diff --git a/cmd/ipfs/daemon.go b/cmd/ipfs/daemon.go
index 9a44c960b..868d4e1b6 100644
--- a/cmd/ipfs/daemon.go
+++ b/cmd/ipfs/daemon.go
@@ -192,9 +192,11 @@ func daemonFunc(req cmds.Request, res cmds.Response) {
 		return
 	}
 
-	// Start assembling corebuilder
-	nb := core.NewNodeBuilder().Online()
-	nb.SetRepo(repo)
+	// Start assembling node config
+	ncfg := &core.BuildCfg{
+		Online: true,
+		Repo:   repo,
+	}
 
 	routingOption, _, err := req.Option(routingOptionKwd).String()
 	if err != nil {
@@ -215,10 +217,11 @@ func daemonFunc(req cmds.Request, res cmds.Response) {
 				Addrs: []ma.Multiaddr{addr.Transport()},
 			})
 		}
-		nb.SetRouting(corerouting.SupernodeClient(infos...))
+
+		ncfg.Routing = corerouting.SupernodeClient(infos...)
 	}
 
-	node, err := nb.Build(req.Context())
+	node, err := core.NewNode(req.Context(), ncfg)
 	if err != nil {
 		log.Error("error from node construction: ", err)
 		res.SetError(err, cmds.ErrNormal)
diff --git a/cmd/ipfs/init.go b/cmd/ipfs/init.go
index 07f1dae88..53b8a8e04 100644
--- a/cmd/ipfs/init.go
+++ b/cmd/ipfs/init.go
@@ -157,7 +157,7 @@ func addDefaultAssets(out io.Writer, repoRoot string) error {
 		return err
 	}
 
-	nd, err := core.NewIPFSNode(ctx, core.Offline(r))
+	nd, err := core.NewNode(ctx, &core.BuildCfg{Repo: r})
 	if err != nil {
 		return err
 	}
@@ -191,7 +191,7 @@ func initializeIpnsKeyspace(repoRoot string) error {
 		return err
 	}
 
-	nd, err := core.NewIPFSNode(ctx, core.Offline(r))
+	nd, err := core.NewNode(ctx, &core.BuildCfg{Repo: r})
 	if err != nil {
 		return err
 	}
diff --git a/cmd/ipfs/main.go b/cmd/ipfs/main.go
index c6c6da8e9..d5d87221c 100644
--- a/cmd/ipfs/main.go
+++ b/cmd/ipfs/main.go
@@ -204,7 +204,10 @@ func (i *cmdInvocation) constructNodeFunc(ctx context.Context) func() (*core.Ipf
 
 		// ok everything is good. set it on the invocation (for ownership)
 		// and return it.
-		n, err := core.NewIPFSNode(ctx, core.Standard(r, cmdctx.Online))
+		n, err := core.NewNode(ctx, &core.BuildCfg{
+			Online: cmdctx.Online,
+			Repo:   r,
+		})
 		if err != nil {
 			return nil, err
 		}
diff --git a/cmd/ipfswatch/main.go b/cmd/ipfswatch/main.go
index 3a4fb8f09..eb52b7ce1 100644
--- a/cmd/ipfswatch/main.go
+++ b/cmd/ipfswatch/main.go
@@ -71,7 +71,11 @@ func run(ipfsPath, watchPath string) error {
 		// TODO handle case: repo doesn't exist or isn't initialized
 		return err
 	}
-	node, err := core.NewIPFSNode(context.Background(), core.Online(r))
+
+	node, err := core.NewNode(context.Background(), &core.BuildCfg{
+		Online: true,
+		Repo:   r,
+	})
 	if err != nil {
 		return err
 	}
diff --git a/core/builder.go b/core/builder.go
index 2eb168a21..ceddc42f8 100644
--- a/core/builder.go
+++ b/core/builder.go
@@ -7,31 +7,60 @@ import (
 
 	ds "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
 	dsync "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore/sync"
+	goprocessctx "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/goprocess/context"
 	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
+	bstore "github.com/ipfs/go-ipfs/blocks/blockstore"
 	key "github.com/ipfs/go-ipfs/blocks/key"
+	bserv "github.com/ipfs/go-ipfs/blockservice"
+	offline "github.com/ipfs/go-ipfs/exchange/offline"
+	dag "github.com/ipfs/go-ipfs/merkledag"
 	ci "github.com/ipfs/go-ipfs/p2p/crypto"
+	peer "github.com/ipfs/go-ipfs/p2p/peer"
+	path "github.com/ipfs/go-ipfs/path"
+	pin "github.com/ipfs/go-ipfs/pin"
 	repo "github.com/ipfs/go-ipfs/repo"
 	cfg "github.com/ipfs/go-ipfs/repo/config"
 )
 
-var ErrAlreadyBuilt = errors.New("this builder has already been used")
+type BuildCfg struct {
+	// If online is set, the node will have networking enabled
+	Online bool
 
-// NodeBuilder is an object used to generate an IpfsNode
-type NodeBuilder struct {
-	online   bool
-	routing  RoutingOption
-	peerhost HostOption
-	repo     repo.Repo
-	built    bool
-	nilrepo  bool
+	// If NilRepo is set, a repo backed by a nil datastore will be constructed
+	NilRepo bool
+
+	Routing RoutingOption
+	Host    HostOption
+	Repo    repo.Repo
 }
 
