Glossary - deCDN

Term	Definition
Bao	The BLAKE3 verified-streaming encoding used for all delivery. Interleaves content with hash proofs so any requested range verifies against the root once aligned to its enclosing 16 KiB chunk-group boundary.
Blob	A content-addressed byte sequence. Every blob is identified by its hash; clients verify received bytes against the known hash.
Bond (capacity)	TOKEN locked in `CapacityBond` proportional to a node’s declared bandwidth (`bond = k × Mbps^α`) — the only TOKEN-side requirement to join the mesh; the bond scales with declared capacity rather than a flat minimum. Returned on deregistration after an unbonding period.
Capability	An owner-signed authorization letting one key spend up to a cap from a pool until an expiry. Node-agnostic — valid at every node — and registered on-chain once, on that signer’s first redemption.
Chain root	The head of a hash chain committed in a voucher. The payer releases one preimage per megabyte delivered, advancing the amount owed without another signature; a preimage proves its own position by hashing forward to the root.
Client	A lightweight QUIC endpoint that streams content and pays per MB. No stake, no on-chain registration, no network role.
Coverage	Which 64 MiB blocks of a blob a holder will serve, carried as a bitmap in DHT records and probe responses. Lets a requester route a wanted range to a holder that actually has it.
Credit window	The unpaid balance a node will carry on one lane before it pauses delivery. Starts at a floor and ramps as the lane pays, bounding what a non-paying counterparty can extract.
DHT	Kademlia-subset content discovery. Nodes self-publish records, with coverage, when caching a blob.
Full holder	A node caching a complete blob, as opposed to a partial holder caching only some blocks. Both are eligible sources for a multi-source fetch.
Hash sequence	An ordered collection of blob hashes (a directory or manifest equivalent).
Lane	The payment relationship between one signer and one node: an independent running total with its own watermark, hash chain, and credit window. A pool backs many lanes at once.
Multi-source fetch	Fetching one large blob from several holders in parallel, each serving disjoint segments, up to a configurable maximum (`max_sources`) and at most one node per operator. Each source is an ordinary paid stream — no new wire protocol.
Namespace	A publisher-owned identifier for a content set, and the unit of origin addressing. A request pairs it with the blob hash; the default namespace names no publisher and no authorized origins.
Node	A bonded QUIC endpoint that caches and delivers blobs. Some are origin-backed; others are pure caches.
Origin-backed node	A node configured with an S3-compatible store, NFS mount, or local disk — the canonical source for specific blobs. Never experiences a true cache miss for blobs in that store; for anything else it is a cache node.
Origin backend	The opaque storage behind an origin-backed node (S3, R2, B2, MinIO, NFS, local disk). Never exposed to the network.
Outboard	A blob’s BLAKE3 hash tree, stored separately from its content. An origin-cold node must import or build the outboard before it can serve verified ranges.
Payment chunk	The payment quantum: 1 MiB, a protocol constant. One released preimage pays for exactly one chunk. Distinct from the 16 KiB bao chunk group, which is the unit of verification.
Peer mesh	The flat set of all bonded nodes. Membership comes from the on-chain registry’s active set; content location comes from the DHT.
Pool (payment)	One on-chain USDC deposit that backs off-chain vouchers from many capped signers to many nodes. Opened once by its owner and reused; the owner reclaims the unspent remainder at close, after a grace window that lets nodes redeem first.
Probe	Parallel latency, availability and coverage check that runs before any delivery commitment. Its signed fields are on-chain slash evidence.
Publisher	An address that owns at least one namespace. Once governance has vetted the publisher wallet, it seats and unseats the origin operators for its own namespaces directly.
Segment	A contiguous, verifiably-aligned byte range assigned to a single source during a multi-source fetch. Independently verifiable, so it can be split or reassigned without re-reading from the start.
Selection score	The ranking a node uses to pick an upstream holder on a cache miss, combining advertised price, observed latency, and its local reputation score. Lower is better. Clients do not use it: they rank by measured round-trip time alone.
Slashing window	The 30 seconds for which a node’s last probe-quoted rate is binding. A stream opened inside it must be served at or below that quote; serving higher is slashable.
TOKEN	The deCDN bonding/governance token: locked as a node’s capacity bond and burned by the buyback sink. Not used for payments; governance weight comes from delivered bytes, not TOKEN balance.
USDC	The payment currency for all delivery. Fixed at deployment; pools deposit, voucher, and settle in USDC.
Voucher	A signed off-chain payment message naming its payee node and carrying a cumulative amount owed. The highest amount settles; a re-submitted voucher pays zero.