AEID: Abjad Encoded ID

Consonant-only encoding for 128-bit identifiers (ULID/UUID), designed for LLM contexts.

AEID encodes 128-bit values as 32-character ASCII strings using only 16 consonant letters (B C D F G H K L M N P R S T V W). No vowels means no accidental English words, eliminating semantic bias when LLMs handle IDs.

ULID:  01KC9R38FJH1XRVWJZBJRRCV5A
AEID:  BCNRCFMCPCWDMMLRMTWDHWHSRCMKKSPP

Why?

Install

pip install aeid                # core
pip install aeid[pydantic]      # + Pydantic support

Usage

AEID class (extends ULID)

from aeid import AEID

# Generate
a = AEID()                                          # new with current timestamp
a = AEID.from_str("BCNRCFMCPCWDMMLRMTWDHWHSRCMKKSPP")  # from AEID string
a = AEID.from_str("01KC9R38FJH1XRVWJZBJRRCV5A")        # from ULID string

# Convert
str(a)          # "BCNRCFMC..."   AEID (32 chars)
a.ulid_str      # "01KC9R38..."   ULID (26 chars)
a.datetime      # datetime(...)   timestamp
a.to_uuid()     # UUID(...)
int(a)          # 128-bit integer

# All ULID factory methods work
AEID.from_datetime(dt)
AEID.from_timestamp(time.time())
AEID.from_uuid(uuid_obj)
AEID.from_int(value)
AEID.parse(any_format)           # auto-detect AEID/ULID/hex/bytes/int

Low-level functions

from aeid import encode, decode, resolve

encode(0x019b1381a1f2887b8df25f5cb1866caa)
# "BCNRCFMCPCWDMMLRMTWDHWHSRCMKKSPP"

decode("BCNRCFMCPCWDMMLRMTWDHWHSRCMKKSPP")
# 0x019b1381a1f2887b8df25f5cb1866caa

# LCS-based error recovery
resolve(corrupted_id, candidate_list)

Pydantic

from pydantic import BaseModel
from aeid import AEID

class Record(BaseModel):
    id: AEID

r = Record(id="BCNRCFMCPCWDMMLRMTWDHWHSRCMKKSPP")  # validates AEID
r = Record(id="01KC9R38FJH1XRVWJZBJRRCV5A")         # validates ULID too
r.model_dump_json()  # {"id": "BCNRCFMCPCWDMMLRMTWDHWHSRCMKKSPP"}

Encoding

Each byte is mapped to a 2-character pair using a 256-entry lookup table:

byte value  ->  ALPHABET[high nibble] + ALPHABET[low nibble]
0x00 -> BB,  0x01 -> BC,  ...  0xFF -> WW

16 bytes (128 bits) produce 32 characters. The encoding preserves sort order: lexicographic order of AEID strings matches the numeric order of the underlying values.

Specification

• English
• Japanese

License

MIT