-func NewNodeBuilder() *NodeBuilder {
-	return &NodeBuilder{
-		online:   false,
-		routing:  DHTOption,
-		peerhost: DefaultHostOption,
+func (cfg *BuildCfg) fillDefaults() error {
+	if cfg.Repo != nil && cfg.NilRepo {
+		return errors.New("cannot set a repo and specify nilrepo at the same time")
 	}
+
+	if cfg.Repo == nil {
+		var d ds.Datastore
+		d = ds.NewMapDatastore()
+		if cfg.NilRepo {
+			d = ds.NewNullDatastore()
+		}
+		r, err := defaultRepo(dsync.MutexWrap(d))
+		if err != nil {
+			return err
+		}
+		cfg.Repo = r
+	}
+
+	if cfg.Routing == nil {
+		cfg.Routing = DHTOption
+	}
+
+	if cfg.Host == nil {
+		cfg.Host = DefaultHostOption
+	}
+
+	return nil
 }
 
 func defaultRepo(dstore ds.ThreadSafeDatastore) (repo.Repo, error) {
@@ -62,53 +91,69 @@ func defaultRepo(dstore ds.ThreadSafeDatastore) (repo.Repo, error) {
 	}, nil
 }
 
-func (nb *NodeBuilder) Online() *NodeBuilder {
-	nb.online = true
-	return nb
-}
-
-func (nb *NodeBuilder) Offline() *NodeBuilder {
-	nb.online = false
-	return nb
-}
-
-func (nb *NodeBuilder) SetRouting(ro RoutingOption) *NodeBuilder {
-	nb.routing = ro
-	return nb
-}
-
-func (nb *NodeBuilder) SetHost(ho HostOption) *NodeBuilder {
-	nb.peerhost = ho
-	return nb
-}
-
-func (nb *NodeBuilder) SetRepo(r repo.Repo) *NodeBuilder {
-	nb.repo = r
-	return nb
-}
-
-func (nb *NodeBuilder) NilRepo() *NodeBuilder {
-	nb.nilrepo = true
-	return nb
-}
-
-func (nb *NodeBuilder) Build(ctx context.Context) (*IpfsNode, error) {
-	if nb.built {
-		return nil, ErrAlreadyBuilt
+func NewNode(ctx context.Context, cfg *BuildCfg) (*IpfsNode, error) {
+	if cfg == nil {
+		cfg = new(BuildCfg)
 	}
-	nb.built = true
-	if nb.repo == nil {
-		var d ds.Datastore
-		d = ds.NewMapDatastore()
-		if nb.nilrepo {
-			d = ds.NewNullDatastore()
-		}
-		r, err := defaultRepo(dsync.MutexWrap(d))
-		if err != nil {
-			return nil, err
-		}
-		nb.repo = r
+
+	err := cfg.fillDefaults()
+	if err != nil {
+		return nil, err
 	}
-	conf := standardWithRouting(nb.repo, nb.online, nb.routing, nb.peerhost)
-	return NewIPFSNode(ctx, conf)
+
+	n := &IpfsNode{
+		mode:      offlineMode,
+		Repo:      cfg.Repo,
+		ctx:       ctx,
+		Peerstore: peer.NewPeerstore(),
+	}
+	if cfg.Online {
+		n.mode = onlineMode
+	}
+
+	// TODO: this is a weird circular-ish dependency, rework it
+	n.proc = goprocessctx.WithContextAndTeardown(ctx, n.teardown)
+
+	if err := setupNode(ctx, n, cfg); err != nil {
+		n.Close()
+		return nil, err
+	}
+
+	return n, nil
+}
+
+func setupNode(ctx context.Context, n *IpfsNode, cfg *BuildCfg) error {
+	// setup local peer ID (private key is loaded in online setup)
+	if err := n.loadID(); err != nil {
+		return err
+	}
+
+	var err error
+	n.Blockstore, err = bstore.WriteCached(bstore.NewBlockstore(n.Repo.Datastore()), kSizeBlockstoreWriteCache)
+	if err != nil {
+		return err
+	}
+
+	if cfg.Online {
+		do := setupDiscoveryOption(n.Repo.Config().Discovery)
+		if err := n.startOnlineServices(ctx, cfg.Routing, cfg.Host, do); err != nil {
+			return err
+		}
+	} else {
+		n.Exchange = offline.Exchange(n.Blockstore)
+	}
+
+	n.Blocks = bserv.New(n.Blockstore, n.Exchange)
+	n.DAG = dag.NewDAGService(n.Blocks)
+	n.Pinning, err = pin.LoadPinner(n.Repo.Datastore(), n.DAG)
+	if err != nil {
+		// TODO: we should move towards only running 'NewPinner' explicity on
+		// node init instead of implicitly here as a result of the pinner keys
+		// not being found in the datastore.
+		// this is kinda sketchy and could cause data loss
+		n.Pinning = pin.NewPinner(n.Repo.Datastore(), n.DAG)
+	}
+	n.Resolver = &path.Resolver{DAG: n.DAG}
+
+	return nil
 }
diff --git a/core/commands/add.go b/core/commands/add.go
index 4f87054b6..458336e43 100644
--- a/core/commands/add.go
+++ b/core/commands/add.go
@@ -104,7 +104,11 @@ remains to be implemented.
 		chunker, _, _ := req.Option(chunkerOptionName).String()
 
