Payload Generators

Generators produce attack payloads via the $generate directive. They implement the PayloadGenerator trait and support lazy evaluation - factory objects are created at config load time, bytes are generated at response time.

See TJ-SPEC-005 for the formal specification.

Generator types

nested_json

Produces deeply nested JSON structures for parser stack exhaustion.

$generate:
  type: nested_json
  depth: 50000
  structure: object

Parameter	Type	Default	Description
depth	integer	1000	Nesting depth
structure	string	object	Structure type

Structure types:

Value	Output
object	{"a":{"a":{"a":...}}}
array	[[[[...]]]]
mixed	Alternating objects and arrays

Limits: Subject to max_nest_depth (default: 100,000).

garbage

Produces random byte payloads in configurable character sets.

$generate:
  type: garbage
  size: 10485760
  charset: utf8

Parameter	Type	Default	Description
size	integer	1024	Output size in bytes
charset	string	ascii	Character set

Character sets:

Value	Characters
ascii	Printable ASCII (0x20–0x7E)
utf8	Valid UTF-8 multibyte sequences
binary	Raw bytes (0x00–0xFF)
numeric	Digits (0–9)
alphanumeric	Letters and digits

Limits: Subject to max_payload_bytes (default: 100 MB).

batch_notifications

Produces a JSON-RPC batch array of MCP notifications for amplification attacks.

$generate:
  type: batch_notifications
  count: 10000
  method: "notifications/message"

Parameter	Type	Default	Description
count	integer	100	Number of notifications in batch
method	string	notifications/message	Notification method name

Limits: Subject to max_batch_size (default: 100,000).

repeated_keys

Produces a JSON object with duplicate keys for hash collision attacks.

$generate:
  type: repeated_keys
  count: 100000
  key_length: 8

Parameter	Type	Default	Description
count	integer	1000	Number of duplicate keys
key_length	integer	8	Length of each key string

Limits: Subject to max_payload_bytes.

unicode_spam

Produces Unicode abuse payloads for display corruption and rendering attacks.

$generate:
  type: unicode_spam
  size: 4096
  categories:
    - zero_width
    - rtl

Parameter	Type	Default	Description
size	integer	1024	Approximate output size in bytes
categories	array	all	Unicode categories to include

Unicode categories:

Value	Characters	Effect
zero_width	U+200B, U+200C, U+200D, U+FEFF	Invisible characters
homoglyph	Cyrillic/Greek lookalikes	Visual spoofing
combining	U+0300–U+036F	Stacked diacritical marks
rtl	U+202E, U+202D, U+2066	Text direction override
emoji	Various emoji sequences	Rendering complexity

Limits: Subject to max_payload_bytes.

ansi_escape

Produces ANSI escape sequences for terminal injection attacks.

$generate:
  type: ansi_escape
  sequences:
    - title
    - hyperlink
    - cursor_move

Parameter	Type	Default	Description
sequences	array	all	Sequence types to include

Sequence types:

Value	Escape	Effect
cursor_move	\x1b[H, \x1b[2J	Move cursor, clear screen
color	\x1b[31m	Change text colors
title	\x1b]0;...\x07	Set terminal title
hyperlink	\x1b]8;;...\x07	OSC 8 hyperlinks
clear	\x1b[2J, \x1b[3J	Clear screen/scrollback

Limits

All generators respect hardcoded limits:

Limit	Default
Max payload size	100 MB
Max nesting depth	100,000
Max batch size	100,000

Limits are validated in the generator constructor. Exceeding a limit causes a runtime error (exit code 10).

Streaming

Payloads larger than 1 MB (the STREAMING_THRESHOLD) are generated as streams via the PayloadStream trait. Streaming generates chunks incrementally instead of buffering the entire payload in memory.

The GeneratedPayload enum has two variants:

• Buffered(Vec<u8>) - small payloads held in memory
• Streamed(Box<dyn PayloadStream>) - large payloads yielded incrementally

Determinism

Generators that use randomness accept an optional seed parameter. Given the same seed, a generator produces identical output. This is useful for reproducible testing.

$generate:
  type: garbage
  size: 1024
  charset: ascii
  seed: 42

See also

• Use Payload Generators - practical guide to using generators in attack scenarios
• Behavioral Modes - delivery behaviors that modify how generator output is transmitted
• OATF Document Schema - full YAML reference including $generate directive