diff --git a/schemas/04_log.sql b/schemas/04_log.sql
index d9a655e..11a076f 100644
--- a/schemas/04_log.sql
+++ b/schemas/04_log.sql
@@ -11,12 +11,16 @@ CREATE EXTENSION IF NOT EXISTS pgcrypto;
 
 -- Tipos
 CREATE TYPE log.actor_type AS ENUM ('user', 'agent', 'orchestrator', 'system', 'tool');
+CREATE TYPE log.ref_type AS ENUM ('context', 'accountant', 'secretary');
 
--- Tabla principal
+-- ============================================
+-- Tabla 1: messages
+-- ============================================
 CREATE TABLE log.messages (
     id              BIGSERIAL PRIMARY KEY,
     hash            CHAR(64) UNIQUE NOT NULL,
     session_hash    CHAR(64) NOT NULL,
+    thread_hash     CHAR(64),
     sender_type     log.actor_type NOT NULL,
     sender_id       CHAR(64) NOT NULL,
     receiver_type   log.actor_type NOT NULL,
@@ -26,52 +30,79 @@ CREATE TABLE log.messages (
     content         TEXT NOT NULL,
     attachments     JSONB DEFAULT '{}',
     prev_hash       CHAR(64),
-    context_hashes  CHAR(64)[] DEFAULT '{}',
     hashtags        CHAR(64)[] DEFAULT '{}',
     ambient         JSONB,
     created_at      TIMESTAMPTZ DEFAULT NOW()
 );
 
--- Índices
 CREATE INDEX idx_messages_session ON log.messages(session_hash);
+CREATE INDEX idx_messages_thread ON log.messages(thread_hash);
 CREATE INDEX idx_messages_sender ON log.messages(sender_id);
 CREATE INDEX idx_messages_receiver ON log.messages(receiver_id);
 CREATE INDEX idx_messages_prev ON log.messages(prev_hash);
 CREATE INDEX idx_messages_created ON log.messages(created_at);
 CREATE INDEX idx_messages_hashtags ON log.messages USING gin(hashtags);
 
--- Función SHA256
+-- ============================================
+-- Tabla 2: message_refs
+-- Relaciona mensaje con contexto y conocimiento
+-- ============================================
+CREATE TABLE log.message_refs (
+    id              BIGSERIAL PRIMARY KEY,
+    message_hash    CHAR(64) NOT NULL,
+    ref_hash        CHAR(64) NOT NULL,
+    ref_type        log.ref_type NOT NULL,
+    position        INT,
+    thread_hash     CHAR(64),
+    UNIQUE(message_hash, ref_hash)
+);
+
+CREATE INDEX idx_refs_message ON log.message_refs(message_hash);
+CREATE INDEX idx_refs_ref ON log.message_refs(ref_hash);
+CREATE INDEX idx_refs_type ON log.message_refs(ref_type);
+CREATE INDEX idx_refs_thread ON log.message_refs(thread_hash);
+
+-- ============================================
+-- Funciones
+-- ============================================
 CREATE OR REPLACE FUNCTION log.sha256(data TEXT) RETURNS CHAR(64) AS $$
 BEGIN
     RETURN encode(digest(data, 'sha256'), 'hex');
 END;
 $$ LANGUAGE plpgsql IMMUTABLE;
 
--- Protección: no UPDATE
 CREATE OR REPLACE FUNCTION log.prevent_update() RETURNS TRIGGER AS $$
 BEGIN
-    RAISE EXCEPTION 'UPDATE no permitido en log.messages';
+    RAISE EXCEPTION 'UPDATE no permitido en %', TG_TABLE_NAME;
 END;
 $$ LANGUAGE plpgsql;
 
--- Protección: no DELETE
 CREATE OR REPLACE FUNCTION log.prevent_delete() RETURNS TRIGGER AS $$
 BEGIN
-    RAISE EXCEPTION 'DELETE no permitido en log.messages';
+    RAISE EXCEPTION 'DELETE no permitido en %', TG_TABLE_NAME;
 END;
 $$ LANGUAGE plpgsql;
 
+-- ============================================
 -- Triggers de protección
-CREATE TRIGGER protect_update BEFORE UPDATE ON log.messages
+-- ============================================
+CREATE TRIGGER protect_messages_update BEFORE UPDATE ON log.messages
     FOR EACH ROW EXECUTE FUNCTION log.prevent_update();
-
-CREATE TRIGGER protect_delete BEFORE DELETE ON log.messages
+CREATE TRIGGER protect_messages_delete BEFORE DELETE ON log.messages
     FOR EACH ROW EXECUTE FUNCTION log.prevent_delete();
 
+CREATE TRIGGER protect_refs_update BEFORE UPDATE ON log.message_refs
+    FOR EACH ROW EXECUTE FUNCTION log.prevent_update();
+CREATE TRIGGER protect_refs_delete BEFORE DELETE ON log.message_refs
+    FOR EACH ROW EXECUTE FUNCTION log.prevent_delete();
+
+-- ============================================
 -- Permisos
+-- ============================================
 GRANT USAGE ON SCHEMA log TO tzzr;
 GRANT SELECT, INSERT ON log.messages TO tzzr;
+GRANT SELECT, INSERT ON log.message_refs TO tzzr;
 GRANT USAGE ON SEQUENCE log.messages_id_seq TO tzzr;
+GRANT USAGE ON SEQUENCE log.message_refs_id_seq TO tzzr;
 
--- Verificación
-SELECT 'Schema log creado' as status;
+SELECT 'Schema log: 2 tablas creadas' as status;