 		if hash {
-			nilnode, err := core.NewNodeBuilder().Build(n.Context())
+			nilnode, err := core.NewNode(n.Context(), &core.BuildCfg{
+				//TODO: need this to be true or all files
+				// hashed will be stored in memory!
+				NilRepo: false,
+			})
 			if err != nil {
 				res.SetError(err, cmds.ErrNormal)
 				return
diff --git a/core/core.go b/core/core.go
index 4e7289cdc..beabb6751 100644
--- a/core/core.go
+++ b/core/core.go
@@ -20,7 +20,6 @@ import (
 	ds "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
 	ma "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
 	goprocess "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/goprocess"
-	goprocessctx "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/goprocess/context"
 	mamask "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/whyrusleeping/multiaddr-filter"
 	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
 	diag "github.com/ipfs/go-ipfs/diagnostics"
@@ -46,7 +45,6 @@ import (
 	exchange "github.com/ipfs/go-ipfs/exchange"
 	bitswap "github.com/ipfs/go-ipfs/exchange/bitswap"
 	bsnet "github.com/ipfs/go-ipfs/exchange/bitswap/network"
-	offline "github.com/ipfs/go-ipfs/exchange/offline"
 	rp "github.com/ipfs/go-ipfs/exchange/reprovide"
 
 	mount "github.com/ipfs/go-ipfs/fuse/mount"
@@ -123,124 +121,6 @@ type Mounts struct {
 	Ipns mount.Mount
 }
 
-type ConfigOption func(ctx context.Context) (*IpfsNode, error)
-
-func NewIPFSNode(ctx context.Context, option ConfigOption) (*IpfsNode, error) {
-	node, err := option(ctx)
-	if err != nil {
-		return nil, err
-	}
-
-	if node.ctx == nil {
-		node.ctx = ctx
-	}
-	if node.proc == nil {
-		node.proc = goprocessctx.WithContextAndTeardown(node.ctx, node.teardown)
-	}
-
-	success := false // flip to true after all sub-system inits succeed
-	defer func() {
-		if !success {
-			node.proc.Close()
-		}
-	}()
-
-	// Need to make sure it's perfectly clear 1) which variables are expected
-	// to be initialized at this point, and 2) which variables will be
-	// initialized after this point.
-
-	node.Blocks = bserv.New(node.Blockstore, node.Exchange)
-
-	if node.Peerstore == nil {
-		node.Peerstore = peer.NewPeerstore()
-	}
-	node.DAG = merkledag.NewDAGService(node.Blocks)
-	node.Pinning, err = pin.LoadPinner(node.Repo.Datastore(), node.DAG)
-	if err != nil {
-		node.Pinning = pin.NewPinner(node.Repo.Datastore(), node.DAG)
-	}
-	node.Resolver = &path.Resolver{DAG: node.DAG}
-
-	success = true
-	return node, nil
-}
-
-func Offline(r repo.Repo) ConfigOption {
-	return Standard(r, false)
-}
-
-func OnlineWithOptions(r repo.Repo, router RoutingOption, ho HostOption) ConfigOption {
-	return standardWithRouting(r, true, router, ho)
-}
-
-func Online(r repo.Repo) ConfigOption {
-	return Standard(r, true)
-}
-
-// DEPRECATED: use Online, Offline functions
-func Standard(r repo.Repo, online bool) ConfigOption {
-	return standardWithRouting(r, online, DHTOption, DefaultHostOption)
-}
-
-// TODO refactor so maybeRouter isn't special-cased in this way
-func standardWithRouting(r repo.Repo, online bool, routingOption RoutingOption, hostOption HostOption) ConfigOption {
-	return func(ctx context.Context) (n *IpfsNode, err error) {
-		// FIXME perform node construction in the main constructor so it isn't
-		// necessary to perform this teardown in this scope.
-		success := false
-		defer func() {
-			if !success && n != nil {
-				n.teardown()
-			}
-		}()
-
-		// TODO move as much of node initialization as possible into
-		// NewIPFSNode. The larger these config options are, the harder it is
-		// to test all node construction code paths.
-
-		if r == nil {
-			return nil, fmt.Errorf("repo required")
-		}
-		n = &IpfsNode{
-			mode: func() mode {
-				if online {
-					return onlineMode
-				}
-				return offlineMode
-			}(),
-			Repo: r,
-		}
-
-		n.ctx = ctx
-		n.proc = goprocessctx.WithContextAndTeardown(ctx, n.teardown)
-
-		// setup Peerstore
-		n.Peerstore = peer.NewPeerstore()
-
-		// setup local peer ID (private key is loaded in online setup)
-		if err := n.loadID(); err != nil {
-			return nil, err
-		}
-
-		n.Blockstore, err = bstore.WriteCached(bstore.NewBlockstore(n.Repo.Datastore()), kSizeBlockstoreWriteCache)
-		if err != nil {
-			return nil, err
-		}
-
-		if online {
-			do := setupDiscoveryOption(n.Repo.Config().Discovery)
-			if err := n.startOnlineServices(ctx, routingOption, hostOption, do); err != nil {
-				return nil, err
-			}
-		} else {
-			n.Exchange = offline.Exchange(n.Blockstore)
-		}
-
-		success = true
-		return n, nil
-	}
-}
-
 func (n *IpfsNode) startOnlineServices(ctx context.Context, routingOption RoutingOption, hostOption HostOption, do DiscoveryOption) error {
 
 	if n.PeerHost != nil { // already online.
@@ -371,10 +251,13 @@ func (n *IpfsNode) teardown() error {
 	// owned objects are closed in this teardown to ensure that they're closed
 	// regardless of which constructor was used to add them to the node.
 	closers := []io.Closer{
-		n.Exchange,
 		n.Repo,
 	}
 
