Overview

The MUFL environment provides a range of pre-defined functions called primitives. The tables in this topic describe all the primitives available in MUFL.

Basic Primitives

Name	Signature	Description
_print	arguments: any… -> nil	Prints arguments to the output buffer
_e_print	arguments: any… -> nil	Prints arguments to the error output buffer
_abort_transaction	error_message: str -> nil	Aborts the transaction execution with the provided error message
_assert	condition: bool -> nil	(Test scripts only) Asserts the given value is true, otherwise aborts the evaluation
_get_code_id	- -> hash_code	Returns a hash code of the current MUFL application
_get_container_id	- -> global_id	Returns the ID of the current MUFL packet
_get_state_id	- -> hash_code	Returns a hash code of the current packet state
_new_id	salt: str -> global_id	Generates a new random 32-byte global ID
_random_integer	max: int -> int	Returns a random integer in the range [0, max). Aborts unless max is positive
_typeof	value: any -> str	Returns the underlying domain name of the given value
_write	value: any -> bin	Serializes the given value.
_root_hash	value: any -> hash_code	Returns the root hash of the given blinded dictionary
_value_id	value: any -> hash_code	Returns the hash code of the given value
_get_hash_code_metadata	hash: hash_code -> ($hash_type -> <”BL2B”, “S256”, “CNST”>, $hash_shape_version -> ($maj -> int, $min -> int))	Returns metadata of the given hash code
_new_safe_ref	- -> saferef	Generates a new safe reference
_reg_match	reg_expr: str, string: str -> (str[] |nil)	Returns list of matches of the regular expression (POSIX extended syntax) in the string. NIL if no matches found. Matching is deterministic across platforms and bounded against catastrophic backtracking — an excessively costly pattern is rejected with an error rather than hanging. A capture group that does not participate in the match yields an empty string
_count	value: any -> int	Returns NIL if the value is integral or the size/length of the value of dictionaries, strings, and binaries
_has	dict: any, key: any -> bool	Checks whether the given dictionary contains a value with the given key
_get_bit	bit_index: int, value: int -> int	Returns the value of the bit at the given index of the given integer value
_validate_global_id_string	_validate_global_id_string (_get_container_id())	Returns whether the given string has a correct length and HEX structure
_is_test_mode	- -> bool	Returns whether the environment was initialized in a test mode
_get_platform_type_id	- -> int	Returns the type ID of the current platform
_get_nitro_platform_type_id	- -> int	Returns the type ID of the AWS Nitro Enclaves platform
_get_wasm_platform_type_id	- -> int	Returns the type ID of the WASM platform
_get_native_platform_type_id	- -> int	Returns the type ID of the native platform

Domain Binary Primitives

Name	Signature	Description	Example
_binary_slice	binary_value: bin, start: int, length: int -> bin	Extracts a slice of the given length from the given binary starting at the given index	_binary_slice 0xabcd 2 2
_binlen	binary_value: bin -> int	Returns the length of the given binary	_binlen 0xabcd
_examine_binary	hex_string: str -> str	Decodes the given hex string and inspects the serialized value it encodes, returning a human-readable string description (useful for debugging serialized data). Rejects input of odd length or containing a non-hex character, and caps the decoded size at 1,048,576 bytes (1 MiB)	_examine_binary (_hex_string_from_binary (_write 10))

Conversions Primitives

Name	Signature	Description	Example
_byte_to_hex	byte: int -> bin	Converts the given integer byte to binary	_byte_to_hex 56
_hex_string_to_binary	hex_string: str -> bin	Parses the given HEX string into a binary	_hex_string_to_binary “0xabcd”
_hex_string_from_binary	binary_value: bin -> str	Converts the given binary into a hex string	_hex_string_from_binary 0xabcd
_number_to_binary	number: int -> bin	Converts the given number into a binary	_number_to_binary 12345678
_binary_to_number	binary_value: bin -> int	Converts the binary to decimal number	_binary_to_number 0xabcd
_string_to_binary	string: str -> bin	Converts the given string into a binary byte by byte	_string_to_binary “Hello world!”
_binary_as_ascii_string	binary_value: bin -> str	Converts the given binary into an ASCII string	_binary_as_ascii_string 0x48656C6C6F20776F726C642100
_hash_code_to_binary	hash: hash_code -> bin	Converts the given hash code value into a binary	_hash_code_to_binary (_value_id 5)
_binary_to_hash_code	binary_value: bin -> hash_code	Converts the binary value into a hash code in case it has the correct length	_binary_to_hash_code (_hash_code_to_binary (_value_id 5))

