Transform Request

Transform Request in Solvix allows you to modify or enhance the request before it is sent to the server.

It is a simpler and more focused alternative to middleware when you only need to modify request data.

What is Transform Request?

Transform Request is a function that runs before the request is executed.

It allows you to:

• Modify headers
• Change request body
• Add authentication
• Normalize request data

Why use Transform Request?

In real-world applications:

• You often need to attach tokens
• You may want to standardize headers
• You may need to modify payloads

Transform Request provides a clean way to do this.

Basic Usage

const client = createClient({
  transformRequest: (ctx) => {
    ctx.options.fetch.headers = {
      ...ctx.options.fetch.headers,
      "X-App-Version": "1.0",
    };

    return ctx;
  },
});

Example: Add Authorization Token

const client = createClient({
  transformRequest: (ctx) => {
    ctx.options.fetch.headers = {
      ...ctx.options.fetch.headers,
      Authorization: "Bearer token",
    };

    return ctx;
  },
});

Example: Modify Request Body

transformRequest: (ctx) => {
  if (ctx.options.fetch.body) {
    const body = JSON.parse(ctx.options.fetch.body as string);

    body.timestamp = Date.now();

    ctx.options.fetch.body = JSON.stringify(body);
  }

  return ctx;
};

Example: Add Default Headers

transformRequest: (ctx) => {
  ctx.options.fetch.headers = {
    "Content-Type": "application/json",
    ...ctx.options.fetch.headers,
  };

  return ctx;
};

Execution Timing

Transform Request runs:

1. Before middleware
2. Before transport
3. Before retry logic

Important Rules

• Must return updated context
• Should not block execution
• Keep logic lightweight

When to use Transform Request vs Middleware

Use Transform Request when:

• You only need to modify request
• Logic is simple and direct

Use Middleware when:

• You need before + after control
• You need response handling

Integration

Works with:

• Token refresh system
• Security layer
• Retry engine

Summary

Transform Request provides a clean and efficient way to modify outgoing requests without adding middleware complexity.