diff --git a/tracker/middleware.go b/tracker/middleware.go
index 5f3c5eb..ba8e133 100644
--- a/tracker/middleware.go
+++ b/tracker/middleware.go
@@ -18,13 +18,16 @@ type AnnounceMiddleware func(AnnounceHandler) AnnounceHandler
 // AnnounceMiddleware from a MiddlewareConfig.
 type AnnounceMiddlewareConstructor func(chihaya.MiddlewareConfig) (AnnounceMiddleware, error)
 
-type announceChain struct{ mw []AnnounceMiddleware }
+// AnnounceChain is a chain of AnnounceMiddlewares.
+type AnnounceChain struct{ mw []AnnounceMiddleware }
 
-func (c *announceChain) Append(mw ...AnnounceMiddleware) {
+// Append appends AnnounceMiddlewares to the AnnounceChain.
+func (c *AnnounceChain) Append(mw ...AnnounceMiddleware) {
 	c.mw = append(c.mw, mw...)
 }
 
-func (c *announceChain) Handler() AnnounceHandler {
+// Handler builds an AnnounceChain into an AnnounceHandler.
+func (c *AnnounceChain) Handler() AnnounceHandler {
 	final := func(cfg *chihaya.TrackerConfig, req *chihaya.AnnounceRequest, resp *chihaya.AnnounceResponse) error {
 		return nil
 	}
@@ -82,13 +85,16 @@ type ScrapeMiddleware func(ScrapeHandler) ScrapeHandler
 // ScrapeMiddleware from a MiddlewareConfig.
 type ScrapeMiddlewareConstructor func(chihaya.MiddlewareConfig) (ScrapeMiddleware, error)
 
-type scrapeChain struct{ mw []ScrapeMiddleware }
+// ScrapeChain is a chain of ScrapeMiddlewares.
+type ScrapeChain struct{ mw []ScrapeMiddleware }
 
-func (c *scrapeChain) Append(mw ...ScrapeMiddleware) {
+// Append appends ScrapeMiddlewares to the ScrapeChain.
+func (c *ScrapeChain) Append(mw ...ScrapeMiddleware) {
 	c.mw = append(c.mw, mw...)
 }
 
-func (c *scrapeChain) Handler() ScrapeHandler {
+// Handler builds the ScrapeChain into a ScrapeHandler.
+func (c *ScrapeChain) Handler() ScrapeHandler {
 	final := func(cfg *chihaya.TrackerConfig, req *chihaya.ScrapeRequest, resp *chihaya.ScrapeResponse) error {
 		return nil
 	}
diff --git a/tracker/middleware_test.go b/tracker/middleware_test.go
index 5fd6011..4d5f19d 100644
--- a/tracker/middleware_test.go
+++ b/tracker/middleware_test.go
@@ -40,7 +40,7 @@ func testAnnounceMW3(next AnnounceHandler) AnnounceHandler {
 }
 
 func TestAnnounceChain(t *testing.T) {
-	var achain announceChain
+	var achain AnnounceChain
 	achain.Append(testAnnounceMW1)
 	achain.Append(testAnnounceMW2)
 	achain.Append(testAnnounceMW3)
diff --git a/tracker/tracker.go b/tracker/tracker.go
index 5a451b2..11a81f5 100644
--- a/tracker/tracker.go
+++ b/tracker/tracker.go
@@ -31,7 +31,7 @@ type Tracker struct {
 // NewTracker constructs a newly allocated Tracker composed of the middleware
 // in the provided configuration.
 func NewTracker(cfg *chihaya.TrackerConfig) (*Tracker, error) {
-	var achain announceChain
+	var achain AnnounceChain
 	for _, mwConfig := range cfg.AnnounceMiddleware {
 		mw, ok := announceMiddlewareConstructors[mwConfig.Name]
 		if !ok {
@@ -44,7 +44,7 @@ func NewTracker(cfg *chihaya.TrackerConfig) (*Tracker, error) {
 		achain.Append(middleware)
 	}
 
-	var schain scrapeChain
+	var schain ScrapeChain
 	for _, mwConfig := range cfg.ScrapeMiddleware {
 		mw, ok := scrapeMiddlewareConstructors[mwConfig.Name]
 		if !ok {