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CKB Address

CKB address packages the Lock Script into a single line of verifiable and human-readable format, adhering to Bitcoin's Bech32m address format (BIP-350). In this format, the Lock Script consists of three key parameters: code_hash, hash_type, and args.

Get Full Payload

To generate a CKB address, the Lock Script is encoded into a byte array, termed "payload," which is then wrapped into the final address format.

Full payload format encodes all data fields of Lock Script using Bech32m encoding:

payload = 0x00 | code_hash | hash_type | args

The hash_type field is for CKB-VM version selection.

  • hash_type 0: the Script group matches code via data hash and will run the code using CKB-VM v0.
  • hash_type 1: the Script group matches code via Type Script hash and will run the code using CKB-VM v1.
  • hash_type 2: the Script group matches code via data hash and will run the code using CKB-VM v1.

Wrap Into Address

The payload is wrapped into an address following Bitcoin Bech32 address format (BIP-173) or Bitcoin bech32m address format (BIP-350), using Bech32/Bech32m encoding and a BCH checksum.


The original Bech32/Bech32m format limits strings to 90 characters. However, we have removed this length restriction, similar to BOLT. For strings longer than 90 characters, the error correction function is disabled to prevent the risk of incorrect corrections, which we do not intend to use.

A Bech32/Bech32m string consists of the human-readable part, the separator, and the data part. The last 6 characters of data part is checksum.

  • Human-readable part: "ckb" for CKB mainnet and "ckt" for the testnet
  • Separator: always being "1"
  • Data part: base32 encoded. The table below provides a translation for Base32 encoding:

The flow chart below outlines the process of encoding a Lock Script into a payload by adding a 6-byte BCH, followed by Base32 encoding, and then appending a human-readable part and checksum to the data.

Encoding a Lock Script into a payload

Examples and Demo Code

== full address test ==
code_hash to encode: 9bd7e06f3ecf4be0f2fcd2188b23f1b9fcc88e5d4b65a8637b17723bbda3cce8
hash_type to encode: 01
with args to encode: b39bbc0b3673c7d36450bc14cfcdad2d559c6c64
full address generated: ckb1qzda0cr08m85hc8jlnfp3zer7xulejywt49kt2rr0vthywaa50xwsqdnnw7qkdnnclfkg59uzn8umtfd2kwxceqxwquc4