Crypto Primitives

Name	Signature	Description	Example
_ecc_c25519_sign	message: str, secret_key: str -> str+	Calculates the ECC C25519 signature with the given secret key	_ecc_c25519_sign message secret_key
_ecc_c25519_verify	signature: str, message: str, public_key: str -> bool	Verifies the ECC C25519 signature	_ecc_c25519_verify signature message public_key
_ecc_c25519_create_key	seed_hex: str -> [str, str]	Generates a new ECC C25519 keypair [public_key, secret_key] with the 32 bytes long given seed	_ecc_c25519_create_key (_hex_string_from_binary (_hash_code_to_binary (_value_id NIL)))
_generate_totp_key	params: (str -» any) | nil -> (str -» any)	Generates a TOTP secret-key dictionary. Accepts an optional parameters dictionary (or NIL for defaults) with keys digits (code length, 1–16, default 6), period (seconds, default 30), key_length (key size in bits, a multiple of 8 in the range (0, 1024], default 256), and algorithm (one of "SHA1", "SHA256", "SHA512", default "SHA1"). Returns a dictionary with fields $digits, $period, $seckey, and $algorithm. Out-of-range parameters are rejected	_generate_totp_key NIL
_generate_totp_code	totp_key: (str -» any), timestamp: time -> str	Generates the time-based one-time password (TOTP) code for the given TOTP key dictionary (as returned by _generate_totp_key) at the given timestamp. Requires digits in 1–16 and period in 1–2147483647	_generate_totp_code totp_key timestamp

Removed: the RSA primitives (_rsa_*, including the 1024/2048/4096-bit variants) are no longer available. Code that relied on them must migrate to another scheme.

Dangerous Primitives

Name	Signature	Description	Example
_read	serialized_value: bin -> any	Deserializes the given serialized value	_read (_write 10)

For more information, refer to Handling Dangerous Primitives.

AWS Nitro Enclaves Primitives

Name	Signature	Description	Example
_enclave_get_ad	user_data_hash: hash_code, nonce: bin, public_key: bin -> str	Generates an AWS Nitro Enclaves attestation document	_enclave_get_ad (_value_id NIL) NIL NIL
_enclave_unseal_ad_json	ad: str, timestamp: time -> str	Parses and validates the given AWS Nitro Enclaves attestation document	_enclave_unseal_ad_json ad timestamp

