Klaviyo revisions don't 410 when they retire - they fall forward. Pinned to 2024-07-15? You've been served 2024-10-15 profile identity-resolution behavior since July 15: a 200, and a header that still says the old date. Writes can land on the wrong profile. Next cliff: Oct 15, 2026.

Aug 1, 2026: Twilio removes conference_participant from Voice Insights Call Summary — REST + Event Streams. It doesn't 404, it uniformly returns attributes: null. Conference analytics don't error, they trend to zero. The field was already null for most calls — which is why nothing trips.

Greenhouse Harvest v1/v2 retires Aug 31, 2026. The loud failure is a 4xx on the dead endpoint. The silent ones hide in the v3 cursor migration: a 422-as-end-of-pages truncation, vanished prev/last Link rels, opaque cursors that drift. What to grep for: https://flarecanary.com

Aug 14, 2026: Contentful's Content Management API makes two breaking changes that both return 200 with less data. The roles endpoint drops total/skip for cursor pagination, and user-data goes role-based so non-admin tokens get trimmed. What to grep for before your space automation quietly desyncs.

monday.com's 2026-07 API is now the default. Unversioned integrations rolled onto it with no deploy — and Query.users without a limit now returns 200 users instead of your whole account. 200 OK, valid JSON, wrong roster. What to grep for: https://flarecanary.com

On Nov 1, 2026, Jira's agile API drops offset pagination (startAt) from board, backlog, sprint & epic endpoints — and stops returning `total`. The loud failure is the removed endpoint. The silent ones: a loop that exits after page one, a short-page heuristic that drops the tail. What to grep for →

Google Ads API v21 sunsets ~Aug 6. The version cutoff is loud — the forced migration to v23 is silent: a removed enum (VIDEO_OUTSTREAM) makes your ad-type switch fall through, asset performance-labels come back blank, a renamed error field zeroes out. All 200 OK. What to grep for:

Xero's `Reference` field stops returning invoice numbers on July 13, 2026 — it flips to real reference data. Same field, same 200 OK, and your prepayment reconciliation silently matches the wrong invoice, or none. Migrate to InvoiceNumber now. https://flarecanary.com

PayPal IPN/Website Payments Standard is deprecated (EOL Jan 2027). The IPN→Webhooks migration drops payments four silent ways: form parser reads every field as undefined, moved/renamed field paths, Completed→COMPLETED status flip, and RSA-SHA256 verification skip becoming an open endpoint.

OpenAI removes the Assistants API on Aug 26, 2026 — that's the easy part. Migrating to Responses breaks state, RAG grounding, and SSE streaming with a 200 and no error at all. The silent-failure checklist to run before you ship:

Shopify stops serving API version 2025-07 on July 16, 2026. Pinned apps don't get an error — requests silently fall forward to 2025-10's schema. Same 200, different response shape. The only tell is a header almost nobody reads.

Shopify retires API version 2025-07 on July 16. Pinned apps don't error - Shopify falls forward to 2025-10 and silently serves a different response shape. The only signal is a header almost nobody reads.

Google shuts down the Content API for Shopping on Aug 18, 2026. The migration to the Merchant API silently misprices your catalog: price becomes amountMicros (int64), the ID delimiter flips : to ~, and id becomes name. No error path. https://flarecanary.com

HighLevel kills the legacy X-WH-Signature (RSA) webhook header on July 1, 2026 — after that it's X-GHL-Signature (Ed25519) only. Three silent failure modes to grep for now. https://flarecanary.com

If you use the GitHub GraphQL API for team notification dashboards, audit-log exports, or any kind of organization compliance reporting, you have nine days when this lands. On **July 1, 2026**, GitHub deletes two fields from the `Team` type and the fields from seventeen audit-log entry...

If you manage Azure SQL Database resources through ARM templates, the Azure SQL REST API, the Az.Sql PowerShell module on an old version, the Azure CLI shipped with an older deployment image, or any third-party tooling that wraps the Azure Resource Manager surface, you have eight days of runway...

If you administer a SharePoint Online tenant, the `EnableAzureADB2BIntegration` setting is the thing you used to flip to choose between the legacy SharePoint One-Time Passcode (SPO OTP) experience for external guests and the modern Entra B2B Invitation Manager flow. The cmdlet has been around...

On **June 30, 2026**, every Shopify Script stops executing. This is the final deadline — it has already been pushed twice (August 2024 → August 2025 → June 2026), and Shopify has stated this one is firm. Editing and publishing new Scripts was already turned off on April 15, 2026. Most...

On June 24, 2026 Google retires every Imagen model. The retirement is loud — but the forced migration to Gemini's image API fails silently in 4 places: response shape, sampleCount, aspectRatio, and personGeneration. Here's the surface.

Atlassian's Cloud Admin v1 user/group APIs (11 endpoints under /admin/v1/orgs/) go fully dark June 30, 2026. v2 isn't a path swap — every call now needs a directoryId resolved first, plus the read:directories:admin scope. What to grep for, and why offboarding scripts fail silently.

Auth0 drops enabled_clients from GET /api/v2/connections on July 13, 2026. Terraform/Pulumi & provisioning scripts read an empty list, decide every client is disabled, and no-op or wipe associations — all on a 200. The failure modes + new endpoints.

Shopify's 2025-01 GraphQL Admin API swapped fulfillmentHold.heldBy (string) for heldByApp (object), deleted PrivateMetafield outright, and dropped accountNumber/routingNumber. Endpoint still returns 200 OK — your fields just go empty. What breaks and how to catch the next one.

Notion's 2026-04-01 API quietly changed two things: pagination cursors became opaque base64 (old cursors break across version skew), and RateLimit-Reset flipped from a Unix timestamp to a seconds delta — silently removing your backoff. Both pass CI. What breaks + how to fix:

Shopify 2026-07 ships market eligibility for discounts — and silently filters those discounts OUT of the GraphQL Admin API on every version before it. Clean 200, no userErrors. Fetch-by-ID returns null and looks like a deletion. Already live for any Basic+ merchant.

Claude Opus 4 and Sonnet 4 retire June 15. The claude-opus-4-0 / claude-sonnet-4-0 aliases retire with them. Six silent-fail surfaces most teams miss: aliases, 4-0 vs 4-1, Bedrock/Vertex schedules, mocked tests, router fallbacks, eval baselines.

xAI retired 8 Grok model slugs on May 15. They still resolve — they silently redirect to grok-4.3 at flagship pricing and reduced reasoning effort. No error, no 404. Your bill and output quality changed without a signal. Here's the silent-fail surface and how to detect it.

Google's Gemini Interactions API flips its default response schema on May 26. interaction.outputs becomes interaction.steps, SSE event names rename, image_config moves — all silently, still returning 200. The six places it fails quietly, and how to detect them before the flip:

Notion's API now caps pagination at 10,000 results. Past that: a 200, no next_cursor, and a new request_status:incomplete field most code never checks — so 'fetch all rows' syncs silently truncate. How it breaks + how to detect it:

Supabase's Management API OAuth /v1/oauth/token endpoint switches 201→200 on May 26. Body unchanged, axios/Fetch unaffected. Hand-rolled clients that check `status === 201` silently misroute success — and burn the auth code on retry.

Adobe escalates AEM Cloud deprecated-API removal in 4 silent stages — Jan email, Feb pause, Apr fail, May 4 update-pause, Jun 11 cutoff. The list, the silent-fail surfaces, and how to detect.