+	if n.Exchange != nil {
+		closers = append(closers, n.Exchange)
+	}
+
 	if n.Mounts.Ipfs != nil {
 		closers = append(closers, mount.Closer(n.Mounts.Ipfs))
 	}
diff --git a/core/core_test.go b/core/core_test.go
index 23b46d36d..d91b9992d 100644
--- a/core/core_test.go
+++ b/core/core_test.go
@@ -48,7 +48,7 @@ func TestInitialization(t *testing.T) {
 			C: *c,
 			D: testutil.ThreadSafeCloserMapDatastore(),
 		}
-		n, err := NewIPFSNode(ctx, Standard(r, false))
+		n, err := NewNode(ctx, &BuildCfg{Repo: r})
 		if n == nil || err != nil {
 			t.Error("Should have constructed.", i, err)
 		}
@@ -59,7 +59,7 @@ func TestInitialization(t *testing.T) {
 			C: *c,
 			D: testutil.ThreadSafeCloserMapDatastore(),
 		}
-		n, err := NewIPFSNode(ctx, Standard(r, false))
+		n, err := NewNode(ctx, &BuildCfg{Repo: r})
 		if n != nil || err == nil {
 			t.Error("Should have failed to construct.", i)
 		}
diff --git a/core/corehttp/gateway_test.go b/core/corehttp/gateway_test.go
index a90bd641e..e84c6f51c 100644
--- a/core/corehttp/gateway_test.go
+++ b/core/corehttp/gateway_test.go
@@ -47,7 +47,7 @@ func newNodeWithMockNamesys(ns mockNamesys) (*core.IpfsNode, error) {
 		C: c,
 		D: testutil.ThreadSafeCloserMapDatastore(),
 	}
-	n, err := core.NewIPFSNode(context.Background(), core.Offline(r))
+	n, err := core.NewNode(context.Background(), &core.BuildCfg{Repo: r})
 	if err != nil {
 		return nil, err
 	}
diff --git a/core/coreunix/add_test.go b/core/coreunix/add_test.go
index 0a17474c4..6d4bfb176 100644
--- a/core/coreunix/add_test.go
+++ b/core/coreunix/add_test.go
@@ -25,7 +25,7 @@ func TestAddRecursive(t *testing.T) {
 		},
 		D: testutil.ThreadSafeCloserMapDatastore(),
 	}
-	node, err := core.NewIPFSNode(context.Background(), core.Offline(r))
+	node, err := core.NewNode(context.Background(), &core.BuildCfg{Repo: r})
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/core/mock/mock.go b/core/mock/mock.go
index 1552d9392..9e96107eb 100644
--- a/core/mock/mock.go
+++ b/core/mock/mock.go
@@ -1,86 +1,39 @@
 package coremock
 
 import (
+	"net"
+
 	"github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
 	syncds "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore/sync"
 	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
 
-	"github.com/ipfs/go-ipfs/blocks/blockstore"
-	blockservice "github.com/ipfs/go-ipfs/blockservice"
 	commands "github.com/ipfs/go-ipfs/commands"
 	core "github.com/ipfs/go-ipfs/core"
-	"github.com/ipfs/go-ipfs/exchange/offline"
-	mdag "github.com/ipfs/go-ipfs/merkledag"
-	nsys "github.com/ipfs/go-ipfs/namesys"
+	metrics "github.com/ipfs/go-ipfs/metrics"
+	host "github.com/ipfs/go-ipfs/p2p/host"
 	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
 	peer "github.com/ipfs/go-ipfs/p2p/peer"
-	path "github.com/ipfs/go-ipfs/path"
-	pin "github.com/ipfs/go-ipfs/pin"
 	"github.com/ipfs/go-ipfs/repo"
 	config "github.com/ipfs/go-ipfs/repo/config"
-	offrt "github.com/ipfs/go-ipfs/routing/offline"
 	ds2 "github.com/ipfs/go-ipfs/util/datastore2"
 	testutil "github.com/ipfs/go-ipfs/util/testutil"
 )
 
-// TODO this is super sketch. Deprecate and initialize one that shares code
-// with the actual core constructor. Lots of fields aren't initialized.
-// "This is as good as broken." --- is it?
-
 // NewMockNode constructs an IpfsNode for use in tests.
 func NewMockNode() (*core.IpfsNode, error) {
 	ctx := context.Background()
 
