diff --git a/abi.js b/abi.js
index 4e758b1..129b815 100644
--- a/abi.js
+++ b/abi.js
@@ -1,3 +1,9 @@
+import {readFile} from './misc.js'
+import {ethers} from "ethers";
+
+const ABI_BASE_PATH = '../contract/out'
+
+
 export const erc20Abi = [
     'function name() view returns (string)',
     'function symbol() view returns (string)',
@@ -26,6 +32,7 @@ const TimedOrderSpec = '(' +
     'bool amountIsInput' +
     ')'
 
+
 export const timedOrderAbi = [
     'event TimedOrderCreated (address owner, uint64 index, Spec spec)',
     'event TimedOrderFilled (address owner, uint64 index, uint256 amountIn, uint256 amountOut)',
@@ -35,8 +42,31 @@ export const timedOrderAbi = [
 ]
 
 
+const vaultDeployerAbi = [
+    'function deployVault(address owner) returns (address vault)',
+    'event VaultCreated( address deployer, address owner )',
+]
+
+
 export const abi = {
     'ERC20': erc20Abi,
     'TimedOrder': timedOrderAbi,
+    'VaultDeployer': vaultDeployerAbi,
 }
 
+
+export async function getAbi(className) {
+    let found = abi[className]
+    if (found === undefined) {
+        console.log('warning: loading ABI from filesystem for '+className)
+        const data = await readFile(ABI_BASE_PATH + `/${className}.sol/${className}.json`)
+        found = JSON.parse(data.toString())['abi']
+        abi[className] = found
+    }
+    return found
+}
+
+
+export async function getInterface(className) {
+    return new ethers.Interface(await getAbi(className))
+}
diff --git a/blockchain.js b/blockchain.js
index ac35fd6..c49249a 100644
--- a/blockchain.js
+++ b/blockchain.js
@@ -1,15 +1,22 @@
 import {ethers} from "ethers";
 
-const providers = {} // indexed by chain id
+export const chains = {}
 
+const _chainInfo = [
+    {id:42161, name:'Arbitrum'},
+]
+for( const chain of _chainInfo )
+    chains[chain.id] = chain
+
+const providers = {} // indexed by chain id
 
 export function getProvider(chainId) {
     let result = providers[chainId]
     if( result === undefined ) {
-        const rpc_url = process.env['DEXORDER_RPC_URL_'+chainId]
+        let rpc_url = process.env['DEXORDER_RPC_URL_'+chainId]
         if( rpc_url === undefined ) {
-            console.error('No provider found for chainId',chainId)
-            return null
+            console.error(`WARNING: No provider found for chainId ${chainId}.  Using localhost.`)
+            rpc_url = 'http://localhost:8545'
         }
         result = rpc_url.startsWith('ws') ?
             new ethers.WebSocketProvider(rpc_url, chainId) :
@@ -19,24 +26,28 @@ export function getProvider(chainId) {
     return result
 }
 
-const signers = {} // indexed by chain id, value is an array to be used in round-robin fashion
-const signerIndexes = {}
+const signers = {} // indexed by chain id
 
 
-export function signer(chainId) {
-    let chainSigners = signers[chainId]
-    if (chainSigners === undefined) {
-        chainSigners = []
+// todo multiple signers per chain, checked out of a pool
+export function getSigner(chainId) {
+    let signer = signers[chainId]
+    if (signer === undefined) {
         const private_keys = process.env['DEXORDER_ACCOUNTS_' + chainId]
-        for (const match of private_keys.matchAll(/([^,]+),?/g))
-            chainSigners.push(new ethers.Wallet(match[1]))
-        signers[chainId] = chainSigners
-        signerIndexes[chainId] = 0
+        if( !private_keys ) {
+            console.log(`DEXORDER_ACCOUNTS_${chainId} not defined`)
+            return null // todo fatal
+        }
+        // for (const match of private_keys.matchAll(/([^,]+),?/g))
+        //     signer.push(new ethers.Wallet(match[1]))
+        signer = new ethers.Wallet(private_keys, getProvider(chainId))
+        signers[chainId] = signer
     }
-    const result = chainSigners[signerIndexes[chainId]]
-    signerIndexes[chainId]++
-    if( signerIndexes[chainId] >= chainSigners.length )
-        signerIndexes[chainId] = 0
-    return result
+    return signer
+    // const result = signer[signerIndexes[chainId]]
+    // signerIndexes[chainId]++
+    // if( signerIndexes[chainId] >= signer.length )
+    //     signerIndexes[chainId] = 0
+    // return result
 }
 
diff --git a/cache.js b/cache.js
new file mode 100644
index 0000000..2ed68c9
--- /dev/null
+++ b/cache.js
@@ -0,0 +1,19 @@
+// implement a cluster-wide cache which is in-memory for each instance
+
+export class Cache {
+
+    constructor(name) {
+        this.name = name
+        this.cache = {}
+    }
+
+    async get(key) {
+        return this.cache[key]
+    }
+
+    async set(key, value) {
+        this.cache[key] = value
+        // todo broadcast
+    }
+}
+
diff --git a/io.js b/io.js
new file mode 100644
index 0000000..17d81d2
--- /dev/null
+++ b/io.js
@@ -0,0 +1,8 @@
+import {createServer} from "http";
+import {Server} from "socket.io";
+
+const options = {}
+if( process.env.DEXORDER_CORS )
+    options['cors'] = {origin:process.env.DEXORDER_CORS}
+export const httpServer = createServer()
+export const io = new Server(httpServer, options)
diff --git a/main.js b/main.js
index 19e13c6..5fa1ec4 100644
--- a/main.js
+++ b/main.js
@@ -1,14 +1,25 @@
 import 'dotenv/config'
 
