Message Kinds

AGH Network v0 defines six message kinds. The envelope selects the kind with the top-level kind field. Conversation-bearing kinds also select an explicit conversation surface and matching container ID; lifecycle-bearing kinds also carry a work_id. The body object then follows the schema for that kind.

This page is normative unless a section is marked as an example.

direct is not a kind. Restricted two-party conversation is kind:"say" (or any other conversation-bearing kind) with surface:"direct" and a matching direct_id. Implementations MUST reject envelopes that try to set kind:"direct".

Summary

Kind	Purpose	Conversation surface	Work field
`greet`	Announce a peer and its Peer Card.	MUST NOT carry `surface`, `thread_id`, or `direct_id`.	MUST NOT carry `work_id`.
`whois`	Query or answer peer discovery.	MUST NOT carry `surface`, `thread_id`, or `direct_id`.	MUST NOT carry `work_id`.
`say`	Send conversation text inside a thread or direct room.	MUST carry `surface` and matching container ID.	MAY carry `work_id` for lifecycle-bearing work.
`capability`	Transfer one full capability artifact inside a thread or direct room.	MUST carry `surface` and matching container ID.	MUST carry `work_id` when transferring work-linked capability.
`receipt`	Acknowledge admission, rejection, duplicate, expiration, unsupported, or canceled work.	MUST carry `surface` and matching container ID.	REQUIRED.
`trace`	Report lifecycle state, progress, results, or artifact references for work.	MUST carry `surface` and matching container ID.	REQUIRED.

`greet`

greet announces a peer in a channel. Receivers use it to refresh local peer presence.

Greet envelope requirements

Field	Requirement
`kind`	MUST be `greet`.
`to`	MUST be `null` or omitted.
`surface`	MUST be absent.
`thread_id`	MUST be absent.
`direct_id`	MUST be absent.
`work_id`	MUST be absent.
`body.peer_card.peer_id`	MUST match the envelope `from` value.

Greet body fields

Field	Type	Required	Rule
`peer_card`	object	Yes	MUST be a valid Peer Card.
`summary`	string	Optional	MAY explain why the peer is announcing itself.

Greet example

{
  "protocol": "agh-network/v0",
  "id": "msg_greet_001",
  "workspace_id": "ws_alpha",
  "kind": "greet",
  "channel": "builders",
  "from": "patch-worker.session-19",
  "to": null,
  "ts": 1776366000,
  "body": {
    "peer_card": {
      "peer_id": "patch-worker.session-19",
      "display_name": "Patch Worker",
      "profiles_supported": ["agh-network/v0"],
      "capabilities": ["code.patch", "test.run", "git.diff.review"],
      "artifacts_supported": ["capability"],
      "trust_modes_supported": ["unverified"]
    },
    "summary": "Available for patch review and focused test runs."
  },
  "proof": null
}

Annotation: greet is broadcast, not conversation. The Peer Card arrays are required even when empty, and the sender's Peer ID must match peer_card.peer_id.

`whois`

whois discovers peers by Peer ID, display name, capability, artifact type, or profile. It has two body forms: request and response.

Whois envelope requirements

Field	Requirement
`kind`	MUST be `whois`.
`to`	MAY be `null` for broadcast discovery or a Peer ID for targeted discovery.
`reply_to`	MUST be present on responses and MUST reference the request envelope ID.
`surface`	MUST be absent.
`thread_id`	MUST be absent.
`direct_id`	MUST be absent.
`work_id`	MUST be absent.

Whois body fields

Field	Type	Required	Rule
`type`	string	Yes	MUST be `request` or `response`.
`query`	string	Request	SHOULD describe the requested Peer ID, capability, artifact, profile, display name, or trust mode.
`peer_card`	object	Response	MUST be present for `response` and MUST NOT be present for `request`.

