VGV Wingspan

An agentic engineering workflow for AI coding agents.

Wingspan structures every AI-assisted coding session into four deliberate phases: brainstorm, plan, build, and review. It’s open source, it runs in Claude Code, Codex, Gemini CLI, and other coding agents, and it encodes the engineering practices we use every day at VGV.

Install Wingspan View on GitHub

Open source under the MIT license.

/brainstorm how should we add authentication to this app?

Email and password, OAuth, or both at launch?
Which screens should a signed-out user still reach?
Saved docs/brainstorm/add-authentication.md

Clear context and plan

/plan add email/password and OAuth login using the auth approach from our brainstorm

Reading the brainstorm and the codebase
Quality pass on the draft, split into 3 phases
Saved docs/plan/add-authentication.md

Clear context and build

/build docs/plan/add-authentication.md

Phases 1 to 3, code and tests
5 review agents in parallel, 2 findings fixed
Pull request opened

/review

VGV standards, architecture, test quality, simplicity
One report, FINDING-01 to FINDING-03

01 docs/brainstorm/add-authentication.md
02 docs/plan/add-authentication.md
03 Pull request

An illustration of one feature through the four phases. The context fills while a phase works and clears before the next, and the file it saved carries the decisions forward.

In their words

Very Good Ventures

“Wingspan allows me to focus on the right level of detail at each step. I can explore and clarify the big questions and trade-offs in brainstorm, turn my decisions into a concrete plan, and review the final product for correctness, not analysis errors.”

Senior Engineering Lead Brian Egan
Very Good Ventures

“I was shocked the first time I used /brainstorm - it asked incredibly intelligent questions about my codebase. I was implementing a cart page on an ecom flow, and the design had a line for modifications. I hadn't yet considered the modifications and it didn't even exist in the API yet. /brainstorm identified the discrepancy and asked me to pick from three resolutions that were all plausible solutions. It was that day I was a believer in this flow.”

Engineering Lead & Google Developer Expert Marcus Twichel
Very Good Ventures

“While teams are struggling to adapt agentic workflows in a predictable way, our AI tooling ecosystem is allowing engineering teams to adopt AI without slop, focusing on the best practices. The combination of VGV AI Flutter Plugin, VGV Wingspan, and VGV Arcana are positively impacting the way we deliver value together with our partners.”

VP of Engineering Jorge Coca

Each phase feeds the next.

Each phase produces artifacts that feed into the next, so you can clear context between steps without losing work.

01
Brainstorm

Explore requirements, constraints, and approaches through collaborative dialogue. The agent asks questions before it writes any code.

LeavesA brainstorm document in docs/brainstorm/
02
Plan

Reviews your codebase, references the brainstorm, and produces a phased, step-by-step plan. Simplicity, VGV, and scope agents review the draft in parallel before you build.

LeavesA plan in docs/plan/, split into phases so /build runs one per context window
03
Build

Executes the plan one phase per context window. Writes code and tests, commits each phase, runs quality review, and drives the checks to green before it opens a pull request.

LeavesA pull request, once five review agents have checked the branch
04
Review

Runs specialized agents in parallel, on demand: VGV standards, architecture, test quality, and simplicity.

LeavesOne consolidated report, with stable FINDING-NN ids

Flexible by design.

Have a simple bug fix? Jump straight to /build with a description. Already know exactly what you want? Start at /plan.

Full cycle, new features, big changes

/brainstorm add image cropping to the edit page
Explores packages, UX approaches, placement decisions
docs/brainstorm/2026-03-31-image-crop-brainstorm-doc.md
/refine-approach
Catches gaps and contradictions
Clear context and plan
/plan implement image cropping from our brainstorm
Codebase review, user-flow analysis, external docs research
docs/plan/2026-03-31-feat-image-crop-plan.md
Clear context and build
/build docs/plan/2026-03-31-feat-image-crop-plan.md
Code + tests + analysis
/review
Agents assess quality in parallel, fixes critical and important findings

Short cycle, medium changes

/brainstorm add a way to edit entries in the gallery
Quick Q&A, approach selection
/plan implement entry detail page
Picks up brainstorm, runs research agents
/build docs/plan/...
Full implementation
/review
Quality check before merge

No cycle, small changes

The empty state shows a paw print icon, change it to a fish

Hotfix, production bugs

/hotfix users are seeing a render overflow on the edit page when the keyboard opens
A minimal, targeted fix. Review and testing still run, brainstorm and planning don’t.

