diff --git a/pkg/jsonsign/signhandler/sig.go b/pkg/jsonsign/signhandler/sig.go
index 7c3ec8cc6..44ad13d05 100644
--- a/pkg/jsonsign/signhandler/sig.go
+++ b/pkg/jsonsign/signhandler/sig.go
@@ -34,6 +34,7 @@ import (
 	"camlistore.org/pkg/jsonsign"
 	"camlistore.org/pkg/osutil"
 	"camlistore.org/pkg/schema"
+	"camlistore.org/pkg/types/camtypes"
 
 	"camlistore.org/third_party/code.google.com/p/go.crypto/openpgp"
 )
@@ -204,25 +205,23 @@ func (h *Handler) handleVerify(rw http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	m := make(map[string]interface{})
-
 	// TODO: use a different fetcher here that checks memory, disk,
 	// the internet, etc.
 	fetcher := h.pubKeyFetcher
 
+	var res camtypes.VerifyResponse
 	vreq := jsonsign.NewVerificationRequest(sjson, fetcher)
 	if vreq.Verify() {
-		m["signatureValid"] = 1
-		m["signerKeyId"] = vreq.SignerKeyId
-		m["verifiedData"] = vreq.PayloadMap
+		res.SignatureValid = true
+		res.SignerKeyId = vreq.SignerKeyId
+		res.VerifiedData = vreq.PayloadMap
 	} else {
-		errStr := vreq.Err.Error()
-		m["signatureValid"] = 0
-		m["errorMessage"] = errStr
+		res.SignatureValid = false
+		res.ErrorMessage = vreq.Err.Error()
 	}
 
 	rw.WriteHeader(http.StatusOK) // no HTTP response code fun, error info in JSON
-	httputil.ReturnJSON(rw, m)
+	httputil.ReturnJSON(rw, &res)
 }
 
 func (h *Handler) handleSign(rw http.ResponseWriter, req *http.Request) {
diff --git a/pkg/types/camtypes/sign.go b/pkg/types/camtypes/sign.go
new file mode 100644
index 000000000..d0a178030
--- /dev/null
+++ b/pkg/types/camtypes/sign.go
@@ -0,0 +1,29 @@
+/*
+Copyright 2015 The Camlistore Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package camtypes
+
+// VerifyResponse is the JSON response for a signature verification request.
+type VerifyResponse struct {
+	// SignatureValid is true if the signature is valid.
+	SignatureValid bool `json:"signatureValid"`
+	// ErrorMessage contains the error that occurred, if any.
+	ErrorMessage string `json:"errorMessage,omitempty"`
+	// SignerKeyId is the ID of the signing key.
+	SignerKeyId string `json:"signerKeyId,omitempty"`
+	// VerifiedData contains the JSON values from the payload that we signed.
+	VerifiedData map[string]interface{} `json:"verifiedData,omitempty"`
+}