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HTTP API ​

Hubble serves a HTTP API on port 2281 by default.

Using the API ​

The API can be called from any programing language or browser by making a normal HTTP request.

View the API responses in a browser

Simply open the URL in a browser

url
http://127.0.0.1:2281/v1/castsByFid?fid=2

Call the API using curl

bash
curl http://127.0.0.1:2281/v1/castsByFid?fid=2

Call the API via Javascript, using the axios library

Javascript
import axios from "axios";

const fid = 2;
const server = "http://127.0.0.1:2281";

try {
    const response = await axios.get(`${server}/v1/castsByFid?fid=${fid}`);

    console.log(`API Returned HTTP status ${response.status}`);    
    console.log(`First Cast's text is ${response.data.messages[0].data.castAddBody.text}`);
} catch (e) {
    // Handle errors
    console.log(response);
}

Response encoding ​

Responses from the API are encoded as application/json, and can be parsed as normal JSON objects.

  1. Hashes, ETH addresses, signers etc... are all encoded as hex strings starting with 0x
  2. Signatures and other binary fields are encoded in base64
  3. Constants are encoded as their string types. For example, the hashScheme is encoded as HASH_SCHEME_BLAKE3 which is equivalent to the HASH_SCHEME_BLAKE3 = 1 from the protobuf schema.

Timestamps ​

Messages contain a timestamp, which is the Farcaster Epoch Timestamp (and not the Unix Epoch).

Paging ​

Most endpoints support paging to get a large number of responses.

Pagination Query Parameters

ParameterDescriptionExample
pageSizeMaximum number of messages to return in a single responsepageSize=100
reverseReverse the sort order, returning latest messages firstreverse=1
pageTokenThe page token returned by the previous query, to fetch the next page. If this parameters is empty, fetch the first pagepageToken=AuzO1V0Dta...fStlynsGWT

The returned nextPageToken is empty if there are no more pages to return.

Pagination query parameters can be combined with other query parameters supported by the endpoint. For example, /v1/casts?fid=2&pageSize=3.

Example

Fetch all casts by FID 2, fetching upto 3 casts per Page

bash
# Fetch first page
http://127.0.0.1:2281/v1/castsByFid?fid=2&pageSize=3 

# Fetch next page. The pageToken is from the previous response(`response.nextPageToken`)
http://127.0.0.1:2281/v1/castsByFid?fid=2&pageSize=3&pageToken=AuzO1V0DtaItCwwa10X6YsfStlynsGWT

Javascript Example

Javascript
import axios from "axios";

const fid = 2;
const server = "http://127.0.0.1:2281";

let nextPageToken = "";
do {
    const response = await axios.get(`${server}/v1/castsByFid?fid=${fid}&pageSize=100&nextPageToken=${nextPageToken}`);
    // Process response....
    nextPageToken = response.nextPageToken;
} while (nextPageToken !== "")

Handling Errors ​

If there's an API error, the HTTP status code is set to 400 or 500 as appropriate. The response is a JSON object with detail, errCode and metadata fields set to identify and debug the errors.

Example

bash
$ curl "http://127.0.0.1:2281/v1/castById?fid=invalid"
{
  "errCode": "bad_request.validation_failure",
  "presentable": false,
  "name": "HubError",
  "code": 3,
  "details": "fid must be an integer",
  "metadata": {
    "errcode": [
      "bad_request.validation_failure",
    ],
  },
}

CORS ​

You can set a custom CORS header in the HTTP server by using the --http-cors-origin parameter when running your Hubble instance. Setting this to * will allow requests from any origin.

Limitations ​

The HTTP API currently does not support any of the Sync APIs that are available in the gRPC vesion. When Hubs sync with each other, they will use the gRPC APIs instead of the HTTP APIs.