<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
**Table of Contents**

- [RDF/Turtle-Only Control Plane Architecture](#rdfturtle-only-control-plane-architecture)
  - [Table of Contents](#table-of-contents)
  - [Executive Summary](#executive-summary)
    - [Key Innovations](#key-innovations)
    - [Design Goals](#design-goals)
  - [Architecture Principles](#architecture-principles)
    - [1. **Semantic-First Design**](#1-semantic-first-design)
    - [2. **POKA YOKE (Mistake-Proofing)**](#2-poka-yoke-mistake-proofing)
    - [3. **No Alternative Paths**](#3-no-alternative-paths)
  - [System Overview](#system-overview)
    - [Architecture Diagram](#architecture-diagram)
    - [Data Flow](#data-flow)
  - [POKA YOKE Mistake-Proofing](#poka-yoke-mistake-proofing)
    - [Level 1: NewType Wrappers](#level-1-newtype-wrappers)
    - [Level 2: Phantom Types](#level-2-phantom-types)
    - [Level 3: Builder Pattern](#level-3-builder-pattern)
    - [Level 4: SHACL Constraints](#level-4-shacl-constraints)
    - [Level 5: State Machine FSM](#level-5-state-machine-fsm)
  - [RDF Control Plane Design](#rdf-control-plane-design)
    - [Configuration (Turtle)](#configuration-turtle)
    - [Operations (SPARQL UPDATE)](#operations-sparql-update)
    - [Queries (SPARQL SELECT)](#queries-sparql-select)
  - [State Machine Architecture](#state-machine-architecture)
    - [Package Lifecycle FSM](#package-lifecycle-fsm)
    - [State Definitions](#state-definitions)
    - [Transition Guards](#transition-guards)
  - [FMEA Integration](#fmea-integration)
    - [Failure Mode Detection](#failure-mode-detection)
    - [Automated Mitigation](#automated-mitigation)
    - [Failure Types](#failure-types)
  - [Implementation Strategy](#implementation-strategy)
    - [Phase 1: Core RDF Infrastructure (Weeks 1-2)](#phase-1-core-rdf-infrastructure-weeks-1-2)
    - [Phase 2: POKA YOKE Types (Weeks 3-4)](#phase-2-poka-yoke-types-weeks-3-4)
    - [Phase 3: SHACL Validation (Week 5)](#phase-3-shacl-validation-week-5)
    - [Phase 4: SPARQL Operations (Weeks 6-7)](#phase-4-sparql-operations-weeks-6-7)
    - [Phase 5: FMEA Integration (Week 8)](#phase-5-fmea-integration-week-8)
    - [Phase 6: CLI Integration (Weeks 9-10)](#phase-6-cli-integration-weeks-9-10)
    - [Phase 7: Testing & Validation (Weeks 11-12)](#phase-7-testing--validation-weeks-11-12)
  - [Performance Considerations](#performance-considerations)
    - [Caching Strategy](#caching-strategy)
    - [Query Optimization](#query-optimization)
  - [Security Model](#security-model)
    - [Cryptographic Verification](#cryptographic-verification)
    - [Access Control](#access-control)
    - [Audit Trail](#audit-trail)
  - [Summary](#summary)

<!-- END doctoc generated TOC please keep comment here to allow auto update -->

# RDF/Turtle-Only Control Plane Architecture

**Version:** 3.0.0
**Status:** Design Complete
**Architecture:** 100% Semantic - No JSON, No SQL, Only RDF/SPARQL/Turtle

## Table of Contents

1. [Executive Summary](#executive-summary)
2. [Architecture Principles](#architecture-principles)
3. [System Overview](#system-overview)
4. [POKA YOKE Mistake-Proofing](#poka-yoke-mistake-proofing)
5. [RDF Control Plane Design](#rdf-control-plane-design)
6. [State Machine Architecture](#state-machine-architecture)
7. [FMEA Integration](#fmea-integration)
8. [Implementation Strategy](#implementation-strategy)
9. [Performance Considerations](#performance-considerations)
10. [Security Model](#security-model)

---

## Executive Summary

This architecture defines a **100% semantic marketplace control plane** using RDF/Turtle/SPARQL exclusively. There are no JSON APIs, no SQL databases, and no REST endpoints. All operations are expressed as SPARQL queries and updates against an RDF triple store.

