Host ABI compatibility profiles

lsf-host-abi-phase3-v4 is the current generic recognition profile in latent-core. The frozen matrix records its exact interface identities, source hashes, function forms and installed bindings. ADR-0031 and RFC-0005 define its ownership, error and compatibility contract; ADR-0032 adds the exact streaming resource extension. ADR-0033 adds immutable blobs with owned chunks.

Recognition and availability

Exact interface	Inspection	Production binding
latent:context/context@0.1.0	supported	built in
latent:log/log@0.1.0	supported	built in
latent:clock/monotonic@0.1.0	supported	built in
latent:clock/wall@0.1.0	supported	built in
latent:random/random@0.1.0	supported, synchronous WIT with cooperative audit waits	configured OS randomness provider
latent:blob/blob@0.1.0	supported, legacy	unavailable
latent:blob/blob@0.2.0	supported, async owned chunks	configured Linux local or S3 blob adapter
latent:secrets/reader@0.1.0	supported, synchronous WIT with cooperative host waits	configured local or Vault KV-v2 secret provider
latent:events/publisher@0.2.0	supported, synchronous WIT with cooperative host waits	configured NATS JetStream publisher
latent:http/streaming@0.3.0	supported, async owned resources	configured streaming HTTP adapter
latent:http/client@0.2.0	supported, async import	configured bounded HTTP adapter
latent:telemetry/custom@0.1.0	supported, synchronous WIT with cooperative audit waits	configured shared custom metrics
latent:service/invoke@0.1.0	supported, async import	configured isolated local adapter

An inspected package has no provider authority. Wasmtime preparation rejects a required provider that has no installed owner. The generated host/guest bindings contain types and registration helpers; the production linker supplies context, log and clock, plus service invocation, buffered/streaming HTTP, local/S3 blobs, local/Vault secrets, NATS publication, cryptographic randomness and custom metrics when their node-owned adapters are installed. Activations must supply their exact prepared imports and pass current eligibility/descriptor checks.

The complete source interface must match authoritative WIT. A compiler may prune unused binary imports/members; every retained member still needs its exact version and complete supported shape. A matching name, partial supplied WIT or forged metadata cannot authorize a different host ABI. Parser, graph, comparison and transfer limits remain independent checks. Complete host comparison shares one finite work allowance across all required interfaces.

Selected forms and versions

The v1 four-interface profile remains defined. Existing context/log/clock bytes and versions are unchanged. The legacy aggregate world at 0.1.0 and its Rust bindings remain available; the aggregate at 0.2.0 selects v2. The separate 0.3.0 aggregate selects V3 and includes both HTTP package versions. The 0.4.0 aggregate selects V4 and additionally includes both blob versions. V1/V2/V3 sources and identities remain unchanged. Binding staging loads only the referenced package versions to preserve generated module names.

HTTP and events use explicit 0.2.0 package versions because their errors and receipts changed. HTTP reports a complete response or a typed failure, including uncertainty after possible dispatch. Events report broker stream/sequence and acknowledgement, including duplicate status, or an explicit uncertain outcome. Neither implies a transaction, consumer processing or automatic retry authority.

HTTP/service/blob operations select freestanding async imports. Local secret reads use their existing synchronous WIT with a cooperative async host bridge. Neither form makes waiting activations free: stores, cells, handles, buffers and reservations stay owned until completion or affirmative cleanup.

The local service, buffered/streaming HTTP and local blob profiles additionally select freestanding async application exports so callers can wait for the canonical async import. Exact source, binary and contract metadata must agree, and production preparation requires an installed async adapter. The frozen host WIT and digest remain unchanged. V3 additionally accepts exact upload/body/chunk own/borrow resources only in latent:http/streaming@0.3.0. V4 additionally accepts exact chunk own/borrow positions in latent:blob/blob@0.2.0. Application exports still use the bounded value codec. Other resource identities, implicit futures/streams, maps, fixed lists and error-context remain rejected. Blob tokens retain their separate lifecycle; state and timer remain later-phase contracts. See the streaming ownership and limits.

Cache identity and security

The canonical SHA-256 profile identity covers the ID, ordered exact interface names, package names, binding kind, async flag and complete WIT bytes. Lengths are framed as little-endian u64 values with a versioned domain separator. The profile ID and digest enter generic preparation compatibility; AOT uses the same capability digest alongside engine/input/policy identities. Old generic prepared or native artifacts require regeneration. Source comments conservatively affect identity; repository LF line endings are checked.

Mutable grants and credential rotations do not authorize native code through a cache key. Eligibility, exact descriptors and required activation bindings remain checked at invocation. The sealed broker and exact binding compiler implement live policy, provider epoch and publication checks independently of ABI recognition.

The baseline is Wasmtime 47.0.4 with guest generator wit-bindgen 0.60.0. No WASI filesystem, HTTP or WASIp3 streams are installed. Expanding that surface requires an advisory reachability review. ABI compatibility does not establish a stronger execution isolation profile. External-capsule deployment enforcement belongs to #280; fixed external guest execution hosts remain unavailable.

Normal CI parses all four worlds, compiles native/Wasm generated bindings and tests real component/linker compatibility, wrong shapes/versions, missing providers, forged/stale descriptors, comparison limits and schema/source/generator parity. The fixtures allocate no dormant application resources and provide no provider performance or hostile-multitenant qualification claim.