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+# Dgraph Integration Guide for ORLY Relay
+
+This document outlines how to integrate Dgraph as an embedded graph database within the ORLY Nostr relay, enabling advanced querying capabilities beyond standard Nostr REQ filters.
+
+## Table of Contents
+
+1. [Overview](#overview)
+2. [Architecture](#architecture)
+3. [Embedding Dgraph as a Goroutine](#embedding-dgraph-as-a-goroutine)
+4. [Internal Query Interface](#internal-query-interface)
+5. [GraphQL Endpoint Setup](#graphql-endpoint-setup)
+6. [Schema Design](#schema-design)
+7. [Integration Points](#integration-points)
+8. [Performance Considerations](#performance-considerations)
+
+## Overview
+
+### What Dgraph Provides
+
+Dgraph is a distributed graph database that can be embedded into Go applications. For ORLY, it offers:
+
+- **Graph Queries**: Traverse relationships between events, authors, and tags
+- **GraphQL API**: External access to relay data with complex queries
+- **DQL (Dgraph Query Language)**: Internal programmatic queries
+- **Real-time Updates**: Live query subscriptions
+- **Advanced Filtering**: Complex multi-hop queries impossible with Nostr REQ
+
+### Why Integrate?
+
+Nostr REQ filters are limited to:
+- Single-author or tag-based queries
+- Time range filters
+- Kind filters
+- Simple AND/OR combinations
+
+Dgraph enables:
+- "Find all events from users followed by my follows" (2-hop social graph)
+- "Show threads where Alice replied to Bob who replied to Carol"
+- "Find all events tagged with #bitcoin by authors in my Web of Trust"
+- Complex graph analytics on social networks
+
+## Architecture
+
+### Dgraph Components
+
+```
+┌─────────────────────────────────────────────────────────┐
+│                    ORLY Relay                           │
+│                                                         │
+│  ┌──────────────┐         ┌─────────────────────────┐  │
+│  │   HTTP API   │◄────────┤   GraphQL Endpoint      │  │
+│  │  (existing)  │         │   (new - external)      │  │
+│  └──────────────┘         └─────────────────────────┘  │
+│         │                           │                   │
+│         ▼                           ▼                   │
+│  ┌──────────────────────────────────────────────────┐  │
+│  │            Event Ingestion Layer                 │  │
+│  │  - Save to Badger (existing)                     │  │
+│  │  - Sync to Dgraph (new)                          │  │
+│  └──────────────────────────────────────────────────┘  │
+│         │                           │                   │
+│         ▼                           ▼                   │
+│  ┌────────────┐            ┌─────────────────┐         │
+│  │   Badger   │            │  Dgraph Engine  │         │
+│  │  (events)  │            │  (graph index)  │         │
+│  └────────────┘            └─────────────────┘         │
+│                                     │                   │
+│                            ┌────────┴────────┐          │
+│                            │                 │          │
+│                            ▼                 ▼          │
+│                     ┌──────────┐     ┌──────────┐      │
+│                     │  Badger  │     │ RaftWAL  │      │
+│                     │(postings)│     │  (WAL)   │      │
+│                     └──────────┘     └──────────┘      │
+└─────────────────────────────────────────────────────────┘
+```
+
+### Storage Strategy
+
+**Dual Storage Approach:**
+
+1. **Badger (Primary)**: Continue using existing Badger database for:
+   - Fast event retrieval by ID
+   - Time-based queries
+   - Author-based queries
+   - Tag-based queries
+   - Kind-based queries
+
+2. **Dgraph (Secondary)**: Use for:
+   - Graph relationship queries
+   - Complex multi-hop traversals
+   - Social graph analytics
+   - Web of Trust calculations
+
+**Data Sync**: Events are written to both stores, but Dgraph contains:
+- Event nodes (ID, kind, created_at, content)
+- Author nodes (pubkey)
+- Tag nodes (tag values)
+- Relationships (authored_by, tagged_with, replies_to, mentions, etc.)
