diff --git a/docs/DEVELOPMENT.md b/docs/DEVELOPMENT.md
index 769d94b..049a758 100644
--- a/docs/DEVELOPMENT.md
+++ b/docs/DEVELOPMENT.md
@@ -14,11 +14,10 @@ TTRPG Initiative Tracker — fork with self-hosted backend. Monorepo via npm wor
   package.json          # workspaces root
   src/                  # React frontend (CRA, existing)
     App.js              # ~2935 lines, Firebase direct (M2 abstracts this)
-  server/               # Backend: Express + ws + better-sqlite3
-    index.js            # REST + WS bootstrap
-    db.js               # SQLite schema, row mappers
-    handlers.js         # action -> shared turn fn -> tx persist -> broadcast
-    server.test.js      # integration tests
+  server/               # Backend: generic KV doc store (firebase mirror)
+    index.js            # REST (doc/coll/batch) + WS bootstrap
+    db.js               # SQLite docs table, KV ops, broadcast
+    ws-contract.test.js # adapter vs live backend (Layer 2)
   shared/               # Pure logic, no I/O (client + server + tests import)
     turn.js             # turn-order state machine
     turn.characterization.test.js
@@ -67,7 +66,7 @@ Three commands:
 ```bash
 npm run test:all          # runs shared/ + server/ suites in sequence
 npm run shared:test       # turn logic only (shared/ folder)
-npm run server:test       # backend REST + combat flow (server/ folder)
+npm run server:test       # backend ws-contract (adapter vs live backend)
 ```
 
 What each runs:
diff --git a/docs/REWORK_PLAN.md b/docs/REWORK_PLAN.md
index 028824f..538cbf0 100644
--- a/docs/REWORK_PLAN.md
+++ b/docs/REWORK_PLAN.md
@@ -96,11 +96,9 @@ Memory impl: in-memory Map + EventEmitter, for tests (M3).
       memory.js             # NEW — test only
       types.js              # interface contract (JSDoc)
   server/                   # NEW
-    index.js                # Express + ws bootstrap
-    db.js                   # better-sqlite3, schema, migrations
-    turn.js                 # turn-order logic (pure, server-authoritative)
-    handlers/               # action handlers (call turn logic, persist, broadcast)
-    server.test.js          # API + WS integration tests
+    index.js                # Express + ws bootstrap, generic KV REST
+    db.js                   # better-sqlite3, docs table (KV), broadcast
+    ws-contract.test.js     # adapter vs live backend (Layer 2 test)
   shared/                   # pure logic, no I/O, importable by client + server + tests
     turn.js                 # turn logic (single source; server imports, tests import)
     types.js
diff --git a/server/db.js b/server/db.js
index c2327f2..63ac4de 100644
--- a/server/db.js
+++ b/server/db.js
@@ -1,15 +1,16 @@
-// server/db.js — SQLite persistence layer.
-// Owns the DB file. Only writer. Synchronous via better-sqlite3.
+// server/db.js — generic KV document store on SQLite.
+// Mirrors Firestore doc-tree model: every doc lives at a string path.
+// Collections are implicit = all docs whose parent path equals the collection path.
 //
-// Schema mirrors the Firestore doc tree used by src/App.js:
-//   artifacts/{APP_ID}/public/data/
-//     campaigns/{id}                       -> name, bg, ownerId, createdAt, players[]
-//     campaigns/{id}/encounters/{eid}      -> name, participants[], round, currentTurnParticipantId, isStarted, isPaused, turnOrderIds[]
-//     activeDisplay/status                 -> activeCampaignId, activeEncounterId, hidePlayerHp
-//     logs/{id}                            -> timestamp, message, encounterName, undo, undone
+// Path examples (canonical, prefix already stripped by adapter):
+//   campaigns/{id}                       doc
+//   campaigns/{cid}/encounters/{eid}     doc
+//   campaigns/{cid}/encounters           collection (parent of encounter docs)
+//   activeDisplay/status                 doc
+//   logs/{id}                            doc
 //
-// Collections (campaigns, encounters, logs) -> rows with JSON blobs for fields.
-// Single-row "status" docs (activeDisplay) -> their own tables.
+// No shape-specific tables. Data is opaque JSON. This is the firebase mirror:
+// the adapter (src/storage/ws.js) is a thin passthrough, app logic unchanged.
 
 'use strict';
 
@@ -18,48 +19,14 @@ const path = require('path');
 const fs = require('fs');
 
 const SCHEMA = `
-CREATE TABLE IF NOT EXISTS campaigns (
-  id TEXT PRIMARY KEY,
-  name TEXT NOT NULL,
-  playerDisplayBackgroundUrl TEXT NOT NULL DEFAULT '',
-  ownerId TEXT,
-  createdAt TEXT NOT NULL,
-  players TEXT NOT NULL DEFAULT '[]'
+CREATE TABLE IF NOT EXISTS docs (
+  path TEXT PRIMARY KEY,
+  parent TEXT,
+  data TEXT NOT NULL,
+  updated_at INTEGER NOT NULL
 );
 
-CREATE TABLE IF NOT EXISTS encounters (
-  id TEXT NOT NULL,
-  campaignId TEXT NOT NULL,
-  name TEXT NOT NULL,
-  participants TEXT NOT NULL DEFAULT '[]',
-  round INTEGER NOT NULL DEFAULT 0,
-  currentTurnParticipantId TEXT,
-  isStarted INTEGER NOT NULL DEFAULT 0,
-  isPaused INTEGER NOT NULL DEFAULT 0,
-  turnOrderIds TEXT NOT NULL DEFAULT '[]',
-  createdAt TEXT NOT NULL,
-  PRIMARY KEY (campaignId, id),
-  FOREIGN KEY (campaignId) REFERENCES campaigns(id) ON DELETE CASCADE
-);
-
-CREATE TABLE IF NOT EXISTS active_display (
-  id INTEGER PRIMARY KEY CHECK (id = 1),
-  activeCampaignId TEXT,
-  activeEncounterId TEXT,
-  hidePlayerHp INTEGER NOT NULL DEFAULT 1
-);
-
-CREATE TABLE IF NOT EXISTS logs (
-  id TEXT PRIMARY KEY,
-  timestamp INTEGER NOT NULL,
-  message TEXT NOT NULL,
-  encounterName TEXT,
-  undo TEXT,
-  undone INTEGER NOT NULL DEFAULT 0
-);
-
-CREATE INDEX IF NOT EXISTS idx_logs_timestamp ON logs(timestamp DESC);
-CREATE INDEX IF NOT EXISTS idx_encounters_campaign ON encounters(campaignId);
+CREATE INDEX IF NOT EXISTS idx_docs_parent ON docs(parent);
 `;
 
 function openDb(dbPath) {
@@ -67,60 +34,77 @@ function openDb(dbPath) {
   if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
   const db = new Database(dbPath);
   db.pragma('journal_mode = WAL');
-  db.pragma('foreign_keys = ON');
   db.exec(SCHEMA);
-  // Ensure the single active_display row exists.
-  db.prepare('INSERT OR IGNORE INTO active_display (id, hidePlayerHp) VALUES (1, 1)').run();
   return db;
 }
 
-// --- JSON helpers ---
-const parseArr = (s) => (s ? JSON.parse(s) : []);
-const parseObj = (s, fallback = null) => (s ? JSON.parse(s) : fallback);
-
-// --- Campaign shape (matches Firestore doc) ---
-function rowToCampaign(row) {
-  if (!row) return null;
-  return {
-    id: row.id,
-    name: row.name,
-    playerDisplayBackgroundUrl: row.playerDisplayBackgroundUrl,
-    ownerId: row.ownerId,
-    createdAt: row.createdAt,
-    players: parseArr(row.players),
-  };
+// parentOf('campaigns/abc/encounters/xyz') => 'campaigns/abc/encounters'
+// parentOf('campaigns') => null (root-level doc, no parent collection tracked)
+function parentOf(p) {
+  const i = p.lastIndexOf('/');
+  return i === -1 ? null : p.slice(0, i);
 }
 