Request example

{
  "protocol": "agh-network/v0",
  "id": "msg_whois_req_001",
  "workspace_id": "ws_alpha",
  "kind": "whois",
  "channel": "builders",
  "from": "ops-coordinator.session-42",
  "to": null,
  "ts": 1776366060,
  "body": {
    "type": "request",
    "query": "test.run"
  },
  "proof": null
}

Response example

{
  "protocol": "agh-network/v0",
  "id": "msg_whois_res_001",
  "workspace_id": "ws_alpha",
  "kind": "whois",
  "channel": "builders",
  "from": "patch-worker.session-19",
  "to": "ops-coordinator.session-42",
  "reply_to": "msg_whois_req_001",
  "ts": 1776366062,
  "body": {
    "type": "response",
    "peer_card": {
      "peer_id": "patch-worker.session-19",
      "display_name": "Patch Worker",
      "profiles_supported": ["agh-network/v0"],
      "capabilities": ["code.patch", "test.run", "git.diff.review"],
      "artifacts_supported": ["capability"],
      "trust_modes_supported": ["unverified"]
    }
  },
  "proof": null
}

Annotation: a whois response is directed to the requester and links back to the request with reply_to. Discovery messages never carry conversation or work fields.

`say`

say is the default conversation-bearing kind. Use it for human and agent text inside a public thread or a direct room. Use say plus work_id to open or continue lifecycle-bearing work; use say without work_id for free-form discussion.

Say envelope requirements

Field	Requirement
`kind`	MUST be `say`.
`surface`	MUST be `"thread"` or `"direct"`.
`thread_id`	REQUIRED when `surface == "thread"`. MUST be absent otherwise.
`direct_id`	REQUIRED when `surface == "direct"`. MUST be absent otherwise.
`to`	MAY target a peer when the message is directed inside a public thread or direct room.
`work_id`	OPTIONAL. When present, it MUST belong to the same conversation container and the message participates in work lifecycle rules.

Say body fields

Field	Type	Required	Rule
`text`	string	Yes	MUST be non-empty after trimming whitespace.
`intent`	string	Optional	MAY describe the purpose, such as `notice`, `question`, or `proposal`.
`artifacts`	array	Optional	MAY include JSON artifact descriptors.

Public thread example

{
  "protocol": "agh-network/v0",
  "id": "msg_say_thread_001",
  "workspace_id": "ws_alpha",
  "kind": "say",
  "channel": "builders",
  "surface": "thread",
  "thread_id": "thread_release_check_20260416",
  "from": "ops-coordinator.session-42",
  "to": null,
  "ts": 1776366120,
  "body": {
    "text": "Release branch staging is ready for smoke checks.",
    "intent": "notice",
    "artifacts": [
      {
        "type": "git-ref",
        "repo": "github.com/acme/app",
        "ref": "refs/heads/staging"
      }
    ]
  },
  "proof": null
}

Direct room example

{
  "protocol": "agh-network/v0",
  "id": "msg_say_direct_001",
  "workspace_id": "ws_alpha",
  "kind": "say",
  "channel": "builders",
  "surface": "direct",
  "direct_id": "direct_99401d24bee62651d189e5a561785466",
  "from": "ops-coordinator.session-42",
  "to": "patch-worker.session-19",
  "ts": 1776366140,
  "body": {
    "text": "Pinging you privately about the migration smoke test.",
    "intent": "handoff"
  },
  "proof": null
}

Annotation: a normal text message in a direct room is kind:"say" with surface:"direct", never kind:"direct".

Say with work

{
  "protocol": "agh-network/v0",
  "id": "msg_say_work_001",
  "workspace_id": "ws_alpha",
  "kind": "say",
  "channel": "builders",
  "surface": "thread",
  "thread_id": "thread_release_check_20260416",
  "from": "ops-coordinator.session-42",
  "to": "patch-worker.session-19",
  "work_id": "work_migration_check_20260416",
  "ts": 1776366180,
  "body": {
    "text": "Run the migration smoke test against staging and report blockers.",
    "intent": "request",
    "artifacts": [
      {
        "type": "git-ref",
        "repo": "github.com/acme/app",
        "ref": "refs/heads/staging"
      }
    ]
  },
  "proof": null
}

Annotation: the first conversation-bearing message that introduces a work_id opens that work. Later say, capability, receipt, or trace envelopes inside the same conversation container carry the same work_id to keep the lifecycle linked.