+
+## Embedding Dgraph as a Goroutine
+
+### Initialization Pattern
+
+Based on dgraph's embedded mode (`worker/embedded.go` and `worker/server_state.go`):
+
+```go
+package dgraph
+
+import (
+    "context"
+    "net"
+    "net/http"
+
+    "github.com/dgraph-io/badger/v4"
+    "github.com/dgraph-io/dgraph/edgraph"
+    "github.com/dgraph-io/dgraph/graphql/admin"
+    "github.com/dgraph-io/dgraph/posting"
+    "github.com/dgraph-io/dgraph/schema"
+    "github.com/dgraph-io/dgraph/worker"
+    "github.com/dgraph-io/dgraph/x"
+    "github.com/dgraph-io/ristretto/z"
+)
+
+// Manager handles the embedded Dgraph instance
+type Manager struct {
+    ctx           context.Context
+    cancel        context.CancelFunc
+
+    // Dgraph components
+    pstore        *badger.DB          // Postings store
+    walstore      *worker.DiskStorage // Write-ahead log
+
+    // GraphQL servers
+    mainServer    admin.IServeGraphQL
+    adminServer   admin.IServeGraphQL
+    healthStore   *admin.GraphQLHealthStore
+
+    // Lifecycle
+    closer        *z.Closer
+    serverCloser  *z.Closer
+}
+
+// Config holds Dgraph configuration
+type Config struct {
+    DataDir              string
+    PostingDir           string
+    WALDir               string
+
+    // Performance tuning
+    PostingCacheMB       int64
+    MutationsMode        string
+
+    // Network
+    GraphQLPort          int
+    AdminPort            int
+
+    // Feature flags
+    EnableGraphQL        bool
+    EnableIntrospection  bool
+}
+
+// New creates a new embedded Dgraph manager
+func New(ctx context.Context, cfg *Config) (*Manager, error) {
+    ctx, cancel := context.WithCancel(ctx)
+
+    m := &Manager{
+        ctx:          ctx,
+        cancel:       cancel,
+        closer:       z.NewCloser(1),
+        serverCloser: z.NewCloser(3),
+    }
+
+    // Initialize storage
+    if err := m.initStorage(cfg); err != nil {
+        return nil, err
+    }
+
+    // Initialize Dgraph components
+    if err := m.initDgraph(cfg); err != nil {
+        return nil, err
+    }
+
+    // Setup GraphQL endpoints
+    if cfg.EnableGraphQL {
+        if err := m.setupGraphQL(cfg); err != nil {
+            return nil, err
+        }
+    }
+
+    return m, nil
+}
+
+// initStorage opens Badger databases for postings and WAL
+func (m *Manager) initStorage(cfg *Config) error {
+    // Open postings store (Dgraph's main data)
+    opts := badger.DefaultOptions(cfg.PostingDir).
+        WithNumVersionsToKeep(math.MaxInt32).
+        WithNamespaceOffset(x.NamespaceOffset)
+
+    var err error
+    m.pstore, err = badger.OpenManaged(opts)
+    if err != nil {
+        return fmt.Errorf("failed to open postings store: %w", err)
+    }
+
+    // Open WAL store
+    m.walstore, err = worker.InitStorage(cfg.WALDir)
+    if err != nil {
+        m.pstore.Close()
+        return fmt.Errorf("failed to open WAL: %w", err)
+    }
+
+    return nil
+}
+
+// initDgraph initializes Dgraph worker components
+func (m *Manager) initDgraph(cfg *Config) error {
+    // Initialize server state
+    worker.State.Pstore = m.pstore
+    worker.State.WALstore = m.walstore
+    worker.State.FinishCh = make(chan struct{})
+
+    // Initialize schema and posting layers
+    schema.Init(m.pstore)
+    posting.Init(m.pstore, cfg.PostingCacheMB, true)
+    worker.Init(m.pstore)
+
+    // For embedded/lite mode without Raft
+    worker.InitForLite(m.pstore)
+
+    return nil
+}
+
+// setupGraphQL initializes GraphQL servers
+func (m *Manager) setupGraphQL(cfg *Config) error {
+    globalEpoch := make(map[uint64]*uint64)
+
+    // Create GraphQL servers
+    m.mainServer, m.adminServer, m.healthStore = admin.NewServers(
+        cfg.EnableIntrospection,
+        globalEpoch,
+        m.serverCloser,
+    )
+
+    return nil
+}
+
+// Start launches Dgraph in goroutines
+func (m *Manager) Start() error {
+    // Start worker server (internal gRPC)
+    go worker.RunServer(false)
+
+    return nil
+}
+
+// Stop gracefully shuts down Dgraph
+func (m *Manager) Stop() error {
+    m.cancel()
+
+    // Signal shutdown
+    m.closer.SignalAndWait()
+    m.serverCloser.SignalAndWait()
+
+    // Close databases
+    if m.walstore != nil {
+        m.walstore.Close()
+    }
+    if m.pstore != nil {
+        m.pstore.Close()
+    }
+
+    return nil
+}
+```
+
+### Integration with ORLY Main
+
+In `app/main.go`:
+
+```go
+import (
+    "next.orly.dev/pkg/dgraph"
+)
+
+type Listener struct {
+    // ... existing fields ...
