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Inter-Node Artifact Channel (INAC)

INAC is the planned peer-to-peer artifact exchange surface for moving byte-identical Orbiplex artifacts between nodes without publishing them through a public substrate.

It is layered above authenticated peer sessions and parallel to Agora, but the component-facing delivery abstraction belongs to Artifact Delivery:

  • Agora is topic-addressed public or semi-public relay.
  • Artifact Delivery is the host-owned delivery and admission plane.
  • INAC is the private/direct node-to-node transport adapter under that plane.
  • Memarium remains the local custody store.

Implementation boundary: the ad-host in-process composer may ask for delivery through INAC through its consumer-side PeerSender trait, and inbound INAC frames enter AD through an InacAdmissionBridge. ad-host still does not own WSS sockets, peer sessions, INAC authorization, invitation ledger state, or offer/push semantics. Those remain the responsibility of the peer runtime / INAC host side of the node.

The current solution status is partial / MVP scaffold. Proposal 042 defines the semantic contract; the implementation guideline in this directory decomposes the work into schemas, peer-message registration, authorization, binary streaming, and storage integration.

Implemented now:

  • inac-control.v1 as the transport-neutral control frame for offer, request, push, and response/refusal operations.
  • memarium-blob.v1 synchronized into the node schema gate as a transferable signed artifact envelope.
  • node/inac-core for pure DTOs, operation validation, refusal vocabulary, inline payload ceiling, and byte identity checks.
  • node/inac-runtime for an explicit artifact handler registry and fail-closed dispatch semantics. Local outbound allows are deny-by-default: empty operations or schemas sets do not mean wildcard authority.
  • node/inac-handlers as the daemon composition point for future concrete handlers (agora-record.v1, memarium-blob.v1, middleware-owned kinds).
  • Daemon host/operator surface: POST /v1/host/capabilities/inac.offer, POST /v1/host/capabilities/inac.request, POST /v1/host/capabilities/inac.push, and GET /v1/inac/status.
  • msg = "inac.v1" registered in the daemon peer-message chain for WSS sessions. Artifact Delivery remote inac-direct targets use this path, and received push frames feed the shared Artifact Delivery inbound admission registry instead of a parallel INAC-specific dispatch table.
  • Node endpoint dials enforce endpoint certificate evidence when discovery has it. Seed Directory node resolution can fetch node-address-attestation.v1, copy the selected endpoint/certificate fingerprint into the daemon's peer endpoint evidence companion, and the peer supervisor then carries that fingerprint into the concrete dial candidate. Static seed pins remain a bootstrap shortcut; attested endpoint evidence wins when both are present. Stale or expired attestations are ignored before they can become dial pins.
  • The daemon exposes peer supervisor endpoint-evidence diagnostics for operator inspection. Fresh evidence can feed direct INAC delivery; usable/stale/dead evidence remains a discovery or troubleshooting hint and does not become a direct delivery target without fresh verification.
  • Story-005 private/direct Whisper is wired as the first concrete vertical consumer of AD -> inac-direct: the sender produces a signed private agora-record.v1 artifact, Artifact Delivery routes it to the configured peer, and the receiver feeds the push into the shared AD admission path.

Based On

Responsibilities

  • Exchange artifact offers, requests, pushes, and refusals over authenticated peer sessions.
  • Keep artifact envelopes byte-identical across transfer and storage.
  • Reuse existing authority surfaces such as capability passports, invitation/custody passports, and attestation-gate style verification.
  • Feed received artifacts into the host-owned Artifact Delivery inbound admission path, which dispatches to exactly one authoritative acceptor.
  • Keep large payload bytes out of the main JSON control frame by using session-scoped, content-addressed stream chunks. The current stream path prefers inac.stream.chunk.binary.v1 with per-chunk digest/offset/size validation, rejects a single decoded chunk above 8 MiB before file append, and retains the JSON/base64url chunk shape as compatibility fallback.

Status

Partial / MVP scaffold.

