diff --git a/Dockerfile b/Dockerfile
index ea99603..716c7d1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,7 +6,7 @@ WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-RUN CGO_ENABLED=0 go build -ldflags "-X main.Version=${CHECKER_VERSION}" -o /checker-tls .
+RUN CGO_ENABLED=0 go build -tags standalone -ldflags "-X main.Version=${CHECKER_VERSION}" -o /checker-tls .
 
 FROM scratch
 COPY --from=builder /checker-tls /checker-tls
diff --git a/Makefile b/Makefile
index bf1467e..8ebb85f 100644
--- a/Makefile
+++ b/Makefile
@@ -6,12 +6,12 @@ CHECKER_SOURCES := main.go $(wildcard checker/*.go)
 
 GO_LDFLAGS := -X main.Version=$(CHECKER_VERSION)
 
-.PHONY: all plugin docker clean
+.PHONY: all plugin docker test clean
 
 all: $(CHECKER_NAME)
 
 $(CHECKER_NAME): $(CHECKER_SOURCES)
-	go build -ldflags "$(GO_LDFLAGS)" -o $@ .
+	go build -tags standalone -ldflags "$(GO_LDFLAGS)" -o $@ .
 
 plugin: $(CHECKER_NAME).so
 
@@ -21,5 +21,8 @@ $(CHECKER_NAME).so: $(CHECKER_SOURCES) $(wildcard plugin/*.go)
 docker:
 	docker build --build-arg CHECKER_VERSION=$(CHECKER_VERSION) -t $(CHECKER_IMAGE) .
 
+test:
+	go test -tags standalone ./...
+
 clean:
 	rm -f $(CHECKER_NAME) $(CHECKER_NAME).so
diff --git a/checker/interactive.go b/checker/interactive.go
index 85a7dc3..048b7a8 100644
--- a/checker/interactive.go
+++ b/checker/interactive.go
@@ -1,3 +1,5 @@
+//go:build standalone
+
 package checker
 
 import (
@@ -24,7 +26,7 @@ func starttlsChoices() []string {
 	return protos
 }
 
-// RenderForm satisfies sdk.CheckerInteractive. The fields mirror the inputs
+// RenderForm satisfies server.Interactive. The fields mirror the inputs
 // a producer checker would put into a contract.TLSEndpoint; a human fills
 // them in directly when running the checker standalone.
 func (p *tlsProvider) RenderForm() []sdk.CheckerOptionField {
@@ -75,7 +77,7 @@ func (p *tlsProvider) RenderForm() []sdk.CheckerOptionField {
 	}
 }
 
-// ParseForm satisfies sdk.CheckerInteractive. It turns the human inputs into
+// ParseForm satisfies server.Interactive. It turns the human inputs into
 // a single contract.TLSEndpoint, wraps it in a DiscoveryEntry, and returns
 // CheckerOptions shaped as if a happyDomain host had auto-filled
 // OptionEndpoints via AutoFillDiscoveryEntries.
diff --git a/checker/rule.go b/checker/rule.go
index 310c283..4c3d105 100644
--- a/checker/rule.go
+++ b/checker/rule.go
@@ -69,11 +69,11 @@ func (r *tlsRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts
 func evaluateProbe(p TLSProbe) sdk.CheckState {
 	subject := fmt.Sprintf("%s://%s", p.Type, p.Endpoint)
 	meta := map[string]any{
-		"type":     p.Type,
-		"host":     p.Host,
-		"port":     p.Port,
-		"sni":      p.SNI,
-		"issues":   len(p.Issues),
+		"type":   p.Type,
+		"host":   p.Host,
+		"port":   p.Port,
+		"sni":    p.SNI,
+		"issues": len(p.Issues),
 	}
 	if p.TLSVersion != "" {
 		meta["tls_version"] = p.TLSVersion
diff --git a/checker/types.go b/checker/types.go
index 58bd547..3509d23 100644
--- a/checker/types.go
+++ b/checker/types.go
@@ -56,17 +56,17 @@ type TLSProbe struct {
 	// IssuerAKI is the uppercase hex of the leaf's Authority Key Identifier
 	// extension (i.e. the issuer cert's SKI). This is the primary lookup key
 	// into the CCADB CAA Identifiers CSV ("Subject Key Identifier (Hex)").
-	IssuerAKI     string    `json:"issuer_aki,omitempty"`
-	Subject       string    `json:"subject,omitempty"`
-	DNSNames      []string  `json:"dns_names,omitempty"`
+	IssuerAKI string   `json:"issuer_aki,omitempty"`
+	Subject   string   `json:"subject,omitempty"`
+	DNSNames  []string `json:"dns_names,omitempty"`
 	// Chain carries one entry per certificate presented by the server
 	// (leaf first, then intermediates in order). Each entry precomputes
 	// the four TLSA selector×matching_type hashes plus the raw DER so
 	// DANE consumers can match without re-handshaking or re-parsing.
-	Chain         []CertInfo `json:"chain,omitempty"`
-	ElapsedMS     int64     `json:"elapsed_ms,omitempty"`
-	Error         string    `json:"error,omitempty"`
-	Issues        []Issue   `json:"issues,omitempty"`
+	Chain     []CertInfo `json:"chain,omitempty"`
+	ElapsedMS int64      `json:"elapsed_ms,omitempty"`
+	Error     string     `json:"error,omitempty"`
+	Issues    []Issue    `json:"issues,omitempty"`
 }
 
 // CertInfo describes one certificate in the presented chain together with
diff --git a/go.mod b/go.mod
index 416eb47..bde2901 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@ module git.happydns.org/checker-tls
 
 go 1.25.0
 
-require git.happydns.org/checker-sdk-go v1.2.0
+require git.happydns.org/checker-sdk-go v1.4.0
diff --git a/go.sum b/go.sum
index 272600a..072aab1 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-git.happydns.org/checker-sdk-go v1.2.0 h1:v4MpKAz0W3PwP+bxx3pya8w893sVH5xTD1of1cc0TV8=
-git.happydns.org/checker-sdk-go v1.2.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI=
+git.happydns.org/checker-sdk-go v1.4.0 h1:sO8EnF3suhNgYLRsbmCZWJOymH/oNMrOUqj3FEzJArs=
+git.happydns.org/checker-sdk-go v1.4.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI=
diff --git a/main.go b/main.go
index f781e37..ae5167c 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,7 @@ import (
 	"flag"
 	"log"
 
-	sdk "git.happydns.org/checker-sdk-go/checker"
+	"git.happydns.org/checker-sdk-go/checker/server"
 	tls "git.happydns.org/checker-tls/checker"
 )
 
@@ -16,8 +16,8 @@ func main() {
 	flag.Parse()
 	tls.Version = Version
 
-	server := sdk.NewServer(tls.Provider())
-	if err := server.ListenAndServe(*listenAddr); err != nil {
+	srv := server.New(tls.Provider())
+	if err := srv.ListenAndServe(*listenAddr); err != nil {
 		log.Fatalf("server error: %v", err)
 	}
 }