scope creep from trying to model every workflow shape
- Mitigation: strict milestone scope and explicit out-of-scope definitions
- Risk: over-abstraction that harms usability
- Mitigation: incremental delivery, real-flow validation, refinement in Milestone 4
- Risk: authorization edge-case regressions in multi-party extensions
- Mitigation: script-based validation of allowed/forbidden transitions and reference composition tests
Milestones and Deliverables
Milestone 1: Core Interaction Primitives
| Detail | Description |
|---|
| Estimated Delivery | Weeks 1-3 |
| Focus | Minimal Intent and Consent primitives with explicit state transitions |
Deliverables / Value Metrics:
- minimal Daml modules for core interaction primitives
- working reference flow: intent -> consent -> state transition
- script validation of lifecycle and authorization boundaries
Acceptance Criteria:
- at least 1 reference interaction flow implemented and executable
- full lifecycle validation via script (intent -> consent -> state transition)
- requester/approver authorization boundaries verified
Out of Scope:
- multi-party approval patterns
- threshold or sequential approvals
- execution or broader resolution logic
Milestone 2: Interaction Resolution and Negative Paths
| Detail | Description |
|---|
| Estimated Delivery | Weeks 4-6 |
| Focus | Reject/cancel transitions and minimal resolution semantics |
Deliverables / Value Metrics:
- primitives extended with negative interaction outcomes
- script validation of allowed and forbidden transitions
Acceptance Criteria:
- explicit
reject and cancel transitions implemented
- script tests cover success and failure paths
- transition validity checks included in validation scripts
Out of Scope:
- workflow orchestration frameworks
- participant/network-level operations
- UI/devtool surfaces
Milestone 3: Multi-Party Approval Patterns
| Detail | Description |
|---|
| Estimated Delivery | Weeks 7-8 |
| Focus | Basic multi-party approval models and composability |
Deliverables / Value Metrics:
- reference implementations for multi-party approval flows
- composability examples with existing primitives
Acceptance Criteria:
- at least 2 multi-party approval patterns implemented
- composability with existing primitives demonstrated
- script-based validation of multi-party behavior
Milestone 4: Refinement and Stabilization
| Detail | Description |
|---|
| Estimated Delivery | Weeks 9-10 |
| Focus | API/primitive boundary cleanup and consistency hardening |
Deliverables / Value Metrics:
- stabilized primitive APIs
- reduced abstraction noise and cleaner composition boundaries
Acceptance Criteria:
- primitive interfaces remain minimal and internally consistent
- redundant abstractions removed
- stable composition patterns documented in code/docs
Milestone 5: Documentation and Release
| Detail | Description |
|---|
| Estimated Delivery | Week 11 |
| Focus | Documentation, release readiness, and open-source publication |
Deliverables / Value Metrics:
- public repository with primitives, examples, and usage docs
- end-to-end documented reference flow
Acceptance Criteria:
- documentation covers all core primitives and usage patterns
- at least one complete reference flow documented end-to-end
- repository is usable as a starting point for new Canton applications
Funding
Total Funding Request: 400,000 CC
Payment Breakdown by Milestone
- Milestone 1 (Core Interaction Primitives): 110,000 CC upon committee acceptance
- Milestone 2 (Interaction Resolution and Negative Paths): 90,000 CC upon committee acceptance
- Milestone 3 (Multi-Party Approval Patterns): 100,000 CC upon committee acceptance
- Milestone 4 (Refinement and Stabilization): 60,000 CC upon committee acceptance
- Milestone 5 (Documentation and Release): 40,000 CC upon final release and acceptance
Volatility Stipulation
The project duration is under 6 months.
If delivery extends beyond 6 months due to Committee-requested scope changes, remaining milestones should be re-evaluated to account for significant USD/CC volatility.
Co-Marketing
Upon release, the implementing entity will collaborate with the Foundation on:
- announcement coordination
- a technical write-up/case study covering lifecycle primitive design
- ecosystem-facing developer education and onboarding content
Motivation
Canton provides strong protocol and authorization primitives, but application teams still repeatedly rebuild multi-party interaction lifecycle logic. This causes duplicated effort, inconsistent state handling, and subtle lifecycle bugs across projects.
The proposed primitive layer addresses this structural gap by providing a shared interaction language that is explicit, composable, and reusable across application domains.
Rationale
This is the right approach because it targets the highest-leverage missing layer: reusable application interaction structure on top of existing Canton capabilities.
Why this design:
- minimal primitives reduce adoption friction
- explicit transitions improve correctness and auditability
- incremental milestones prevent overengineering
- reference flows turn abstractions into practical integration guidance
Alternatives considered:
- building a full workflow framework: rejected due to heavy adoption overhead and reduced flexibility
- relying on ad-hoc project templates: rejected because it does not create a stable reusable interaction standard