-// --- Encounter shape (matches Firestore doc) ---
-function rowToEncounter(row) {
-  if (!row) return null;
-  return {
-    id: row.id,
-    campaignId: row.campaignId,
-    name: row.name,
-    participants: parseArr(row.participants),
-    round: row.round,
-    currentTurnParticipantId: row.currentTurnParticipantId,
-    isStarted: !!row.isStarted,
-    isPaused: !!row.isPaused,
-    turnOrderIds: parseArr(row.turnOrderIds),
-    createdAt: row.createdAt,
-  };
+function makeStore(db, broadcast) {
+  const stmtGet = db.prepare('SELECT data FROM docs WHERE path = ?');
+  const stmtUpsert = db.prepare(`
+    INSERT INTO docs (path, parent, data, updated_at) VALUES (@path, @parent, @data, @ts)
+    ON CONFLICT(path) DO UPDATE SET data = @data, updated_at = @ts
+  `);
+  const stmtDelete = db.prepare('DELETE FROM docs WHERE path = ?');
+  const stmtColl = db.prepare('SELECT path, data FROM docs WHERE parent = ? ORDER BY path ASC');
+
+  function getDoc(p) {
+    const row = stmtGet.get(p);
+    return row ? JSON.parse(row.data) : null;
+  }
+
+  function setDoc(p, data) {
+    const ts = Date.now();
+    stmtUpsert.run({ path: p, parent: parentOf(p), data: JSON.stringify(data), ts });
+    if (broadcast) broadcast({ path: p, parent: parentOf(p) });
+    return data;
+  }
+
+  // shallow merge; if doc missing, patch becomes the doc (matches firebase updateDoc create-on-miss)
+  function updateDoc(p, patch) {
+    const existing = getDoc(p) || {};
+    const merged = { ...existing, ...patch };
+    setDoc(p, merged);
+    return merged;
+  }
+
+  function deleteDoc(p) {
+    stmtDelete.run(p);
+    if (broadcast) broadcast({ path: p, parent: parentOf(p), deleted: true });
+  }
+
+  function getCollection(collPath) {
+    return stmtColl.all(collPath).map(row => ({ id: row.path.split('/').pop(), path: row.path, ...JSON.parse(row.data) }));
+  }
+
+  function batchWrite(ops) {
+    const run = db.transaction((items) => {
+      const changed = [];
+      for (const op of items) {
+        if (op.type === 'set') {
+          setDoc(op.path, op.data);
+          changed.push({ path: op.path, parent: parentOf(op.path) });
+        } else if (op.type === 'delete') {
+          deleteDoc(op.path);
+          changed.push({ path: op.path, parent: parentOf(op.path), deleted: true });
+        } else if (op.type === 'update') {
+          updateDoc(op.path, op.data);
+          changed.push({ path: op.path, parent: parentOf(op.path) });
+        }
+      }
+      return changed;
+    });
+    const changed = run(ops);
+    if (broadcast) changed.forEach(c => broadcast(c));
+  }
+
+  return { getDoc, setDoc, updateDoc, deleteDoc, getCollection, batchWrite };
 }
 