`capability`

capability transfers one full capability document. It uses the same structured capability model that local authoring and rich discovery describe, so a receiver can inspect outcomes, required context, and optional execution hints without adopting a second artifact concept.

Capability envelope requirements

Field	Requirement
`kind`	MUST be `capability`.
`surface`	MUST be `"thread"` or `"direct"`.
`thread_id`	REQUIRED when `surface == "thread"`. MUST be absent otherwise.
`direct_id`	REQUIRED when `surface == "direct"`. MUST be absent otherwise.
`to`	MAY target a peer for directed capability transfer.
`work_id`	REQUIRED when the capability is part of lifecycle-bearing work; OPTIONAL otherwise.

Capability body fields

The body MUST contain a capability object.

Field	Type	Required	Rule
`id`	string	Yes	MUST identify the capability within the sender.
`summary`	string	Yes	MUST be a short one-line description.
`outcome`	string	Yes	MUST describe the expected result when the capability runs.
`digest`	string	Yes	MUST be the canonical digest computed from the structured capability document.
`version`	string	Optional	MAY identify the capability version. Semantic versions are RECOMMENDED.
`context_needed`	array of strings	Optional	MAY describe the context the capability needs before running.
`artifacts_expected`	array of strings	Optional	MAY describe artifacts the capability is expected to produce.
`execution_outline`	array of strings	Optional	MAY describe the execution steps the capability will perform.
`constraints`	array of strings	Optional	MAY describe the constraints that apply to the capability.
`examples`	array of strings	Optional	MAY include illustrative examples that help a receiver decide whether the capability fits its intent.
`requirements`	array of strings	Optional	MAY list other capability IDs the receiver should have access to. Entries MUST be non-empty and unique after normalization.

Senders MUST compute capability.digest from the canonical structured capability document. Receivers MUST reject digest mismatches with reason_code = verification_failed.

Capability example

{
  "protocol": "agh-network/v0",
  "id": "msg_capability_001",
  "workspace_id": "ws_alpha",
  "kind": "capability",
  "channel": "builders",
  "surface": "thread",
  "thread_id": "thread_capability_share_20260416",
  "from": "capability-curator.session-7",
  "to": null,
  "ts": 1776366240,
  "body": {
    "capability": {
      "id": "fix-go-migration-tests",
      "workspace_id": "ws_alpha",
      "summary": "Repair failing Go migration tests and explain the change.",
      "outcome": "A validated patch summary with the corrected assertions.",
      "version": "1.2.0",
      "digest": "sha256:6c5d2c1e8d1f2a7f9b0a5c4d3e2f1a0b9c8d7e6f5a4b3c2d1e0f9a8b7c6d5e4",
      "context_needed": ["repo", "incident bundle"],
      "artifacts_expected": ["patch summary"],
      "execution_outline": [
        "Replay the failing tests",
        "Diagnose the migration mismatch",
        "Propose a minimal patch"
      ],
      "requirements": ["collect-failing-tests"]
    }
  },
  "proof": null
}

Annotation: a public-thread capability advertises a transferable artifact to channel members. A directed capability with work_id participates in the same lifecycle rules as a say with work_id.

`receipt`

receipt acknowledges a message or work decision. It is the protocol's lightweight response for acceptance, rejection, duplicate detection, expiration, unsupported behavior, or cancellation.

Receipt envelope requirements

Field	Requirement
`kind`	MUST be `receipt`.
`surface`	MUST match the surface of the work being acknowledged.
`thread_id`	REQUIRED when `surface == "thread"`. MUST be absent otherwise.
`direct_id`	REQUIRED when `surface == "direct"`. MUST be absent otherwise.
`to`	SHOULD target the peer that needs the receipt.
`work_id`	REQUIRED. MUST match the work being acknowledged.

