const CodecExts = [
  ("poseidon2-alt_bn_128-sponge-r2", 0xCD10), # bn128 rate 2 sponge
  ("poseidon2-alt_bn_128-merkle-2kb", 0xCD11), # bn128 2kb compress & merkleize
  ("poseidon2-alt_bn_128-keyed-compress", 0xCD12), # bn128 keyed compress]
  ("codex-manifest", 0xCD01),
  ("codex-block", 0xCD02),
  ("codex-root", 0xCD03),
  ("codex-slot-root", 0xCD04),
  ("codex-proving-root", 0xCD05),
  ("codex-slot-cell", 0xCD06),
]