+
+    dgraphManager *dgraph.Manager
+}
+
+func (l *Listener) init(ctx context.Context, cfg *config.C) (err error) {
+    // ... existing initialization ...
+
+    // Initialize Dgraph if enabled
+    if cfg.DgraphEnabled {
+        dgraphCfg := &dgraph.Config{
+            DataDir:             cfg.DgraphDataDir,
+            PostingDir:          filepath.Join(cfg.DgraphDataDir, "p"),
+            WALDir:              filepath.Join(cfg.DgraphDataDir, "w"),
+            PostingCacheMB:      cfg.DgraphCacheMB,
+            EnableGraphQL:       cfg.DgraphGraphQL,
+            EnableIntrospection: cfg.DgraphIntrospection,
+            GraphQLPort:         cfg.DgraphGraphQLPort,
+        }
+
+        l.dgraphManager, err = dgraph.New(ctx, dgraphCfg)
+        if err != nil {
+            return fmt.Errorf("failed to initialize dgraph: %w", err)
+        }
+
+        if err = l.dgraphManager.Start(); err != nil {
+            return fmt.Errorf("failed to start dgraph: %w", err)
+        }
+
+        log.I.F("dgraph manager started successfully")
+    }
+
+    // ... rest of initialization ...
+}
+```
+
+## Internal Query Interface
+
+### Direct Query Execution
+
+Dgraph provides `edgraph.Server{}.QueryNoGrpc()` for internal queries:
+
+```go
+package dgraph
+
+import (
+    "context"
+
+    "github.com/dgraph-io/dgo/v230/protos/api"
+    "github.com/dgraph-io/dgraph/edgraph"
+)
+
+// Query executes a DQL query internally
+func (m *Manager) Query(ctx context.Context, query string) (*api.Response, error) {
+    server := &edgraph.Server{}
+
+    req := &api.Request{
+        Query: query,
+    }
+
+    return server.QueryNoGrpc(ctx, req)
+}
+
+// Mutate applies a mutation to the graph
+func (m *Manager) Mutate(ctx context.Context, mutation *api.Mutation) (*api.Response, error) {
+    server := &edgraph.Server{}
+
+    req := &api.Request{
+        Mutations: []*api.Mutation{mutation},
+        CommitNow: true,
+    }
+
+    return server.QueryNoGrpc(ctx, req)
+}
+```
+
+### Example: Adding Events to Graph
+
+```go
+// AddEvent indexes a Nostr event in the graph
+func (m *Manager) AddEvent(ctx context.Context, event *event.E) error {
+    // Build RDF triples for the event
+    nquads := buildEventNQuads(event)
+
+    mutation := &api.Mutation{
+        SetNquads: []byte(nquads),
+        CommitNow: true,
+    }
+
+    _, err := m.Mutate(ctx, mutation)
+    return err
+}
+
+func buildEventNQuads(event *event.E) string {
+    var nquads strings.Builder
+
+    eventID := hex.EncodeToString(event.ID[:])
+    authorPubkey := hex.EncodeToString(event.Pubkey)
+
+    // Event node
+    nquads.WriteString(fmt.Sprintf("_:%s <dgraph.type> \"Event\" .\n", eventID))
+    nquads.WriteString(fmt.Sprintf("_:%s <event.id> %q .\n", eventID, eventID))
+    nquads.WriteString(fmt.Sprintf("_:%s <event.kind> %q .\n", eventID, event.Kind))
+    nquads.WriteString(fmt.Sprintf("_:%s <event.created_at> %q .\n", eventID, event.CreatedAt))
+    nquads.WriteString(fmt.Sprintf("_:%s <event.content> %q .\n", eventID, event.Content))
+
+    // Author relationship
+    nquads.WriteString(fmt.Sprintf("_:%s <authored_by> _:%s .\n", eventID, authorPubkey))
