Submit API

This page provides instructions on how to interact with the Cardano Submit API service offered by Demeter.

About Submit API

Submit API is an HTTP service that accepts pre-signed, CBOR-encoded transactions and submits them into a local running node. It is a tool developed by IntersectMBO under Apache 2.0 license. Examples, schema, and documentation can be found in the GitHub repository (opens in a new tab).

Demeter implementation

Each Demeter cluster provides highly-available, multi-tenant instances of Cardano SubmitAPI. Requests to these instances are load balanced. When creating a project in Demeter you get access to the Submit API for submitting transactions to a Node running in the network of your choosing. Demeter SubmitAPI will consume DCUs from your project's wallet proportional to the volume of the requests. If no requests are executed, Demeter will not charge anything.

The free tier includes 120 requests per minute, with a maximum of 50000 requests per day.

Enabling access

To enable access in your project, you need to add a Cardano Submit API resource:

1. Login to Demeter.run (opens in a new tab)
2. Select your project (opens in a new tab)
3. From your project's dashboard, click "Add Resource"
4. Find the resource "Cardano Submit API Port" card and click on the "Deploy" button
5. Enable a shared instance in the cluster using your preferred network.

Getting started

Demeter provides access points from inside and outside the Workspace cluster.

• HTTP Endpoint URL: The HTTP endpoint where the Submit API instance is running (eg: submitapi-m1.demeter.run).

• API Key: The key for authenticating, will need to be set on the header dmtr-api-key header.

• HTTP Authenticated Endpoint URL: The publicly accessible hostname of the SubmitAPI instance, but with the key set on the hostname without necessary to set it on the header, for use in frameworks that do not support setting custom headers. (eg: KEY.submitapi-m1.demeter.run).