Ethereum Primitives

Name	Signature	Description	Example
_eth_public_from_private	private_key: bin -> bin	Derives a public key from the given private key	_eth_public_from_private private_key
_eth_address_from_public	public_key: bin -> bin	Calculates an Ethereum address from the given public key	_eth_address_from_public public_key
_eth_seed_from_mnemonic	mnemonic_phrase: str -> bin	Calculates a seed from the given mnemonic phrase	_eth_seed_from_mnemonic mnemonic_phrase
_eth_seed_from_mnemonic_with_passphrase	mnemonic_phrase: str, passphrase: str -> bin	Calculates a seed from the given mnemonic phrase and an additional passphrase	_eth_seed_from_mnemonic_with_passphrase mnemonic_phrase passphrase
_eth_generate_mnemonic	length: int -> str	Generates a random mnemonic phrase of the given length	_eth_generate_mnemonic 12
_eth_generate_mnemonic_from_entropy	entropy: bin -> str	Generates a mnemonic phrase from the given entropy in a deterministic way	_eth_generate_mnemonic_from_entropy (_hash_code_to_binary (_value_id NIL))
_eth_extended_root_key_from_seed	seed: bin, chain_id: int+ -> str	Generates a Base-58 encoded extended root private key from the given seed	_eth_extended_root_key_from_seed seed
_eth_extract_private_from_extended	extended_key_base_58: str -> bin	Extracts an Ethereum private key from the given extended root key	_eth_extract_public_from_extended extended_key
_eth_extract_public_from_extended	extended_key_base_58: str -> bin	Extracts an Ethereum public key from the given extended root key	_eth_extract_public_from_extended extended_key
_eth_extended_public_from_extended_private	extended_private_base_58: str -> bin	Calculates an extended public key from the given extended private key	_eth_extended_public_from_extended_private extended_private_key
_eth_derive_private_key	extended_private_base_58: str, array: int[], depth: int -> str	Derives a new extended private key from the given extended private key	_eth_derive_private_key extended_private [0,0,0,1] 0
_eth_derive_public_key	extended_key_base_58: str, array: int[], depth: int -> str	Derives a new extended public key from the given extended private/public key	_eth_derive_public_key extended_key [0,0,1] 0
_eth_hardened	index: int -> int	Calculates a hardened Ethereum index from the given index	_eth_hardened 0
_eth_sign	private_key: bin, transaction: eth_transaction, chain_id: int+ -> bin	Calculates a signature of the given Ethereum transaction with the given private key	_eth_sign private_key transaction NIL
_rlp_decode	rlp_encoded_binary: bin -> any	Decodes the given RLP decoded value	_rlp_decode rlp_encoded_binary
_eth_parse_signature	signature: bin -> eth_transaction_signed	Parses the given Ethereum signature. This primitives does not validate the signature	_eth_parse_signature eth_signature
_eth_validate_and_parse_signature	signature: bin, public_key: bin -> eth_transaction_signed	Parses the given signature and validates it against the given public key	_eth_validate_and_parse_signature eth_signature public_key
_eth_compress_public	decompressed_public_key: bin -> bin	Calculates a compressed public key from the given public key	_eth_compress_public decompressed_public_key
_eth_decompress_public	public_key: bin -> bin	Calculates a decompressed public key from the given public key	_eth_decompress_public public_key

Chain IDs. Wherever a chain_id argument appears (_eth_extended_root_key_from_seed, _eth_sign, and related functions), it accepts any positive integer, giving full EIP-155 support for arbitrary EVM networks (for example Sepolia 11155111, Optimism 10, BSC 56, Polygon 137, Base 8453, Arbitrum 42161). Passing NIL selects legacy, pre-EIP-155 signing (where the signature v value is 27/28). A chain_id of 0 is not valid — use NIL for the legacy case.

Deterministic signing. _eth_sign produces signatures with deterministic nonces (RFC-6979): signing the same transaction with the same private key and chain ID always yields the identical signature, with no dependence on external randomness. Signatures are canonical low-S (EIP-2), and signature validation (_eth_validate_and_parse_signature) rejects non-canonical high-S signatures, so signatures are non-malleable.

JSON Primitives

Name	Signature	Description	Example
_to_json	value: any -> str+	Converts the given value to JSON string or returns NIL on failure	_to_json ($hello -> 1, $world -> TRUE)
_to_json_with_limits	limits_dict: (str -» int), value: any -> str+	Converts the given value to JSON string with imposed limits or returns NIL on failure	_to_json_with_limits ($ws -> 1000, $depth -> 1000, $strlen -> 1000, $keylen -> 1000, $items -> 1000)
_to_json_or_abort	value: any -> str	Converts the given value to JSON string or aborts on failure	_to_json_or_abort value
_from_json	json_string: str -> any	Parses the given JSON string into a MUFL value or returns NIL on failure	_from_json “{"hello": 1}”
_from_json_with_limits	limits_dict: (str -» int), json_string: str -> any	Parses the given JSON string into a MUFL value with imposed limits or returns NIL on failure	_from_json_with_limits limits value
_from_json_or_abort	json_string: str -> any	Parses the given JSON string into a MUFL value or aborts on failure	_from_json_or_abort json_string