### Key Innovations

1. **Type-Level Mistake Prevention**: NewType wrappers, phantom types, and builder patterns make invalid states unrepresentable at compile time
2. **Semantic Control Plane**: All configuration, operations, and queries in RDF/Turtle format
3. **State Machine FSM**: Package lifecycle as finite state automaton with validated transitions
4. **FMEA Integration**: Failure mode detection and automated mitigation built into RDF schema
5. **Zero Alternative Paths**: Impossible to bypass semantic validation or use non-RDF interfaces

### Design Goals

| Goal | Implementation | Benefit |
|------|---------------|---------|
| **Mistake-Proof** | POKA YOKE types, SHACL validation | Invalid operations impossible |
| **100% Semantic** | RDF/Turtle/SPARQL only | No impedance mismatch |
| **Type-Safe** | Phantom types, NewTypes | Compile-time guarantees |
| **Auditable** | Immutable RDF audit trail | Complete observability |
| **Self-Healing** | FMEA + automatic mitigation | Resilient operations |

---

## Architecture Principles

### 1. **Semantic-First Design**

```turtle
# Everything is RDF - Configuration
:marketplace a mp:Marketplace ;
    mp:storageBackend mp:OxigraphStore ;
    mp:enableFMEA true .

# Everything is RDF - Operations
INSERT {
    ?pkg mp:state mp:Active ;
        mp:activatedAt ?now .
} WHERE {
    ?pkg mp:packageId "my-pkg" ;
        mp:state mp:Published .
    BIND(NOW() AS ?now)
}

# Everything is RDF - Queries
SELECT ?pkg WHERE {
    ?pkg mp:hasQualityScore/mp:overallScore ?score .
    FILTER (?score > 80)
}
```

**NO JSON**. **NO SQL**. **ONLY RDF**.

### 2. **POKA YOKE (Mistake-Proofing)**

The system prevents errors at multiple levels:

| Level | Mechanism | Example |
|-------|-----------|---------|
| **Type** | NewType wrappers | `PackageId` cannot be constructed with invalid format |
| **State** | Phantom types | `Package<Draft>` cannot call `.activate()` |
| **Schema** | SHACL constraints | RDF store rejects packages without required fields |
| **Logic** | State machine FSM | Invalid state transitions impossible |
| **Runtime** | FMEA detection | Automatic failure detection and mitigation |

### 3. **No Alternative Paths**

Traditional systems have multiple ways to perform operations:

```rust
// ❌ Traditional (multiple paths)
- REST API: POST /packages
- GraphQL: mutation { createPackage(...) }
- SQL: INSERT INTO packages (...)
- JSON file: { "name": "pkg", "version": "1.0.0" }
```

This architecture has **ONE path** for each operation:

```sparql
-- ✅ RDF Control Plane (one path)
INSERT DATA {
    <pkg/my-lib@1.0.0> a mp:Package ;
        mp:packageName "my-lib" ;
        mp:version "1.0.0" .
}
```

Cannot bypass RDF validation. Cannot use JSON. Cannot write SQL.

---

## System Overview

### Architecture Diagram

```
┌─────────────────────────────────────────────────────────────┐
│                     CLI Interface                            │
│                  (Rust + SPARQL Generator)                  │
└──────────────────────┬──────────────────────────────────────┘
                       │
                       ▼
┌─────────────────────────────────────────────────────────────┐
│                  SPARQL Executor                            │
│   - Query parsing and validation                           │
│   - Transaction management                                 │
│   - Error handling                                          │
└──────────────────────┬──────────────────────────────────────┘
                       │
                       ▼
┌─────────────────────────────────────────────────────────────┐
│              SHACL Validation Layer                         │
│   - Type constraints (Package, Author, License)            │
│   - Cardinality (min/max count)                            │
│   - State machine rules                                     │
│   - FMEA triggers                                            │
└──────────────────────┬──────────────────────────────────────┘
                       │
                       ▼
┌─────────────────────────────────────────────────────────────┐
│                 Oxigraph RDF Store                          │
│   - Triple storage (persistent)                            │
│   - SPARQL 1.1 query engine                                │
│   - Transaction log (WAL)                                   │
│   - Backup/restore                                          │
└─────────────────────────────────────────────────────────────┘
```

### Data Flow

```
User Command
    ↓
CLI generates SPARQL query
    ↓
SPARQL executor validates syntax
    ↓
SHACL validator checks constraints
    ↓
State machine FSM validates transitions
    ↓
FMEA detector checks for failure modes
    ↓
Oxigraph executes transaction
    ↓
Audit event created (immutable RDF)
    ↓
Result returned to user
```