-	// Generate Identity
-	ident, err := testutil.RandIdentity()
-	if err != nil {
-		return nil, err
+	// effectively offline, only peer in its network
+	return core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   MockHostOption(mocknet.New(ctx)),
+	})
+}
+
+func MockHostOption(mn mocknet.Mocknet) core.HostOption {
+	return func(ctx context.Context, id peer.ID, ps peer.Peerstore, bwr metrics.Reporter, fs []*net.IPNet) (host.Host, error) {
+		return mn.AddPeerWithPeerstore(id, ps)
 	}
-	p := ident.ID()
-
-	c := config.Config{
-		Identity: config.Identity{
-			PeerID: p.String(),
-		},
-	}
-
-	nd, err := core.Offline(&repo.Mock{
-		C: c,
-		D: ds2.CloserWrap(syncds.MutexWrap(datastore.NewMapDatastore())),
-	})(ctx)
-	if err != nil {
-		return nil, err
-	}
-
-	nd.PrivateKey = ident.PrivateKey()
-	nd.Peerstore = peer.NewPeerstore()
-	nd.Peerstore.AddPrivKey(p, ident.PrivateKey())
-	nd.Peerstore.AddPubKey(p, ident.PublicKey())
-	nd.Identity = p
-
-	nd.PeerHost, err = mocknet.New(nd.Context()).AddPeer(ident.PrivateKey(), ident.Address()) // effectively offline
-	if err != nil {
-		return nil, err
-	}
-
-	// Routing
-	nd.Routing = offrt.NewOfflineRouter(nd.Repo.Datastore(), nd.PrivateKey)
-
-	// Bitswap
-	bstore := blockstore.NewBlockstore(nd.Repo.Datastore())
-	bserv := blockservice.New(bstore, offline.Exchange(bstore))
-
-	nd.DAG = mdag.NewDAGService(bserv)
-
-	nd.Pinning = pin.NewPinner(nd.Repo.Datastore(), nd.DAG)
-
-	// Namespace resolver
-	nd.Namesys = nsys.NewNameSystem(nd.Routing)
-
-	// Path resolver
-	nd.Resolver = &path.Resolver{DAG: nd.DAG}
-
-	return nd, nil
 }
 
 func MockCmdsCtx() (commands.Context, error) {
@@ -97,10 +50,14 @@ func MockCmdsCtx() (commands.Context, error) {
 		},
 	}
 
-	node, err := core.NewIPFSNode(context.Background(), core.Offline(&repo.Mock{
+	r := &repo.Mock{
 		D: ds2.CloserWrap(syncds.MutexWrap(datastore.NewMapDatastore())),
 		C: conf,
-	}))
+	}
+
+	node, err := core.NewNode(context.Background(), &core.BuildCfg{
+		Repo: r,
+	})
 
 	return commands.Context{
 		Online:     true,
diff --git a/p2p/net/mock/interface.go b/p2p/net/mock/interface.go
index 28687d70b..a984d865a 100644
--- a/p2p/net/mock/interface.go
+++ b/p2p/net/mock/interface.go
@@ -25,6 +25,7 @@ type Mocknet interface {
 	// AddPeer adds an existing peer. we need both a privkey and addr.
 	// ID is derived from PrivKey
 	AddPeer(ic.PrivKey, ma.Multiaddr) (host.Host, error)
+	AddPeerWithPeerstore(peer.ID, peer.Peerstore) (host.Host, error)
 
 	// retrieve things (with randomized iteration order)
 	Peers() []peer.ID
diff --git a/p2p/net/mock/mock_net.go b/p2p/net/mock/mock_net.go
index f7cabf463..45e6f8450 100644
--- a/p2p/net/mock/mock_net.go
+++ b/p2p/net/mock/mock_net.go
@@ -64,13 +64,26 @@ func (mn *mocknet) GenPeer() (host.Host, error) {
 }
 
 func (mn *mocknet) AddPeer(k ic.PrivKey, a ma.Multiaddr) (host.Host, error) {
-	n, err := newPeernet(mn.ctx, mn, k, a)
+	p, err := peer.IDFromPublicKey(k.GetPublic())
+	if err != nil {
+		return nil, err
+	}
+
+	ps := peer.NewPeerstore()
+	ps.AddAddr(p, a, peer.PermanentAddrTTL)
+	ps.AddPrivKey(p, k)
+	ps.AddPubKey(p, k.GetPublic())
+
+	return mn.AddPeerWithPeerstore(p, ps)
+}
+
+func (mn *mocknet) AddPeerWithPeerstore(p peer.ID, ps peer.Peerstore) (host.Host, error) {
+	n, err := newPeernet(mn.ctx, mn, p, ps)
 	if err != nil {
 		return nil, err
 	}
 
 	h := bhost.New(n)
-	log.Debugf("mocknet added listen addr for peer: %s -- %s", n.LocalPeer(), a)
 
 	mn.proc.AddChild(n.proc)
 
diff --git a/p2p/net/mock/mock_peernet.go b/p2p/net/mock/mock_peernet.go
index 373953f87..6df096d12 100644
--- a/p2p/net/mock/mock_peernet.go
+++ b/p2p/net/mock/mock_peernet.go
@@ -5,7 +5,6 @@ import (
 	"math/rand"
 	"sync"
 
-	ic "github.com/ipfs/go-ipfs/p2p/crypto"
 	inet "github.com/ipfs/go-ipfs/p2p/net"
 	peer "github.com/ipfs/go-ipfs/p2p/peer"
 
@@ -40,19 +39,7 @@ type peernet struct {
 }
 
 // newPeernet constructs a new peernet
-func newPeernet(ctx context.Context, m *mocknet, k ic.PrivKey,
-	a ma.Multiaddr) (*peernet, error) {
-
-	p, err := peer.IDFromPublicKey(k.GetPublic())
-	if err != nil {
-		return nil, err
-	}
-
-	// create our own entirely, so that peers knowledge doesn't get shared
-	ps := peer.NewPeerstore()
-	ps.AddAddr(p, a, peer.PermanentAddrTTL)
-	ps.AddPrivKey(p, k)
-	ps.AddPubKey(p, k.GetPublic())
+func newPeernet(ctx context.Context, m *mocknet, p peer.ID, ps peer.Peerstore) (*peernet, error) {
 
 	n := &peernet{
 		mocknet: m,
diff --git a/test/integration/addcat_test.go b/test/integration/addcat_test.go
index c81672e6c..bd6d964fe 100644
--- a/test/integration/addcat_test.go
+++ b/test/integration/addcat_test.go
@@ -15,12 +15,16 @@ import (
 
