Apigee is a mature, full-featured API platform, and priced like one: per-call and capacity charges, add-ons for environments and analytics, and a developer portal you pay to keep. When that bill outgrows the value, the good news is that the part of Apigee most teams actually live in, the gateway that proxies and secures API traffic, is fully covered by free, production-grade software. The work is understanding what else Apigee does for you and replacing those pieces deliberately.
What you are really replacing
Apigee is a gateway plus a control plane. The gateway runs your API proxies and applies policies (Quota, Spike Arrest, OAuthV2, key verification, transformations). The control plane gives you a developer portal, analytics, and governance. An open gateway replaces the first part cleanly. The second part, portal and analytics, you assemble from open components. Inventory which of those you depend on before you start; it is the difference between a focused gateway migration and a broader platform project.
Kong OSS vs Apache APISIX
Both are open source, both use the same mental model as Apigee (a request hits a route, gets matched to a backend, and passes through a chain of policies), and both have a plugin for essentially every Apigee policy you rely on.
Kong Gateway OSS has the largest ecosystem and the most published migration guidance, and its declarative configuration (managed with decK and GitOps) fits teams that want infrastructure-as-code for their APIs. Apache APISIX is a strong alternative with a similar plugin model, an included dashboard, and an etcd-backed control plane. For most Apigee estates either is a capable landing spot; the choice usually comes down to which ecosystem and configuration style your team prefers.
Beyond the gateway
The pieces that need explicit planning are the developer portal, the analytics you got for free from Apigee, and any custom logic in JavaScript or Java callouts. Replace analytics with a Prometheus and Grafana stack, stand up an open or external portal, and re-implement callouts as plugins or upstream services. The migration itself is low-drama when done incrementally: run the open gateway alongside Apigee, move APIs one at a time behind DNS, and keep each consumer’s contract identical so nothing downstream has to change. Each path below opens to a full cost model, a plan, and an in-depth guide.