HTTP API

Snapchain nodes serve a HTTP API on port 3381 by default.

Using the API

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

View the API responses in a browser

Simply open the URL in a browser

http://127.0.0.1:3381/v1/castsByFid?fid=2

Call the API using curl

curl http://127.0.0.1:3381/v1/castsByFid?fid=2

Call the API via Javascript, using the axios library

import axios from "axios";
 
const fid = 2;
const server = "http://127.0.0.1:3381";
 
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.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.

Hashes, ETH addresses, keys etc... are all encoded as hex strings starting with 0x
Signatures and other binary fields are encoded in base64
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 timestamps which are seconds since the Farcaster Epoch, which began on Jan 1, 2021 00:00:00 UTC.

Paging

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

Pagination Query Parameters

Parameter	Description	Example
pageSize	Maximum number of messages to return in a single response	`pageSize=100`
reverse	Reverse the sort order, returning latest messages first	`reverse=1`
pageToken	The page token returned by the previous query, to fetch the next page. If this parameters is empty, fetch the first page	`pageToken=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

# Fetch first page
http://127.0.0.1:3381/v1/castsByFid?fid=2&pageSize=3
 
# Fetch next page. The pageToken is from the previous response(`response.nextPageToken`)
http://127.0.0.1:3381/v1/castsByFid?fid=2&pageSize=3&pageToken=AuzO1V0DtaItCwwa10X6YsfStlynsGWT

Javascript Example

import axios from "axios";
 
const fid = 2;
const server = "http://127.0.0.1:3381";
 
let nextPageToken = "";
do {
    const response = await axios.get(`${server}/v1/castsByFid?fid=${fid}&pageSize=100&nextPageToken=${nextPageToken}`);
    // Process response....
    nextPageToken = response.nextPageToken;
} while (nextPageToken !== "")

Timestamp Filtering

Some endpoints support filtering by timestamp, allowing you to retrieve results within a specific time range:

Parameter	Description	Example
startTimestamp	Start of the time range (inclusive)	`startTimestamp=1000`
stopTimestamp	End of the time range (inclusive)	`stopTimestamp=2000`

Example:

# Get casts from FID 2 between timestamps 1000 and 2000
http://127.0.0.1:3381/v1/castsByFid?fid=2&startTimestamp=1000&stopTimestamp=2000

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

$ curl "http://127.0.0.1:3381/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",
    ],
  },
}

Limitations

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