Glossary

Terms used across the Myelin documentation. Cross-references go to the page where the term is defined in detail.

A

Anchor package — A CKB-compatible CellTx package that binds a DA manifest to an L1-anchored cell. See DA flow.

Asset custody — The CKB Cells that participants lock into a Myelin session at open. See Session lifecycle.

B

Block hash — The canonical hash over the Molecule-serialised MyelinBlock header plus all commitments. Stable for the same input; sensitive to any field mutation. See Consensus engines.

Boundary (claim) — Where an evidence path stops being a claim. See Claim ladder.

C

Cell — A unit of CKB state, containing capacity, data, a lock script, and an optional type script. See What is CKB?.

CellDAG — The static conflict graph the scheduler builds from input OutPoints, consumed Cells, created Cells, read references, typed-cell conflict hashes, and declared read/write domains. See CellDAG scheduler.

CellScript — The language Myelin's application code is written in. Vendored under cellscript/ with an added typed-cell profile. See CellScript & typed-cell metadata.

CellTx — A unit of state transition: consumes Cells, creates Cells, carries witnesses and dep references. See Anatomy of a Myelin CellTx.

CKB — The Nervos CKB proof-of-work layer-1 blockchain. See What is CKB?.

CKB-VM — The RISC-V-based virtual machine that runs every CKB script. See What is CKB-VM?.

ckb-compatible — A semantic profile meaning a CellTx is projectable into a CKB-style transaction without changing semantics. See Semantic profiles.

ckb-inspired-only — A semantic profile meaning a CellTx follows the Cell model but has unsupported projection flags. See Semantic profiles.

Claim ladder — The four-tier ladder from "designed to stay close to CKB semantics" up to "CKB-aligned adjudication path." See Claim ladder.

Closed committee — A configured set of validators with a known public-key set. Used by the StaticClosedCommittee consensus engine. See Consensus engines.

Committee certificate — The signature set that finalises a MyelinBlock. Quorum-weighted for the static engine; strict-majority precommit for the Tendermint engine. See Consensus engines.

Conflict domain — A typed grouping of Cells over which two CellTxs would conflict if both wrote to the same element. See CellDAG scheduler.

Conflict hash — A typed-cell metadata field that commits to (read_set, write_set, conflict_domains). See CellScript & typed-cell metadata.

Court bundle — A self-contained input to the future CKB court verifier: chunk payload bytes, CKB Molecule tx bytes, projection report, challenge payload hash, and committee certificate. See Court path.

Court verifier — A future CKB type script that takes a court bundle as input and emits an accept / slash verdict. Not yet implemented.

D

DA — Data availability. See State & data availability and Data availability flow.

DA manifest — The artefact that records payload_hash, segment_root, segment_proof, optional external DA receipt, and da_availability level. See Data availability flow.

Determinism — The strong property that the same script binary, with the same input transaction and the same Cell deps, produces the same exit code on every node. See What is CKB-VM?.

Devnet smoke — The local CKB devnet smoke script (scripts/myelin_ckb_devnet_smoke.sh) that runs live carrier submissions against a parent CKB devnet. See Local CKB devnet smoke.

E

End-to-end production readiness — The aggregate flag that says "all six production gates pass." Stays false until DA is published, court economics are deployed, threshold-lock is enforced, the external DA SLA is present, and the operator policy is typed and verified. See L1 submission flow.

Evidence path — A chain of artefacts that together prove a specific claim. Myelin has four: execution, projection, court, settlement. See Evidence paths.

Execution report — The MyelinExecutionReport that records the VM's verdict on a CellTx: cycles, exit code, state-root transition, semantic profile. See Execution pipeline.

F

Fee density — The primary ordering key in the scheduler: fee / max(declared_cycles, 1). See CellDAG scheduler.

Finalised block — A MyelinBlock plus its committee certificate. The output of finalise_block. See Consensus engines.

