Files
alknet/docs/architecture
glm-5.2 cdf340bec7 docs(architecture): add ADR-024 — operation registry layering, resolve C6
Diagnoses a conflation in the pre-ADR-024 spec: the OperationRegistry
inherited immutability by analogy from ADR-010's HandlerRegistry (ALPN-level),
but the TLS-config argument that justifies HandlerRegistry immutability does
not apply to the operation registry, which lives behind a single ALPN
(alknet/call). This made from_call (which discovers ops over a live connection
at runtime) structurally incompatible with the blanket immutability claim.

ADR-024 layers the operation registry by trust boundary: curated (Local) ops
are static and immutable — the startup trust boundary is where their
composition authority is granted; session (Session) and imported (FromCall
etc.) ops are dynamic at their respective scopes (per-session, per-connection)
— their trust boundaries are per-scope, not per-startup. The principle:
immutability follows the trust boundary. Immutability is the security control
for composing ops (can escalate privilege); provenance + composition authority
are the controls for non-composing ops (can't escalate).

The OperationEnv trait becomes the integration point (Arc<dyn OperationEnv>),
following the IdentityProvider precedent (ADR-004): the CallAdapter composes
the root OperationContext.env per incoming call from the active layers
(curated base + connection overlay + session overlay). Children inherit the
parent's composite env by Arc::clone — overlay composition happens once at
the root and propagates through the composition tree.

Resolves review #002 C6 (OperationContext.env type identity crisis): the
field is split into scoped_env: ScopedOperationEnv (reachability data, from
the registration bundle) and env: Arc<dyn OperationEnv + Send + Sync>
(dispatch trait object). One field was being used as two different types
(reachability set with .allows() and dispatch trait with .invoke());

Localizes W4 (hot-swap ↔ registry mutability coupling) to the connection
scope: no global mutable registry to hot-swap; overlays replace naturally
with connect/disconnect and session start/end. Schema-drift on reconnect is
a per-connection overlay-rebuild concern, not a global hot-swap protocol.

Partially addresses W3 (CallClient registry security): the registry-shape
sub-question is resolved by the overlay model; the capability-exposure
sub-question (what capabilities a remote peer can trigger) remains for
ADR-017 — ADR-024 does not overclaim resolution there.

Amends OQ-04 to scope its immutability claim to the HandlerRegistry and
cross-reference ADR-024 for the operation registry. Generalizes OQ-19's
session-overlay mechanism to also cover connection-scoped remote imports —
both are per-scope dynamic overlays on the static curated base, using the
same trait-layering mechanism.
2026-06-22 13:44:58 +00:00
..

status, last_updated
status last_updated
draft 2026-06-22-20

Alknet Architecture

Current State

Pre-implementation. The project has completed a pivot from a three-layer model to an ALPN-as-service model. The greenfield workspace contains only alknet-vault (stable — implementation exists) and research/reference material. Foundational ADRs (001024) are in place, including the BiStream type definition (ADR-007), vault integration (ADR-008), ALPN router/endpoint (ADR-010), AuthContext structure (ADR-011), call protocol stream model (ADR-012), Rust as canonical implementation language (ADR-013), secret material flow with capability injection (ADR-014), privilege model with authority context (ADR-015), abort cascade for nested calls (ADR-016), call protocol client and adapter contract (ADR-017), vault standalone crate (ADR-018), vault assembly-layer-only access (ADR-019), HD derivation for encryption keys (ADR-020), key rotation via version-indexed paths (ADR-021), handler registration, provenance, and composition authority (ADR-022), operation error schemas (ADR-023), and operation registry layering (ADR-024). ADR-024 resolves the registry mutability question that ADR-022/017 surfaced (from_call imports require a runtime-mutable home) and the OperationContext.env type identity crisis (review #002 C6), by layering the registry by trust boundary (curated static + session/connection dynamic overlays) and making OperationEnv a trait-object integration point. The alknet-core, alknet-call, and alknet-vault crate specs are in draft.

Next step: Continue working through review #002's remaining Tier 4 findings (vault security decisions, guard clauses, ADR-writing exercises, smaller spec decisions). All open questions for the core and call crates are resolved; the vault crate has one deferred OQ (OQ-21, remote vault administration) that does not block implementation.

Architecture Documents

Document Status Description
overview.md draft Workspace-level overview, crate graph, shared types, design principles
open-questions.md draft Centralized OQ tracker with door-type classifications
crates/core/README.md draft alknet-core crate index
crates/core/core-types.md draft ProtocolHandler, HandlerError, Connection, BiStream, StreamError
crates/core/endpoint.md draft ALPN router, HandlerRegistry, accept loop, shutdown
crates/core/auth.md draft AuthContext, Identity, IdentityProvider, AuthToken, resolution flow
crates/core/config.md draft StaticConfig, DynamicConfig, ArcSwap, ConfigReloadHandle
crates/call/README.md draft alknet-call crate index
crates/call/call-protocol.md draft CallAdapter, EventEnvelope framing, stream model, PendingRequestMap, bidirectional calls, streaming subscribe example
crates/call/operation-registry.md draft OperationSpec, Handler, OperationRegistry, AccessControl, capability injection, service discovery, irpc integration
crates/vault/README.md draft alknet-vault crate index
crates/vault/mnemonic-derivation.md draft BIP39, SLIP-0010, BIP-0032, derivation paths, key types
crates/vault/encryption.md draft AES-256-GCM, EncryptedData, key versioning, salt (Phase B reserved)
crates/vault/service.md draft VaultServiceHandle lifecycle, actor dispatch, cache, error model
crates/vault/protocol.md draft VaultProtocol irpc messages, DerivedKey redaction, serialization

