ncurl

nano cURL - a minimalist http(s) client.

Usage

ncurl(
  url,
  convert = TRUE,
  follow = FALSE,
  method = NULL,
  headers = NULL,
  data = NULL,
  response = NULL,
  timeout = NULL,
  tls = NULL
)

Arguments

url: the URL address.
convert: [default TRUE] logical value whether to attempt conversion of the received raw bytes to a character vector. Set to FALSE if downloading non-text data.
follow: [default FALSE] logical value whether to automatically follow redirects (not applicable for async requests). If FALSE, the redirect address is returned as response header 'Location'.
method: (optional) the HTTP method as a character string. Defaults to 'GET' if not specified, and could also be 'POST', 'PUT' etc.
headers: (optional) a named character vector specifying the HTTP request headers, for example:
c(Authorization = "Bearer APIKEY", "Content-Type" = "text/plain")
A non-character or non-named vector will be ignored.
data: (optional) request data to be submitted. Must be a character string or raw vector, and other objects are ignored. If a character vector, only the first element is taken. When supplying binary data, the appropriate 'Content-Type' header should be set to specify the binary format.
response: (optional) a character vector specifying the response headers to return e.g. c("date", "server"). These are case-insensitive and will return NULL if not present. Specify TRUE to return all response headers. A non-character vector will be ignored (other than TRUE).
timeout: (optional) integer value in milliseconds after which the transaction times out if not yet complete.
tls: (optional) applicable to secure HTTPS sites only, a client TLS Configuration object created by tls_config(). If missing or NULL, certificates are not validated.

Value

Named list of 3 elements:

$status - integer HTTP repsonse status code (200 - OK). Use status_code() for a translation of the meaning.
$headers - named list of response headers (all headers if response = TRUE, or those specified in response, or NULL otherwise). If the status code is within the 300 range, i.e. a redirect, the response header 'Location' is automatically appended to return the redirect address.
$data - the response body, as a character string if convert = TRUE (may be further parsed as html, json, xml etc. as required), or a raw byte vector if FALSE (use writeBin() to save as a file).

Public Internet HTTPS

When making HTTPS requests over the public internet, you should supply a TLS configuration to validate server certificates. See tls_config() for details.

