M0 Validation Report

Date: 2026-08-15
Status: PASS

Scope

M0 validates only the high-risk runtime path:

• official three@0.185.1 bundled from npm;
• one stdio MCP Server tool linked to ui://threejs-editor/app;
• a self-contained Pong View running inside the real dsh-uni-editor double iframe;
• WebGL pixels, animation, keyboard input, pause/resume, responsive layout and console output.

Project persistence and Editor controls remain M1/M2 work.

Results

Gate	Evidence	Result
threejs-editor-mcp static checks	TypeScript, production build and MCP protocol test	PASS
dsh-uni-editor checks	TypeScript, build and 3 package tests	PASS
MCP discovery	mcp__threejs__open_three_demo in the live Host catalog	PASS
Real Harness flow	Replay Agent called the MCP tool and rendered its App in Chat	PASS
Sandbox sizing	Outer iframe 748x414; nested iframe 748x414	PASS
WebGL canvas	722x344 drawing surface	PASS
Nonblank pixels	41,395 sampled; 7,737 lit; 240 sampled colors	PASS
Keyboard input	Left paddle Z changed from 0 to -1.61007	PASS
Pause/resume	Ball position remained stable while paused	PASS
Responsive layout	Canvas changed from 722x344 to 494x352 at 640px viewport	PASS
App diagnostics	No page error, console error or Three.js warning	PASS

Findings

Resource size

The offline View is 862,453 bytes, or 208,945 bytes gzip. It correctly failed the Host's default 512 KiB Resource limit during the first E2E run.

The final fixture sets the existing dsh-uni-editor.maxBodyBytes option to 2 MiB. The Host remains bounded; no size validation was removed.

Nested iframe height

The Host resized its outer iframe to 406px, but the Sandbox's nested iframe stayed near the browser default because its wrapper used min-height: 100%.

M0 changes the generic wrapper to html, body { width: 100%; height: 100% }. The final E2E proved equal outer and inner dimensions. This is the only dsh-uni-editor source adjustment; it adds no Three.js behavior and no fullscreen support.

Replay isolation

The deterministic replay fixture records one Session. Final validation used a fresh isolated DSH_HOME so stale Sessions could not consume or invalidate the replay.

Changes

threejs-editor-mcp:

• package, TypeScript and tsdown configuration;
• stdio Server and ui://threejs-editor/app Resource;
• official Three.js Pong View;
• MCP protocol test and Playwright browser gate;
• keyless Harness replay fixtures.

dsh-uni-editor:

• one generic Sandbox height fix in src/sandbox.ts.

Unchanged:

• DeepSeek Harness product source;
• Agent Loop and Session semantics;
• fullscreen and ui/message.

Verification

pnpm run check
pnpm run test:e2e:m0

Build artifacts:

• dist/view.js: SHA-256 0116e05729a6e83769fd071736948a90c2cec00fe5cccbdf7ea6c588f042f12e
• dist/server.js: SHA-256 2ca6552129c0f4d1b8ec71b544270724d98703043ea086d25182f41cee371a77

Next Gate

M1 may add project create/open/pull/push and durable storage. It must not begin until this report is explicitly approved.