Five agents review every build.

Agents reviewing from different angles catch more issues than a single comprehensive review. The disagreements between them often surface the most interesting problems.

@vgv-review-agent VGV engineering standards: architecture, state management, testing, simplicity Clear
@architecture-review-agent Layer separation, dependency direction, package structure 2 findings
@test-quality-review-agent Every testable unit has proper tests Clear
@code-simplicity-review-agent YAGNI violations and simplification opportunities 1 finding
@pr-readiness-review-agent Formatting, static analysis, debug artifacts, commit hygiene Clear

One report 3 findings

FINDING-01 Critical The AI identification button is wired to the UI, but its Cubit event handler never was. No crash, no error, just silent failure. code-simplicity
FINDING-02 Important A TextEditingController is initialized inside build(), so it is recreated on every rebuild and loses its state. architecture
FINDING-03 Important A widget calls the repository directly instead of going through the cubit. architecture

Fix scope

Critical only
All issues
Just bugs

Fixed, then analysis and tests run again

Three findings the agents caught while building the Fish Tank Tracker, gathered into one report for this illustration. Read the tutorial

Wingspan covers the workflow. The plugin covers the conventions.

The workflow phases are stack-agnostic by design. On a Flutter project, Wingspan recommends the VGV AI Flutter Plugin once per session, before any code exists.

Five Flutter apps in a month, by one engineer.

Very Yummy Coffee: a mobile ordering app, a self-service kiosk, a point-of-sale terminal, a kitchen display system, and a menu board, all built with Wingspan on one shared codebase.

Read how Marcus built them

Install it in every agent you use.

Then open a project in your coding agent and try /brainstorm to start your first structured engineering session.

Follow the getting started tutorial

Any coding agent, with the VGV AI CLI

$dart pub global activate vgv_ai_cli $vgv_ai install

It sets Wingspan up in each agent it finds on your machine: Claude Code, Codex, Gemini CLI, OpenCode, Pi, GitHub Copilot CLI, and Antigravity CLI.

Claude Code only, from your terminal

$claude plugin marketplace add VeryGoodOpenSource/very-good-claude-code-marketplace && claude plugin install vgv-wingspan

Or inside a Claude Code session, one after the other

›/plugin marketplace add VeryGoodOpenSource/very-good-claude-code-marketplace
›/plugin install vgv-wingspan

From the blog

Before your first brainstorm.

01 Is Wingspan free?

Yes. It’s open source under the MIT license, and all of it is on GitHub.

02 Does it only work for Flutter?

No. The workflow phases are stack-agnostic by design, so teams on web, native, or embedded systems can use the same loop. The Flutter depth comes from the VGV AI Flutter Plugin, which Wingspan recommends when it detects a Flutter project.

03 Which coding agents does it work with?

Seven today. The VGV AI CLI sets Wingspan up in Claude Code, Codex, Gemini CLI, OpenCode, Pi, GitHub Copilot CLI, and Antigravity CLI, whichever it finds on your machine. In Claude Code you can also install it from our plugin marketplace.

04 Do I have to run all four phases?

No. Have a simple bug fix? Jump straight to /build with a description. Already know exactly what you want? Start at /plan. For production bugs, /hotfix applies a minimal fix and still runs review and tests.

05 What does it leave in my repo?

The brainstorm and the plan, as markdown in docs/brainstorm/ and docs/plan/, so the next phase can pick them up after you clear context. The review reports from /build are deleted once the pull request is ready.

06 Is it ready for production work?

It’s in alpha, at version 0.0.5, and the team iterates on it from how VGV uses it every day. Issues and ideas go on the GitHub repo.