Examples

ncurl(
  "https://postman-echo.com/get",
  convert = FALSE,
  response = c("date", "content-type"),
  timeout = 1200L
)
#> $status
#> [1] 200
#> 
#> $headers
#> $headers$date
#> [1] "Fri, 27 Mar 2026 18:38:06 GMT"
#> 
#> $headers$`content-type`
#> [1] "application/json; charset=utf-8"
#> 
#> 
#> $data
#>   [1] 7b 22 61 72 67 73 22 3a 7b 7d 2c 22 68 65 61 64 65 72 73 22 3a 7b 22 68 6f
#>  [26] 73 74 22 3a 22 70 6f 73 74 6d 61 6e 2d 65 63 68 6f 2e 63 6f 6d 22 2c 22 61
#>  [51] 63 63 65 70 74 2d 65 6e 63 6f 64 69 6e 67 22 3a 22 67 7a 69 70 2c 20 62 72
#>  [76] 22 2c 22 78 2d 66 6f 72 77 61 72 64 65 64 2d 70 72 6f 74 6f 22 3a 22 68 74
#> [101] 74 70 73 22 7d 2c 22 75 72 6c 22 3a 22 68 74 74 70 73 3a 2f 2f 70 6f 73 74
#> [126] 6d 61 6e 2d 65 63 68 6f 2e 63 6f 6d 2f 67 65 74 22 7d
#> 
ncurl(
  "https://postman-echo.com/get",
  response = TRUE,
  timeout = 1200L
)
#> $status
#> [1] 200
#> 
#> $headers
#> $headers$Date
#> [1] "Fri, 27 Mar 2026 18:38:06 GMT"
#> 
#> $headers$`Content-Type`
#> [1] "application/json; charset=utf-8"
#> 
#> $headers$`Content-Length`
#> [1] "143"
#> 
#> $headers$Connection
#> [1] "close"
#> 
#> $headers$etag
#> [1] "W/\"8f-7zN8nSad8A9WlFJjKQZB04z5nHE\""
#> 
#> $headers$vary
#> [1] "Accept-Encoding"
#> 
#> $headers$`x-envoy-upstream-service-time`
#> [1] "5"
#> 
#> $headers$`cf-cache-status`
#> [1] "DYNAMIC"
#> 
#> $headers$`Set-Cookie`
#> [1] "sails.sid=s%3A8dpWWMSdwdW34pQqr-b4bOVHdN4X1Dww.I1u%2BTTuLzKmKYc7wBptw%2Bp8vcaR6PGyEfxUw8k2sBKk; Path=/; HttpOnly, __cf_bm=PRJQbGDhxgPEZvlEgsmJe..Z8eGMnCQKEmSJt7KYxXc-1774636686.824995-1.0.1.1-LLbj45OgA2dibSCsNdpqUTt432eziP3sCUElX.dF5rt4jCJB7zwLRiReCPkcEr8eJHscQrGSgTF5SZ2p8Gzlh4tN4PmBBVGK2LGcWFTN4T2T__cs58.W6vUOhu0JFvOx; HttpOnly; Secure; Path=/; Domain=postman-echo.com; Expires=Fri, 27 Mar 2026 19:08:06 GMT, _cfuvid=NZoT87y8hEYIux5HT2ZVQYpe2aGqrSlg34RqEt0rWRY-1774636686.824995-1.0.1.1-oFR2TmtaOYiJ7XVn5xKqm7XfKYiUwuYPv.kVS09r9bs; HttpOnly; SameSite=None; Secure; Path=/; Domain=postman-echo.com"
#> 
#> $headers$Server
#> [1] "cloudflare"
#> 
#> $headers$`CF-RAY`
#> [1] "9e30829caa712da2-CMH"
#> 
#> 
#> $data
#> [1] "{\"args\":{},\"headers\":{\"host\":\"postman-echo.com\",\"accept-encoding\":\"gzip, br\",\"x-forwarded-proto\":\"https\"},\"url\":\"https://postman-echo.com/get\"}"
#> 
ncurl(
  "https://postman-echo.com/put",
  method = "PUT",
  headers = c(Authorization = "Bearer APIKEY"),
  data = "hello world",
  timeout = 1500L
)
#> $status
#> [1] 200
#> 
#> $headers
#> NULL
#> 
#> $data
#> [1] "{\"args\":{},\"data\":\"hello world\",\"files\":{},\"form\":{},\"headers\":{\"host\":\"postman-echo.com\",\"accept-encoding\":\"gzip, br\",\"authorization\":\"Bearer APIKEY\",\"content-length\":\"11\",\"x-forwarded-proto\":\"https\",\"content-type\":\"application/json\"},\"json\":null,\"url\":\"https://postman-echo.com/put\"}"
#> 
ncurl(
  "https://postman-echo.com/post",
  method = "POST",
  headers = c(`Content-Type` = "application/json"),
  data = '{"key":"value"}',
  timeout = 1500L
)
#> $status
#> [1] 200
#> 
#> $headers
#> NULL
#> 
#> $data
#> [1] "{\"args\":{},\"data\":{\"key\":\"value\"},\"files\":{},\"form\":{},\"headers\":{\"host\":\"postman-echo.com\",\"accept-encoding\":\"gzip, br\",\"content-type\":\"application/json\",\"content-length\":\"15\",\"x-forwarded-proto\":\"https\"},\"json\":{\"key\":\"value\"},\"url\":\"https://postman-echo.com/post\"}"
#>

Usage

Arguments

Value

Public Internet HTTPS

See also

Examples