alknet/docs/architecture

status, last_updated

status	last_updated
draft	2026-06-19

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 (001–020) 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), and HD derivation for encryption keys (ADR-020). The alknet-core, alknet-call, and alknet-vault crate specs are in draft.

Next step: Review the vault spec documents, then begin implementation. All open questions for the core and call crates are resolved; the vault crate has two open/deferred OQs (OQ-21, OQ-22) that do 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

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)
• 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
• OQ-20: Encryption key derivation — HD derivation from BIP39 seed, not PBKDF2; salt field unused in v2 (wire-format compat) (ADR-020)

Open (low priority, does not block implementation):

• OQ-22: Key rotation mechanism — key versioning is in place; the rotation workflow is not specced. Two-way door.

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 administration — network unlock not supported; needs ADR if ever needed

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/