 	"github.com/ipfs/go-ipfs/core"
 	coreunix "github.com/ipfs/go-ipfs/core/coreunix"
+	mock "github.com/ipfs/go-ipfs/core/mock"
 	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
 	"github.com/ipfs/go-ipfs/p2p/peer"
+	eventlog "github.com/ipfs/go-ipfs/thirdparty/eventlog"
 	"github.com/ipfs/go-ipfs/thirdparty/unit"
 	testutil "github.com/ipfs/go-ipfs/util/testutil"
 )
 
+var log = eventlog.Logger("epictest")
+
 const kSeed = 1
 
 func Test1KBInstantaneous(t *testing.T) {
@@ -87,35 +91,38 @@ func RandomBytes(n int64) []byte {
 func DirectAddCat(data []byte, conf testutil.LatencyConfig) error {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	const numPeers = 2
 
 	// create network
-	mn, err := mocknet.FullMeshLinked(ctx, numPeers)
-	if err != nil {
-		return err
-	}
+	mn := mocknet.New(ctx)
 	mn.SetLinkDefaults(mocknet.LinkOptions{
 		Latency: conf.NetworkLatency,
 		// TODO add to conf. This is tricky because we want 0 values to be functional.
 		Bandwidth: math.MaxInt32,
 	})
 
-	peers := mn.Peers()
-	if len(peers) < numPeers {
-		return errors.New("test initialization error")
-	}
-
-	adder, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(peers[0], mn.Host(peers[0]), conf, core.DHTOption)))
+	adder, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer adder.Close()
-	catter, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(peers[1], mn.Host(peers[1]), conf, core.DHTOption)))
+
+	catter, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer catter.Close()
 
+	err = mn.LinkAll()
+	if err != nil {
+		return err
+	}
+
 	bs1 := []peer.PeerInfo{adder.Peerstore.PeerInfo(adder.Identity)}
 	bs2 := []peer.PeerInfo{catter.Peerstore.PeerInfo(catter.Identity)}
 
diff --git a/test/integration/bench_cat_test.go b/test/integration/bench_cat_test.go
index 319ea75a1..c3853860b 100644
--- a/test/integration/bench_cat_test.go
+++ b/test/integration/bench_cat_test.go
@@ -10,6 +10,7 @@ import (
 	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
 	"github.com/ipfs/go-ipfs/core"
 	coreunix "github.com/ipfs/go-ipfs/core/coreunix"
+	mock "github.com/ipfs/go-ipfs/core/mock"
 	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
 	"github.com/ipfs/go-ipfs/p2p/peer"
 	"github.com/ipfs/go-ipfs/thirdparty/unit"
@@ -35,35 +36,38 @@ func benchCat(b *testing.B, data []byte, conf testutil.LatencyConfig) error {
 	b.StopTimer()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	const numPeers = 2
 
 	// create network
-	mn, err := mocknet.FullMeshLinked(ctx, numPeers)
-	if err != nil {
-		return err
-	}
+	mn := mocknet.New(ctx)
 	mn.SetLinkDefaults(mocknet.LinkOptions{
 		Latency: conf.NetworkLatency,
 		// TODO add to conf. This is tricky because we want 0 values to be functional.
 		Bandwidth: math.MaxInt32,
 	})
 
-	peers := mn.Peers()
-	if len(peers) < numPeers {
-		return errors.New("test initialization error")
-	}
-
-	adder, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(peers[0], mn.Host(peers[0]), conf, core.DHTOption)))
+	adder, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer adder.Close()
-	catter, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(peers[1], mn.Host(peers[1]), conf, core.DHTOption)))
+
+	catter, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer catter.Close()
 
+	err = mn.LinkAll()
+	if err != nil {
+		return err
+	}
+
 	bs1 := []peer.PeerInfo{adder.Peerstore.PeerInfo(adder.Identity)}
 	bs2 := []peer.PeerInfo{catter.Peerstore.PeerInfo(catter.Identity)}
 
diff --git a/test/integration/bitswap_wo_routing_test.go b/test/integration/bitswap_wo_routing_test.go
index 76dc96be3..f764b2987 100644
--- a/test/integration/bitswap_wo_routing_test.go
+++ b/test/integration/bitswap_wo_routing_test.go
@@ -2,15 +2,13 @@ package integrationtest
 
 import (
 	"bytes"
-	"errors"
 	"testing"
-	"time"
 
 	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
 	"github.com/ipfs/go-ipfs/blocks"
 	"github.com/ipfs/go-ipfs/core"
+	"github.com/ipfs/go-ipfs/core/mock"
 	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
-	testutil "github.com/ipfs/go-ipfs/util/testutil"
 )
 
 func TestBitswapWithoutRouting(t *testing.T) {
@@ -19,22 +17,15 @@ func TestBitswapWithoutRouting(t *testing.T) {
 	const numPeers = 4
 