ADR Table

ADR Title Status
001 ALPN-Based Protocol Dispatch Accepted
002 ProtocolHandler Trait Accepted
003 Crate Decomposition Accepted
004 Auth as Shared Core (IdentityProvider) Accepted
005 irpc as Call Protocol Foundation Accepted
006 ALPN String Convention and Connection Model Accepted
007 BiStream Type Definition Accepted
008 Vault Integration Point Accepted
009 One-Way Door Decision Framework Accepted
010 ALPN Router and Endpoint Accepted
011 AuthContext Structure and Resolution Flow Accepted
012 Call Protocol Stream Model Accepted
013 Rust as Canonical Implementation Language Accepted
014 Secret Material Flow and Capability Injection Accepted
015 Privilege Model and Authority Context Accepted
016 Abort Cascade for Nested Calls Accepted
017 Call Protocol Client and Adapter Contract Accepted
018 Vault as Standalone Crate Accepted
019 Vault Assembly-Layer-Only Access Accepted
020 HD Derivation for Encryption Keys Accepted
021 Key Rotation via Version-Indexed Paths Accepted
022 Handler Registration, Provenance, and Composition Authority Accepted
023 Operation Error Schemas Accepted
024 Operation Registry Layering Accepted

Open Questions

See open-questions.md for the full tracker.

Resolved one-way doors:

  • OQ-01: BiStream type — trait with Connection parameter (ADR-007)
  • OQ-02: AuthContext timing — hybrid model (ADR-004)
  • OQ-03: ALPN naming — alknet/ prefix, no version (ADR-006)
  • OQ-05: Multi-connectivity endpoint — quinn + iroh, both feature-gated (ADR-010)
  • OQ-06: ALPN per connection, not per stream (ADR-006)
  • OQ-08: Vault integration — CLI-embedded, assembly-layer only (ADR-008, ADR-014)
  • OQ-16: Safe vault operations for call protocol exposure — none for now (ADR-014)
  • OQ-18: Privilege model — internal = authority switch, External/Internal visibility, handler identity + scoped env (ADR-015)
  • OQ-17: Abort cascade — call.aborted cascades to descendants; default abort-dependents, continue-running opt-in (ADR-016)
  • OQ-15: Call protocol client and adapter contract — CallClient opens connections; from_call imports remote ops; connection direction independent of call direction (ADR-017)

Resolved two-way doors:

  • OQ-04: Dynamic handler registration — static at startup (ADR-010); scoped to the HandlerRegistry (ALPN-level) by ADR-024, which governs OperationRegistry mutability separately
  • OQ-07: Call protocol scope — bidirectional streams, EventEnvelope, ID-based correlation (ADR-012)
  • OQ-11: Handler-level auth resolution observability — handlers store resolved identity on Connection (Option B); two identity scopes: connection-level (observability) and per-request (ACL)
  • OQ-12: TLS identity provisioning — two use cases: RFC 7250 raw keys (default, P2P) and X.509 certs (domain-hosted, browsers). ACME is a proven pattern.
  • OQ-13: Operation path format — /{service}/{op} is the correct design for alknet-call, not a simplification
  • OQ-14: Batch operation semantics — multiple correlated call.requested events is the correct protocol design, not a simplification
  • OQ-19: Session-scoped registries — agent-written operations via OperationEnv trait layering; protocol doesn't need changes; OperationEnv must remain a trait. Generalized by ADR-024 to cover connection-scoped overlays as well.
  • OQ-20: Encryption key derivation — HD derivation from BIP39 seed, not PBKDF2; salt field unused in v2 (wire-format compat) (ADR-020)
  • OQ-22: Key rotation — version-indexed derivation paths; rotate method re-encrypts (ADR-021)
  • OQ-23: Handler identity registration path — registration bundle with provenance, composition authority, scoped env, capabilities (ADR-022)
  • OQ-24: Operation error schemas — declared domain errors with typed details payload; adapter fidelity for from_openapi/to_openapi (ADR-023)

Deferred (not active):

  • OQ-09: WASM target boundaries — design constraint, not deliverable
  • OQ-10: Git adapter scope — start with smart protocol, add ERC721 later
  • OQ-21: Remote vault access — protocol is remote-capable by construction (irpc RemoteService); enabling is a server-setup change with an auth-wrapping handler in the assembly layer; Unlock/Lock are local-only

Document Lifecycle

Status Meaning Transitions
draft Under active development. May change significantly. reviewed when open questions are resolved
reviewed Architecture is final. Implementation may begin. Changes require review. stable when implementation is complete and verified
stable Locked. Changes require review and may warrant an ADR. deprecated when superseded
deprecated Superseded. Kept for reference. Removed when no longer referenced

References

  • Pivot proposal: docs/research/pivot/alpn-service-architecture.md
  • Cleanup plan: docs/research/pivot/cleanup-plan.md
  • SDD process: docs/sdd_process.md
  • Reference implementation: /workspace/@alkdev/alknet-main/