-// --- Active display shape ---
-function rowToActiveDisplay(row) {
-  if (!row) return null;
-  return {
-    activeCampaignId: row.activeCampaignId,
-    activeEncounterId: row.activeEncounterId,
-    hidePlayerHp: !!row.hidePlayerHp,
-  };
-}
-
-module.exports = {
-  openDb,
-  rowToCampaign,
-  rowToEncounter,
-  rowToActiveDisplay,
-};
+module.exports = { openDb, parentOf, makeStore };
diff --git a/server/handlers.js b/server/handlers.js
deleted file mode 100644
index e40d138..0000000
--- a/server/handlers.js
+++ /dev/null
@@ -1,378 +0,0 @@
-// server/handlers.js — action → shared turn fn → tx persist → broadcast notify.
-// Server-authoritative. Client sends action; server computes result, persists, notifies subscribers.
-
-'use strict';
-
-const shared = require('@ttrpg/shared');
-const { buildCharacterParticipant, buildMonsterParticipant, generateId } = shared;
-
-// Create a store facade with all encounter/campaign mutations + a notify hook.
-// notify(change) fans out to WS subscribers. Caller wires it.
-function createStore(db, notify) {
-  // --- read helpers ---
-  function getCampaign(campaignId) {
-    const row = db.prepare('SELECT * FROM campaigns WHERE id = ?').get(campaignId);
-    return rowToCampaignLocal(row);
-  }
-  function getEncounter(campaignId, encounterId) {
-    const row = db.prepare('SELECT * FROM encounters WHERE campaignId = ? AND id = ?').get(campaignId, encounterId);
-    return rowToEncounterLocal(row);
-  }
-  function listEncounters(campaignId) {
-    return db.prepare('SELECT * FROM encounters WHERE campaignId = ? ORDER BY createdAt ASC').all(campaignId).map(rowToEncounterLocal);
-  }
-  function getActiveDisplay() {
-    const row = db.prepare('SELECT * FROM active_display WHERE id = 1').get();
-    return {
-      activeCampaignId: row.activeCampaignId,
-      activeEncounterId: row.activeEncounterId,
-      hidePlayerHp: !!row.hidePlayerHp,
-    };
-  }
-
-  // --- write helpers ---
-  function saveCampaign(c) {
-    db.prepare(`INSERT INTO campaigns (id, name, playerDisplayBackgroundUrl, ownerId, createdAt, players)
-                VALUES (@id, @name, @playerDisplayBackgroundUrl, @ownerId, @createdAt, @players)
-                ON CONFLICT(id) DO UPDATE SET
-                  name=@name, playerDisplayBackgroundUrl=@playerDisplayBackgroundUrl,
-                  ownerId=@ownerId, players=@players`)
-      .run({
-        id: c.id, name: c.name, playerDisplayBackgroundUrl: c.playerDisplayBackgroundUrl || '',
-        ownerId: c.ownerId || null, createdAt: c.createdAt, players: JSON.stringify(c.players || []),
-      });
-  }
-  function saveEncounter(e) {
-    db.prepare(`INSERT INTO encounters (id, campaignId, name, participants, round, currentTurnParticipantId, isStarted, isPaused, turnOrderIds, createdAt)
-                VALUES (@id, @campaignId, @name, @participants, @round, @currentTurnParticipantId, @isStarted, @isPaused, @turnOrderIds, @createdAt)
-                ON CONFLICT(campaignId, id) DO UPDATE SET
-                  name=@name, participants=@participants, round=@round,
-                  currentTurnParticipantId=@currentTurnParticipantId, isStarted=@isStarted,
-                  isPaused=@isPaused, turnOrderIds=@turnOrderIds`)
-      .run({
-        id: e.id, campaignId: e.campaignId, name: e.name, participants: JSON.stringify(e.participants || []),
-        round: e.round || 0, currentTurnParticipantId: e.currentTurnParticipantId || null,
-        isStarted: e.isStarted ? 1 : 0, isPaused: e.isPaused ? 1 : 0,
-        turnOrderIds: JSON.stringify(e.turnOrderIds || []), createdAt: e.createdAt,
-      });
-  }
-  function setActiveDisplay(patch) {
-    const cur = getActiveDisplay();
-    const next = { ...cur, ...patch };
-    db.prepare('UPDATE active_display SET activeCampaignId=?, activeEncounterId=?, hidePlayerHp=? WHERE id=1')
-      .run(next.activeCampaignId || null, next.activeEncounterId || null, next.hidePlayerHp ? 1 : 0);
-  }
-  function deleteEncounter(campaignId, encounterId) {
-    db.prepare('DELETE FROM encounters WHERE campaignId=? AND id=?').run(campaignId, encounterId);
-  }
-  function addLog(entry) {
-    if (!entry) return null;
-    const id = generateId();
-    db.prepare(`INSERT INTO logs (id, timestamp, message, encounterName, undo, undone)
-                VALUES (?, ?, ?, ?, ?, 0)`)
-      .run(id, Date.now(), entry.message, entry.encounterName || null,
-           entry.undo ? JSON.stringify(entry.undo) : null);
-    return id;
-  }
-
-  // --- apply patch from a shared turn fn ---
-  function applyEncounterPatch(campaignId, encounterId, patch) {
-    if (!patch) return null;
-    const e = getEncounter(campaignId, encounterId);
-    if (!e) throw new Error('Encounter not found.');
-    const updated = { ...e, ...patch };
-    saveEncounter(updated);
-    return updated;
-  }
-
-  // --- public store API: each action runs in a tx, returns result + notifies ---
-  const store = {
-    // --- reads ---
-    getCampaign,
-    getEncounter,
-    listEncounters,
-    getActiveDisplay,
-    listCampaigns() {
-      return db.prepare('SELECT * FROM campaigns ORDER BY createdAt ASC').all().map(rowToCampaignLocal);
-    },
-    listLogs(limit = 500) {
-      return db.prepare('SELECT * FROM logs ORDER BY timestamp DESC LIMIT ?').all(limit)
-        .map(r => ({
-          id: r.id, timestamp: r.timestamp, message: r.message,
-          encounterName: r.encounterName, undo: r.undo ? JSON.parse(r.undo) : null, undone: !!r.undone,
-        }));
-    },
-
-    // --- campaign mutations ---
-    createCampaign({ name, backgroundUrl, ownerId }) {
-      const c = {
-        id: generateId(), name: name.trim(), playerDisplayBackgroundUrl: (backgroundUrl || '').trim(),
-        ownerId, createdAt: new Date().toISOString(), players: [],
-      };
-      saveCampaign(c);
-      notify({ type: 'campaigns' });
-      return c;
-    },
-    deleteCampaign(campaignId) {
-      const tx = db.transaction(() => {
-        db.prepare('DELETE FROM encounters WHERE campaignId=?').run(campaignId);
-        db.prepare('DELETE FROM campaigns WHERE id=?').run(campaignId);
-        const ad = getActiveDisplay();
-        if (ad.activeCampaignId === campaignId) {
-          setActiveDisplay({ activeCampaignId: null, activeEncounterId: null });
-        }
-      });
-      tx();
-      notify({ type: 'campaigns' });
-      notify({ type: 'encounters', campaignId });
-      notify({ type: 'activeDisplay' });
-    },
-    addCampaignCharacter(campaignId, character) {
-      const c = getCampaign(campaignId);
-      if (!c) throw new Error('Campaign not found.');
-      const newChar = {
-        id: generateId(), name: character.name.trim(),
-        defaultMaxHp: parseInt(character.defaultMaxHp, 10) || 10,
-        defaultInitMod: parseInt(character.defaultInitMod, 10) || 0,
-      };
-      c.players = [...c.players, newChar];
-      saveCampaign(c);
-      notify({ type: 'campaign', campaignId });
-      return newChar;
-    },
-    updateCampaignCharacter(campaignId, characterId, data) {
-      const c = getCampaign(campaignId);
-      if (!c) throw new Error('Campaign not found.');
-      c.players = c.players.map(ch => ch.id === characterId
-        ? { ...ch, name: data.name.trim(), defaultMaxHp: parseInt(data.defaultMaxHp, 10) || 10, defaultInitMod: parseInt(data.defaultInitMod, 10) || 0 }
-        : ch);
-      saveCampaign(c);
-      notify({ type: 'campaign', campaignId });
-    },
-    deleteCampaignCharacter(campaignId, characterId) {
-      const c = getCampaign(campaignId);
-      if (!c) throw new Error('Campaign not found.');
-      c.players = c.players.filter(ch => ch.id !== characterId);
-      saveCampaign(c);
-      notify({ type: 'campaign', campaignId });
-    },
-
-    // --- encounter mutations ---
-    createEncounter(campaignId, name) {
-      const e = {
-        id: generateId(), campaignId, name: name.trim(),
-        participants: [], round: 0, currentTurnParticipantId: null,
-        isStarted: false, isPaused: false, turnOrderIds: [],
-        createdAt: new Date().toISOString(),
-      };
-      saveEncounter(e);
-      notify({ type: 'encounters', campaignId });
-      return e;
-    },
-    deleteEncounter(campaignId, encounterId) {
-      deleteEncounter(campaignId, encounterId);
-      const ad = getActiveDisplay();
-      if (ad.activeEncounterId === encounterId) {
-        setActiveDisplay({ activeCampaignId: null, activeEncounterId: null });
-      }
-      notify({ type: 'encounters', campaignId });
-      notify({ type: 'activeDisplay' });
-    },
-    togglePlayerDisplay(campaignId, encounterId) {
-      const ad = getActiveDisplay();
-      if (ad.activeCampaignId === campaignId && ad.activeEncounterId === encounterId) {
-        setActiveDisplay({ activeCampaignId: null, activeEncounterId: null });
-      } else {
-        setActiveDisplay({ activeCampaignId: campaignId, activeEncounterId: encounterId });
-      }
-      notify({ type: 'activeDisplay' });
-    },
-
-    // --- participant mutations (call shared turn fns) ---
-    addParticipant(campaignId, encounterId, { type, ...rest }) {
-      let built;
-      if (type === 'character') {
-        const c = getCampaign(rest.campaignId || campaignId);
-        const char = (c && c.players || []).find(ch => ch.id === rest.characterId);
-        if (!char) throw new Error('Character not found.');
-        const e = getEncounter(campaignId, encounterId);
-        if ((e.participants || []).some(p => p.type === 'character' && p.originalCharacterId === char.id)) {
-          throw new Error(`${char.name} already in encounter.`);
-        }
-        built = buildCharacterParticipant(char);
-      } else {
-        built = buildMonsterParticipant(rest);
-      }
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.addParticipant(e, built.participant);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return { encounter: updated, roll: built.roll };
-    },
-    addAllCampaignCharacters(campaignId, encounterId) {
-      const c = getCampaign(campaignId);
-      const e = getEncounter(campaignId, encounterId);
-      const existing = (e.participants || []).filter(p => p.type === 'character' && p.originalCharacterId).map(p => p.originalCharacterId);
-      const newParts = (c.players || []).filter(ch => !existing.includes(ch.id)).map(ch => buildCharacterParticipant(ch).participant);
-      const { patch } = shared.addParticipants(e, newParts);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      notify({ type: 'encounter', campaignId, encounterId });
-      return { encounter: updated, added: newParts.length };
-    },
-    updateParticipant(campaignId, encounterId, participantId, data) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch } = shared.updateParticipant(e, participantId, {
-        name: data.name.trim(),
-        initiative: parseInt(data.initiative, 10),
-        currentHp: parseInt(data.currentHp, 10),
-        maxHp: parseInt(data.maxHp, 10),
-        isNpc: data.isNpc || false,
-      });
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    removeParticipant(campaignId, encounterId, participantId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.removeParticipant(e, participantId);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    toggleParticipantActive(campaignId, encounterId, participantId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.toggleParticipantActive(e, participantId);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    applyHpChange(campaignId, encounterId, participantId, changeType, amount) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.applyHpChange(e, participantId, changeType, parseInt(amount, 10));
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      if (log) addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    deathSave(campaignId, encounterId, participantId, saveNumber) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, isDying } = shared.deathSave(e, participantId, saveNumber);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      notify({ type: 'encounter', campaignId, encounterId });
-      return { encounter: updated, isDying };
-    },
-    toggleCondition(campaignId, encounterId, participantId, conditionId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.toggleCondition(e, participantId, conditionId);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    reorderParticipants(campaignId, encounterId, draggedId, targetId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch } = shared.reorderParticipants(e, draggedId, targetId);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-
-    // --- combat controls (call shared turn fns) ---
-    startEncounter(campaignId, encounterId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.startEncounter(e);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      setActiveDisplay({ activeCampaignId: campaignId, activeEncounterId: encounterId });
-      notify({ type: 'encounter', campaignId, encounterId });
-      notify({ type: 'activeDisplay' });
-      return updated;
-    },
-    nextTurn(campaignId, encounterId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.nextTurn(e);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      if (log) addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    togglePause(campaignId, encounterId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.togglePause(e);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      notify({ type: 'encounter', campaignId, encounterId });
-      return updated;
-    },
-    endEncounter(campaignId, encounterId) {
-      const e = getEncounter(campaignId, encounterId);
-      const { patch, log } = shared.endEncounter(e);
-      const updated = applyEncounterPatch(campaignId, encounterId, patch);
-      addLog({ ...log, encounterName: e.name });
-      setActiveDisplay({ activeCampaignId: null, activeEncounterId: null });
-      notify({ type: 'encounter', campaignId, encounterId });
-      notify({ type: 'activeDisplay' });
-      return updated;
-    },
-
-    // --- display settings ---
-    toggleHidePlayerHp() {
-      const ad = getActiveDisplay();
-      setActiveDisplay({ hidePlayerHp: !ad.hidePlayerHp });
-      notify({ type: 'activeDisplay' });
-      return !ad.hidePlayerHp;
-    },
-
-    // --- logs ---
-    clearLogs() {
-      db.prepare('DELETE FROM logs').run();
-      notify({ type: 'logs' });
-    },
-    undoLog(logId) {
-      const entry = db.prepare('SELECT * FROM logs WHERE id=?').get(logId);
-      if (!entry) throw new Error('Log not found.');
-      if (entry.undone) throw new Error('Already undone.');
-      if (!entry.undo) throw new Error('No undo data.');
-      const undo = JSON.parse(entry.undo);
-      // Undo payload shape: { encounterPath, updates } (legacy) OR { updates } (ours)
-      const updates = undo.updates || undo;
-      // find encounter from message context if available; require campaignId/encounterId via payload
-      if (undo.encounterPath) {
-        // legacy firebase path — we can't resolve here. Caller must pass ids.
-        throw new Error('Legacy undo payload; requires campaignId/encounterId.');
-      }
-      db.prepare('UPDATE logs SET undone=1 WHERE id=?').run(logId);
-      notify({ type: 'logs' });
-      return undo;
-    },
-
-    // --- internals exposed for tests/handlers ---
-    _db: db,
-  };
-
-  // local row mappers (avoid circular import with db.js shape)
-  function rowToCampaignLocal(row) {
-    if (!row) return null;
-    return {
-      id: row.id, name: row.name, playerDisplayBackgroundUrl: row.playerDisplayBackgroundUrl,
-      ownerId: row.ownerId, createdAt: row.createdAt, players: row.players ? JSON.parse(row.players) : [],
-    };
-  }
-  function rowToEncounterLocal(row) {
-    if (!row) return null;
-    return {
-      id: row.id, campaignId: row.campaignId, name: row.name,
-      participants: row.participants ? JSON.parse(row.participants) : [],
-      round: row.round, currentTurnParticipantId: row.currentTurnParticipantId,
-      isStarted: !!row.isStarted, isPaused: !!row.isPaused,
-      turnOrderIds: row.turnOrderIds ? JSON.parse(row.turnOrderIds) : [], createdAt: row.createdAt,
-    };
-  }
-
-  return store;
-}
-
-module.exports = { createStore };
diff --git a/server/index.js b/server/index.js
index 8f2d09b..d79260d 100644
--- a/server/index.js
+++ b/server/index.js
@@ -1,19 +1,15 @@
-// server/index.js — Express (HTTP) + ws (WebSocket) bootstrap.
-// HTTP: REST-ish endpoints for actions. WS: real-time state push (replaces onSnapshot).
-//
-// Env:
-//   PORT (default 4001)
-//   DB_PATH (default ./data/tracker.sqlite)
-//   CORS_ORIGIN (default '*'; in-house only)
+// server/index.js — generic KV document store over HTTP + WebSocket.
+// firebase mirror: doc-tree model. Thin REST, path-based WS push.
+// Adapter (src/storage/ws.js) = passthrough, no shape translation.
 
