> ## 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. Confect sets it automatically for every function that runs in the Convex runtime—queries, mutations, actions, and HTTP API handlers—so Effect's [`Config`](https://effect.website/docs/configuration/) module works out of the box.

[Node actions](/v10/server/node-actions) are the exception. They run in the Node.js runtime, where `process.env` behaves like an ordinary object, so they use Effect's default [`ConfigProvider.fromEnv`](https://effect.website/docs/configuration/#loading-configuration-from-environment-variables) instead. Reading environment variables works the same way in both runtimes.

## 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),
);
```

Combinators that read a single variable work as expected—`Config.string`, `Config.number`, `Config.boolean`, `Config.withDefault`, `Config.option`, and `Config.nested`, among others.

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

## Collections

`Config.Array` and `Config.Record` read a collection from a single delimited variable, so they work in the Convex runtime like any other combinator. Pass them to `Config.schema` with the variable's name.

Given `ALLOWED_ORIGINS="https://a.example,https://b.example"`:

```ts theme={null}
import * as Schema from "effect/Schema";

Config.schema(Config.Array(Schema.String), "ALLOWED_ORIGINS");
// ["https://a.example", "https://b.example"]
```

Given `FEATURE_LIMITS="uploads=10,exports=5"`:

```ts theme={null}
Config.schema(Config.Record(Schema.String, Schema.String), "FEATURE_LIMITS");
// { uploads: "10", exports: "5" }
```

Both default to `","` as the separator, and `Config.Record` to `"="` between key and value; pass `separator` or `keyValueSeparator` to change them. Neither trims whitespace around elements, so write the variable without spaces after the separator, or map over the result to trim.

The collection has to live in one variable. Effect's default provider can also assemble one from several variables—`ORIGINS_0` and `ORIGINS_1` for an array, `FEATURE_LIMITS_UPLOADS` for a record—because it reads the whole environment and discovers the keys under a prefix. Confect's provider resolves each config path to a single variable and never reports child keys, so that spread-out form fails with `Expected array at ["ORIGINS"]` or `Expected object at ["FEATURE_LIMITS"]`. It works in [Node actions](/v10/server/node-actions), which use the default provider; avoid it if the handler might later move to the Convex runtime.

## Custom config provider

The `ConvexConfigProvider` module is exported from `@confect/server`. `ConvexConfigProvider.make()` takes no arguments and returns the provider Confect already installs for you.

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

const provider = ConvexConfigProvider.make();
```

It resolves each config path to a single environment variable, joining the path segments with `"_"`. `Config.nested(Config.string("KEY"), "API")` therefore reads `API_KEY`. An empty string counts as a missing value, so `Config.withDefault` and `Config.option` recover from it.

To override the provider for part of a handler, provide `ConfigProvider.ConfigProvider` as a service.

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

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

const getApiKey = FunctionImpl.make(databaseSchema, settings, "getApiKey", () =>
  Config.nested(Config.string("KEY"), "API").pipe(
    Effect.provideService(
      ConfigProvider.ConfigProvider,
      ConvexConfigProvider.make(),
    ),
    Effect.orDie,
  ),
);
```