---

## POKA YOKE Mistake-Proofing

### Level 1: NewType Wrappers

Wrap primitive types to enforce domain constraints:

```rust
// ✅ Valid - enforces all invariants
let pkg_id = PackageId::new("my-package")?;  // Validated

// ❌ Compile error - cannot create from string directly
let pkg_id: PackageId = "my-package";  // Won't compile
```

**Invariants enforced:**
- Non-empty (1-200 chars)
- Only alphanumeric, `-`, `_`, `/`
- No path traversal (`..`)
- No control characters

### Level 2: Phantom Types

Encode state in type system:

```rust
// Draft state - only .publish() available
let draft: Package<Draft> = Package::new(...);

// Published state - only .activate() available
let published: Package<Published> = draft.publish(signature)?;

// Active state - only .deprecate() or .withdraw() available
let active: Package<Active> = published.activate()?;

// ❌ Compile error - cannot activate Draft directly
let active: Package<Active> = draft.activate()?;  // Won't compile
```

**State transitions consume old state, produce new state:**
- Impossible to have package in two states
- Impossible to perform operation on wrong state
- Compiler enforces FSM at compile time

### Level 3: Builder Pattern

Enforce required fields:

```rust
let package = PackageBuilder::new()
    .id(PackageId::new("pkg")?)
    .name(PackageName::new("my-pkg")?)
    .version(SemanticVersion::new("1.0.0")?)
    .author(AuthorName::new("Alice")?)
    .license(LicenseId::MIT)
    .checksum(Sha256Checksum::from_hex("...")?)
    .build()?;  // ✅ All required fields provided

// ❌ Runtime error - missing required field
let package = PackageBuilder::new()
    .name(PackageName::new("my-pkg")?)
    .build()?;  // Error: Package ID is required
```

### Level 4: SHACL Constraints

Validate RDF at schema level:

```turtle
:PackageShape sh:property [
    sh:path mp:packageId ;
    sh:minCount 1 ;
    sh:maxCount 1 ;
    sh:pattern "^[a-zA-Z0-9_/-]+$" ;
    sh:message "Package ID must match format"
] .
```

**Cannot insert invalid RDF into store** - SHACL rejects it.

### Level 5: State Machine FSM

Only valid transitions allowed:

```turtle
mp:Draft mp:canTransitionTo mp:Published .
mp:Published mp:canTransitionTo mp:Active, mp:Withdrawn .
mp:Active mp:canTransitionTo mp:Deprecated, mp:Withdrawn .
# No other transitions possible
```

**SPARQL queries check FSM before state changes:**

```sparql
# ❌ This query will fail - invalid transition
UPDATE {
    ?pkg mp:state mp:Active .
} WHERE {
    ?pkg mp:packageId "my-pkg" ;
        mp:state mp:Draft .  # Cannot go Draft → Active
}
```

---

## RDF Control Plane Design

### Configuration (Turtle)

All marketplace configuration in RDF:

```turtle
:marketplace a mp:Marketplace ;
    mp:marketplaceName "ggen-marketplace-v3" ;
    mp:storageBackend :storage ;
    mp:searchEngine :search ;
    mp:cacheConfiguration :caches .

:storage a mp:StorageBackend ;
    mp:backendType mp:OxigraphStore ;
    mp:storagePath "/var/lib/ggen/marketplace/store" ;
    mp:transactional true .

:search a mp:SearchEngine ;
    mp:indexType mp:HybridIndex ;
    mp:enableSemanticSearch true .
```

**No YAML. No JSON. No TOML.** Everything is RDF.

### Operations (SPARQL UPDATE)

All marketplace operations as SPARQL:

```sparql
# Publish package
INSERT {
    ?pkg mp:state mp:Published ;
        mp:publishedAt ?now ;
        mp:signature ?sig .
    ?sig a mp:Signature ;
        mp:signatureValue $signature ;
        mp:algorithm "Ed25519" .
} WHERE {
    ?pkg mp:packageId $packageId ;
        mp:state mp:Draft .
    BIND(NOW() AS ?now)
    BIND(IRI(CONCAT("https://ggen.io/sig/", STRUUID())) AS ?sig)
}

# Activate package
DELETE { ?pkg mp:state mp:Published . }
INSERT { ?pkg mp:state mp:Active ; mp:activatedAt ?now . }
WHERE {
    ?pkg mp:packageId $packageId ;
        mp:state mp:Published ;
        mp:signature ?sig .
    ?sig mp:signatureVerified true .
    BIND(NOW() AS ?now)
}
```