 'use strict';
 
 const express = require('express');
 const cors = require('cors');
 const http = require('http');
+const crypto = require('crypto');
 const { WebSocketServer } = require('ws');
-const { openDb } = require('./db');
-const { createStore } = require('./handlers');
+const { openDb, makeStore } = require('./db');
 
 function createServer({ dbPath, port, corsOrigin } = {}) {
   const db = openDb(dbPath || './data/tracker.sqlite');
@@ -21,144 +17,98 @@ function createServer({ dbPath, port, corsOrigin } = {}) {
   app.use(cors({ origin: corsOrigin || '*' }));
   app.use(express.json({ limit: '1mb' }));
 
-  // WS subscribers. Map: key -> Set<ws>. key = 'campaigns' | 'campaign:id' | etc.
-  const subscribers = new Map();
-  function subscribe(key, ws) {
-    if (!subscribers.has(key)) subscribers.set(key, new Set());
-    subscribers.get(key).add(ws);
+  // WS subscribers: path -> Set<ws>.
+  // Subscribers register a path (doc or collection). On change, notify:
+  //   - doc subscribers at the changed path
+  //   - collection subscribers at the changed doc's parent path
+  const docSubscribers = new Map();      // path -> Set<ws>
+  const collSubscribers = new Map();     // collPath -> Set<ws>
+
+  function addSub(map, key, ws) {
+    if (!map.has(key)) map.set(key, new Set());
+    map.get(key).add(ws);
   }
-  function unsubscribe(key, ws) {
-    const set = subscribers.get(key);
-    if (set) { set.delete(ws); if (set.size === 0) subscribers.delete(key); }
+  function removeSub(map, key, ws) {
+    const set = map.get(key);
+    if (set) { set.delete(ws); if (set.size === 0) map.delete(key); }
   }
+  function dropWs(ws) {
+    for (const [key, set] of docSubscribers) { set.delete(ws); if (set.size === 0) docSubscribers.delete(key); }
+    for (const [key, set] of collSubscribers) { set.delete(ws); if (set.size === 0) collSubscribers.delete(key); }
+  }
+
   function broadcast(change) {
-    const set = subscribers.get(change.type) || new Set();
-    // 'encounter'/'campaign' changes also notify bare type subscribers.
-    [...set].forEach(ws => { if (ws.readyState === ws.OPEN) ws.send(JSON.stringify({ type: 'change', change })); });
+    const payload = JSON.stringify({ type: 'change', change });
+    // doc subscriber at exact path
+    const docSet = docSubscribers.get(change.path);
+    if (docSet) [...docSet].forEach(ws => ws.readyState === ws.OPEN && ws.send(payload));
+    // collection subscribers at parent path (collection contains this doc)
+    if (change.parent) {
+      const collSet = collSubscribers.get(change.parent);
+      if (collSet) [...collSet].forEach(ws => ws.readyState === ws.OPEN && ws.send(payload));
+    }
   }
 
-  const store = createStore(db, broadcast);
+  const store = makeStore(db, broadcast);
+
+  // --- generic REST ---
 
