Azure Functions Proxies: community support ends 2025‑09‑30 — migrate off Proxies now

Key update

Microsoft has declared that community support for Azure Functions Proxies ends on 30 September 2025 — Proxies will remain in maintenance mode only until that date and after it will receive no fixes, updates, or official support. Microsoft recommends migrating proxy functionality to Azure API Management (APIM) (or other supported routing/gateway solutions) because Proxies are no longer being invested in. (azure.microsoft.com)

Why it matters

If your apps use Function Proxies for routing, redirects, simple auth, or request/response transforms, you now face a concrete operational and security risk: after 2025‑09‑30 Microsoft stops supporting the feature and may remove or break behavior at any time. The product team and Microsoft support channels have reiterated that Proxies are deprecated and migration is strongly advised; there will be no further bug fixes or security updates. (learn.microsoft.com)

Practical impact and immediate next steps for engineering teams:

• Treat this as a hard deprecation deadline: inventory Function apps that use proxies (search for proxies.json / function.json proxy definitions), capture behavior (routes, rewrites, headers, CORS, auth), and prioritize by production impact.
• Plan migration paths now — APIM provides like‑for‑like features (OpenAPI import, rate limiting, policies, JWT/OPA auth), but can be heavier and costlier; lightweight alternatives are Azure Front Door / Application Gateway, or running a small, maintained reverse proxy (NGINX/Caddy) in front of functions for simple rewrites and routing.
• Test behavior equivalence (redirect semantics, header transforms, timeouts) in staging, and update CI/CD to deploy APIM configuration or routing infra alongside Function deployments.
• If you cannot migrate immediately, take a mitigation posture: reduce exposure, add additional logging/alerts for proxy paths, and prepare rollback plans because Proxies may stop working unexpectedly after the deadline.

If you use Proxies today, this is actionable and urgent — migrate or implement compensating controls before 2025‑09‑30 to avoid unsupported, potentially broken production behavior. (azure.microsoft.com)

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