How do I show ads only to free users in FastAPI?

Branch on your FastAPI app's user tier: inject for free-tier sessions and return the un-injected stream for paying users.

Does a paid tier reduce my ad revenue in FastAPI?

Only for the users who upgrade — and those users pay you directly instead, so the two models are complementary.

How-to guide

How to Combine Ads With a Subscription in FastAPI

This guide shows how to combine ads with a subscription in a FastAPI app, the goal being to run ads on the free tier and a paid ad-free tier together. It builds on the Monetzly gRPC service (no Python SDK exists for this stack), so the approach is specific to how FastAPI produces and streams responses.

Overview

Ads and subscriptions are not mutually exclusive for a FastAPI app. A common setup runs Monetzly ads on the free tier and offers a paid, ad-free tier for power users — capturing revenue from casual and committed users alike.

Implementation is a branch on the response path: enable injection for free-tier sessions and skip it for paying users, based on your own FastAPI app's user state.

FastAPI apps are usually built for LLM API backends, SSE/streaming chat endpoints, and agent microservices, so combine ads with a subscription typically comes up while a user is mid-conversation, the moment where monetization has to be additive rather than disruptive.

How this works on FastAPI

There is no official Monetzly Python SDK — the package is Node-only. The supported path for a Python stack is the gRPC service the package ships as tps_alter.proto: generate Python stubs and open a ProcessStream bidi call (StartRequest, then a TokenRequest per LLM token, then StopRequest), reading back the ad-injected TokenResponses. Alternatively, run a tiny Node sidecar that uses the SDK and stream tokens to it. Either way, confirm the auth handshake for non-JS clients before publishing.

Since FastAPI is a Python stack with no official SDK, this task runs through the shipped tps_alter.proto gRPC service (or a Node sidecar); the auth handshake for a direct client is still TODO_VERIFY.