-  // --- REST read endpoints ---
   app.get('/health', (req, res) => res.json({ ok: true }));
-  app.get('/api/campaigns', (req, res) => res.json(store.listCampaigns()));
-  app.get('/api/campaigns/:campaignId', (req, res) => {
-    const c = store.getCampaign(req.params.campaignId);
-    if (!c) return res.status(404).json({ error: 'Not found' });
-    res.json(c);
-  });
-  app.get('/api/campaigns/:campaignId/encounters', (req, res) => res.json(store.listEncounters(req.params.campaignId)));
-  app.get('/api/campaigns/:campaignId/encounters/:encounterId', (req, res) => {
-    const e = store.getEncounter(req.params.campaignId, req.params.encounterId);
-    if (!e) return res.status(404).json({ error: 'Not found' });
-    res.json(e);
-  });
-  app.get('/api/activeDisplay', (req, res) => res.json(store.getActiveDisplay()));
-  app.get('/api/logs', (req, res) => res.json(store.listLogs(parseInt(req.query.limit, 10) || 500)));
 
-  // --- campaign mutations ---
-  app.post('/api/campaigns', (req, res) => {
-    try { res.json(store.createCampaign(req.body)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.delete('/api/campaigns/:campaignId', (req, res) => {
-    try { store.deleteCampaign(req.params.campaignId); res.json({ ok: true }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/characters', (req, res) => {
-    try { res.json(store.addCampaignCharacter(req.params.campaignId, req.body)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.put('/api/campaigns/:campaignId/characters/:characterId', (req, res) => {
-    try { store.updateCampaignCharacter(req.params.campaignId, req.params.characterId, req.body); res.json({ ok: true }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.delete('/api/campaigns/:campaignId/characters/:characterId', (req, res) => {
-    try { store.deleteCampaignCharacter(req.params.campaignId, req.params.characterId); res.json({ ok: true }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
+  // GET /api/doc?path=campaigns/abc/encounters/xyz
+  app.get('/api/doc', (req, res) => {
+    const { path: p } = req.query;
+    if (!p) return res.status(400).json({ error: 'path required' });
+    res.json({ path: p, data: store.getDoc(p) });
   });
 
-  // --- encounter mutations ---
-  app.post('/api/campaigns/:campaignId/encounters', (req, res) => {
-    try { res.json(store.createEncounter(req.params.campaignId, req.body.name)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.delete('/api/campaigns/:campaignId/encounters/:encounterId', (req, res) => {
-    try { store.deleteEncounter(req.params.campaignId, req.params.encounterId); res.json({ ok: true }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/display', (req, res) => {
-    try { store.togglePlayerDisplay(req.params.campaignId, req.params.encounterId); res.json({ ok: true }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
+  // GET /api/collection?path=campaigns/abc/encounters
+  app.get('/api/collection', (req, res) => {
+    const { path: p } = req.query;
+    if (!p) return res.status(400).json({ error: 'path required' });
+    res.json(store.getCollection(p));
   });
 
-  // --- participant mutations ---
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/participants', (req, res) => {
-    try { res.json(store.addParticipant(req.params.campaignId, req.params.encounterId, req.body)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/participants/addAll', (req, res) => {
-    try { res.json(store.addAllCampaignCharacters(req.params.campaignId, req.params.encounterId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.put('/api/campaigns/:campaignId/encounters/:encounterId/participants/:participantId', (req, res) => {
-    try { res.json(store.updateParticipant(req.params.campaignId, req.params.encounterId, req.params.participantId, req.body)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.delete('/api/campaigns/:campaignId/encounters/:encounterId/participants/:participantId', (req, res) => {
-    try { res.json(store.removeParticipant(req.params.campaignId, req.params.encounterId, req.params.participantId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/participants/:participantId/active', (req, res) => {
-    try { res.json(store.toggleParticipantActive(req.params.campaignId, req.params.encounterId, req.params.participantId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/participants/:participantId/hp', (req, res) => {
-    try { res.json(store.applyHpChange(req.params.campaignId, req.params.encounterId, req.params.participantId, req.body.changeType, req.body.amount)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/participants/:participantId/deathSave', (req, res) => {
-    try { res.json(store.deathSave(req.params.campaignId, req.params.encounterId, req.params.participantId, req.body.saveNumber)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/participants/:participantId/condition', (req, res) => {
-    try { res.json(store.toggleCondition(req.params.campaignId, req.params.encounterId, req.params.participantId, req.body.conditionId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/reorder', (req, res) => {
-    try { res.json(store.reorderParticipants(req.params.campaignId, req.params.encounterId, req.body.draggedId, req.body.targetId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
+  // PUT /api/doc  body: { path, data }   (replace)
+  app.put('/api/doc', (req, res) => {
+    const { path: p, data } = req.body || {};
+    if (!p) return res.status(400).json({ error: 'path required' });
+    res.json({ path: p, data: store.setDoc(p, data) });
   });
 
-  // --- combat controls ---
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/start', (req, res) => {
-    try { res.json(store.startEncounter(req.params.campaignId, req.params.encounterId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/nextTurn', (req, res) => {
-    try { res.json(store.nextTurn(req.params.campaignId, req.params.encounterId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/pause', (req, res) => {
-    try { res.json(store.togglePause(req.params.campaignId, req.params.encounterId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.post('/api/campaigns/:campaignId/encounters/:encounterId/end', (req, res) => {
-    try { res.json(store.endEncounter(req.params.campaignId, req.params.encounterId)); }
-    catch (err) { res.status(400).json({ error: err.message }); }
+  // PATCH /api/doc  body: { path, patch }   (shallow merge, create-on-miss)
+  app.patch('/api/doc', (req, res) => {
+    const { path: p, patch } = req.body || {};
+    if (!p) return res.status(400).json({ error: 'path required' });
+    res.json({ path: p, data: store.updateDoc(p, patch) });
   });
 
-  // --- display + logs ---
-  app.post('/api/activeDisplay/hidePlayerHp', (req, res) => {
-    try { res.json({ hidePlayerHp: store.toggleHidePlayerHp() }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
-  });
-  app.delete('/api/logs', (req, res) => {
-    try { store.clearLogs(); res.json({ ok: true }); }
-    catch (err) { res.status(400).json({ error: err.message }); }
+  // DELETE /api/doc?path=...
+  app.delete('/api/doc', (req, res) => {
+    const { path: p } = req.query;
+    if (!p) return res.status(400).json({ error: 'path required' });
+    store.deleteDoc(p);
+    res.json({ ok: true });
   });
 
-  // --- WebSocket: real-time push ---
+  // POST /api/collection  body: { path, data }  (addDoc: auto-id under collection)
+  app.post('/api/collection', (req, res) => {
+    const { path: collPath, data } = req.body || {};
+    if (!collPath) return res.status(400).json({ error: 'path required' });
+    const id = crypto.randomUUID();
+    const docPath = `${collPath}/${id}`;
+    res.json({ id, path: docPath, data: store.setDoc(docPath, data) });
+  });
+
+  // POST /api/batch  body: { ops: [{type:'set'|'update'|'delete', path, data?}] }
+  app.post('/api/batch', (req, res) => {
+    const { ops } = req.body || {};
+    if (!Array.isArray(ops)) return res.status(400).json({ error: 'ops array required' });
+    store.batchWrite(ops);
+    res.json({ ok: true });
+  });
+
+  // --- WebSocket: subscribe by path ---
   const server = http.createServer(app);
   const wss = new WebSocketServer({ server, path: '/ws' });
 
