Glossary
Every HCP term, one line each, with a link to where it is defined.
Normative definitions live in §1 Terminology. This page is the quick lookup.
| Term | One line | More |
|---|---|---|
| HCP | Harness Context Protocol: installs a capability into an agent harness as one pack with two loops | What is HCP |
| Harness | The environment an agent runs in: model, tools, memory, policy, runtime | Architecture |
| Harness Pack | Directory of surface.json, policy.json, HARNESS.md | Pack |
| Manifest | surface.json: identity, adapter, binding, commands, triggers | Manifest |
| Command | Named operation a pack exposes; wire name verb_key | Command |
verb_key | Wire identifier of a command (plan, setup.connect) | §3 |
| Twin face | A command's CLI form and JSON form produce the same result | §6.5 |
| Execute | Inbound loop: an Invoker runs a command | §6 |
| Sense | Outbound loop: a pack announces a world change | §7 |
| Trigger | Declared Sense event, stimulusTriggers[].ref | Triggers |
| Policy | Per command/trigger: operation, privacy.land, confirm | Policy |
| Operation | The effect class of a command, read or write | §4.3 |
| Land | The data domain a command touches: personal | brain | local | §4.4 |
| Confirm | Gate on writes; satisfied by args.confirm or args.apply | §4.5 |
| Binding | How a command obtains credentials at exec time; mode + hub, never a secret | Binding |
| Mode | public | user | local | mothership | mock | §8.2 |
| Hub | Component kind that mints: keyring, local-credential, public, none | §8.3 |
| Family | Group of packs sharing one consent | §8.3 |
| Mint | Runtime obtains a credential from the hub for one exec | §8.4 |
| Connect | Lifecycle step that establishes Binding; capability pack.connect | §8.5 |
| Principal | The acting identity: human, service, agent, or mothership | Principal |
| Mothership | Operator or fleet identity; the Binding mode for control-plane packs | §8.2 |
| Tenant | Organisational scope from the session, never from args | §9.2 |
| Project | Sub-scope required for land brain | §9.2 |
| Capability | One of five grant axes | §9.4 |
| Grant | { capability, pack_id?, verb_keys? } held by a Principal | Grants |
| Invoker | Who calls Execute: agent tool, API, UI, human CLI | Invoker |
| Adapter | How a command runs: wrap, composite, openapi, sense_only | Adapter |
| Wrap | Adapter that spawns wrap.bin with rendered argv | Wrap a CLI |
| Composite | In-process adapter | Adapter |
| Pass-through | Bootstrap-only whole-CLI wrap with allowed subcommands | §3.3 |
| Plane | runtime (user work) or control (operator lifecycle) | §2.5 |
| Runtime | Loads, authorizes, binds, executes, routes Sense | Runtime |
| Reference runtime | createReferenceLocalRuntime in the SDK | SDK |
| Host | An agent product that adopts HCP | Hosts |
| Projection | A pack's view on a surface: CLI, host tool, Skill, MCP export | §12 |
| Four faces | Wire, CLI, host tool, Skill must name a command consistently | §12.4 |
| Skill | HARNESS.md, the teaching document for humans and agents | Skill |
| Lead | Text between the Skill title and first ##; the stable-context excerpt | §5.3 |
| Sandbox | Default exec posture: bin allow-list, cwd jail, no ambient credentials | §10 |
| Native-local | Explicit opt-out of the jail on a trusted machine | §10.3 |
| Availability | installed / activated / connected / executable | §11.2 |
| Store | $HCP_HOME, which holds packs, skills, and state | CLI |
| Bootstrap pack | hcp-cli; describes the runtime's own lifecycle | §11.4 |
| Gold pack | A reference pack that ships with the SDK (transit, ledger, echo) | Examples |
| Sink | Where Sense records land: inbox or silent | Sense delivery |
| Conformance vector | Executable test tied to a spec section | §14 |
| RFC | Change proposal to the protocol | RFC process |
| Agent Skills | External standard for teaching documents; HARNESS.md is compatible | Landscape |
| MCP | Model Context Protocol; a transport HCP can export to | Landscape |
| Connector | Not an HCP type; vendor SDK inside a product runtime | Non-goals |