 	// create network
-	mn, err := mocknet.FullMeshLinked(ctx, numPeers)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	peers := mn.Peers()
-	if len(peers) < numPeers {
-		t.Fatal(errors.New("test initialization error"))
-	}
-
-	// set the routing latency to infinity.
-	conf := testutil.LatencyConfig{RoutingLatency: (525600 * time.Minute)}
+	mn := mocknet.New(ctx)
 
 	var nodes []*core.IpfsNode
-	for _, p := range peers {
-		n, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(p, mn.Host(p), conf, core.NilRouterOption)))
+	for i := 0; i < numPeers; i++ {
+		n, err := core.NewNode(ctx, &core.BuildCfg{
+			Online:  true,
+			Host:    coremock.MockHostOption(mn),
+			Routing: core.NilRouterOption, // no routing
+		})
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -42,6 +33,8 @@ func TestBitswapWithoutRouting(t *testing.T) {
 		nodes = append(nodes, n)
 	}
 
+	mn.LinkAll()
+
 	// connect them
 	for _, n1 := range nodes {
 		for _, n2 := range nodes {
diff --git a/test/integration/core.go b/test/integration/core.go
deleted file mode 100644
index 4c60d40dc..000000000
--- a/test/integration/core.go
+++ /dev/null
@@ -1,54 +0,0 @@
-package integrationtest
-
-import (
-	"github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
-	syncds "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore/sync"
-	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
-	blockstore "github.com/ipfs/go-ipfs/blocks/blockstore"
-	core "github.com/ipfs/go-ipfs/core"
-	bitswap "github.com/ipfs/go-ipfs/exchange/bitswap"
-	bsnet "github.com/ipfs/go-ipfs/exchange/bitswap/network"
-	host "github.com/ipfs/go-ipfs/p2p/host"
-	peer "github.com/ipfs/go-ipfs/p2p/peer"
-	"github.com/ipfs/go-ipfs/repo"
-	delay "github.com/ipfs/go-ipfs/thirdparty/delay"
-	eventlog "github.com/ipfs/go-ipfs/thirdparty/eventlog"
-	ds2 "github.com/ipfs/go-ipfs/util/datastore2"
-	testutil "github.com/ipfs/go-ipfs/util/testutil"
-)
-
-var log = eventlog.Logger("epictest")
-
-func MocknetTestRepo(p peer.ID, h host.Host, conf testutil.LatencyConfig, routing core.RoutingOption) core.ConfigOption {
-	return func(ctx context.Context) (*core.IpfsNode, error) {
-		const kWriteCacheElems = 100
-		const alwaysSendToPeer = true
-		dsDelay := delay.Fixed(conf.BlockstoreLatency)
-		r := &repo.Mock{
-			D: ds2.CloserWrap(syncds.MutexWrap(ds2.WithDelay(datastore.NewMapDatastore(), dsDelay))),
-		}
-		ds := r.Datastore()
-
-		n := &core.IpfsNode{
-			Peerstore: h.Peerstore(),
-			Repo:      r,
-			PeerHost:  h,
-			Identity:  p,
-		}
-		dhtt, err := routing(ctx, n.PeerHost, n.Repo.Datastore())
-		if err != nil {
-			return nil, err
-		}
-
-		bsn := bsnet.NewFromIpfsHost(h, dhtt)
-		bstore, err := blockstore.WriteCached(blockstore.NewBlockstore(ds), kWriteCacheElems)
-		if err != nil {
-			return nil, err
-		}
-		exch := bitswap.New(ctx, p, bsn, bstore, alwaysSendToPeer)
-		n.Blockstore = bstore
-		n.Exchange = exch
-		n.Routing = dhtt
-		return n, nil
-	}
-}
diff --git a/test/integration/grandcentral_test.go b/test/integration/grandcentral_test.go
index 39ee00db5..e2e53c11e 100644
--- a/test/integration/grandcentral_test.go
+++ b/test/integration/grandcentral_test.go
@@ -16,9 +16,9 @@ import (
 	core "github.com/ipfs/go-ipfs/core"
 	"github.com/ipfs/go-ipfs/core/corerouting"
 	"github.com/ipfs/go-ipfs/core/coreunix"
+	mock "github.com/ipfs/go-ipfs/core/mock"
 	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
 	"github.com/ipfs/go-ipfs/p2p/peer"
-	"github.com/ipfs/go-ipfs/thirdparty/iter"
 	"github.com/ipfs/go-ipfs/thirdparty/unit"
 	ds2 "github.com/ipfs/go-ipfs/util/datastore2"
 	testutil "github.com/ipfs/go-ipfs/util/testutil"
@@ -82,28 +82,21 @@ func InitializeSupernodeNetwork(
 	conf testutil.LatencyConfig) ([]*core.IpfsNode, []*core.IpfsNode, error) {
 
 	// create network
-	mn, err := mocknet.FullMeshLinked(ctx, numServers+numClients)
-	if err != nil {
-		return nil, nil, err
-	}
+	mn := mocknet.New(ctx)
 
 	mn.SetLinkDefaults(mocknet.LinkOptions{
 		Latency:   conf.NetworkLatency,
 		Bandwidth: math.MaxInt32,
 	})
 