G

Gate — A check that the runtime produces a specific report with a specific flag. The production gate runs nine gates in sequence. See Production gate.

L

L1 / L2 / off-chain — The three layers Myelin bridges. L1 is CKB; L2 is Myelin's session runtime; off-chain is producer / witnesses / DA. See The three-layer model.

Live Cell — A Cell currently spendable inside a Myelin session. See State & data availability.

Lock script — The script that controls who can spend a Cell. Runs when the Cell is consumed. See What is CKB?.

M

Mempool — The myelin-mempool queue that CellTxs sit in between submission and admission. See Mempool & admission.

Molecule — CKB's deterministic, zero-copy binary serialization format. Used by Myelin throughout. See What is CKB?.

MyelinBlock — The block shape that the committee finalises. See Consensus engines.

Myelin-only syscall — A syscall that exists in Myelin's VM but has no CKB equivalent. CellTxs that use them get semantic_profile = "myelin-native". See Semantic profiles.

O

Off-chain — The layer where producers, witnesses, and DA storage live. See The three-layer model.

OutPoint — The reference to a Cell by (tx_id, output_index).

P

Parallel batch — A list of CellTxs that the scheduler guarantees are safe to execute together. See CellDAG scheduler.

Producer — The off-chain actor that submits CellTxs and witnesses to Myelin.

Production gate — The scripts/myelin_production_gate.sh script that runs the full local release gate. See Production gate.

Projection — The function from a Myelin CellTx to a CkbProjectionReport. See CKB-style projection.

R

RBF — Replace-by-fee. A higher-fee CellTx can replace a lower-fee conflicting one in the mempool. See Mempool & admission.

Readiness chain — The five-step sequence (context, economics, inclusion, stability, finality) that proves a CellTx was actually accepted by CKB. See L1 submission flow.

S

Scheduler — The myelin-exec component that builds the CellDAG and emits parallel batches. See CellDAG scheduler.

Script group — A set of inputs and outputs that share the same type script. Verified in parallel by the CKB-VM verifier. See Execution pipeline.

SegmentProof — A Merkle proof that a payload hash is included in a segment tree. See State & data availability.

Semantic profile — The label that says what a transition means: ckb-compatible, myelin-native, or ckb-inspired-only. See Semantic profiles.

Session — The bounded context in which off-chain Cell execution happens. Has an open, a sequence of finalised blocks, an optional dispute, and a close. See Session lifecycle.

Settlement intent — The off-chain artefact that binds a verified court bundle and verified DA manifest to a disputed-close decision. See Court path.

Settlement package — A CKB-compatible CellTx package that encodes the settlement intent. See L1 submission flow.

State root — The 32-byte commitment to the live Cell set. See State & data availability.

Static closed committee — A consensus engine with a configured validator set and a quorum-weight finality rule. See Consensus engines.

Syscall — A VM-level call that scripts use to inspect the transaction they're validating. See What is CKB-VM?.

T

Tendermint — A consensus engine with weighted precommit finality. Same trait as the static engine; different certificate shape. See Consensus engines.

Threshold-lock — A canonical lock-args scheme enforced by the final settlement verifier. Requires an authority Cell with declared threshold-lock args. See Local CKB devnet smoke.

Type script — The script that enforces state rules across a set of Cells sharing a type. Runs at commit time for every output with a matching type. See What is CKB?.

Typed-cell metadata — The compiler-emitted artefact that commits to a CellTx's read/write sets, scheduler witness, and proof obligations. See CellScript & typed-cell metadata.

V

VM profile — The VM profile that a chunk was verified under (e.g. ckb-strict-basic). Reports which syscall surface the chunk used. See Execution pipeline.

W

Witness — Off-chain provided data attached to a CellTx (signatures, arguments, game tape, etc.). See Anatomy of a Myelin CellTx.

Witness slots — The numbered slots in a CKB transaction that the script reads. Teeworlds uses slots 1 (tape), 2 (map), 3 (config). See Execution pipeline.