This page defines the words the rest of the site uses. Each entry is short and links to the page with the full model, so you can use it as a map as well as a dictionary. Terms are grouped by the layer they belong to, from identity at the bottom to the software at the top.

Hypermedia is the protocol and Seed is the software that implements it. When an entry describes what "the daemon" does, it means the Seed daemon as of September 2026.

Identity and keys

Account. A key pair used as an identity. Its public key is its name, and no account record exists anywhere else. See Identity.

Space. The namespace of documents an account owns, addressed as hm://<account>/<path>. Account and space are the same key seen from two sides: the identity that signs and the place its documents live. See Documents.

Principal. The wire form of a public key: a multicodec prefix followed by the raw key bytes, written as base58btc text that starts with z6Mk for Ed25519 keys and zDn for P-256 keys. See Principal.

Account ID, uid. The text form of an account's principal as it appears in URLs, for example z6Mko5npVz4Bx9Rf4vkRUf2swvb568SDbhLwStaha3HzgrLS. See Identity.

Key name. A local alias under which the daemon or the CLI stores a key, such as main. It is never the same thing as the principal, and only the principal means anything to other people. See Keys.

Mnemonic. A BIP-39 word list, 12 to 24 words with an optional passphrase, from which an Ed25519 account key is derived on the path m/44'/104109'/0'. One mnemonic and passphrase give exactly one account. See Identity.

Key file. An exported .hmkey.json holding one key, optionally encrypted with a password, used by the CLI and in CI. See Keys.

Vault. The encrypted key store behind sign-in on the web and, since 2026, the desktop app. The server that holds a vault cannot read the keys inside it. See Sign in with Seed.

Session key. A browser-held key that a vault account delegates to with an AGENT capability, so a site can sign for you without ever receiving your account key. See Sign in with Seed.

Device key. The Ed25519 key that identifies one running daemon as a libp2p peer. It secures connections and never signs content. See Network.

Profile. A small signed snapshot blob that gives an account a name, an avatar and a description. The daemon merges all of an account's profile blobs field by field. See Profile.

Alias. A profile whose only field points at another account, meaning "this key is really that account". The daemon accepts it only if that account granted the key an AGENT capability. See Identity.

Key linking. Joining several keys into one identity with an AGENT capability from the main account and an alias profile from the other key. It is how desktop, phone and browser keys all show up as one person. See Identity.

Bearer token. A token the daemon issues in exchange for a signed, short-lived capability, which the Seed web app forwards so that a public-only node can serve you private content. It never authorizes a write. See Privacy.

Blobs and encoding

Blob. An immutable piece of data named by the hash of its bytes. Structured blobs are signed DAG-CBOR maps, and file chunks are unsigned IPFS data. See Signed Blobs.

CID. A content identifier: a self-describing hash that names a blob. Hypermedia uses CIDv1 with the dag-cbor codec for structured blobs, and dag-pb and raw for files. See CID.

DAG-CBOR. The deterministic binary encoding every structured blob uses: CBOR with sorted keys, shortest integers and native CID links. Because the encoding is canonical, one value always has one CID. See DAG-CBOR.

DAG-JSON. The JSON projection of the same data, where a link is written {"/": "<cid>"} and bytes are written {"/": {"bytes": "…"}}. The CLI prints blobs in this form. See DAG-JSON.

Signed envelope. The four fields every structured blob carries: type, signer, sig and ts. See Blob.

Signature. 64 bytes over the blob's canonical encoding taken with the sig field set to 64 zero bytes. The field is present, never omitted. See Signature.

Timestamp (ts). The signer's claimed time in Unix milliseconds. Nothing checks it against real time when a blob arrives. See Integrity.

Snapshot blob. A blob that carries a record's whole value and is replaced whole on edit: comments, contacts and profiles. Documents are the other kind, built from deltas. See Signed Blobs.

TSID. A timestamped id: 10 bytes of a 48-bit millisecond timestamp and the first 4 bytes of a SHA-256 hash, written as 14 or 15 base58 characters. It gives a snapshot record a stable identity across edits. See Signed Blobs.

Stash. Where the daemon keeps a blob it has stored but cannot yet interpret, because a dependency has not arrived or the signer is not yet authorized. The blob is retried when the missing piece lands. See Signed Blobs.

BLAKE2b and SHA-256 CIDs. The daemon hashes blobs it creates with BLAKE2b and the SDK and apps use SHA-256. Both are valid names for the same bytes. A blob that another blob references must be uploaded under the exact CID the referrer used. See Signed Blobs.

Documents and resources

Resource. The umbrella term for anything mutable that is rebuilt from immutable blobs: documents, comments, contacts and profiles. It is the word the Seed API uses. See The Hypermedia protocol.