The schema-gated control plane, local runtime skeleton, and WSS peer-message transport are implemented. The runtime intentionally fails closed when no authoritative handler is registered for an artifact kind. push requires exactly one payload location (bytes/base64url, artifact/ref, or artifact/href). The first remote path is inline-first over WSS peer messages; referenced payloads can be resolved before admission through Artifact Delivery's resolver registry, with artifact-store: as the first production resolver. Direct component calls to inac.* host capabilities are governed by INAC outbound allowlists; Artifact Delivery routes that happen to use inac-direct are governed by Artifact Delivery outbound allowlists. Matrix mailbox transport is now the first store-and-forward fallback: it carries the same authorization proof as WSS, seals plaintext payloads as artifact-mailbox-sealed.v1 before posting to Matrix, chunks sealed payloads as artifact-mailbox-chunk.v1 when a single Matrix event would exceed the configured mailbox event byte limit, and feeds the unsealed frame through the same receiver-side authorization and Artifact Delivery admission path. Matrix remains a carrier, not an authority. WSS stream chunks are implemented for payloads above the inline ceiling; senders prefer inac.stream.chunk.binary.v1 and receivers keep the JSON/base64url chunk carrier as a fail-closed compatibility path. Receiver-side WSS push authorization now has a first production gate: without an explicit profile allowlist the frame must carry an inline capability-passport.v1 under authorization. Invitation passports (capability_id = "inac.invitation"), general INAC push passports (inac-push@v1), and Memarium custody passports (capability_id = "memarium.custody", profile memarium-custody@v1) all pass through the shared capability-binding authorization path before Artifact Delivery admission. Rejected transfers are written to a local INAC transfer ledger before Artifact Delivery admission. Passport authorization fails closed when the receiver has no current revocation view source; the WSS peer identity still authenticates the transport session, while the passport only authorizes that verified peer to present a specific artifact push.

Baseline Artifact Delivery acceptors are now present for the two INAC baseline artifact kinds. agora-record.v1 is verified and re-ingested through the local Agora service when available; absence of local Agora is an explicit handler unavailable condition, not an implicit Memarium fallback. memarium-blob.v1 is verified as a Memarium blob envelope and stored through Memarium as an accepted custody fact. The baseline acceptor requires an explicit signature.key/public, rejects delegated blob signatures for now, and accepts only encrypted/opaque custody envelopes. Plaintext/private blob custody remains fail-closed unless a future explicit policy enables it. MVP custody facts are written to the local public Memarium space; configurable target spaces are a later custody-policy layer.

For streamed payloads, the receiver writes chunks to <data-dir>/storage/artifact-delivery/streams/, verifies declared size, offsets, per-chunk digest where present, and final sha256:* artifact digest before the final push enters Artifact Delivery admission, and removes temporary state after completed admission, startup cleanup, or a bounded stale-stream TTL. Malformed, interrupted, offset-mismatched, or digest-mismatched streams do not invoke domain acceptors.

Inbound INAC budgets are receiver-side policy: they match remote node id, operation, artifact schema, and optional content type, then refuse before Artifact Delivery admission or notification creation. Refusals such as payload-too-large, rate-limited, and quota-exceeded are local transfer decisions, not public protocol judgments. A per-minute limit of zero is an explicit policy-denied deny rule. Active pending offers are also bounded per remote node before notification creation, so unsolicited offer cannot be used as an unbounded local queue.

Invitation delivery and acceptance now uses the generic user/operator notification queue. An unsolicited offer that passes schema, size, and budget checks creates a local pending offer plus an operator notification with host-owned inac.invitation.accept and inac.invitation.reject action refs. Accepting issues a narrow inac.invitation passport and returns it on the next matching offer; rejecting records the local decision without minting authority. This notification flow is a local UX that issues a passport; it is not a second INAC authority system and does not replace Artifact Delivery admission. The receiver-issued invitation passport TTL is daemon policy (inac_peer_transport.invitation_passport_ttl_seconds, default 3600 seconds). Repeating Accept after the offer is already accepted is idempotent and does not issue a replacement passport.

  • agora-record.v1
  • memarium-blob.v1
  • inac-control.v1
  • capability-passport.v1
  • node-address-attestation.v1