String Operation Primitives

Name	Signature	Description	Example
_str	value: any -> str	Converts the given value to its string representation	_str ($hello -> 1, $world -> ($nested -> TRUE))
_str_is_number	string: str -> bool	Checks whether the given string represents an integer in the signed 64-bit range. Returns FALSE for non-numeric strings and for values outside that range	_str_is_number “1000”
_str_to_number	string: str -> int	Converts the given string to the corresponding integer. Aborts if the string is not a valid number or lies outside the signed 64-bit range	_str_to_number “1000”
_str_from_number	number: int -> str	Converts the given number to its string representation	_str_from_number 1000
_substr	string: str, start: int, length: int -> str	Returns a substring of the given string starting at the given index with the given length	_substr “Hello world!” 0 5
_str_find	string: str, substring: str, start_pos: int -> int	Searches for the given substring in the given string starting from the given position	_str_find “Hello world!” “world” 2
_str_left	string: str, count: int -> str	Returns a substring of the given string consisting of the first characters	_str_left “Hello world” 5
_str_right	string: str, count int -> str	Returns a substring of the given string consisting of the last characters	_str_right “Hello world” 5
_str_trim_left	string: str -> str	Trims all the whitespaces from the given string from the left	_str_trim_left “ Hello world”
_str_trim_right	string: str -> str	Trims all the whitespaces from the given string from the right	_str_trim_right “Hello world “
_str_trim	string: str -> str	Trims all the whitespaces from the given string from both left and right	_str_trim “ Hello world “
_str_cut	string: str, len: int -> str[]	Cuts the given string into a pieces of the given length	_str_cut “Hello world” 6
_str_to_lower	string: str -> str	Converts all the characters in the given string to lowercase	_str_to_lower “Hello WORLD”
_str_split	separator: str, string: str -> str[]	Splits the given string into a list of two strings - the first with characters up to the first occurrence of the given separator in one string and the remainder of the given string in the second. The separator must be a single character.	_str_split “ “ “Hello world”
_strlen	string: str -> int	Returns the length of the given string	_strlen “Hello world”

Time Primitives

Name	Signature	Description	Example
_parse_time	time_str: str -> time	Parses the time string into a value of domain TIME	_parse_time “2022-01-01 00:00:00.123456789 (UTC+2)”
_time_from_seconds_and_nanoseconds_since_epoch	seconds: int, nanoseconds: int -> time	Constructs a value of domain TIME from the given values of seconds and nanoseconds since epoch	_time_from_seconds_and_nanoseconds_since_epoch 1234 112233
_substract_seconds	lhs: time, rhs: time -> int	Returns the result in seconds of subtracting of the right-hand side time point from the left-hand side time point	_substract_seconds time1 time2
_substract_additional_nanoseconds	lhs: time, rhs: time -> int	Returns an additional difference in nanoseconds after executing the _substract_seconds lhs rhs	_substract_additional_nanoseconds time1 time2
_get_year	time_point: time -> int	Extracts the four-digit year from the given time point	_get_year t
_get_month	time_point: time -> int	Extracts the month (1-12) from the given time point	_get_month t
_get_day_of_year	time_point: time -> int	Extracts the day of year (1-365) from the given time point	_get_day_of_year t
_get_day_of_month	time_point: time -> int	Extracts the day of the month (1-31) from the given time point	_get_day_of_month t
_get_day_of_week	time_point: time -> int	Extracts the day of the week (0-6) from the given time point	_get_day_of_week t
_get_hours	time_point: time -> int	Extracts hours (0-23) from the given time point	_get_hours t
_get_minutes	time_point: time -> int	Extracts minutes (0-59) from the given time point	_get_minutes t
_get_seconds	time_point: time -> int	Extracts seconds (0-59) from the given time point	_get_minutes t
_get_nanoseconds	time_point: time -> int	Extracts nanoseconds from the given time point	_get_nanoseconds t
_get_seconds_since_epoch	time_point: time -> int	Converts the given time point to the number of seconds since epoch	_get_seconds_since_epoch