> ## Documentation Index
> Fetch the complete documentation index at: https://confect.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Environment Variables

> Read environment variables using Effect's Config module.

Confect provides a `ConfigProvider` that is compatible with the Convex runtime, where `process.env` is not enumerable. This provider is automatically set for all Confect functions (queries, mutations, actions, and HTTP API handlers), so Effect's [`Config`](https://effect.website/docs/configuration/) module works out of the box.

## Reading environment variables

Use `Config` from Effect to read [Convex environment variables](https://docs.convex.dev/production/environment-variables) in your function handlers.

```ts confect/settings.impl.ts theme={null}
import { FunctionImpl } from "@confect/server";
import * as Config from "effect/Config";
import * as Effect from "effect/Effect";

import databaseSchema from "./_generated/schema";
import settings from "./settings.spec";

const getApiKey = FunctionImpl.make(databaseSchema, settings, "getApiKey", () =>
  Config.string("API_KEY").pipe(Effect.orDie),
);
```

All of Effect's `Config` combinators work as expected—`Config.string`, `Config.number`, `Config.boolean`, `Config.withDefault`, `Config.option`, etc.

```ts theme={null}
Config.integer("MAX_RESULTS").pipe(Config.withDefault(100));
```

## Limitations

Config operations that require enumerating `process.env` are unsupported in the Convex runtime. This includes `Config.hashMap` and other combinators that need to discover keys dynamically. Attempting to use them will result in an `Unsupported` config error.

## Custom config provider

The `ConvexConfigProvider` module is exported from `@confect/server` if you need to create a provider with custom options. It supports the same options as Effect's default [`ConfigProvider.fromEnv`](https://effect.website/docs/configuration/#loading-configuration-from-environment-variables).

```ts theme={null}
import { ConvexConfigProvider } from "@confect/server";

const provider = ConvexConfigProvider.make({
  pathDelim: "__",
  seqDelim: ";",
});
```

To use a custom provider in a function handler, pass it to `Effect.withConfigProvider`.

```ts theme={null}
const getApiKey = FunctionImpl.make(databaseSchema, settings, "getApiKey", () =>
  Config.string("API_KEY").pipe(
    Effect.withConfigProvider(provider),
    Effect.orDie,
  ),
);
```