### Queries (SPARQL SELECT)

All data retrieval as SPARQL:

```sparql
# Search packages by quality
SELECT ?pkg ?name ?version ?score
WHERE {
    ?pkg a mp:Package ;
        mp:packageName ?name ;
        mp:version ?version ;
        mp:state mp:Active ;
        mp:hasQualityScore/mp:overallScore ?score .
    FILTER (?score > $minScore)
}
ORDER BY DESC(?score)
```

---

## State Machine Architecture

### Package Lifecycle FSM

```
                    ┌─────────┐
                    │  Draft  │ (initial)
                    └────┬────┘
                         │ publish()
                         ▼
                  ┌────────────┐
                  │ Published  │
                  └─────┬──────┘
                        │ activate()
                        ▼
                   ┌─────────┐
              ┌────┤ Active  ├────┐
              │    └─────────┘    │
    deprecate()│                  │ withdraw()
              ▼                   ▼
        ┌────────────┐      ┌────────────┐
        │ Deprecated │      │ Withdrawn  │ (terminal)
        └──────┬─────┘      └────────────┘
               │ archive()
               ▼
         ┌──────────┐
         │ Archived │ (terminal)
         └──────────┘
```

### State Definitions

Each state has specific properties:

```turtle
mp:Draft a mp:PackageState ;
    mp:isInitialState true ;
    mp:allowPublicAccess false ;
    mp:allowInstallation false ;
    mp:requiresSignature false ;
    mp:canTransitionTo mp:Published, mp:Withdrawn .

mp:Active a mp:PackageState ;
    mp:allowPublicAccess true ;
    mp:allowInstallation true ;
    mp:requiresSignature true ;
    mp:minQualityScore 60.0 ;
    mp:canTransitionTo mp:Deprecated, mp:Withdrawn .
```

### Transition Guards

Pre-conditions enforced via SPARQL:

```sparql
# Guard: Can only activate if signature verified
ASK {
    $pkg mp:signature ?sig .
    ?sig mp:signatureVerified true .
}

# Guard: Can only deprecate if replacement specified
ASK {
    $pkg mp:replacementPackage ?replacement .
}
```

---

## FMEA Integration

### Failure Mode Detection

Automated detection via SPARQL queries:

```turtle
:signatureFailureDetector a mp:FailureDetector ;
    mp:detectorType mp:SignatureVerificationFailed ;
    mp:severity 9 ;
    mp:sparqlQuery """
        SELECT ?pkg WHERE {
            ?pkg mp:signature ?sig .
            ?sig mp:signatureVerified false .
        }
    """ ;
    mp:mitigation :signatureMitigation .
```

### Automated Mitigation

Recovery procedures in RDF:

```turtle
:signatureMitigation a mp:Mitigation ;
    mp:mitigationStrategy mp:Retry ;
    mp:maxRetries 3 ;
    mp:backoffMultiplier 2.0 ;
    mp:fallbackAction mp:Alert .
```

### Failure Types

All failure modes defined in ontology:

```turtle
mp:FailureType owl:oneOf (
    mp:SignatureVerificationFailed
    mp:ChecksumMismatch
    mp:DependencyNotFound
    mp:VersionConflict
    mp:InvalidState
    mp:NetworkFailure
    mp:StorageCorruption
    mp:AccessDenied
) .
```

---

## Implementation Strategy

### Phase 1: Core RDF Infrastructure (Weeks 1-2)

1. **Set up Oxigraph store**
   - Persistent storage configuration
   - Transaction log (WAL)
   - Backup/restore

2. **Load ontology and schemas**
   - marketplace-ontology.ttl
   - validation-rules.ttl
   - state-machines.ttl

3. **Implement SPARQL executor**
   - Query parsing
   - Transaction management
   - Error handling

### Phase 2: POKA YOKE Types (Weeks 3-4)

1. **NewType wrappers**
   - PackageId, PackageName, SemanticVersion
   - Sha256Checksum, Ed25519Signature, Ed25519PublicKey
   - AuthorName, LicenseId

2. **Phantom types for states**
   - Package<Draft>, Package<Published>, Package<Active>
   - State transition methods
   - Compile-time FSM enforcement

