POST request handlers

This page explains how to implement POST request handlers in Next.js route handlers.

Creating a POST handler

To handle POST requests, export an async function named POST in your route handler file:

export async function POST(request: Request) {
  const comment = await request.json();

  // Process the comment and return a response
  return Response.json(comment, { status: 201 });
}

Example implementation

Here’s a complete example of a POST handler that adds a new comment:

interface Comment {
  id: number;
  text: string;
}

let comments: Comment[] = [];

export async function POST(request: Request) {
  try {
    const body = await request.json();

    const newComment = {
      id: comments.length + 1,
      text: body.text,
    };

    comments.push(newComment);

    return Response.json(newComment, {
      status: 201,
      headers: {
        "Content-Type": "application/json",
      },
    });
  } catch (error) {
    return new Response("Invalid request body", { status: 400 });
  }
}

Status codes

Common status codes for POST requests:

201: Resource created successfully
400: Bad request (invalid input)
401: Unauthorized
403: Forbidden
500: Internal server error

Request validation

Validate incoming data before processing:

export async function POST(request: Request) {
  try {
    const body = await request.json();

    if (!body.text || typeof body.text !== "string") {
      return new Response("Invalid comment text", { status: 400 });
    }

    // Process valid comment...
  } catch (error) {
    return new Response("Invalid request body", { status: 400 });
  }
}

Good to know

POST handlers receive the Request object as their first parameter
Always validate input data before processing
Use appropriate status codes in responses