@@ -166,16 +116,16 @@ function createServer({ dbPath, port, corsOrigin } = {}) {
     ws.on('message', (raw) => {
       let msg;
       try { msg = JSON.parse(raw.toString()); } catch { ws.send(JSON.stringify({ type: 'error', error: 'bad json' })); return; }
-      if (msg.type === 'subscribe' && msg.key) {
-        subscribe(msg.key, ws);
-        ws.send(JSON.stringify({ type: 'subscribed', key: msg.key }));
-      } else if (msg.type === 'unsubscribe' && msg.key) {
-        unsubscribe(msg.key, ws);
+      if (msg.type === 'subscribe' && msg.path) {
+        if (msg.kind === 'collection') addSub(collSubscribers, msg.path, ws);
+        else addSub(docSubscribers, msg.path, ws);
+        ws.send(JSON.stringify({ type: 'subscribed', path: msg.path, kind: msg.kind || 'doc' }));
+      } else if (msg.type === 'unsubscribe' && msg.path) {
+        if (msg.kind === 'collection') removeSub(collSubscribers, msg.path, ws);
+        else removeSub(docSubscribers, msg.path, ws);
       }
     });
-    ws.on('close', () => {
-      for (const [key, set] of subscribers) { set.delete(ws); if (set.size === 0) subscribers.delete(key); }
-    });
+    ws.on('close', () => dropWs(ws));
     ws.on('error', () => {});
   });
 
diff --git a/server/server.test.js b/server/server.test.js
deleted file mode 100644
index 3ff315a..0000000
--- a/server/server.test.js
+++ /dev/null
@@ -1,113 +0,0 @@
-// Integration smoke for server. Spin on random port, hit REST, check WS broadcast.
-'use strict';
-
-const http = require('http');
-const { createServer } = require('./index');
-
-let BASE;
-let handle;
-
-beforeEach(async () => {
-  handle = createServer({ dbPath: ':memory:' });
-  await new Promise(r => handle.server.listen(0, r));
-  const addr = handle.server.address();
-  BASE = `http://127.0.0.1:${addr.port}`;
-});
-afterEach(async () => {
-  await new Promise(r => handle.close(r));
-});
-
-async function req(method, path, body) {
-  const res = await fetch(`${BASE}${path}`, {
-    method,
-    headers: body ? { 'Content-Type': 'application/json' } : undefined,
-    body: body ? JSON.stringify(body) : undefined,
-  });
-  const text = await res.text();
-  const json = text ? JSON.parse(text) : null;
-  return { status: res.status, json };
-}
-
-describe('server REST', () => {
-  test('health', async () => {
-    const { status, json } = await req('GET', '/health');
-    expect(status).toBe(200);
-    expect(json.ok).toBe(true);
-  });
-
-  test('campaign create + list', async () => {
-    const { json: c } = await req('POST', '/api/campaigns', { name: 'Test', backgroundUrl: '' });
-    expect(c.name).toBe('Test');
-    const { json: list } = await req('GET', '/api/campaigns');
-    expect(list).toHaveLength(1);
-    expect(list[0].id).toBe(c.id);
-  });
-
-  test('encounter create + add monster + start', async () => {
-    const { json: c } = await req('POST', '/api/campaigns', { name: 'C' });
-    const { json: e } = await req('POST', `/api/campaigns/${c.id}/encounters`, { name: 'E' });
-    expect(e.participants).toEqual([]);
-
-    const { json: addRes } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/participants`, {
-      type: 'monster', name: 'Goblin', maxHp: 7, initMod: 2, isNpc: false,
-    });
-    expect(addRes.encounter.participants).toHaveLength(1);
-    expect(addRes.encounter.participants[0].name).toBe('Goblin');
-    expect(addRes.roll.total).toBeGreaterThan(2);
-
-    const { json: started } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/start`);
-    expect(started.isStarted).toBe(true);
-    expect(started.round).toBe(1);
-    expect(started.currentTurnParticipantId).toBe(addRes.encounter.participants[0].id);
-  });
-
-  test('next turn advances', async () => {
-    const { json: c } = await req('POST', '/api/campaigns', { name: 'C' });
-    const { json: e } = await req('POST', `/api/campaigns/${c.id}/encounters`, { name: 'E' });
-    const ids = [];
-    for (let i = 0; i < 3; i++) {
-      const { json: r } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/participants`, {
-        type: 'monster', name: `M${i}`, maxHp: 10, initMod: i,
-      });
-      ids.push(r.encounter.participants[r.encounter.participants.length - 1].id);
-    }
-    await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/start`);
-    const { json: t1 } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/nextTurn`);
-    expect(t1.currentTurnParticipantId).not.toBe(t1.turnOrderIds[0]);
-  });
-
-  test('damage to 0 deactivates', async () => {
-    const { json: c } = await req('POST', '/api/campaigns', { name: 'C' });
-    const { json: e } = await req('POST', `/api/campaigns/${c.id}/encounters`, { name: 'E' });
-    const { json: r } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/participants`, {
-      type: 'monster', name: 'Orc', maxHp: 5, initMod: 0,
-    });
-    const pid = r.encounter.participants[0].id;
-    await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/start`);
-    const { json: after } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/participants/${pid}/hp`, {
-      changeType: 'damage', amount: 5,
-    });
-    expect(after.participants[0].currentHp).toBe(0);
-    expect(after.participants[0].isActive).toBe(false);
-  });
-
-  test('error: start with no participants', async () => {
-    const { json: c } = await req('POST', '/api/campaigns', { name: 'C' });
-    const { json: e } = await req('POST', `/api/campaigns/${c.id}/encounters`, { name: 'E' });
-    const { status, json } = await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/start`);
-    expect(status).toBe(400);
-    expect(json.error).toMatch(/participants/i);
-  });
-
-  test('logs recorded on actions', async () => {
-    const { json: c } = await req('POST', '/api/campaigns', { name: 'C' });
-    const { json: e } = await req('POST', `/api/campaigns/${c.id}/encounters`, { name: 'E' });
-    await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/participants`, {
-      type: 'monster', name: 'Goblin', maxHp: 7, initMod: 2,
-    });
-    await req('POST', `/api/campaigns/${c.id}/encounters/${e.id}/start`);
-    const { json: logs } = await req('GET', '/api/logs');
-    expect(logs.length).toBeGreaterThanOrEqual(2);
-    expect(logs.some(l => /Combat started/.test(l.message))).toBe(true);
-  });
-});
diff --git a/server/ws-contract.test.js b/server/ws-contract.test.js
new file mode 100644
index 0000000..6ad9c13
--- /dev/null
+++ b/server/ws-contract.test.js
@@ -0,0 +1,36 @@
+// Layer 2 test: exercise ws.js storage adapter against a LIVE backend.
+// Complements Layer 1 (App + firebase mock) which proves App call shape but
+// never touches ws.js. This catches translation bugs in the adapter.
+//
+// Runs the shared storage contract (same spec memory/firebase satisfy) against
+// createWsStorage pointed at an ephemeral backend instance. A FRESH backend is
+// spun up per test to guarantee isolation (backend has no reset endpoint yet).
+
+'use strict';
+
+const path = require('path');
+const os = require('os');
+const { createServer } = require('../server/index');
+const { createWsStorage } = require('../src/storage/ws');
+const { runStorageContract } = require('../src/storage/contract');
+
+let nextPort = 4000 + Math.floor(Math.random() * 999);
+
+// Factory: fresh backend (unique sqlite file) + storage pointed at it.
+// Disposing the storage closes the backend so each test is fully isolated.
+async function makeStorage() {
+  const port = nextPort++;
+  const dbPath = path.join(os.tmpdir(), `ws-contract-${port}-${Date.now()}.sqlite`);
+  const handle = createServer({ dbPath, port });
+  await new Promise((resolve, reject) => {
+    handle.server.on('error', reject);
+    handle.server.listen(port, resolve);
+  });
+  const baseUrl = `http://127.0.0.1:${port}`;
+  const wsUrl = `ws://127.0.0.1:${port}/ws`;
+  const storage = createWsStorage({ baseUrl, wsUrl });
+  storage.dispose = (done) => handle.close(done);
+  return storage;
+}
+
+runStorageContract('ws (live backend)', makeStorage);
diff --git a/src/storage/contract.js b/src/storage/contract.js
index b05ef48..8e76bcd 100644
--- a/src/storage/contract.js
+++ b/src/storage/contract.js
@@ -191,9 +191,10 @@ function runStorageContract(name, factory) {
   });
 }
 
