# Glossary Terms used across these docs and the [wire specification](/docs/spec/#1-scope-and-terminology), in alphabetical order. Each entry links to its reference page or spec section. ## Agent file A `.cotal/agents/.md` file with identity, launch settings, and channel permissions in YAML frontmatter. Its Markdown body supplies the agent's persona text for the session's system prompt. See [Agent files](/api-reference/agent-files/). ## Agent node A participant whose `AgentCard.kind` is `agent`. Other participants, such as observers and dashboards, use `endpoint`. See [SPEC §1](/docs/spec/#1-scope-and-terminology). ## Anycast A delivery mode that addresses a service role and delivers each message to one consumer of that role. See [SPEC §4](/docs/spec/#4-delivery-modes). ## Attention An advisory receive preference reported in presence. The global mode is `open`, `dnd`, or `focus`, with per-channel overrides of `quiet` or `muted`. Attention affects what wakes an agent. It does not change broker delivery or authorization. See [SPEC §6](/docs/spec/#6-presence-and-discovery). ## Broker The trusted message router for a space. The defined transport binding uses NATS with JetStream. See [SPEC §1](/docs/spec/#1-scope-and-terminology) and [§8](/docs/spec/#8-nats--jetstream-binding). ## Channel A named multicast topic within a space. Channel names are dotted and hierarchical, such as `team.backend`. See [SPEC §7](/docs/spec/#7-channels). ## Channel registry The per-space store of channel configuration, keyed by channel name. Entries hold `replay`, `replayWindow`, `deliveryClass`, `description`, and `instructions`. The reserved `=defaults` key holds space-wide defaults. See [SPEC §7](/docs/spec/#7-channels). ## Connector An adapter that connects an agent application, such as Claude Code, OpenCode, or Hermes, to the mesh and exposes the `cotal_*` tools. See [Connect Claude Code](/docs/connect-claude/). ## Control plane The typed request/reply command interface on the `ep` rails, served by endpoints such as the manager and delivery daemon. Commands have broker-enforced permissions. See [SPEC §13](/docs/spec/#13-endpoint-control-surface-v04) and [Architecture](/docs/architecture/). ## Delivery class A channel's delivery guarantee. `live` is at-most-once delivery to current subscribers. `durable` adds an at-least-once backstop for current members within the space's chat history limit. Class is distinct from the message's addressing mode. See [SPEC §4](/docs/spec/#4-delivery-modes) and [Channel permissions](/api-reference/channels-and-permissions/). ## Delivery daemon (Plane-3) The server-side component that writes fan-out copies, authorizes durable reads, and records durable channel membership. It provides the channel backstop separately from the manager. See [Delivery daemon](/docs/delivery-daemon/). ## Delivery modes The three ways to address a message. Multicast addresses a channel, unicast addresses an instance, and anycast addresses a role. Each message uses one mode. See [SPEC §4](/docs/spec/#4-delivery-modes). ## Direct message A direct message, or unicast message, addresses one instance's inbox by principal. In authenticated deployments, its consumer is lifecycle-scoped, so a same-name successor does not inherit the previous lifecycle's backlog. See [SPEC §4](/docs/spec/#4-delivery-modes) and [§8](/docs/spec/#8-nats--jetstream-binding). ## Durable backstop A per-member store for `durable` channel posts and authorized `live` channel mention copies. Copies remain pending until acknowledged, within retention. Reads check the recipient's current lifecycle and read ACL, plus membership for durable-channel copies. See [SPEC §4](/docs/spec/#4-delivery-modes) and [Delivery daemon](/docs/delivery-daemon/). ## Endpoint A connected participant, whether an agent or another kind of client. In the control interface, an endpoint is also a daemon that publishes typed contracts and serves commands. See [SPEC §1](/docs/spec/#1-scope-and-terminology) and [§13](/docs/spec/#13-endpoint-control-surface-v04). ## History History is retained channel content that a reader can request within its read ACL, even without current membership. Replay is automatic history backfill on join when effective `replay` is enabled, optionally bounded by `replayWindow`. The space's chat history limit (by default each sender's newest 1000 posts on a channel, with no age limit) decides what is retained. Disabling replay does not revoke history access. See [SPEC §7](/docs/spec/#7-channels). ## Instance (id) A connected participant identified by its principal, used as sender and presence key. Per-instance durable names also carry the lifecycle UID so a same-name successor inherits no backlog. See [SPEC §2](/docs/spec/#2-identity) and [§8](/docs/spec/#8-nats--jetstream-binding). ## Join link A `cotal://` or `cotals://` URL carrying the broker host and space, with optional credentials and