-import { createServer } from "http";
-import { Server } from "socket.io"
 import {lookupToken} from "./token.js";
+import {startWatcher} from "./watcher.js";
+import {chains} from "./blockchain.js";
+import {watchErc20Transfer, watchVaultCreated} from "./vault.js";
+import {httpServer, io} from "./io.js";
 
-const options = {}
-if( process.env.DEXORDER_CORS )
-    options['cors'] = {origin:process.env.DEXORDER_CORS}
-const httpServer = createServer()
-const io = new Server(httpServer, options)
+
+// setup watcher
+
+const filterCallbacks = [
+    // format is [[className, eventName, ...eventArgs], callback(provider, database, logInfo)]
+    [['VaultDeployer','VaultCreated', null, null], watchVaultCreated],
+    [['ERC20', 'Transfer'], watchErc20Transfer],
+]
+
+for( const chain of Object.values(chains) )
+    await startWatcher( chain.id, 1000, filterCallbacks )
+
+
+// setup socket.io
 
 io.on("connection", (socket) => {
     // initially, only anonymous messages are allowed
@@ -23,4 +34,3 @@ io.on("connection", (socket) => {
 const port = parseInt(process.env.DEXORDER_PORT) || 3000;
 httpServer.listen(port)
 console.log('Started server on port '+port)
-console.log(options)
diff --git a/migrations/20230829202027-initial.js b/migrations/20230829202027-initial.js
index f7286a5..cdaae8b 100644
--- a/migrations/20230829202027-initial.js
+++ b/migrations/20230829202027-initial.js
@@ -22,7 +22,7 @@ exports.up = async function (db) {
     await db.createTable('eoa', {
         chain: { type: 'int', primaryKey: true },
         address: { type: 'bytea', primaryKey: true},
-        vaulted: 'boolean',
+        // vaulted: 'boolean',
     })
     await db.createTable('tokenusage', {
         chain: { type: 'int', primaryKey: true },
diff --git a/misc.js b/misc.js
new file mode 100644
index 0000000..73f2099
--- /dev/null
+++ b/misc.js
@@ -0,0 +1,4 @@
+import fs from "fs";
+import util from "util";
+
+export const readFile = (fileName) => util.promisify(fs.readFile)(fileName, 'utf8');
diff --git a/vault.js b/vault.js
index aa14066..7b051e9 100644
--- a/vault.js
+++ b/vault.js
@@ -1,5 +1,51 @@
+import {ethers} from "ethers";
+import {getAbi} from "./abi.js";
+import {getProvider, getSigner} from "./blockchain.js";
+import {Cache} from './cache.js';
+
+const DEPLOYER_ADDRESS = '0xF99aB16Bd8398EAf12407D05A0F8824316008E99'
+const VAULT_INIT_CODE_HASH = '0xbf043f7035d5aa3be2b3c94df5b256fbe24675689327af4ab71c48194c463031'
+
+const vaults = new Cache('vaults') // vault:owner
+
+const deployerAbi = await getAbi('VaultDeployer');
+
+
+function newVault(address, owner) {
+    return {address, owner, balances: {}}
+}
+
+export function vaultAddress(chainId, ownerAddress) {
+    const encoded = ethers.AbiCoder.defaultAbiCoder().encode(['address'], [ownerAddress])
+    const salt = ethers.keccak256(encoded)
+    return ethers.getCreate2Address(DEPLOYER_ADDRESS, salt, VAULT_INIT_CODE_HASH)
+}
+
 
 export function loginAddress(socket, chainId, address) {
     // todo check for existing vault
-    // todo send welcome with basic info
-}
\ No newline at end of file
+    if (!vaults[address]) {
+        //
+    } else {
+        // todo send welcome with basic info and extra tokens
+
+    }
+}
+
+
+export async function ensureVault(socket, chainId, owner) {
+    const address = vaultAddress(chainId, owner)
+    if (!vaults[address]) {
+        const deployer = new ethers.Contract(DEPLOYER_ADDRESS, deployerAbi, getSigner(chainId))
+        await deployer.deployVault(owner)
+    }
+}
+
+
+export async function watchVaultCreated(provider, db, event) {
+    console.log(`vault created`, event)
+}
+
+export async function watchErc20Transfer(provider, db, event) {
+    console.log('Transfer', event)
+}
diff --git a/watcher.js b/watcher.js
index c951953..bff29b6 100644
--- a/watcher.js
+++ b/watcher.js
@@ -1,54 +1,96 @@
 import {getProvider} from "./blockchain.js";
-import {ethers} from "ethers";
-import {erc20Abi} from "./abi.js";
 import {pool} from "./db.js";
+import {getInterface} from "./abi.js";
 
