July 2026 | 13 meetings | ~10.6 hours of recordings
If Q1 2026 was about foundational investment, Q2 was about cashing it in. The Concerto V4 migration completed in Q1 paid off as the entire template stack — Markdown Transform, Cicero, and the Archive Format — reached stable 1.0 releases. The project’s funded Google Summer of Code 2026 programme moved from selection to execution, with contributors starting a Rust port of Concerto Core, a Dockerized CodeGen CI pipeline spanning 16 target languages, an LLM-based template executor, and APAP/MCP hardening, and browser-based execution of templates in Template Playground — all reaching midpoint demos by quarter’s end. June brought a clear strategic pivot: the group began positioning the Accord Project as the legal and obligations layer above emerging agent-to-agent payment protocols, backed by live multi-agent demos settling smart legal contracts on the Sui blockchain. The quarter closed with preparations for the project’s 2026 summit, in Dublin on July 6–7, hosted by Docusign.
Key Developments
- Template stack shipped 1.0. Markdown Transform, Cicero, and the Archive Format were all upgraded to version 1.0 on Concerto v4 — the direct payoff from Q1’s V4 migration. The group set plans to consolidate its three separate VS Code extensions into a single Concerto-based extension.
- GSoC 2026 ran at full scale. Google funded 5 proposals; contributors were announced April 30 and projects officially began May 7 on an eight-week timeline with formal evaluation milestones.
- Concerto CodeGen matured to V5. Breaking changes in the C# generator drove a major version bump. Hardening resolved empty-enum failures in GraphQL/JSON Schema generation and non-primitive Protobuf map-type issues.
- Validation API redesigned. An ergonomic Concerto validation API is under design, consolidating validate/validateOrThrow/isValid and introducing validateInstance, with meta-model validation (strict vs. loose deserialization, reject-unknown-key/reject-null).
- Locale-aware, vocabulary-driven templates. Sustained work across the quarter built out vocabulary features for multi-language template support across different locales — a recurring thread from April through late May.
- Strategic pivot to agentic payments. June saw the project engage emerging agent-to-agent payment protocols (AP2, x402, A2A, UCP, Mastercard’s Agent Pay), with live multi-agent demos settling smart legal contracts on the Sui blockchain and a clear positioning of the Accord Project as the legal and constraint layer above agentic payment rails.
- Concerto Playground prototype. An interactive playground for learning Concerto’s data-modelling syntax was released.
Announcements
- Google Summer of Code 2026: Google funded 5 mentorship proposals (April 8)
- GSoC 2026 contributors announced April 30; projects officially began May 7
- Template stack 1.0 released — Markdown Transform, Cicero, and the Archive Format on Concerto v4 (June 10)
- Concerto CodeGen V5 released — C# breaking changes plus a patch for an accidental breaking change
- In-person summit confirmed for Dublin, July 6–7, hosted by Docusign
- July 1 call dedicated to GSoC 2026 midpoint demos
Meeting Summaries
April 1 – Open Agreements Demo, Tree-Sitter & Obligations Framework
Three community demos anchored the call. Steven presented Open Agreements, using Concerto as a DSL for legal templates with an MCP server for AI-powered form filling via Claude; Jamie showed a Tree-Sitter parser bringing Concerto syntax highlighting and editor motions to Neovim, Helix, and Zed with WASM compilation support; and Niall walked through an obligations framework modelling a hierarchy of performance, payment, SLA, and notification obligations, covering both the legal and technical implementation. On GSoC, 201 applications had been received, with accepted contributors due to be announced April 30.
April 8 – Template Engine v4 & GSoC 2026 Funding
The headline was GSoC: Google confirmed funding for 5 of the project’s 7 submitted mentorship proposals. Discussion covered Template Engine v4 breaking API changes, the versioning strategy, and a new strict parameter, alongside planning for Concerto .NET and Rust runtime integration and their validation approach. A key recovery project update and ongoing PR reviews rounded out a shorter call.
April 15 – CodeGen V5 & Research Presentations
The group planned a major version release of the Concerto code-generation framework (CodeGen V5) and worked through the breaking changes it would involve. Contributors also presented research findings and technical investigations feeding into the quarter’s roadmap.
April 22 – Vocabulary Support, CodeGen Architecture & Template Development
Work centred on implementing vocabulary features to enable multi-language template support, improvements to the code-generation framework and its target-language coverage, and ongoing smart legal contract template design and enhancements.