IRI. The daemon's internal identifier for a resource, an hm://<account>/<path> string without version or fragment. Sync scopes and subscriptions are keyed by IRI. See Network.

Document. A change-based resource: a graph of signed Changes, replayed into metadata and a tree of blocks, and placed at an address by a Ref. See Documents.

Change. A signed delta on a document: a list of operations plus links to the changes it builds on. See Change.

Genesis. A document's first Change, and therefore its identity. Two Refs that name the same genesis talk about the same document, wherever they place it. See Documents.

Home document. The document at the empty path of a space, hm://<account>. Its genesis is a deterministic empty Change with ts 0, so every device of the account derives the same one. See Documents.

Deps and depth. A Change's deps are the heads its author saw, sorted by CID. Its depth is one more than the deepest dep. Together they order the history. See Change.

Operation (op). One edit inside a Change: SetAttributes, ReplaceBlock, MoveBlocks, DeleteBlocks, or the deprecated SetKey. Each has an id of timestamp, position and actor that decides concurrent conflicts. See Operations.

CRDT. A conflict-free replicated data type: a merge rule that makes every replica reach the same state in any delivery order. Documents use a last-writer-wins register for metadata and a move tree with ordered sibling lists for blocks. See Documents.

Head. A Change that no other Change depends on yet. A document with two heads has two concurrent edits that nobody has merged. See Documents.

Version. The set of head CIDs, sorted and joined with ., written ?v= in a URL. A version always replays to the same content. See URLs.

Latest (l). A URL flag meaning "the newest version, and at least this one". Today the daemon simply returns the newest version it knows. See URLs.

Ref. A signed claim that an address currently shows a given version, is deleted, or redirects elsewhere. A document appears at an address only through an indexed Ref from an authorized signer. See Ref.

Generation. One life of an address, numbered by the writer. The highest generation wins. Publishing a Ref with a higher generation replaces whatever lived at the path. See Documents.

Tombstone. A Ref with a genesis and no heads, which marks the document deleted. The history stays on every node that holds it. See Documents.

Redirect. A Ref with no heads and a redirect target, so readers of the old address are sent to the new one. See Redirect target.

Republish. A redirect with republish set: the old address keeps showing the target's content under its own URL. See Documents.

Fork (branch). Publishing your own Ref, in your own space, that points at another document's genesis and heads. You get an address you control with the whole history intact. See Documents.

Path. The /-separated name of a document inside a space, such as /notes/sushi. Paths are plain strings, and a parent path confers no authority over its children except through capabilities. See Documents.

Directory. The documents whose paths sit under a given path, found by a prefix query. The daemon stores no tree. A directory is only a listing. See Documents.

Draft. Unpublished edits kept by a client: the Seed app, the CLI and Seed Agents each keep their own. The daemon has no drafts. Publishing means signing a Change and a Ref. See Documents.

Metadata (attributes). A document's key-value attributes such as name, summary, icon and siteUrl, set with SetAttributes and merged last-writer-wins. See Document Metadata.

Content

Block. One addressable piece of a document or comment body, such as a paragraph, heading, image or table row, with a permanent id. See Blocks.

Block node. A block plus its list of child block nodes. A document body is an ordered list of them. See Block node.

Children type. The childrenType attribute that lays out a block's children: Group, Ordered, Unordered, Blockquote or Grid. A list is a property of the parent, and its items carry no list type. See Children type.

Annotation. An inline layer over a range of a block's text: a style, a link, a highlight or an inline embed. Offsets count Unicode code points. See Annotation.

Mention. An inline embed over a placeholder character that links to an account or a document and renders the target's current name. The daemon indexes it as a link, which is how "mentions of me" works. See Comments.

Embed. A block that shows another resource in place: a document, a block, a block with its children, a text range or a discussion, pinned to a version or following the latest. See Embed.

Query block. A block that stores a query (included spaces and paths, sort, limit) and shows its live result as cards, a list or a table. See Query block.

Collection. A document whose content is a single top-level query block that lists its own children. The indexer derives this from the content and reports it as isCollection. No attribute declares it. It is a presentation convention in the Seed app, and the protocol has no such concept. See Blocks.

Detached block. A block that has content but no position in the tree. The daemon returns it separately, and the Seed app keeps a site's menu in one named navigation, whose children are Link blocks. See Navigation item.

Revision. The CID of the Change that last replaced a block, reported on every block the daemon serves. A citation records it so readers can tell whether the cited text has changed. See Blocks.

Text fragment. A URL fragment that names a block (#id), a block with its children (#id+) or a range of its text (#id[start:end]). See URLs.

Comment. A signed snapshot blob in its author's space that targets a document version and carries a body of blocks. Anyone can comment on any document. See Comments.