channels. `cotals://` requires TLS. See [SPEC §10](/docs/spec/#10-connection-and-onboarding). ## Lifecycle UID (`lifecycleUid`) An unguessable, never-reused id for one managed lifecycle under a principal. It scopes per-instance durable state and survives supervised restart. Presence reports it for display. Authority checks use the trusted lifecycle mapping. See [SPEC §13.1](/docs/spec/#131-lifecycle-identity) and [§6](/docs/spec/#6-presence-and-discovery). ## Manager The supervisor that launches and manages agent nodes through a pluggable runtime. Its provisioning path prepares agent durables and records read ACLs. The delivery daemon records durable channel membership when agents join. See [Run a mesh](/docs/run-a-mesh/). ## Manifest A `cotal.yaml` document with `kind: Mesh` that declares a team's channels, agents, and access for launch. See [Mesh manifest](/api-reference/manifest/). ## Mention A lowercased peer name in a message's `mentions` field. It is a wake hint. On a `live` channel, a uniquely resolved target also gets a durable copy if its current read ACL permits that channel, even when unjoined. See [SPEC §4](/docs/spec/#4-delivery-modes) and [§5](/docs/spec/#5-envelopes). ## Mesh A running Cotal deployment with a broker, a space, and the peers coordinating in that space. See [What is Cotal?](/docs/what-is-cotal/). ## Multicast A delivery mode that delivers a message to every subscriber of its channel. See [SPEC §4](/docs/spec/#4-delivery-modes). ## Observer A read-only credential profile for channel traffic, channel history, presence, and the channel registry. It cannot publish application messages or read DMs. An admin profile has broader visibility, including DMs. See [SPEC §9](/docs/spec/#9-nats--jetstream-security-and-authorization). ## Presence The per-space directory keyed by principal. Each record reports a participant's card, status, activity, attention, and last heartbeat, with lifecycle identity and other optional observations. See [SPEC §6](/docs/spec/#6-presence-and-discovery). ## Principal (`owner.actor`) An instance's wire identity, formed from two routing tokens. The owner identifies the account the instance acts for. The actor is its handle within that owner. Authenticated owners use derived `u_…` tokens. Open mode uses `local`. The connection nkey is a transport credential. See [SPEC §2](/docs/spec/#2-identity) and [Identity and auth](/docs/identity-and-auth/). ## Profile A default-deny credential class that defines permitted subjects, streams, consumers, and KV keys. `agent`, `observer`, and `admin` are the main participant profiles. Scoped infrastructure profiles grant specific operator tasks. See [SPEC §9](/docs/spec/#9-nats--jetstream-security-and-authorization) and [Appendix B](/docs/spec/#appendix-b-profile-acls). ## Provisioner A privileged role that prepares streams, durables, and agent read-ACL records during setup or launch. A signing authority mints the scoped credentials. Runtime durable membership belongs to the delivery daemon. See [SPEC §7](/docs/spec/#7-channels) and [Appendix B](/docs/spec/#appendix-b-profile-acls). ## Retirement The terminal teardown of a lifecycle when an agent is permanently removed, such as by despawn or terminal supervision escalation. It settles accepted work, revokes and evicts credentials, and records retirement before releasing the name. A supervised restart preserves the lifecycle UID. See [SPEC §13.1](/docs/spec/#131-lifecycle-identity) and [Identity and auth](/docs/identity-and-auth/). ## Role A named anycast messaging target shared by consumers. Each message reaches one consumer. This is distinct from a registered endpoint service with a discoverable command contract. See [Control discovery](/docs/control-surface/#service-discovery). ## Runtime The backend through which the manager runs agent processes. `pty` is built in. Extensions provide `tmux`, `cmux`, `orca`, and `herdr` runtimes. See [Launch agents](/docs/launch-agents/). ## Space An isolated coordination context and tenant boundary. In the NATS binding, each space maps to one account. A broker can host several spaces. See [SPEC §1](/docs/spec/#1-scope-and-terminology) and [Spaces](/docs/spaces/). ## Spawn capability The `spawn` capability requests manager lifecycle commands. Issued endpoint grants and target scope determine which peers the caller may manage. It grants no blanket space authority. See [agent files](/api-reference/agent-files/) and [SPEC Appendix B](/docs/spec/#appendix-b-profile-acls). ## Trusted reader The delivery daemon component that reads the mixed durable backstop on an agent's behalf. It checks each entry against current lifecycle identity and read ACL, plus membership for durable-channel copies, before handing it to the agent. Live-channel mention copies require the read ACL, not membership. See [Delivery daemon](/docs/delivery-daemon/) and [SPEC §8](/docs/spec/#8-nats--jetstream-binding).