Output Format Control

This page provides detailed information about controlling the output format of RDAP responses using the RDAP command line client.

Overview

The RDAP client supports multiple output formats to accommodate different use cases, from human-readable terminal output to machine-readable formats for automation. You can control the output format using command-line options or environment variables.

Type	Works with Filters	Shortcut
Rendered Markdown	No
Plain Markdown	No
RPSL	No	`--rpsl`
gTLD Whois	No
Compact JSON	Yes
Pretty JSON	Yes
Pretty Compact JSON	Yes	`--json`
JSON Extra	Yes
ND-JSON	Yes
JSON Sequences	Yes
GeoFeed	No
CSV	Yes

Output Format Options

Auto Detection (Default)

By default, the client automatically determines the best output format:

# normal user output
rdap example.com

# json output for non-interactive (e.g., scripting)
rdap example.com | jq .

Interactive terminals: Rendered markdown with ANSI colors
Non-interactive: Compact JSON
Configuration: Can be overridden with -O command line flag.

Markdown Formats

Rendered Markdown

rdap -O rendered-markdown example.com
# or default for interactive terminals
rdap example.com

Output is rendered with ANSI terminal capabilities including: - Color coding - Highlighting - Terminal-specific formatting

Plain Text Markdown

rdap -O markdown example.com

Output is in plain markdown format suitable for: - Documentation systems - Plain text files - Non-ANSI terminals

JSON Formats

Compact JSON

rdap -O json example.com

Standard JSON output with minimal whitespace, ideal for: - Script processing - API responses - Data storage

Pretty JSON

rdap -O pretty-json example.com

Human-readable JSON with indentation and line breaks, ideal for: - Debugging - Development - Manual inspection

Pretty Compact JSON (Recommended)

rdap -O pretty-compact-json example.com
# or shortcut:
rdap --json example.com

JSON output that is both compact and readable, providing: - Intelligent line breaks - Strategic indentation - Optimal balance for human and machine reading

JSON with Extra Information

rdap -O json-extra example.com

Includes additional metadata such as: - HTTP request/response data - Processing timestamps - Internal state information - Request/response correlation data

Newline Delimited JSON

Otherwise called ND-JSON, JSONL, or JSON Lines.

rdap -O nd-json example.com

For append-only file writing.

JSON Text Sequences

Similar to ND-JSON. See RFC 7464.

rdap -O json-seq example.com

For append-only file writing.

Specialized Formats

Routing Policy Specification Language (RPSL)

rdap -O rpsl 192.0.2.1
# or shortcut:
rdap --rpsl 192.0.2.1

RPSL format for network routing information, ideal for: - Network management systems - Routing policy databases - ISP automation

GeoFeed

See RFC 9877.

rdap -O geofeed 192.0.2.1

CSV

See RFC 9877.

rdap -O csv --filter registrant-email icann.org

gTLD WHOIS Format

rdap -O gtld-whois example.com

Traditional WHOIS-style format for gTLD domains, featuring: - WHOIS-compatible output - Line-based formatting - Legacy system compatibility

Note: Only available for domain queries.

Environment Variable Configuration

Set default output format using RDAP_OUTPUT environment variable:

# Set default to pretty compact JSON
export RDAP_OUTPUT=pretty-compact-json

# Set default to rendered markdown
export RDAP_OUTPUT=rendered-markdown

# Set default to RPSL
export RDAP_OUTPUT=rpsl