Discussion (thread). A comment with no threadRoot and every reply that names it as root. See Comments.

Citation (backlink). A link record the daemon indexes for every hm:// link it finds in a document or comment, from the source to the target. ListCitations returns a target's backlinks. See Comments.

File. An image, video or attachment stored as unsigned IPFS UnixFS data and linked from a block as ipfs://<cid>. It becomes public once a public blob links to it. See Files.

Permissions and relationships

Capability. A signed grant from a space owner to another key, with a role and an optional path scope. It never expires and cannot be revoked today. See Permissions.

Role. The kind of capability: WRITER may publish Refs at and under a path. AGENT is full delegation of the issuer's key and must have an empty path. No other role exists in data. See Role.

Delegate. The key a capability grants authority to. See Capability.

Path scope. The path a capability covers, matched by segment and always recursive: /team covers /team/notes but not /teammates. See Permissions.

Collaborator. A key that may write in a space through a capability, listed by the ListDocumentCollaborators request and the /:collaborators view. See Permissions.

Contact. A public, signed address-book entry in which one account names another. The daemon never consults a contact for access. See Contact.

Join. Publishing a contact for a site's account with subscribe.site set. The site's members list is derived from these contacts. See Contact subscription.

Follow. Publishing a contact for a person with subscribe.profile set. See Contact subscription.

Member. An account that has joined a site. A member who also holds a capability is shown with its role. Membership grants no permissions. See Permissions.

Visibility. Whether a Ref or comment is public (the empty string) or Private. Changes and files inherit visibility from whatever links to them. See Visibility.

Private document. A document published with a private Ref, readable only by the owner, keys holding a root-scoped grant, and the site server. Creating new private documents is disabled in the daemon at the moment. See Privacy.

Web of trust. The long-term idea that trust between accounts filters what you see. Today only capabilities, aliases and contacts exist, and none of them carry trust transitively. See Permissions.

Network and sites

Peer. One running daemon on the libp2p network, identified by a peer id derived from its device key, such as 12D3KooW…. See Network.

Protocol id. The libp2p protocol string every peer announces, /hypermedia/0.9.2, with a -<name> suffix on a testnet. Peers with different strings do not talk. See Network.

Bootstrap gateway. One of the Seed servers compiled into every daemon, such as hyper.media, which hold nearly all public content and are asked first in every discovery. See Sites.

Gateway. A word with three meanings: a bootstrap gateway, a web app run with the gateway flag that serves any account at /hm/<account>/…, and the daemon's /ipfs/<cid> file route. See Sites.

Discovery. The daemon's search for an address it does not fully have: it asks the space's site server and the gateways, then connected peers, then stored peers. DiscoverEntity is its entry point. See Network.

RBSR. Range-based set reconciliation: two peers compare hash summaries of ordered ranges of blobs and subdivide only where they differ. The cost grows with the number of differences, not the size of the set. See Network.

Bitswap. The IPFS block-exchange protocol that fetches blobs once reconciliation has named the missing CIDs. Seed filters each request so private blobs reach only authorized peers. See Network.

Subscription. A standing, periodic discovery for one address, optionally recursive. The Seed app subscribes to the spaces you join or follow, and a site server subscribes to its registered account. See Network.

Push. Announcing a set of blobs to a specific peer, usually a site server, so it fetches them right away instead of waiting for its subscription. See Network.

Peer exchange. Asking a connected peer for its recent peer list, which is how a node finds peers beyond the bootstrap list. There is no DHT today. See Network.

Relay. A server that forwards connections for peers behind NAT. The daemon uses two compiled-in Seed relays and never relays for others. See Network.

Site. A space published at a web domain by a server that holds its content and renders it as web pages. See Sites.

siteUrl. The home document attribute that names a space's site. Nodes treat the server behind it as the space's authority and let it receive the space's private blobs. See Sites.

Site registration. The handshake that binds one account to one site: the owner's app presents a one-time secret to /hm/api/register, pushes the space, and sets siteUrl. See Sites.

/hm/api/config. A site's public description of itself: its registered account, peer id, addresses and protocol id. Any client holding only a web URL starts here. See Sites.

Custom domain. A domain you own that points at a hosted <name>.hyper.media site or a self-hosted server. See Sites.

Public-only node. A daemon started with -public-only, which serves only public data over HTTP and gRPC unless a request carries a valid bearer token. Hosted sites and gateways run this way. See Privacy.

Hot and cold discovery. Hot tasks come from something on screen and rerun every ten seconds while viewed. Cold tasks are subscriptions that rerun every minute. See Network.

URLs and APIs

hm:// URL. hm://<account>/<path>?v=<version>#<block>, an address that names a space, a path, optionally an exact version and a block or text range. See URLs.