 const BATCH_SIZE = 100 // the most blocks allowed per batch
 
-async function watchChain(chainId, filterCallbacks) {
+
+// watcher collects all events from the blockchain and then matches them against our local filters, invoking any
+// registered callbacks.  we do the filtering/switching locally to prevent invoking a separate api call for
+// each type of event
+
+
+async function processLogs(chainId, topicEventCallbacks) {
+    // console.log('processLogs')
     const provider = getProvider(chainId)
-    const db = await pool.connect()
     const block = await provider.getBlockNumber()
-    let fromBlock, toBlock
-    const result = await db.query('select block from progress where chain=$1', [chainId])
-    if( result.rowCount === 0 ) {
-        console.log('initializing chain', chainId)
-        fromBlock = block
-        db.query('insert into progress values ($1,$2)', [chainId, block-1])
-    }
-    else if( result.rowCount === 1 ) {
-        fromBlock = result.rows[0].block + 1
-    }
-    else
-        throw Error(`Found ${result.rowCount} rows for progress table chain ${chainId}`)
+    const db = await pool.connect()
     try {
-        do {
-            toBlock = Math.min(block, fromBlock + BATCH_SIZE-1) // toBlock is inclusive
-            const promises = []
-            await db.query('BEGIN')
-            for (const [filter, callback] of filterCallbacks) {
-                filter.fromBlock = fromBlock
-                filter.toBlock = toBlock
-                console.log('filter', filter)
-                const found = await provider.getLogs(filter)
-                promises.push(callback(provider, db, found))
-            }
-            await Promise.all(promises)
-            db.query('update progress set block=$1 where chain=$2', [toBlock, chainId])
-            db.query('COMMIT')
-            fromBlock = toBlock + 1
-        } while (toBlock > block)
-    } catch (e) {
-        await db.query('ROLLBACK')
-        throw e
-    } finally {
+        let fromBlock, toBlock
+        const result = await db.query('select block from progress where chain=$1', [chainId])
+        if (result.rowCount === 0) {
+            console.log('initializing chain', chainId)
+            fromBlock = block
+            db.query('insert into progress values ($1,$2)', [chainId, block - 1])
+        } else if (result.rowCount === 1) {
+            fromBlock = result.rows[0].block + 1
+        } else
+            throw Error(`Found ${result.rowCount} rows for progress table chain ${chainId}`)
+        if (fromBlock > block)
+            return
+        try {
+            do {
+                toBlock = Math.min(block, fromBlock + BATCH_SIZE - 1) // toBlock is inclusive
+                await db.query('BEGIN')
+                const logs = await provider.getLogs({fromBlock, toBlock})
+                // console.log(`logs for block range [${fromBlock},${toBlock}]`, logs)
+                const promises = []
+                for (const log of logs) {
+                    for (const topic of log.topics) {
+                        const cb = topicEventCallbacks[topic]
+                        if (cb !== undefined)
+                            promises.push(cb(provider, db, log))
+                    }
+                }
+                await Promise.all(promises)
+                db.query('update progress set block=$1 where chain=$2', [toBlock, chainId])
+                db.query('COMMIT')
+                fromBlock = toBlock + 1
+            } while (toBlock > block)
+        } catch (e) {
+            await db.query('ROLLBACK')
+            throw e
+        }
+    }
+    finally {
         db.release()
     }
 }
 
 
-export function startWatcher(chainId, period, filterCallbacks) {
-    setInterval(async () => await watchChain(chainId, filterCallbacks), period)
+export async function startWatcher(chainId, period, filterCallbacks) {
+    const topicEventCallbacks = {} // topic: callback(log)
+    for (const [[className, eventName, ...args], callback] of filterCallbacks) {
+        const interf = await getInterface(className)
+        const event = interf.getEvent(eventName)
+        const topics = interf.encodeFilterTopics(event, args)
+        for( const topic of topics ) {
+            topicEventCallbacks[topic] = async (provider, db, log) => {
+                let info
+                try {
+                    // info = interf.decodeEventLog(event, log.data, log.topics)
+                    info = interf.parseLog(log)
+                }
+                catch (e) {
+                    // console.error(`could not decode log for topic ${topic}`, log)
+                    return
+                }
+                if( info !== null ) {
+                    info.address = log.address
+                    await callback(provider, db, info)
+                }
+            }
+        }
+    }
+    console.log('registered topics', Object.keys(topicEventCallbacks))
+
+    setInterval(async () => {
+        try {
+            await processLogs(chainId, topicEventCallbacks)
+        } catch (e) {
+            console.error('error during processLogs',e)
+        }
+    }, period)
 }