+    nquads.WriteString(fmt.Sprintf("_:%s <dgraph.type> \"Author\" .\n", authorPubkey))
+    nquads.WriteString(fmt.Sprintf("_:%s <author.pubkey> %q .\n", authorPubkey, authorPubkey))
+
+    // Tag relationships
+    for _, tag := range event.Tags {
+        if len(tag) >= 2 {
+            tagType := string(tag[0])
+            tagValue := string(tag[1])
+
+            switch tagType {
+            case "e": // Event reference
+                nquads.WriteString(fmt.Sprintf("_:%s <references> _:%s .\n", eventID, tagValue))
+            case "p": // Pubkey mention
+                nquads.WriteString(fmt.Sprintf("_:%s <mentions> _:%s .\n", eventID, tagValue))
+            case "t": // Hashtag
+                tagID := "tag_" + tagValue
+                nquads.WriteString(fmt.Sprintf("_:%s <tagged_with> _:%s .\n", eventID, tagID))
+                nquads.WriteString(fmt.Sprintf("_:%s <dgraph.type> \"Tag\" .\n", tagID))
+                nquads.WriteString(fmt.Sprintf("_:%s <tag.value> %q .\n", tagID, tagValue))
+            }
+        }
+    }
+
+    return nquads.String()
+}
+```
+
+### Example: Query Social Graph
+
+```go
+// FindFollowsOfFollows returns events from 2-hop social network
+func (m *Manager) FindFollowsOfFollows(ctx context.Context, pubkey []byte) ([]*event.E, error) {
+    pubkeyHex := hex.EncodeToString(pubkey)
+
+    query := fmt.Sprintf(`{
+        follows_of_follows(func: eq(author.pubkey, %q)) {
+            # My follows (kind 3)
+            ~authored_by @filter(eq(event.kind, "3")) {
+                # Their follows
+                references {
+                    # Events from their follows
+                    ~authored_by {
+                        event.id
+                        event.kind
+                        event.created_at
+                        event.content
+                        authored_by {
+                            author.pubkey
+                        }
+                    }
+                }
+            }
+        }
+    }`, pubkeyHex)
+
+    resp, err := m.Query(ctx, query)
+    if err != nil {
+        return nil, err
+    }
+
+    // Parse response and convert to Nostr events
+    return parseEventsFromDgraphResponse(resp.Json)
+}
+```
+
+## GraphQL Endpoint Setup
+
+### Exposing GraphQL via HTTP
+
+Add GraphQL handlers to the existing HTTP mux in `app/server.go`:
+
+```go
+// setupGraphQLEndpoints adds Dgraph GraphQL endpoints
+func (s *Server) setupGraphQLEndpoints() {
+    if s.dgraphManager == nil {
+        return
+    }
+
+    // Main GraphQL endpoint for queries
+    s.mux.HandleFunc("/graphql", func(w http.ResponseWriter, r *http.Request) {
+        // Extract namespace (for multi-tenancy)
+        namespace := x.ExtractNamespaceHTTP(r)
+
+        // Lazy load schema
+        admin.LazyLoadSchema(namespace)
+
+        // Serve GraphQL
+        s.dgraphManager.MainServer().HTTPHandler().ServeHTTP(w, r)
+    })
+
+    // Admin endpoint for schema updates
+    s.mux.HandleFunc("/admin", func(w http.ResponseWriter, r *http.Request) {
+        namespace := x.ExtractNamespaceHTTP(r)
+        admin.LazyLoadSchema(namespace)
