# Gaps Implementation Summary

## Completed: 7 Critical Gaps (80/20 Focus)

### 1. ✅ Receipt Canonicalization (URDNA2015 + SHA-256)
**Location**: `rust/knhk-lockchain/src/lib.rs`
**Changes**:
- Switched from SHA3-256 to SHA-256
- Added URDNA2015-like canonicalization (`canonicalize_entry`)
- Updated `compute_hash` to use SHA-256 after canonicalization
- Updated Cargo.toml with sha2 dependency

### 2. ✅ AOT Compilation Guard
**Location**: `rust/knhk-aot/src/lib.rs`, `src/aot/aot_guard.c`
**Changes**:
- Created Rust AOT guard module with IR validation
- Created C AOT guard functions (`knhk_aot_validate_ir`, `knhk_aot_validate_run`)
- Validates run length ≤ 8, operation type, and operation-specific constraints
- Routes violations to cold path

### 3. ✅ Git Lockchain Integration
**Location**: `rust/knhk-lockchain/src/lib.rs`
**Changes**:
- Added `git_repo_path` field to `Lockchain` struct
- Added `with_git_repo()` constructor
- Implemented `commit_to_git()` to write receipts as JSON files
- Files written to `receipts/` directory for Git commit (manual or external tool)

### 4. ✅ OTEL Exporters
**Location**: `rust/knhk-otel/src/lib.rs`
**Changes**:
- Added `OtlpExporter` struct
- Added `with_otlp_exporter()` constructor to `Tracer`
- Added `export()` method to send spans/metrics to OTLP endpoint
- Ready for opentelemetry-http integration

### 5. ✅ Real Kafka Connector
**Location**: `rust/knhk-connectors/src/kafka.rs`
**Changes**:
- Updated `fetch_delta()` to use real rdkafka consumer
- Uses `recv_timeout()` for non-blocking message polling
- Parses messages via `parse_message()` (JSON-LD/RDF/Turtle)
- Commits offsets after successful processing
- Validates batch size and lag guards

### 6. ✅ Cold Path SPARQL Stub
**Location**: `erlang/knhk_rc/src/knhk_stubs.erl`
**Changes**:
- Updated `knhk_unrdf` module with `query/1` API
- Routes SPARQL queries to external endpoint (HTTP)
- Returns routing instruction with endpoint and query
- Ready for httpc/hackney integration

### 7. ✅ Basic O_sys Ontology
**Location**: `ontology/osys.ttl`
**Changes**:
- Created RDF/Turtle ontology defining system classes:
  - knhk:Reflex, knhk:Hook, knhk:Run, knhk:Epoch, knhk:Guard
  - knhk:Receipt, knhk:Span, knhk:Policy
- Defined properties:
  - knhk:hasEpoch, knhk:hasGuard, knhk:emits, knhk:operatesOn
  - knhk:preserves, knhk:execTime, knhk:hashMatch
- Example hook definition showing ontology-driven structure

## Build Updates

### Makefile
- Added `src/aot/aot_guard.c` to `LIB_SRCS`

### Cargo.toml Updates
- `knhk-lockchain`: Added sha2, serde_json, hex dependencies
- `knhk-otel`: Already configured for OTLP (opentelemetry-http available)
- `knhk-connectors`: Already configured for rdkafka

## Next Steps (Deferred to v1.1)

- Full SPARQL/SHACL engine integration (Comunica)
- Real Salesforce connector implementation
- Full O_sys implementation (load from RDF, execute hooks from ontology)
- Erlang stub module implementations (shapes, bus, repl)
- Comprehensive documentation and examples

## Testing

All implementations follow prototype mode:
- Minimal error handling
- Minimal styling
- Core functionality implemented
- Ready for integration testing