-	peers := mn.Peers()
-	if len(peers) < numServers+numClients {
-		return nil, nil, errors.New("test initialization error")
-	}
-	clientPeers, serverPeers := peers[0:numClients], peers[numClients:]
-
 	routingDatastore := ds2.CloserWrap(syncds.MutexWrap(datastore.NewMapDatastore()))
 	var servers []*core.IpfsNode
-	for i := range iter.N(numServers) {
-		p := serverPeers[i]
-		bootstrap, err := core.NewIPFSNode(ctx, MocknetTestRepo(p, mn.Host(p), conf,
-			corerouting.SupernodeServer(routingDatastore)))
+	for i := 0; i < numServers; i++ {
+		bootstrap, err := core.NewNode(ctx, &core.BuildCfg{
+			Online:  true,
+			Host:    mock.MockHostOption(mn),
+			Routing: corerouting.SupernodeServer(routingDatastore),
+		})
 		if err != nil {
 			return nil, nil, err
 		}
@@ -117,15 +110,18 @@ func InitializeSupernodeNetwork(
 	}
 
 	var clients []*core.IpfsNode
-	for i := range iter.N(numClients) {
-		p := clientPeers[i]
-		n, err := core.NewIPFSNode(ctx, MocknetTestRepo(p, mn.Host(p), conf,
-			corerouting.SupernodeClient(bootstrapInfos...)))
+	for i := 0; i < numClients; i++ {
+		n, err := core.NewNode(ctx, &core.BuildCfg{
+			Online:  true,
+			Host:    mock.MockHostOption(mn),
+			Routing: corerouting.SupernodeClient(bootstrapInfos...),
+		})
 		if err != nil {
 			return nil, nil, err
 		}
 		clients = append(clients, n)
 	}
+	mn.LinkAll()
 
 	bcfg := core.BootstrapConfigWithPeers(bootstrapInfos)
 	for _, n := range clients {
diff --git a/test/integration/three_legged_cat_test.go b/test/integration/three_legged_cat_test.go
index 45b05f769..9d9cc146c 100644
--- a/test/integration/three_legged_cat_test.go
+++ b/test/integration/three_legged_cat_test.go
@@ -12,6 +12,7 @@ import (
 
 	core "github.com/ipfs/go-ipfs/core"
 	coreunix "github.com/ipfs/go-ipfs/core/coreunix"
+	mock "github.com/ipfs/go-ipfs/core/mock"
 	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
 	"github.com/ipfs/go-ipfs/p2p/peer"
 	"github.com/ipfs/go-ipfs/thirdparty/unit"
@@ -67,35 +68,40 @@ func RunThreeLeggedCat(data []byte, conf testutil.LatencyConfig) error {
 	const numPeers = 3
 
 	// create network
-	mn, err := mocknet.FullMeshLinked(ctx, numPeers)
-	if err != nil {
-		return err
-	}
+	mn := mocknet.New(ctx)
 	mn.SetLinkDefaults(mocknet.LinkOptions{
 		Latency: conf.NetworkLatency,
 		// TODO add to conf. This is tricky because we want 0 values to be functional.
 		Bandwidth: math.MaxInt32,
 	})
 
-	peers := mn.Peers()
-	if len(peers) < numPeers {
-		return errors.New("test initialization error")
-	}
-	bootstrap, err := core.NewIPFSNode(ctx, MocknetTestRepo(peers[2], mn.Host(peers[2]), conf, core.DHTOption))
+	bootstrap, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer bootstrap.Close()
-	adder, err := core.NewIPFSNode(ctx, MocknetTestRepo(peers[0], mn.Host(peers[0]), conf, core.DHTOption))
+
+	adder, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer adder.Close()
-	catter, err := core.NewIPFSNode(ctx, MocknetTestRepo(peers[1], mn.Host(peers[1]), conf, core.DHTOption))
+
+	catter, err := core.NewNode(ctx, &core.BuildCfg{
+		Online: true,
+		Host:   mock.MockHostOption(mn),
+	})
 	if err != nil {
 		return err
 	}
 	defer catter.Close()
+	mn.LinkAll()
 
 	bis := bootstrap.Peerstore.PeerInfo(bootstrap.PeerHost.ID())
 	bcfg := core.BootstrapConfigWithPeers([]peer.PeerInfo{bis})
diff --git a/test/supernode_client/main.go b/test/supernode_client/main.go
index d6111a118..a0150c232 100644
--- a/test/supernode_client/main.go
+++ b/test/supernode_client/main.go
@@ -93,14 +93,11 @@ func run() error {
 		})
 	}
 
-	node, err := core.NewIPFSNode(
-		ctx,
-		core.OnlineWithOptions(
-			repo,
-			corerouting.SupernodeClient(infos...),
-			core.DefaultHostOption,
-		),
-	)
+	node, err := core.NewNode(ctx, &core.BuildCfg{
+		Online:  true,
+		Repo:    repo,
+		Routing: corerouting.SupernodeClient(infos...),
+	})
 	if err != nil {
 		return err
 	}
@@ -168,10 +165,13 @@ func runFileCattingWorker(ctx context.Context, n *core.IpfsNode) error {
 		return err
 	}
 
-	dummy, err := core.NewIPFSNode(ctx, core.Offline(&repo.Mock{
+	r := &repo.Mock{
 		D: ds2.CloserWrap(syncds.MutexWrap(datastore.NewMapDatastore())),
 		C: *conf,
-	}))
+	}
+	dummy, err := core.NewNode(ctx, &core.BuildCfg{
+		Repo: r,
+	})
 	if err != nil {
 		return err
 	}