April 2025 | 12 meetings | ~9.3 hours of recordings
Q1 2025 was defined by two parallel tracks: deepening Concerto’s modeling capabilities and orchestrating the project’s most ambitious Google Summer of Code campaign to date. The quarter opened with a series of Concerto metamodel improvements — alias resolution fixes, DecoratorManager migration APIs, and metamodel versioning strategy — and closed with GSoC applications open and five projects accepted. The first external runtime community member, Tim, introduced the De Combine SLC Go-based finite state machine as a candidate successor to Ergo for contract execution, and template playground performance work began in earnest. The quarter also included the first Accord Project in-person TSC meetup, planned for Dublin in early April.
Key Developments
- GSoC 2025 accepted at record scale. The project applied with seven ideas, was accepted as a GSoC org in late February, and received contributor proposals opening March 24th. Five projects were ultimately funded – the most in the project’s history.
- De Combine SLC introduced. Tim brought De Combine, a Go-based smart legal contract runtime using finite state machines and Open Policy Agent, into the Accord Project orbit – the first serious external proposal for a Concerto-integrated execution runtime post-Ergo.
- Concerto metamodel refinements. Alias resolution was fixed via a new resolvedName property on TypeIdentifier; the DecoratorManager gained public canMigrate and migrate APIs; and the team began formalising a metamodel versioning strategy.
- Template Playground performance push. Mahesh’s bundle-splitting, lazy loading, and web-worker research moved GT Metrics from 28% to 58%, laying the groundwork for the GSoC Tailwind CSS redesign project.
- In-person meetup confirmed. The first Accord Project in-person TSC gathering was confirmed for April 7-8 in Dublin, hosted at DocuSign’s offices, covering roadmap planning, GSoC contributor selection, and project budgeting.
Announcements
- Accord Project accepted as a Google Summer of Code 2025 mentor organisation (February 27)
- TSC expanded to seven seats; Jonathan Lautenschlager (DocuSign) elected as newest member
- Matt Roberts re-elected as TSC chair
- GSoC contributor applications open March 24 – April 8
- In-person TSC meetup confirmed: April 7-8, DocuSign Dublin office
- Concerto .NET library updated to .NET 8 and C# 12
Meeting Summaries
January 8 – Concerto Aliasing and Web Components
The first call of the year covered a newly-discovered Concerto bug where resolving an aliased model import in the AST loses the alias name reference; Sanket proposed adding a new resolvedName property to the TypeIdentifier concept. Nile presented proposed AP spec changes including pagination support, REST-style conventions, and ETag headers. The group agreed that the web-components repository needed a full reinvigoration rather than piecemeal fixes.
January 22 – Metamodel Versioning and GSoC 2025
Sanket merged a Concerto metamodel PR adding a dedicated property to TypeIdentifier to hold the resolved declaration name. A follow-up PR exposed canMigrate and migrate methods on the DecoratorManager. The group debated metamodel versioning strategies, and Diana and Sunki agreed to co-administer the GSoC 2025 application, targeting the February 11th org deadline.
January 29 – GSoC Ideas and Concerto .NET Status
The Concerto .NET package was reviewed as needing a dedicated maintainer. GSoC 2025 ideas were brainstormed – Rust validator, decorator DSL/YAML, AI-assisted template authoring – with a milestone set to finalise the ideas list at the Feb 5 call. The concerto-analysis package DCO issue was resolved and the PR cleared for merge.
January 30 – TSC Elections and Edinburgh Meetup (TSC Meeting)
The TSC voted to expand membership from six to seven seats and elected all seven nominees – Martin, Matt, Jonathan, Diana, Dan, Tom, and Naill – by acclamation. Jonathan Casey, a senior Concerto engineer at DocuSign Dublin, was formally welcomed as the newest TSC member. Diana presented the draft GSoC 2025 ideas list and the group agreed to expand it to 8-10 projects.
February 5 – Google Summer of Code 2025 Planning
The team finalised seven project ideas: a Concerto linter, decorator command set YAML serialisation, conformance test refactoring, Docker-based code-generation testing, AI copilot for Template Playground, an APAP reference implementation, and a Tailwind CSS redesign. The Rust/WASM validator was removed from GSoC scope in favour of an in-house proof-of-concept first.
February 12 – Metamodel Versioning and Template Performance
Tim introduced the DE Combined Smart Legal Contract specification and expressed interest in integrating Concerto as the default text-layer standard – the first external runtime community interest of the quarter. The group discussed replacing hardcoded metamodel version references with a dynamic getMetamodelNamespace() method. Mahesh reported a preliminary ~20% performance improvement using web workers for Template Playground compilation.
February 26 – De Combine SLC Runtime and Playground Performance
Tim presented De Combine, a Go-based SLC runtime using UML state machines and NATS/CloudEvents for event-driven state transitions, with planned Concerto model integration. Mahesh demonstrated Monaco editor performance improvements boosting GT Metrics from 28% to 58% via lazy loading.
February 27 – TSC Elections and GSoC Acceptance (TSC Meeting)
Matt was re-elected as TSC chair. Diana announced that Accord Project was formally accepted into Google Summer of Code 2025, with contributor proposals opening March 24th. The TSC confirmed the in-person meetup for April 7-8 at DocuSign’s Dublin office, with travel funding agreed for Tom.
March 5 – GSoC, Template Playground, De-Combine SLC
With GSoC acceptance confirmed, contributors were directed to submit proposals through March 24th. A recurring CloudFront 403 error on shareable template links was traced to a URI size limit breach at 2 MB. Tim presented De Combine SLC’s architecture and opened discussion on using Concerto models to replace Ergo as the contract execution runtime.
March 12 – DeCombine SLC Demo and GSoC Prep
Tim demonstrated DeCombine SLC Runtime v0.2.0-alpha: a Go-based smart legal contract engine using a finite state machine with Open Policy Agent (Rego) guard conditions and bidirectional NATS event streaming. The group explored integrating Concerto, TemplateMark, and APAP with DeCombine. The Dublin meetup was formally confirmed for April 7-8.
March 19 – GSoC, Template Playground, deCombine
Template Playground shipped undo/redo buttons, a tour skip button, and a dark-mode Learn page. GSoC mentors were reminded to log in and accept 2025 terms before March 24th. Tim presented a deCombine integration design mapping Concerto/APAP parsed agreement data to state machine variables.
March 26 – AI Playground, Template Archive, APAP
GSoC alumni David presented an AI integration prototype for Template Playground featuring HuggingFace and Gemini fallback models, editor-aware prompting, and a diff-based accept/reject UI. Dan outlined template archive v0.25 work-in-progress to replace Ergo with TypeScript logic. Tim explored building a Go-based TemplateMark parser using the Goldmark library for the APAP reference implementation.
Plans and Upcoming Work
- Dublin in-person meetup (April 7-8) covering roadmap, GSoC selection, and budgeting
- GSoC 2025 contributor selection and onboarding (announced May 8)
- TypeScript template engine in Cicero (Dan, demo planned)
- Template archive v0.25 with TypeScript logic replacing Ergo
- De Combine SLC / Concerto integration design
- APAP reference implementation build-out