April 29 – GSoC Onboarding, CodeGen Development & Model Design
With GSoC contributors selected, the call focused on project planning and onboarding preparations for the incoming cohort. CodeGen framework updates and feature development continued, alongside architecture discussions for templates and Concerto data models.
May 6 – Vocabulary Implementation, CodeGen & Template Architecture
The group advanced vocabulary features for multi-language templates, worked through code-generation enhancements and breaking-change management, and discussed template design patterns and implementation strategies.
May 7 – GSoC Kick-Off & Project Evaluation Framework
Google Summer of Code projects officially began, with the mentorship timeline set out. The CodeGen project was scoped as an eight-week effort with formal evaluation milestones, and the group established the broader GSoC evaluation structure and contributor milestones.
May 13 – Concerto Playground Prototype & V4 Upgrade
A prototype interactive Concerto playground was demonstrated as a way to learn the data-modelling syntax hands-on. The call also covered vocabulary implementation improvements and bug fixes for Concerto models, and progress upgrading Concerto to V4 across dependent packages.
May 20 – CodeGen PR Review & Research Presentations
Two CodeGen pull requests were reviewed, addressing breaking changes and new features. GSoC contributors were introduced and research initiatives discussed, along with Concerto model architecture and integration patterns.
May 27 – Concerto Validation API, Locale-Aware Templates & CodeGen V5
The group reviewed an ergonomic Concerto validation API offering both instance and model validation. Design work continued on vocabulary-based multi-language templates across different locales, and breaking changes in the C# code generator prompted a major version bump for CodeGen V5.
June 10 – Template Stack 1.0, GSoC Updates & AP2 Preview
A milestone quarter delivered a milestone release: the template stack — Markdown Transform, Cicero, and the Archive Format — was upgraded to version 1.0, all built on Concerto v4. The group planned to consolidate its three separate VS Code extensions into a single Concerto-based extension, reviewed GSoC progress on the Rust port of Concerto Core and CodeGen CI (including a v5 patch for an accidental breaking change), and worked through a deep-dive on ModelManager mutability and cloning inconsistencies, weighing a copy-on-write approach inspired by Rust’s Cow type. A preview teased the following week’s session on AP2/x402/A2A agentic payment protocols with a live agent-to-agent settlement on the Sui blockchain.
June 17 – Concerto CodeGen CI & Agentic Payments
Apoorv demoed a GSoC-built Dockerized CI pipeline that compile-checks generated code across 16 target languages via a GitHub Actions matrix, surfacing two hardening bugs — empty enums breaking GraphQL/JSON Schema generation, and non-primitive Protobuf map key/value types failing during HR model integration. The group also proposed simplifying the Concerto validation API, renaming the core operation to validateInstance and consolidating validate/validateOrThrow/isValid. Niall then surveyed emerging agentic payment protocols (A2A, x402, AP2, UCP, Mastercard’s Agent Pay) and ran a live multi-agent demo settling a smart legal contract payment on the Sui blockchain, with Matt framing SaaS-renewal and shipping-insurance use cases for human-agent payment guardrails. GSoC midterm demos were scheduled and the Dublin meetup confirmed for July 6–7.
June 24 – Concerto Validation, Dublin Meetup & Agentic Payments
Discussion of meta-model validation PRs (#1239 and #1273) covered strict vs. loose deserialization, reject-unknown-key and reject-null options, and API consistency between meta-model and normal model validation. The group confirmed that the July 1 call would be dedicated to four GSoC contributors presenting midpoint demos, and walked through the agenda for the July 6–7 Dublin summit hosted by DocuSign — hands-on demo-building, partnerships, and the TSC election timeline. Continuing the agentic-payments thread, a milestone-based payment contract was demoed settling on Sui, with the strategic framing of the Accord Project as the legal and constraint layer sitting above agentic payment rails, ahead of building a flagship demo for Dublin.
Plans & Upcoming Work
- Dublin summit (July 6–7): hands-on demo-building, partnerships, and the TSC election timeline
- Flagship agentic-payments demo for Dublin — the Accord Project as the legal/obligations layer over AP2/x402/A2A rails
- GSoC 2026 midpoint demos (July 1 call) and final evaluations through August
- Concerto Rust port continuing toward multi-platform validation (WASM, C FFI, CLI targets)
- Concerto validation API consolidation (validateInstance) shipping
- VS Code tooling consolidation into a single Concerto-based extension
- AI-driven Playground demo: upload a contract PDF and interact via chat
- TSC elections