Document root is now a single Specification (Project wrapper and specifications[] array removed)

Structured planning core: goals, requirements, scope, NFRs, guardrails, techStack, folderStructures

New: epicTargets, fieldDeclarations (N/A escape hatch), sharedPatterns, estimatedMinutes

schemaVersion replaces openSpecVersion; ticket dependency uses ticketId

Strict schema (additionalProperties: false); status/priority enums removed

v1.0 retained permanently at its existing schema URL

Initial OpenSpec v1.0 schema published

6 core entities: Project, Specification, Epic, Ticket, Blueprint, Patterns

Three format support: JSON, YAML, TOON

@blacksmithers/openspec npm package with CLI and programmatic API

Dependency graph with blocks/requires relationship types

Ticket status: pending → ready → active → done (blocked signaled via statusReason)

RFC 0001 documenting all v1.0 design decisions

GOVERNANCE.md with OpenAPI-style change tiers (patch/minor/major)