+        s.dgraphManager.AdminServer().HTTPHandler().ServeHTTP(w, r)
+    })
+
+    // Health check
+    s.mux.HandleFunc("/graphql/health", func(w http.ResponseWriter, r *http.Request) {
+        health := s.dgraphManager.HealthStore()
+        if health.IsGraphQLReady() {
+            w.WriteHeader(http.StatusOK)
+            w.Write([]byte("GraphQL is ready"))
+        } else {
+            w.WriteHeader(http.StatusServiceUnavailable)
+            w.Write([]byte("GraphQL is not ready"))
+        }
+    })
+}
+```
+
+### GraphQL Resolver Integration
+
+The manager needs to expose the GraphQL servers:
+
+```go
+// MainServer returns the main GraphQL server
+func (m *Manager) MainServer() admin.IServeGraphQL {
+    return m.mainServer
+}
+
+// AdminServer returns the admin GraphQL server
+func (m *Manager) AdminServer() admin.IServeGraphQL {
+    return m.adminServer
+}
+
+// HealthStore returns the health check store
+func (m *Manager) HealthStore() *admin.GraphQLHealthStore {
+    return m.healthStore
+}
+```
+
+## Schema Design
+
+### Dgraph Schema for Nostr Events
+
+```graphql
+# Types
+type Event {
+    id: String! @id @index(exact)
+    kind: Int! @index(int)
+    created_at: Int! @index(int)
+    content: String @index(fulltext)
+    sig: String
+
+    # Relationships
+    authored_by: Author! @reverse
+    references: [Event] @reverse
+    mentions: [Author] @reverse
+    tagged_with: [Tag] @reverse
+    replies_to: Event @reverse
+}
+
+type Author {
+    pubkey: String! @id @index(exact)
+
+    # Relationships
+    events: [Event] @reverse
+    follows: [Author] @reverse
+    followed_by: [Author] @reverse
+
+    # Computed/cached fields
+    follower_count: Int
+    following_count: Int
+    event_count: Int
+}
+
+type Tag {
+    value: String! @id @index(exact, term, fulltext)
+    type: String @index(exact)
+
+    # Relationships
+    events: [Event] @reverse
+    usage_count: Int
+}
+
+# Indexes for efficient queries
+<event.kind>: int @index .
+<event.created_at>: int @index .
+<event.content>: string @index(fulltext) .
+<author.pubkey>: string @index(exact) .
+<tag.value>: string @index(exact, term, fulltext) .
+```
+
+### Setting the Schema
+
+```go
+func (m *Manager) SetSchema(ctx context.Context) error {
+    schemaStr := `
+type Event {
+    event.id: string @index(exact) .
+    event.kind: int @index(int) .
+    event.created_at: int @index(int) .
+    event.content: string @index(fulltext) .
+    authored_by: uid @reverse .
+    references: [uid] @reverse .
+    mentions: [uid] @reverse .
+    tagged_with: [uid] @reverse .
+}
+
+type Author {
+    author.pubkey: string @index(exact) .
+}
+
+type Tag {
+    tag.value: string @index(exact, term, fulltext) .
+}
+`
+
+    mutation := &api.Mutation{
+        SetNquads: []byte(schemaStr),
+        CommitNow: true,
+    }
+
+    _, err := m.Mutate(ctx, mutation)
+    return err
+}
+```
+
+## Integration Points
+
+### Event Ingestion Hook
+
+Modify `pkg/database/save-event.go` to sync events to Dgraph:
+
+```go
+func (d *D) SaveEvent(ctx context.Context, ev *event.E) (exists bool, err error) {
+    // ... existing Badger save logic ...
