Part of Stem. Every word the specification relies on is defined exactly once. Terms Stem introduces have their own definition page or schema page here; terms Stem leaves unchanged link to the official documentation.
Identity and data
Term | Meaning | Defined at |
|---|---|---|
blob | A signed DAG-CBOR value named by its CID. Unchanged. | |
principal | A public key in its byte form; an account or device identity. Unchanged. | |
CID, timestamp, signature | The content identifier, the millisecond timestamp and the signature of a blob. Unchanged. | |
resource | A mutable thing with a stable identity, rebuilt from blobs. | |
node | The identity and placement record of a resource; the same thing as the resource seen from the blob side. | |
node id | The stable id of a node: the CID of the Node blob that created it ( | |
space | An account's namespace: the node tree under its space root. | |
space root | The one node of a space whose creating Node blob is deterministic from the owner's key; owner-only; carries the profile attributes and the home document; | |
kind | The definition of a resource type: state representation, schema, naming, access mode, retention, links. | |
state | The current value of a resource, computed from the targets of its Node blobs. | |
version | An immutable reference to one state: the sorted head CIDs or the Snapshot CID. | |
Node blob | The signed blob that declares a resource's identity, kind, placement, state target, causal position and access mode. | |
target | The state declaration inside a Node blob: heads, snapshot, tombstone or redirect. | |
Change | A signed delta in a document's CRDT graph. Layout unchanged. | |
Snapshot | A signed blob holding the complete state of a resource. | |
block, file | The content tree inside a document, and UnixFS data. Unchanged. | |
schema | A Hypermedia Schema value; the meta-schema describes itself. Unchanged. |
Placement and addressing
Term | Meaning | Defined at |
|---|---|---|
placement | A node's parent and name; the placement tree is for naming and addressing only. | |
name | A node's relative name inside its parent: one path segment. | |
path, pretty path | A slash-joined chain of names from the root; derived, never identity. | |
node reference | A space, a node id and an optional version, naming a resource wherever a link, redirect or policy needs one. | |
hm:// URL | The address grammar. Unchanged except that a first segment holding a node id ( | |
redirect | A Node target that sends readers to another node. | |
tombstone | A Node target that deletes the resource while keeping its id taken. |
Authority and audience
Term | Meaning | Defined at |
|---|---|---|
grant | A signed statement that an audience holds an access level over a subject. | |
access level | One of | |
subject | What a grant covers: a node with or without its subtree, or a group. | |
audience | The set of principals a grant speaks about: everyone, a key, a group, a bearer secret, or the readers of a node. | |
readers | The computed set of principals that may read a node. | |
access mode | How a node derives its readers: inherit, own or target. | |
group | A permanode whose members are the holders of live grants on it. | |
revocation | A signed statement that cuts a grant. | |
authority graph | The grants and revocations of a space, evaluated in two passes. | |
proof | The grant a blob relies on for its authority; a hint for fetching, not an input to evaluation. | |
owner | The account whose key is the space; a permanent admin of the space root and so of every node under it. |
Sync and bookkeeping
Term | Meaning | Defined at |
|---|---|---|
scope | What a sync conversation is about: a space, a node, a depth and a set of facets. | |
scope set | The blobs a peer holds for a scope that the requesting peer may read. | |
policy | An account's sync rules, a Snapshot resource shared among its devices. | |
peer, peer id | A device connection on the network, identified by a libp2p key that never signs content. | |
authority peer | A peer that holds write, admin or sync on a space, or is its declared site. | |
trusted peer | A peer of an account the local account has joined, or that holds a grant from it. | |
site | A peer that publishes a space on the web under a relationship signed by both sides. | |
transfer | One batch of blobs received from a peer under a claimed scope, with per-blob verdicts. | |
disclosure | One blob served to a peer, with the basis that allowed it. | |
basis | Why a serve was allowed: public, a grant, a bearer secret, a site relationship, or an offer in progress. | |
range-based set reconciliation | The fingerprint-and-split comparison of two sorted sets. Unchanged. |
Indexing
Term | Meaning | Defined at |
|---|---|---|
handler | The one indexing routine every blob passes through, driven by kind descriptors. | |
link | A derived, typed edge from a blob to a blob or a resource. | |
fact | An indexed statement about a resource, marked signed or derived. | |
stash | A stored blob not yet applied because a dependency or a grant is missing. Unchanged. | |
HM24 | The protocol that ships today, with path-keyed Refs and Capabilities. |
Words Stem does not use
Stem pages do not say Ref, capability, visibility, generation, named root, inode, permission, subscription, discovery or Bitswap except when describing HM24. The replacements are Node, grant, audience and readers, prev, resource, node id, access level, policy rule, Sync and Fetch.
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