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HTTP Actions

HTTP actions allow you to build an HTTP API right in Convex!

HTTP actions take in a Request and return a Response following the Fetch API. HTTP actions can manipulate the request and response directly, and interact with data in Convex indirectly by running queries, mutations, and actions. HTTP actions might be used for receiving webhooks from external applications or defining a public HTTP API.

HTTP actions are exposed at https://<your deployment name>.convex.site (e.g. https://happy-animal-123.convex.site).

Example: HTTP Actions

Defining HTTP actions​

HTTP action handlers are defined using the httpAction constructor, similar to the action constructor for normal actions:

convex/myHttpActions.ts
TS
import { httpAction } from "./_generated/server";

export const doSomething = httpAction(async () => {
  // implementation will be here
  return new Response();
});

The first argument to the handler is an ActionCtx object, which provides auth, storage, and scheduler, as well as runQuery, runMutation, runAction.

The second argument contains the Request data. HTTP actions do not support argument validation, as the parsing of arguments from the incoming Request is left entirely to you.

Here's an example:

convex/messages.ts
TS
import { httpAction } from "./_generated/server";
import { internal } from "./_generated/api";

export const postMessage = httpAction(async (ctx, request) => {
  const { author, body } = await request.json();

  await ctx.runMutation(internal.messages.sendOne, {
    body: `Sent via HTTP action: ${body}`,
    author,
  });

  return new Response(null, {
    status: 200,
  });
});

To expose the HTTP Action, export an instance of HttpRouter from the convex/http.ts file. To create the instance call the httpRouter function. On the HttpRouter you can expose routes using the route method:

convex/http.ts
TS
import { httpRouter } from "convex/server";
import { postMessage, getByAuthor } from "./messages";

const http = httpRouter();

http.route({
  path: "/postMessage",
  method: "POST",
  handler: postMessage,
});

// Define additional routes
http.route({
  path: "/getMessagesByAuthor",
  method: "GET",
  handler: getByAuthor,
});

// Convex expects the router to be the default export of `convex/http.js`.
export default http;

You can now call this action via HTTP and interact with data stored in the Convex Database. HTTP actions are exposed on https://<your deployment name>.convex.site.

export DEPLOYMENT_NAME=... # example: "happy-animal-123"
curl -d '{ "author": "User 123", "body": "Hello world" }' \
    -H 'content-type: application/json' "https://$DEPLOYMENT_NAME.convex.site/postMessage"

Like other Convex functions, you can view your HTTP actions in the Functions view of your dashboard and view logs produced by them in the Logs view.

Limits​

HTTP actions run in the same environment as queries and mutations so also do not have access to Node.js-specific JavaScript APIs. HTTP actions can call actions, which can run in Node.js.

Like actions, HTTP actions may have side-effects and will not be automatically retried by Convex when errors occur. It is a responsibility of the caller to handle errors and retry the request if appropriate.

Request and response size is limited to 20MB.

HTTP actions support request and response body types of .text(), .json(), .blob(), and .arrayBuffer().

Note that you don't need to define an HTTP action to call your queries, mutations and actions over HTTP if you control the caller, since you can use use the JavaScript ConvexHttpClient or the Python client to call these functions directly.

Common patterns​

File Storage​

HTTP actions can be used to handle uploading and fetching stored files, see File Storage with HTTP actions.

CORS​

To make requests to HTTP actions from a website you need to add Cross-Origin Resource Sharing (CORS) headers to your HTTP actions.

There are existing resources for exactly which CORS headers are required based on the use case. This site provides an interactive walkthrough for what CORS headers to add. Here's an example of adding CORS headers to a Convex HTTP action:

convex/http.ts
TS
import { httpRouter } from "convex/server";
import { httpAction } from "./_generated/server";
import { api } from "./_generated/api";

const http = httpRouter();

http.route({
  path: "/sendImage",
  method: "POST",
  handler: httpAction(async (ctx, request) => {
    // Step 1: Store the file
    const blob = await request.blob();
    const storageId = await ctx.storage.store(blob);

    // Step 2: Save the storage ID to the database via a mutation
    const author = new URL(request.url).searchParams.get("author");
    await ctx.runMutation(api.messages.sendImage, { storageId, author });

    // Step 3: Return a response with the correct CORS headers
    return new Response(null, {
      status: 200,
      // CORS headers
      headers: new Headers({
        // e.g. https://mywebsite.com
        "Access-Control-Allow-Origin": process.env.CLIENT_ORIGIN!,
        Vary: "origin",
      }),
    });
  }),
});

Here's an example of handling a pre-flight OPTIONS request:

convex/http.ts
TS
// Pre-flight request for /sendImage
http.route({
  path: "/sendImage",
  method: "OPTIONS",
  handler: httpAction(async (_, request) => {
    // Make sure the necessary headers are present
    // for this to be a valid pre-flight request
    const headers = request.headers;
    if (
      headers.get("Origin") !== null &&
      headers.get("Access-Control-Request-Method") !== null &&
      headers.get("Access-Control-Request-Headers") !== null
    ) {
      return new Response(null, {
        headers: new Headers({
          // e.g. https://mywebsite.com
          "Access-Control-Allow-Origin": process.env.CLIENT_ORIGIN!,
          "Access-Control-Allow-Methods": "POST",
          "Access-Control-Allow-Headers": "Content-Type, Digest",
          "Access-Control-Max-Age": "86400",
        }),
      });
    } else {
      return new Response();
    }
  }),
});

Authentication​

You can leverage Convex's built-in authentication integration and access a user identity from ctx.auth.getUserIdentity(). To do this call your endpoint with an Authorization header including a JWT token:

myPage.ts
TS
const jwtToken = "...";

fetch("https://<deployment name>.convex.site/myAction", {
  headers: {
    Authorization: `Bearer ${jwtToken}`,
  },
});