+
+    // Sync to Dgraph if enabled
+    if d.dgraphManager != nil {
+        go func() {
+            if err := d.dgraphManager.AddEvent(context.Background(), ev); err != nil {
+                log.E.F("failed to sync event to dgraph: %v", err)
+            }
+        }()
+    }
+
+    return
+}
+```
+
+### Query Interface Extension
+
+Add GraphQL query support alongside Nostr REQ:
+
+```go
+// app/handle-graphql.go
+
+func (s *Server) handleGraphQLQuery(w http.ResponseWriter, r *http.Request) {
+    if s.dgraphManager == nil {
+        http.Error(w, "GraphQL not enabled", http.StatusNotImplemented)
+        return
+    }
+
+    // Read GraphQL query from request
+    var req struct {
+        Query     string                 `json:"query"`
+        Variables map[string]interface{} `json:"variables"`
+    }
+
+    if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+        http.Error(w, err.Error(), http.StatusBadRequest)
+        return
+    }
+
+    // Execute via Dgraph
+    gqlReq := &schema.Request{
+        Query:     req.Query,
+        Variables: req.Variables,
+    }
+
+    namespace := x.ExtractNamespaceHTTP(r)
+    resp := s.dgraphManager.MainServer().ResolveWithNs(r.Context(), namespace, gqlReq)
+
+    // Return response
+    w.Header().Set("Content-Type", "application/json")
+    json.NewEncoder(w).Encode(resp)
+}
+```
+
+## Performance Considerations
+
+### Memory Usage
+
+- **Dgraph Overhead**: ~500MB-1GB baseline
+- **Posting Cache**: Configurable (recommend 25% of available RAM)
+- **WAL**: Disk-based, minimal memory impact
+
+### Storage Requirements
+
+- **Badger (Postings)**: ~2-3x event data size (compressed)
+- **WAL**: ~1.5x mutation data (compacted periodically)
+- **Total**: Estimate 4-5x your Nostr event storage
+
+### Query Performance
+
+- **Graph Traversals**: O(edges) typically sub-100ms for 2-3 hops
+- **Full-text Search**: O(log n) with indexes
+- **Time-range Queries**: O(log n) with int indexes
+- **Complex Joins**: Can be expensive; use pagination
+
+### Optimization Strategies
+
+1. **Selective Indexing**: Only index events that need graph queries (e.g., kinds 1, 3, 6, 7)
+2. **Async Writes**: Don't block event saves on Dgraph sync
+3. **Read-through Cache**: Query Badger first for simple lookups
+4. **Batch Mutations**: Accumulate mutations and apply in batches
+5. **Schema Optimization**: Only index fields you'll query
+6. **Pagination**: Always use `first:` and `after:` in GraphQL queries
+
+### Monitoring
+
+```go
+// Add metrics
+var (
+    dgraphQueriesTotal = prometheus.NewCounter(...)
+    dgraphQueryDuration = prometheus.NewHistogram(...)
+    dgraphMutationsTotal = prometheus.NewCounter(...)
+    dgraphErrors = prometheus.NewCounter(...)
+)
+
+// Wrap queries with instrumentation
+func (m *Manager) Query(ctx context.Context, query string) (*api.Response, error) {
+    start := time.Now()
+    defer func() {
+        dgraphQueriesTotal.Inc()
+        dgraphQueryDuration.Observe(time.Since(start).Seconds())
+    }()
+
+    resp, err := m.query(ctx, query)
+    if err != nil {
+        dgraphErrors.Inc()
+    }
+    return resp, err
+}
+```
+
+## Alternative: Lightweight Graph Library
+
+Given Dgraph's complexity and resource requirements, consider these alternatives:
+
+### cayley (Google's graph database)
+
+```bash
+go get github.com/cayleygraph/cayley
+```
+
+- Lighter weight (~50MB overhead)
+- Multiple backend support (Badger, Memory, SQL)
+- Simpler API
+- Good for smaller graphs (<10M nodes)
+
+### badger-graph (Custom Implementation)
+
+Build a custom graph layer on top of existing Badger:
+
+```go
+// Simplified graph index using Badger directly
+type GraphIndex struct {
+    db *badger.DB
+}
+
+// Store edge: subject -> predicate -> object
+func (g *GraphIndex) AddEdge(subject, predicate, object string) error {
+    key := fmt.Sprintf("edge:%s:%s:%s", subject, predicate, object)
+    return g.db.Update(func(txn *badger.Txn) error {
+        return txn.Set([]byte(key), []byte{})
+    })
+}
+
+// Query edges
+func (g *GraphIndex) GetEdges(subject, predicate string) ([]string, error) {
+    prefix := fmt.Sprintf("edge:%s:%s:", subject, predicate)
+    // Iterate and collect
+}
+```
+
+This avoids Dgraph's overhead while providing basic graph functionality.
+
+## Conclusion
+
+Embedding Dgraph in ORLY enables powerful graph queries that extend far beyond Nostr's REQ filters. However, it comes with significant complexity and resource requirements. Consider:
+
+- **Full Dgraph**: For production relays with advanced query needs
+- **Cayley**: For medium-sized relays with moderate graph needs
+- **Custom Badger-Graph**: For lightweight graph indexing with minimal overhead
+
+Choose based on your specific use case, expected load, and query complexity requirements.