Scripting with the RDAP CLI

The RDAP CLI provides several output formats designed for consumption by scripts, along with parameters that simplify processing the output.

Output Formats for Scripts

The CLI provides multiple output formats via the -O (or --output-type) argument:

Output Type	Shortcut	Description
`json`		Standard RDAP JSON output
`pretty-json`		Pretty-printed JSON output
`pretty-compact-json`	`--json`	Compact but readable JSON (best for scripts)
`json-extra`		RDAP JSON with additional processing information
`nd-json`		Newline Delimited JSON for append-only purposes
`json-seq`		JSON Text Sequences (RFC7464) for append-only purposes
`csv`		For filtering and output for spreadsheets
`url`		Just the RDAP server URL (useful for bootstrapping)
`rpsl`	`--rpsl`	Routing Policy Specification Language

Quick JSON Output

The simplest way to get script-friendly output:

rdap --json example.com

This is equivalent to -O pretty-compact-json.

Content is sent to stdout while log messages are sent to stderr, so log messages will not interfere with piping or redirecting.

Some Scripting Examples

Extract specific fields with jq

rdap --json example.com | jq -r '.entities[0].vcardArray[1][] | select(.[0] == "fn").[3]'

Target the registrar

rdap --registrar --json icann.org | jq -r '.entities[0].vcardArray[1][] | select(.[0] == "fn").[3]'

Use the built-in filters

The built-in filters make many simple tasks easier.

rdap --registrar --filter ldh-name,registrant-full-name,status icann.org

JSContact Output

The --to-jscontact parameter converts vCard/jCard contact information in RDAP responses to JSContact format. This simplifies parsing contact information in scripts since JSContact is a more modern and easier-to-parse JSON format.

rdap --json --to-jscontact example.com

When used with JSON output, entity contact information will be in JSContact format instead of jCard/vCard, making it easier to extract specific fields:

# Get entity name from JSContact output
rdap --json --to-jscontact example.com | jq -r '.entities[0].contact.name.fullName'

# Get entity email
rdap --json --to-jscontact example.com | jq -r '.entities[0].contact.email[0].address'

Environment Variables for Scripts

Several environment variables can simplify scripting:

Variable	Description
`RDAP_OUTPUT`	Set default output format
`RDAP_NO_CACHE`	Disable caching (`true` or `false`)
`RDAP_LOG`	Set log level (off, error, warn, info, debug, trace)
`RDAP_BASE_URL`	Set explicit base URL
`RDAP_REDACTION_FLAGS`	Set redaction flags

Example:

export RDAP_OUTPUT=json
export RDAP_NO_CACHE=true
rdap example.com

Exit Codes

The CLI returns specific exit codes that scripts can use for error handling:

Exit Code	Description
0	Success
40	I/O error
42	Client error
60	Response error (non-200 OK)
62	Parsing error
100-106	RDAP-specific errors
200+	User error (invalid query, etc.)

See the Usage documentation for the complete exit code table.