-// microtask flush so async subscribers settle.
+// flush so async subscribers settle. WS roundtrip needs real delay (network),
+// memory fires near-instant. 50ms covers localhost WS comfortably.
 function flush() {
-  return new Promise((resolve) => setTimeout(resolve, 0));
+  return new Promise((resolve) => setTimeout(resolve, 50));
 }
 
 module.exports = { runStorageContract, flush };
diff --git a/src/storage/ws.js b/src/storage/ws.js
index 92b8b35..712e741 100644
--- a/src/storage/ws.js
+++ b/src/storage/ws.js
@@ -1,15 +1,14 @@
-// ws.js — storage adapter talking to backend over REST + WebSocket.
+// ws.js — thin storage adapter over generic KV backend (HTTP + WebSocket).
+// Passthrough: no shape translation. Backend = firebase mirror.
 // Implements same interface as memory.js. Tested by storage contract vs running server.
 
 'use strict';
 
-// Use native browser WebSocket when available (production). Fallback to the
-// `ws` npm package in Node/jest where global WebSocket is absent.
+// Native browser WebSocket if present, else ws pkg (Node/jest).
 let WebSocketImpl;
 if (typeof WebSocket !== 'undefined') {
   WebSocketImpl = WebSocket;
 } else {
-  // require inside else so webpack ignores it in browser bundle
   WebSocketImpl = require('ws').WebSocket;
 }
 
@@ -17,9 +16,10 @@ function createWsStorage({ baseUrl, wsUrl } = {}) {
   const API = (baseUrl || 'http://127.0.0.1:4001').replace(/\/$/, '');
   const WS = wsUrl || (API.replace(/^http/, 'ws') + '/ws');
 
-  // App.js passes firebase-prefixed paths: artifacts/{APP_ID}/public/data/campaigns/...
-  // Backend uses canonical: campaigns/... Strip the prefix so all matchers work.
+  // App passes firebase-prefixed paths: artifacts/{APP_ID}/public/data/campaigns/...
+  // Backend uses canonical paths. Strip prefix.
   function norm(p) {
+    if (!p) return p;
     return p.replace(/^[\s\S]*\/public\/data\//, '');
   }
 
@@ -27,13 +27,11 @@ function createWsStorage({ baseUrl, wsUrl } = {}) {
   const collSubs = new Map();     // collPath -> Set<cb>
   let ws = null;
   let wsReady = null;
-  const pendingPaths = new Set();
 
   function ensureWs() {
     if (wsReady) return wsReady;
     wsReady = new Promise((resolve, reject) => {
       ws = new WebSocketImpl(WS);
-      // addEventListener works on both browser WebSocket and Node ws pkg.
       const onOpen = () => resolve(ws);
       const onError = (err) => { wsReady = null; reject(err instanceof Event ? new Error('ws error') : err); };
       const onClose = () => { wsReady = null; };
@@ -42,12 +40,10 @@ function createWsStorage({ baseUrl, wsUrl } = {}) {
         let msg; try { msg = JSON.parse(typeof raw === 'string' ? raw : raw.toString()); } catch { return; }
         handleMessage(msg);
       };
-      // browser-style property handlers
       ws.onopen = onOpen;
       ws.onerror = onError;
       ws.onclose = onClose;
       ws.onmessage = onMessage;
-      // Node ws-style addEventListener fallback (noop in browser if absent)
       if (typeof ws.addEventListener === 'function') {
         ws.addEventListener('open', onOpen);
         ws.addEventListener('error', onError);
@@ -58,47 +54,33 @@ function createWsStorage({ baseUrl, wsUrl } = {}) {
     return wsReady;
   }
 
-  // Backend pushes change notices (coarse: type-based). We re-fetch affected paths.
+  // Backend pushes change notices keyed by path. Re-fetch affected subscribers.
   async function handleMessage(msg) {
     if (msg.type !== 'change' || !msg.change) return;
     const c = msg.change;
-    // Notify doc subscribers whose normalized path we cached.
-    for (const [rawPath, cbs] of docSubs) {
-      const path = norm(rawPath);
-      if (pathMatchesChange(path, c)) {
-        const doc = await storage.getDoc(path);
-        cbs.forEach(cb => cb(doc));
-      }
+    // doc subscriber at exact changed path
+    const docCbs = docSubs.get(c.path);
+    if (docCbs) {
+      const doc = await storage.getDoc(c.path);
+      docCbs.forEach(cb => cb(doc));
     }
-    for (const [rawCollPath, cbs] of collSubs) {
-      const collPath = norm(rawCollPath);
-      if (collMatchesChange(collPath, c)) {
-        const docs = await storage.getCollection(collPath);
-        cbs.forEach(cb => cb(docs));
+    // collection subscribers at parent path (doc belongs to this collection)
+    if (c.parent) {
+      const collCbs = collSubs.get(c.parent);
+      if (collCbs) {
+        const docs = await storage.getCollection(c.parent);
+        collCbs.forEach(cb => cb(docs));
       }
     }
   }
 
-  function pathMatchesChange(path, c) {
-    // Naive: campaign doc path includes campaignId; encounter doc includes encounterId.
-    if (c.type === 'campaign' && c.campaignId && path === docPathForCampaign(c.campaignId)) return true;
-    if (c.type === 'encounter' && c.campaignId && c.encounterId && path === docPathForEncounter(c.campaignId, c.encounterId)) return true;
-    if (c.type === 'activeDisplay' && path === 'activeDisplay/status') return true;
-    return false;
-  }
-  function collMatchesChange(collPath, c) {
-    if (c.type === 'campaigns' && collPath === 'campaigns') return true;
-    if (c.type === 'encounters' && c.campaignId && collPath === `campaigns/${c.campaignId}/encounters`) return true;
-    if (c.type === 'logs' && collPath === 'logs') return true;
-    return false;
-  }
-
-  // Backend uses different shape (rows) than firebase docs. We adapt to doc model.
-  // To keep contract passing + match App.js expectations, we expose docs at canonical paths
-  // AND translate backend REST responses into doc-shaped data.
-
-  async function api(method, path, body) {
-    const res = await fetch(`${API}${path}`, {
+  async function api(method, path, query, body) {
+    let url = `${API}${path}`;
+    if (query) {
+      const qs = new URLSearchParams(query).toString();
+      url += `?${qs}`;
+    }
+    const res = await fetch(url, {
       method,
       headers: body ? { 'Content-Type': 'application/json' } : undefined,
       body: body ? JSON.stringify(body) : undefined,
@@ -112,134 +94,67 @@ function createWsStorage({ baseUrl, wsUrl } = {}) {
   }
 
   const storage = {
-    // --- reads ---
     async getDoc(rawPath) {
-      const path = norm(rawPath);
-      if (path === 'activeDisplay/status') {
-        const ad = await api('GET', '/api/activeDisplay');
-        return ad;
-      }
-      const m = path.match(/^campaigns\/([^/]+)$/);
-      if (m) {
-        const c = await api('GET', `/api/campaigns/${m[1]}`);
-        return c || null;
-      }
-      const em = path.match(/^campaigns\/([^/]+)\/encounters\/([^/]+)$/);
-      if (em) {
-        const e = await api('GET', `/api/campaigns/${em[1]}/encounters/${em[2]}`);
-        return e || null;
-      }
-      return null;
+      const p = norm(rawPath);
+      const res = await api('GET', '/api/doc', { path: p });
+      return res && res.data !== undefined ? res.data : null;
     },
 
