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Blockchain API


The Helium blockchain API serves up the blockchain from a database that is filled by a blockchain node that populates the database as blocks come in.

While anyone can run a node and a corresponding API, the Helium hosted version offers up the API through two endpoints.

  • — Beta, scalable endpoint for new features and tests. Currently connected to mainnet. This endpoint is used for feature development. Submitted transactions may get dropped.
  • — Stable, scalable production service. Connected to mainnet.

Specify a User-Agent

To access the helium api via script you will need to specify a valid User-Agent HTTP header field identifying your agent, all requests made without a User-Agent header will result in an error 429 Slow down gun powder!.


The API routes are grouped together in sub-pages of this page. Refer to the subpages for details.


In order to return data quickly and reduce the load on the API, a cursor may be returned from an API request. The documentation for each route will indicate whether the result is paged with a cursor.

In order to request the next page of results, add a cursor URL parameter to the URL that was used to make the first request.

For example:

export API_URL=
http get $(API_URL)/v1/blocks

will return a data array with zero or more block results and a cursor field. To request the next page:

http get $(API_URL)/v1/blocks?cursor=eyJiZWZvcmUiOjQzOTIwMX0

Which will return the next page of results and a next cursor for the following page.


In order to improve caching the API may return an empty data array and a cursor. Use the cursor to request more data.