Xync Network - Account ID Specification

CAIP-10

For context, see the CAIP-10 specification.

Introduction

Xync accounts are compact non-negative integer indexes issued sequentially by the protocol at registration (account 0 is the genesis operator). Public keys are rotatable (rekey operation), so the stable identifier of an account is its index — NOT a key or a hash of one. An optional 2-character checksum suffix protects against typos and cross-network confusion; it is REQUIRED in user-facing contexts.

Specification

Semantics

The address is the account index in decimal, optionally followed by -CC where CC is a checksum. Because the index space is dense (most small integers are existing accounts), a mistyped address usually hits a real account — unlike sparse hash-address namespaces. Wallets, QR codes and deep links MUST therefore render the checksummed form; parsers MUST validate the checksum when present. Exchanges SHOULD require the checksummed form for withdrawals.

Syntax

account_id:        chain_id + ":" + address
address:           index | index + "-" + checksum
index:             0 | [1-9][0-9]{0,9}      (< 1,073,741,824 = 2^30)
checksum:          2 characters of Crockford base32

As a single regular expression, the canonical (upper-case) address is (0|[1-9][0-9]{0,9})(-[0-9A-HJKMNP-TV-Z]{2})? — at most 13 characters. Parsers SHOULD additionally range-check the index against 2^30 - 1, which a character class cannot express.

Checksum computation:

CC = crockford_base32( first 10 bits of SHA-256(chain_id_caip2 + ":" + index) )
# big-endian: byte 0 of the digest, plus the top 2 bits of byte 1, split 5 + 5
# example: SHA-256("xync:main:518") = 1f b3 a3 … -> 0b0001111110 = 126 -> "3Y"

Crockford base32 alphabet (0123456789ABCDEFGHJKMNPQRSTVWXYZ); parsing is case-insensitive and maps I/L→1, O→0. Binding the CAIP-2 identifier into the hash makes a testnet address fail checksum validation on mainnet and vice versa.

Resolution Mechanics

// GET https://<node>/account/518
{
  "index": 518,
  "caip10": "xync:main:518-3Y",
  "pubkey": "…",          // current key; rotatable, NOT part of the address
  ...
}

Rationale

1. Index, not pubkey: keys rotate (rekey); an address derived from a key would break on every rotation. The index maps 1:1 to the 30-bit recipient field of the native 128-bit transaction format.
2. Checksum-in-address: analogous in spirit to EIP-55 — a canonical plain form and a checksummed display form coexist inside CAIP-10’s own account_address production ([-.%a-zA-Z0-9]{1,128}), which permits both. Xync itself uses only a narrow subset of that production: at most 13 characters, no . and no %, and the two halves have different alphabets — the index is decimal, the checksum is exactly two Crockford base32 characters.

Backwards Compatibility

Not applicable.

Test Cases

All values below are real outputs of the algorithm above and are usable as test vectors.

# mainnet account 518, checksummed (display form)
xync:main:518-3Y

# the same account, canonical plain form (accepted, checksum not verified)
xync:main:518

# genesis operator account
xync:main:0-FH

# largest index representable by the protocol (2^30 - 1)
xync:main:1073741823-TV

# devnet, same index — DIFFERENT checksum than mainnet
xync:dev-1:518-0A

# MUST fail: single-digit typo (3Y belongs to 518, not 519 — whose CC is 9A)
xync:main:519-3Y

# MUST fail: correct index, wrong network (0A is the dev-1 checksum)
xync:main:518-0A

# MUST fail: index beyond the 30-bit address space
xync:main:1073741824-XX

# MUST be accepted (Crockford leniency): lower case, I -> 1
xync:main:1-i2      # canonical form: xync:main:1-12

References

• Xync Network Yellow Paper - account model, rekey, transaction format
• EIP-55 - the precedent of in-identifier optional checksums

Copyright

Copyright and related rights waived via CC0.

Citation

Please cite this document as:

Xync Network, "namespaces/xync-caip10: Xync Network - Account ID Specification [DRAFT]," Chain Agnostic Namespaces, xync-caip10, July 2026 / . [Online serial]. Available: https://github.com/ChainAgnostic/namespaces/xync-caip10.md