View suffix. A path segment starting with : that selects a view of the same document, such as /:comments, /:directory or /:attributes. See URLs.

Seed API. The typed HTTP API every Seed web app serves at /api/<Key>, such as /api/Resource?id=…. See Web API.

Site services. The web app's own endpoints under /hm/api/*: config, auth, file, register, discover and others. See Web API.

Daemon gRPC API. The Seed daemon's gRPC services, served natively and as gRPC-web on its HTTP port, for deep integration. The local API has no authentication, so keep it on localhost. See gRPC.

SDK. @seed-hypermedia/client, the TypeScript library for reading through the Seed API and for building, signing and publishing blobs. See SDK.

Seed CLI. seed-cli, the command-line tool for keys, documents, comments, blobs and schemas, and the tool external agents use through the seed-cli skill. See Seed CLI.

Hypermedia Schemas

Hypermedia Schemas. The self-describing type system for content-addressed data: schemas are published as DAG-CBOR blobs and documents bind to them by CID. See Schema and Why Schemas.

Meta-schema. The schema of schemas, a discriminated union of every shape a schema can take, which is itself a valid instance of that union. See Schema and Self-description.

Typed document. A document whose metadata binds it to a schema. See Typed Documents.

schemaDefinition. A metadata key holding the ipfs:// CID of the schema a document defines. See Typed Documents.

attributesSchema. A metadata key naming the schema a document's own attributes must satisfy. See Typed Documents.

childAttributesSchema. A metadata key naming the schema that documents under this path must satisfy. See Typed Documents.

Data model and kind. Every value is one of nine IPLD kinds: null, boolean, integer, float, string, bytes, list, map and link. See Data Model and Kind.

Variant. One member of the meta-schema union: a scalar, literal, list, map, struct, link, union, reference or variable schema. See Variant.

Struct schema. A schema for a map with known fields, each a property. See Struct schema and Property.

Map schema. A schema for a map whose arbitrary keys all hold values of one schema. See Map schema and Closed map.

List schema. A schema for a list whose items match one schema. See List schema.

Literal. A schema that accepts exactly one value. A fixed set of choices is a union of literals. See Literal schema.

Union. A schema that matches any one of several alternatives, told apart by a discriminant when they are tagged. See Union schema and Discriminated union.

Link schema. A schema for a CID link, optionally naming the type the link must point at with target. See Link schema.

Include and extension. A schema node whose type names another schema. Bare, it is an include, and with extra refining keys it is an extension. See Reference Schema and Extension.

Generic and variable. A schema parameterized over a type, and the {"var": "<name>"} reference that stands for the bound parameter inside it. See Generic and Variable schema.

Primitive. One of the standard-library schemas that is exactly one kind, such as string or integer. See Primitive.

Canonical encoding. The single deterministic byte form of a value in DAG-CBOR, which is why a schema has exactly one CID. See Canonical Encoding.

Fixpoint problem. A blob cannot contain its own CID, so a cycle of CID links has no encoding order. Names break such cycles. See Fixpoint Problem and References and Naming.

Library. The schemas and pages in the hypermedia/ folder of the Seed repository, which the Seed app and the SDK bundle. Each schema is named hm://hyper.media/<path>. See How Schemas Work.

Authority. The key that owns an hm:// URL and signs what is published under it. The library writes its authority as the domain hyper.media, which the SDK and the docs sync understand but the network does not resolve yet. See Authority.

Lockfile. schemas.lock.json in the repository, which pins every library schema's CID and is checked before publishing. See How Schemas Work.

Seed Agents

Software and process

Seed daemon. seed-daemon, the Go program that stores, indexes, verifies and syncs blobs. Every other Seed program talks to one. See Daemon.

Seed app. The Electron desktop app, which runs its own daemon. See Desktop.

Seed web app. The server-rendered web app that turns a daemon into a site and serves the Seed API. See Web.

Extensions (plugins). A planned plugin system in which a document carries a small app that a site installs. It is being redone and nothing ships today. See Roadmap.

HM26. The working name for a redesign of the blob layout and resource model under discussion in 2026. Nothing of it ships. See Where this is going.

Protocol change. Any change to permanent data, the sync protocol, capabilities, identity, or any interoperable wire or disk format. It goes through a written proposal and review. See Contributing.

Repo HM sync. The round trip between a git folder and a Hypermedia space that publishes this site from the repository. See Publish a folder.

Retired names

See also

The Hypermedia protocol, the layered tour these terms come from.

Agents glossary, for every Seed Agents term.

Why Hypermedia, the motivation behind these terms, for any reader.

Building on Hypermedia, for task guides that use them.