-    async getCollection(rawCollPath) {
-      const collPath = norm(rawCollPath);
-      if (collPath === 'campaigns') return await api('GET', '/api/campaigns');
-      const m = collPath.match(/^campaigns\/([^/]+)\/encounters$/);
-      if (m) return await api('GET', `/api/campaigns/${m[1]}/encounters`);
-      if (collPath === 'logs') return await api('GET', '/api/logs');
-      return [];
-    },
-
-    // --- writes (translated to backend action endpoints) ---
     async setDoc(rawPath, data) {
-      const path = norm(rawPath);
-      // activeDisplay merges
-      if (path === 'activeDisplay/status') {
-        if ('activeCampaignId' in data || 'activeEncounterId' in data) {
-          await api('POST', `/api/campaigns/${data.activeCampaignId}/encounters/${data.activeEncounterId}/display`).catch(() => {});
-        }
-        if ('hidePlayerHp' in data) {
-          await api('POST', '/api/activeDisplay/hidePlayerHp').catch(() => {});
-        }
-        return;
-      }
-      const cm = path.match(/^campaigns\/([^/]+)$/);
-      if (cm) {
-        // create or replace campaign
-        await api('POST', '/api/campaigns', { name: data.name, backgroundUrl: data.playerDisplayBackgroundUrl, ownerId: data.ownerId });
-        return;
-      }
-      const em = path.match(/^campaigns\/([^/]+)\/encounters\/([^/]+)$/);
-      if (em) {
-        await api('POST', `/api/campaigns/${em[1]}/encounters`, { name: data.name });
-        return;
-      }
+      const p = norm(rawPath);
+      await api('PUT', '/api/doc', null, { path: p, data });
     },
 
     async updateDoc(rawPath, patch) {
-      const path = norm(rawPath);
-      const cm = path.match(/^campaigns\/([^/]+)$/);
-      if (cm) {
-        if (Array.isArray(patch.players)) {
-          // players array is full replacement of character roster
-          // backend has dedicated char endpoints; for bulk we just set via direct if needed.
-          // For now: no-op bulk (App.js uses add/update/delete char endpoints individually upstream)
-          return;
-        }
-        return;
-      }
-      const em = path.match(/^campaigns\/([^/]+)\/encounters\/([^/]+)$/);
-      if (em) {
-        const [campaignId, encounterId] = [em[1], em[2]];
-        // participants array patch = full replace. Map to per-participant ops is complex;
-        // backend owns participants via dedicated endpoints, so direct array replace unsupported here.
-        // Most App.js writes go through dedicated endpoints; this path mainly used by drag-drop reorder.
-        if (patch.participants && patch.dragInfo) {
-          await api('POST', `/api/campaigns/${campaignId}/encounters/${encounterId}/reorder`, patch.dragInfo);
-        }
-        return;
-      }
+      const p = norm(rawPath);
+      await api('PATCH', '/api/doc', null, { path: p, patch });
     },
 
     async deleteDoc(rawPath) {
-      const path = norm(rawPath);
-      const cm = path.match(/^campaigns\/([^/]+)$/);
-      if (cm) { await api('DELETE', `/api/campaigns/${cm[1]}`); return; }
-      const em = path.match(/^campaigns\/([^/]+)\/encounters\/([^/]+)$/);
-      if (em) { await api('DELETE', `/api/campaigns/${em[1]}/encounters/${em[2]}`); return; }
+      const p = norm(rawPath);
+      await api('DELETE', '/api/doc', { path: p });
     },
 
     async addDoc(rawCollPath, data) {
-      const collPath = norm(rawCollPath);
-      if (collPath === 'logs') {
-        // backend auto-logs; direct insert not needed
-        return { id: 'auto', path: 'logs/auto' };
-      }
-      return { id: 'unsupported', path: collPath + '/unsupported' };
+      const p = norm(rawCollPath);
+      const res = await api('POST', '/api/collection', null, { path: p, data });
+      return { id: res.id, path: res.path };
+    },
+
+    async getCollection(rawCollPath) {
+      const p = norm(rawCollPath);
+      return await api('GET', '/api/collection', { path: p });
     },
 
     async batchWrite(ops) {
-      for (const op of ops) {
-        if (op.type === 'set') await storage.setDoc(op.path, op.data);
-        else if (op.type === 'delete') await storage.deleteDoc(op.path);
-      }
+      const normOps = ops.map(op => ({ ...op, path: norm(op.path) }));
+      await api('POST', '/api/batch', null, { ops: normOps });
     },
 
     subscribeDoc(rawPath, cb) {
-      const path = norm(rawPath);
+      const p = norm(rawPath);
+      // Initial value via REST (independent of WS connect).
+      storage.getDoc(p).then(cb).catch(() => {});
+      // WS only for subsequent change notifications.
       ensureWs().then(() => {
-        // subscribe to coarse change types that could affect this path
-        const types = changeTypesForDocPath(path);
-        types.forEach(t => ws.send(JSON.stringify({ type: 'subscribe', key: t })));
-        // fire current
-        storage.getDoc(path).then(cb).catch(() => {});
+        ws.send(JSON.stringify({ type: 'subscribe', kind: 'doc', path: p }));
       }).catch(() => {});
-      if (!docSubs.has(path)) docSubs.set(path, new Set());
-      docSubs.get(path).add(cb);
-      return () => { docSubs.get(path)?.delete(cb); };
+      if (!docSubs.has(p)) docSubs.set(p, new Set());
+      docSubs.get(p).add(cb);
+      return () => { docSubs.get(p)?.delete(cb); };
     },
 
     subscribeCollection(rawCollPath, cb) {
-      const collPath = norm(rawCollPath);
+      const p = norm(rawCollPath);
+      // Initial value via REST (independent of WS connect).
+      storage.getCollection(p).then(cb).catch(() => {});
+      // WS only for subsequent change notifications.
       ensureWs().then(() => {
-        const types = changeTypesForCollPath(collPath);
-        types.forEach(t => ws.send(JSON.stringify({ type: 'subscribe', key: t })));
-        storage.getCollection(collPath).then(cb).catch(() => {});
+        ws.send(JSON.stringify({ type: 'subscribe', kind: 'collection', path: p }));
       }).catch(() => {});
-      if (!collSubs.has(collPath)) collSubs.set(collPath, new Set());
-      collSubs.get(collPath).add(cb);
-      return () => { collSubs.get(collPath)?.delete(cb); };
+      if (!collSubs.has(p)) collSubs.set(p, new Set());
+      collSubs.get(p).add(cb);
+      return () => { collSubs.get(p)?.delete(cb); };
     },
 
     dispose() { if (ws) ws.close(); docSubs.clear(); collSubs.clear(); },
@@ -250,21 +165,4 @@ function createWsStorage({ baseUrl, wsUrl } = {}) {
   return storage;
 }
 
-function changeTypesForDocPath(rawPath) {
-  const path = rawPath.replace(/^[\s\S]*\/public\/data\//, '');
-  if (path === 'activeDisplay/status') return ['activeDisplay'];
-  if (path.match(/^campaigns\/[^/]+\/encounters\//)) return ['encounter', 'activeDisplay'];
-  if (path.match(/^campaigns\//)) return ['campaign', 'campaigns'];
-  return [];
-}
-function changeTypesForCollPath(rawCollPath) {
-  const collPath = rawCollPath.replace(/^[\s\S]*\/public\/data\//, '');
-  if (collPath === 'campaigns') return ['campaigns'];
-  if (collPath.match(/^campaigns\/[^/]+\/encounters$/)) return ['encounters'];
-  if (collPath === 'logs') return ['logs'];
-  return [];
-}
-function docPathForCampaign(id) { return `campaigns/${id}`; }
-function docPathForEncounter(campaignId, encounterId) { return `campaigns/${campaignId}/encounters/${encounterId}`; }
-
 module.exports = { createWsStorage };