> ## Documentation Index
> Fetch the complete documentation index at: https://docs.m3ter.com/llms.txt
> Use this file to discover all available pages before exploring further.

# m3ter APIs

The m3ter platform supports two HTTP-based REST APIs returning JSON encoded responses:

* The **Config API**, which you can use for configuration requests and management.
* The **Ingest API**, which you can use for submitting raw data measurements.

We impose separate limits on the calls you make to both of our APIs to maintain optimum performance and high availability for all customers. This section explains those limits and offers guidance on how to manage and optimize your measurement data submissions to the Ingest API within those limits:

* [Config API Limits](/guides/m3ter-apis/config-api-limits)
* [Ingest API Limits and Optimizing Measurement Submissions](/guides/m3ter-apis/ingest-api-limits)
* [WAF Rules for HTTP Requests](/guides/m3ter-apis/waf-rules-for-http-requests)

A starter topic is also provided to help you to quickly get set up for making API calls into the platform with example requests:

* [Getting Started with API Calls](/guides/m3ter-apis/getting-started-with-api-calls)

We return error messages under HTTP error codes for API calls that are invalid or incomplete. These messages are designed to help you troubleshoot and quickly remedy the rejected call. The following topic lists the HTTP error codes and some common examples of why calls fail are given:

* [HTTP Error Codes](/guides/m3ter-apis/http-error-codes)

<Tip>
  **Note:** The request rate and payload limits are imposed independently on our two APIs.
</Tip>

## API Documentation

Before you attempt to submit any API calls to the m3ter system, *we strongly recommend* that you review our [API Reference Documentation](https://m3ter.com/docs/api).

## Bearer Token for API Calls

You'll need a Bearer Token when making API calls. For details on how to obtain a Bearer Token, see [Service Authentication](/guides/authenticating-with-the-platform/service-authentication).

## SDKs

SDKs are available in different languages to support convenient access to our REST APIs and maintain feature parity with our APIs - please see [Developer Tools](/guides/developer-tools) for more details.