diff --git a/openspec/changes/2025-11-17-web-stack-decision/proposal.md b/openspec/changes/2025-11-17-web-stack-decision/proposal.md
new file mode 100644
index 0000000..bc01518
--- /dev/null
+++ b/openspec/changes/2025-11-17-web-stack-decision/proposal.md
@@ -0,0 +1,46 @@
+# Proposal: Web Stack Decision
+
+Status: draft
+Authors: Platform Team
+Owners: Architecture Lead, Web Lead
+Created: 2025-11-17
+Scope: spec
+Related: openspec/specs/architecture.md
+
+Summary
+- Decide between Next.js (React/SSR) vs Flutter Web to deliver accessible, SEO‑friendly, performant web with parity to mobile.
+
+Motivation
+- Ensure the web stack supports public SEO content (resources/blog), members‑only features, and strong a11y/compliance.
+
+Goals / Non‑Goals
+- Goals: select stack, document SSR/SEO approach, a11y/testing strategy, and performance budgets.
+- Non‑Goals: design system details (future proposal).
+
+Evaluation Criteria
+- Accessibility: semantic HTML, keyboard/focus, screen readers, reduced motion, large text.
+- SEO & SSR: canonical URLs, Open Graph, sitemaps, incremental static regen.
+- Performance: Core Web Vitals targets (LCP < 2.5s, INP < 200ms, CLS < 0.1).
+- Ecosystem: routing, data fetching, auth integration, CMS/blog interop.
+
+Options
+- Next.js (App Router, React 18, RSC + server actions)
+- Flutter Web (single codebase, a11y improvements; evaluate SEO constraints)
+
+Risks & Mitigations
+- SEO constraints with Flutter Web → fallback to Next.js for public surfaces if chosen.
+
+Rollout Plan
+- Implement public resource list and blog index prototype; measure CWV and a11y checks.
+
+Test Plan
+- Lighthouse/CWV, axe, keyboard nav tests; SEO meta validation.
+
+Acceptance Criteria
+- Decision recorded with rationale; prototype metrics captured; a11y/SEO sign‑off.
+
+Slash Commands
+- `/review areas=web,accessibility,security`
+- `/apply spec=openspec/specs/architecture.md`
+- `/archive link=<PR>`
+