Making HTTP Requests

Functions can call 3rd party HTTP servers to get additional information for your webhook or just make an API call and end function execution.

Functions can make multiple HTTP request calls to any external server. Some of the uses cases:

• Call 3rd party API to get additional authentication tokens before forwarding request.

• Send data to the external service directly, without relying on the webhook.

• Get additional data to the function so it can dynamically mutate the payload.

Using HTTP package

To make an HTTP request from Lua function, import ‘http’ package:

-- importing HTTP package
local http = require("http")

-- making HTTP call
response, err = http.request("GET", "https://example.com")
if err then error(err) end

-- parsing response body from the API
local api_response, err = json.decode(response.body)
if err then error(err) end

Specify request body

You can also make a POST, PUT, DELETE requests to a 3rd party APIs:

-- importing HTTP and JSON packages
local json = require("json")
local http = require("http")

local payload, err = json.encode({
    action = "create_record",
    user = "example",
})
if err then error(err) end

local resp, err = http.request("POST", "http://example.com/api", { body = payload})
if err then error(err) end

Reading response body

To read response body:

-- importing HTTP package
local http = require("http")

-- making HTTP call
response, err = http.request("GET", "https://example.com")
if err then error(err) end

-- received JSON string:
-- {
--   "firstname": "luke",
--   "lastname": "skywalker"  
-- }

-- parsing response body from the API
local api_response, err = json.decode(response.body)
if err then error(err) end

-- access values like 'api_response.firstname'

Query, headers, timeout

To specify query, timeout and headers:

-- importing HTTP package
local http = require("http")

-- specifying headers
local headers = {}
headers["Authorization"] = "Basic " .. "123456"

-- making HTTP call
response, err = http.request("GET", "https://example.com", {
    query="page=1",
    timeout="5s",
    headers={
        Accept="*/*"
    }
})
if err then error(err) end

-- parsing response body from the API
local api_response, err = json.decode(response.body)
if err then error(err) end

Batch requests

To send multiple requests asynchronously, create a table containing the requests and call the http.request_batch method:

local http = require("http")

-- Prepare a table with requests. Each row in this table contains a table 
-- that needs to have a request method and a URL. You can also add options
-- that add query arguments, authentication, headers, body, etc.
local requests = {
    {"GET", "https://first.example.com", {query="page=1"}},
    {"POST", "https://second.example.com", auth={user="user", pass="pass"}},
    {"PUT", "https://third.example.com", {form="username=john&password=wick"}},
    {"PATCH", "https://fourth.example.com", 
      {
        headers={
	  ["Content-Type"]="application/json"
        },
        body = '{"elon": "musk"}'
      }
    },
}

-- Dispatch the requests and wait for all the responses
responses, errors = http.request_batch(requests)
if errors then error(errors) end

-- If you need to do something with the responses or 
-- errors, you can view them:
local errorStrings = {}
for _, err in pairs(errors) do
    table.insert(errorStrings, tostring(err))
end
table.sort(errorStrings)

-- To access response:
if responses[2]["body"] == "not-expected" then
    -- Do something
end

Since all requests are launched asynchronously,

HTTP package API reference

http.delete(url [, options])

Attributes

Name	Type	Description
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.get(url [, options])

Attributes

Name	Type	Description
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.head(url [, options])

Attributes

Name	Type	Description
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.patch(url [, options])

Attributes

Name	Type	Description
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
body	String	Request body.
form	String	Deprecated. URL encoded request body. This will also set the Content-Type header to application/x-www-form-urlencoded
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.post(url [, options])

Attributes

Name	Type	Description
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
body	String	Request body.
form	String	Deprecated. URL encoded request body. This will also set the Content-Type header to application/x-www-form-urlencoded
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.put(url [, options])

Attributes

Name	Type	Description
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
body	String	Request body.
form	String	Deprecated. URL encoded request body. This will also set the Content-Type header to application/x-www-form-urlencoded
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.request(method, url [, options])

Attributes

Name	Type	Description
method	String	The HTTP request method
url	String	URL of the resource to load
options	Table	Additional options

Options

Name	Type	Description
query	String	URL encoded query params
cookies	Table	Additional cookies to send with the request
body	String	Request body.
form	String	Deprecated. URL encoded request body. This will also set the Content-Type header to application/x-www-form-urlencoded
headers	Table	Additional headers to send with the request

Returns

http.response or (nil, error message)

http.request_batch(requests)

Attributes

Name	Type	Description
requests	Table	A table of requests to send. Each request item is by itself a table containing http.request parameters for the request

Returns

[http.response] or ([http.response], [error message])

http.response

The http.response table contains information about a completed HTTP request.

Attributes

Name	Type	Description
body	String	The HTTP response body
body_size	Number	The size of the HTTP response body in bytes
headers	Table	The HTTP response headers
cookies	Table	The cookies sent by the server in the HTTP response
status_code	Number	The HTTP response status code
url	String	The final URL the request ended pointing to after redirects