Context Provider

The contextProvider plugin controls how Minima.js manages async context using Node.js AsyncLocalStorage. Use this to change the default async context behavior.

How It Works

Minima.js uses AsyncLocalStorage to maintain request context across async operations. The contextProvider plugin lets you configure how this context is established.

import { contextProvider } from "@minimajs/server/plugins";
import { executionContext } from "@minimajs/server";

app.register(contextProvider((ctx, next) => executionContext.run(ctx, next)));

The contextProvider callback receives:

• ctx - The request context
• next - Function to continue the middleware chain

Default: executionContext.run

By default, Minima.js uses executionContext.run() which creates an isolated async context for each request:

import { contextProvider } from "@minimajs/server/plugins";
import { executionContext } from "@minimajs/server";

// This is the default - no need to register manually
app.register(
  contextProvider((ctx, next) => {
    return executionContext.run(ctx, next);
  })
);

Characteristics:

• Each request gets its own isolated context
• Context is automatically cleaned up when the request completes
• Safe for concurrent requests
• Recommended for most use cases

Alternative: executionContext.enterWith

For scenarios where you need the context to persist beyond the callback scope, use enterWith:

import { contextProvider } from "@minimajs/server/plugins";
import { executionContext } from "@minimajs/server";

app.register(
  contextProvider((ctx, next) => {
    executionContext.enterWith(ctx);
    return next();
  })
);

Characteristics:

• Sets the context for all subsequent async operations in the current execution
• Does not automatically clean up - context persists until overwritten
• Useful when integrating with libraries that manage their own async context
• Use with caution in concurrent environments

Important Notes

1. Only one contextProvider is active - Registering a new one replaces the previous
2. Always call next() - Failing to call next() will hang the request
3. Preserve async context - Always use executionContext.run() or enterWith() to ensure context helpers like context(), params(), and body() work correctly

When to Use

Use contextProvider only when you need to change the AsyncLocalStorage behavior. For request wrapping, timing, or tracing, use middleware instead.