Deploy and Host Flipt v2 + Envoy (gRPC-Web) on Railway

Flipt v2 is an open-source feature flag engine that keeps flag state as plain files in a Git repository instead of a database. This template pairs it with an Envoy proxy that bridges gRPC-Web, so browser code and backend services can both evaluate flags against the same instance.

About Hosting Flipt v2 + Envoy (gRPC-Web)

Flipt speaks gRPC and REST, but not gRPC-Web, which is what browsers need. Envoy sits in front and translates. Its route list is restricted to the evaluation service alone, so every other path answers 403 and the management API never reaches the public internet. Flipt keeps its gRPC port and its UI on Railway's private network and writes Git-backed flag state to an attached volume. Server-side callers skip Envoy entirely and evaluate over native gRPC on the private network, which keeps the hot path free of an extra hop.

Common Use Cases

Roll a feature out to a fraction of users, then to everyone, without redeploying
Merge unfinished work to main early, gated behind a flag that stays off
Kill-switch an expensive code path or a flaky dependency during an incident

Dependencies for Flipt v2 + Envoy (gRPC-Web) Hosting

A volume on the Flipt service, which holds the Git repository of flag state
A Redis service, needed only if you publish the Flipt UI and turn on session authentication

Implementation Details

Envoy renders its configuration at boot from PORT, FLIPT_UPSTREAM_HOST and FLIPT_UPSTREAM_PORT, so pointing it at Flipt is a variable change rather than a config edit. Evaluation stays reachable without credentials even when the rest of Flipt is locked down, through FLIPT_AUTHENTICATION_EXCLUDE_EVALUATION.

Why Deploy Flipt v2 + Envoy (gRPC-Web) on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying Flipt v2 + Envoy (gRPC-Web) on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.