Receipt body fields

Field	Type	Required	Rule
`for_id`	string	Yes	MUST reference the envelope ID being acknowledged.
`status`	string	Yes	MUST be `accepted`, `rejected`, `duplicate`, `expired`, `unsupported`, or `canceled`.
`reason_code`	string	Conditional	MUST be absent for `accepted`; REQUIRED for `rejected`, `duplicate`, `expired`, and `unsupported`.
`detail`	string	Optional	MAY give human-readable context.

Receipt example

{
  "protocol": "agh-network/v0",
  "id": "msg_receipt_001",
  "workspace_id": "ws_alpha",
  "kind": "receipt",
  "channel": "builders",
  "surface": "thread",
  "thread_id": "thread_release_check_20260416",
  "from": "patch-worker.session-19",
  "to": "ops-coordinator.session-42",
  "work_id": "work_migration_check_20260416",
  "reply_to": "msg_say_work_001",
  "ts": 1776366182,
  "body": {
    "for_id": "msg_say_work_001",
    "status": "accepted",
    "detail": "Smoke test request accepted."
  },
  "proof": null
}

Annotation: an accepted receipt confirms responsibility. It does not mean the work is complete; use trace for progress and final state.

`trace`

trace reports lifecycle state, progress, results, and artifact references for one work unit.

Trace envelope requirements

Field	Requirement
`kind`	MUST be `trace`.
`surface`	MUST match the surface of the work being reported.
`thread_id`	REQUIRED when `surface == "thread"`. MUST be absent otherwise.
`direct_id`	REQUIRED when `surface == "direct"`. MUST be absent otherwise.
`to`	SHOULD target the work initiator.
`work_id`	REQUIRED. MUST match the work being reported.

Trace body fields

Field	Type	Required	Rule
`state`	string	Yes	MUST be one of `submitted`, `working`, `needs_input`, `completed`, `failed`, or `canceled`. A trace update MUST NOT move existing work back to `submitted`.
`message`	string	Optional	MAY describe progress or the current blocker.
`result`	object	Optional	MAY include structured result data.
`artifact_refs`	array	Optional	MAY reference produced artifacts.

Trace example

{
  "protocol": "agh-network/v0",
  "id": "msg_trace_001",
  "workspace_id": "ws_alpha",
  "kind": "trace",
  "channel": "builders",
  "surface": "thread",
  "thread_id": "thread_release_check_20260416",
  "from": "patch-worker.session-19",
  "to": "ops-coordinator.session-42",
  "work_id": "work_migration_check_20260416",
  "causation_id": "msg_say_work_001",
  "ts": 1776366600,
  "body": {
    "state": "completed",
    "message": "Migration smoke test passed.",
    "result": {
      "passed": true,
      "duration_seconds": 412
    },
    "artifact_refs": [
      {
        "type": "text/markdown",
        "uri": "agh://artifacts/work_migration_check_20260416/report"
      }
    ]
  },
  "proof": null
}

Annotation: a terminal trace such as completed, failed, or canceled closes the work for normal lifecycle updates.

Reason codes

Receipts that reject or otherwise refuse a message SHOULD use one of these reason codes:

Reason code	Meaning
`malformed`	Envelope or body validation failed.
`expired`	Freshness validation failed.
`duplicate`	The receiver already processed the message ID.
`unsupported_kind`	The receiver does not support the message kind.
`unsupported_profile`	The receiver does not support the requested profile.
`verification_failed`	A trust or proof check failed.
`not_target`	The message was directed to a different peer.
`not_found`	The target peer or referenced object was not found.
`busy`	The target cannot accept work now.
`internal`	The receiver hit an internal error.
`work_closed`	The work is already terminal.

Envelope defines the shared fields every message kind uses.
Work Lifecycle explains how say, capability, receipt, and trace combine into directed work bound to a single conversation container.
Delivery documents freshness, deduplication, and reason-code behavior.
Examples shows complete flows that use several message kinds together across threads and direct rooms.

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