3. **Builder patterns**
   - PackageBuilder with required fields
   - SignatureBuilder
   - QualityScoreBuilder

### Phase 3: SHACL Validation (Week 5)

1. **Integrate SHACL validation**
   - Validate all INSERT/UPDATE operations
   - Enforce cardinality constraints
   - Check datatype constraints

2. **State machine validation**
   - Validate state transitions
   - Check pre-conditions
   - Enforce guards

### Phase 4: SPARQL Operations (Weeks 6-7)

1. **Implement query library**
   - Package CRUD operations
   - Search queries
   - Dependency resolution
   - Quality queries

2. **Implement update operations**
   - Publish, activate, deprecate, withdraw
   - Quality score updates
   - Signature verification

### Phase 5: FMEA Integration (Week 8)

1. **Failure detectors**
   - Signature verification failures
   - Checksum mismatches
   - Missing dependencies
   - Invalid state transitions

2. **Mitigation strategies**
   - Retry logic
   - Fallback mechanisms
   - Automatic rollback
   - Alert generation

### Phase 6: CLI Integration (Weeks 9-10)

1. **Command-to-SPARQL translation**
   - `ggen pack install` → SPARQL SELECT
   - `ggen pack publish` → SPARQL INSERT/UPDATE
   - `ggen pack search` → SPARQL SELECT

2. **Result formatting**
   - Parse SPARQL results
   - Pretty-print to console
   - Error message translation

### Phase 7: Testing & Validation (Weeks 11-12)

1. **Unit tests**
   - NewType validation
   - Phantom type transitions
   - SPARQL query generation

2. **Integration tests**
   - End-to-end package lifecycle
   - State machine transitions
   - FMEA detection and mitigation

3. **Property-based tests**
   - Invariant checking
   - State machine properties
   - SHACL constraint verification

---

## Performance Considerations

### Caching Strategy

Multi-tier caching:

```turtle
:hotCache mp:ttl 300 ;      # 5 minutes
         mp:capacity 1000 .

:metadataCache mp:ttl 3600 ; # 1 hour
              mp:capacity 5000 .

:queryCache mp:ttl 1800 ;    # 30 minutes
           mp:capacity 2000 .
```

### Query Optimization

1. **SPARQL optimization**
   - Cost-based optimizer
   - Join reordering
   - Filter pushdown
   - Index scans

2. **Materialized views**
   - Pre-compute expensive queries
   - Incremental updates
   - Background refresh

3. **Bulk operations**
   - Batch SPARQL INSERT
   - Parallel query execution
   - Connection pooling

---

## Security Model

### Cryptographic Verification

All packages require Ed25519 signatures:

```turtle
mp:Active sh:sparql [
    sh:message "Active packages must have verified signature" ;
    sh:select """
        SELECT $this WHERE {
            $this mp:state mp:Active ;
                mp:signature ?sig .
            ?sig mp:signatureVerified false .
        }
    """
] .
```

### Access Control

RDF-based permissions:

```turtle
:security mp:enableSignatureVerification true ;
         mp:requireSignedPackages true ;
         mp:trustedPublishers :trustedList .

:trustedList mp:publisher [
    mp:publisherId "ggen-official" ;
    mp:publicKeyFingerprint "a1b2c3..." ;
    mp:verificationRequired true
] .
```

### Audit Trail

Immutable RDF audit events:

```turtle
:event a mp:AuditEvent ;
    mp:eventId "550e8400-e29b-41d4-a716-446655440000" ;
    mp:eventType mp:PackagePublished ;
    mp:timestamp "2025-01-15T10:30:00Z"^^xsd:dateTime ;
    mp:targetPackage <pkg/my-lib@1.0.0> ;
    mp:actor <author/alice> ;
    mp:changeSet "..." .
```

---

## Summary

This architecture provides:

1. ✅ **100% Semantic**: Everything in RDF/Turtle/SPARQL
2. ✅ **Mistake-Proof**: POKA YOKE at 5 levels (Type, State, Schema, Logic, Runtime)
3. ✅ **Type-Safe**: Phantom types and NewTypes prevent invalid states
4. ✅ **Self-Healing**: FMEA automatic detection and mitigation
5. ✅ **Auditable**: Immutable RDF audit trail
6. ✅ **No Alternative Paths**: Cannot bypass RDF validation

**Next Steps**: See `IMPLEMENTATION_ROADMAP.md` for detailed implementation plan.
