First publishable platform addon surface. Developer apps owned by orgs, addon listings with automated checks plus manual review, install flow with explicit scope consent and auto-provisioned per-install credentials, dual-secret webhook rotation, and this twelve-page documentation hub.

Scopes

No new scopes added at v2.1. The read catalog stays stable at 13 public.* scopes (see the Scopes page). Write scopes (*:write) remain deferred to a future milestone with an idempotency contract.

Events

Ten new audit-grade platform.* event types landed alongside the existing transactional event catalog. Each is emitted synchronously inside the originating transaction (B1 audit interceptor contract).

• platform.developer_app.created — A developer app is created by a builder org.
• platform.developer_app.activated — A developer app transitions from draft to active.
• platform.developer_app.revoked — A developer app is permanently revoked; downstream cascade fires.
• platform.listing.submitted — An addon listing is submitted into the review queue.
• platform.listing.approved — A platform admin approves a listing.
• platform.listing.rejected — A platform admin rejects a listing with required ≥40-char notes.
• platform.webhook.secret_rotated — A webhook endpoint secret is rotated; 72h dual-secret window opens.
• platform.install.created — A consumer org installs an addon listing; credentials are auto-provisioned.
• platform.install.revoked — An install is revoked; api_key + webhook_endpoint cascade to disabled.
• platform.install.key_rotated — An install's auto-provisioned API key is rotated.

Webhooks

Dual-secret rotation with 72-hour grace window shipped in B2.1. During the window, every delivery is signed with both old and new secret in separate X-GA-Webhook-Signature headers so receivers can roll their verifier without dropping deliveries.

Capability flags

Three capability flags gate the v2.1 surface. All default to OFF in production at v2.1 ship; opt-in is per-organization via Settings → Capability Flags.

• feature.developer_apps — Builder hub at Settings → Developers (B4).
• feature.addon_marketplace — Consumer-side Integrations → Apps catalog and install flow (B5).
• feature.platform_admin_console — Listing review queue at Settings → Platform → Listing Review (B5).

Console

New Settings → Developers builder hub (B4: developer apps + addon listings + scope/justification editor). New consumer Integrations → Apps catalog + consent modal with plaintext-once credentials screen + per-install rotate/revoke (B5). New Settings → Platform → Listing Review admin queue with conflict-of-interest enforcement (B5).

Site

This /developers hub expanded from a single landing page to twelve pages (B6): landing, quickstart, authentication, scopes, webhooks, events, sdks, apps, review-policy, changelog, security, and four template recipes.

New endpoints

Twenty-eight new console-internal endpoints across builder/consumer/admin surfaces. The public read API surface stays at the v1 contract; no new public.* endpoints landed at v2.1.

Not shipped (deferred)

OAuth 2.0 server endpoints (authorize/callback/token) are not implemented. Write API surfaces remain deferred pending an idempotency contract. No first-party SDKs published. No automated cross-repo end-to-end test; the cross-repo integration playbook is the manual contract. No paid addons, no billing surface, no revenue-share mechanic.