diff --git a/go.mod b/go.mod
index 66c96d0e..e910e93e 100644
--- a/go.mod
+++ b/go.mod
@@ -16,7 +16,7 @@ require (
 	github.com/onsi/gomega v1.34.2
 	github.com/pingcap/errors v0.11.4
 	github.com/pkg/errors v0.9.1
-	github.com/prometheus/client_golang v1.20.2
+	github.com/prometheus/client_golang v1.20.3
 	github.com/redis/go-redis/v9 v9.6.1
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.16.0
diff --git a/go.sum b/go.sum
index b553ae45..1d9e8248 100644
--- a/go.sum
+++ b/go.sum
@@ -518,8 +518,8 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pkg/sftp v1.13.1/go.mod h1:3HaPG6Dq1ILlpPZRO0HVMrsydcdLt6HRDccSgb87qRg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/prometheus/client_golang v1.20.2 h1:5ctymQzZlyOON1666svgwn3s6IKWgfbjsejTMiXIyjg=
-github.com/prometheus/client_golang v1.20.2/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
+github.com/prometheus/client_golang v1.20.3 h1:oPksm4K8B+Vt35tUhw6GbSNSgVlVSBH0qELP/7u83l4=
+github.com/prometheus/client_golang v1.20.3/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
 github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
diff --git a/signature-aggregator/README.md b/signature-aggregator/README.md
index 413a65d6..1c8b60a1 100644
--- a/signature-aggregator/README.md
+++ b/signature-aggregator/README.md
@@ -29,10 +29,20 @@ The only exposed endpoint is `/aggregate-signatures`  expecting `application/jso
     "message": "",            // (string) hex-encoded unsigned message bytes to be signed
     "justification": "",      // (string) hex-encoded bytes to supply to the validators as justification
     "signing-subnet-id": "",  // (string) hex or cb58 encoded signing subnet ID. Defaults to source blockchain's subnet from data if omitted.
-    "quorum-percentage": 67  // (int) quorum percentage required to sign the message. Defaults to 67 if omitted
+    "quorum-percentage": 67   // (int) quorum percentage required to sign the message. Defaults to 67 if omitted
 }
 ```
 
+The successful `HTTP 200` response format is
+
+```json
+{
+    "signed-message": ""  // (string) hex-encoded signed message bytes signed by at least `quorum-percentage` of the validator set.
+}
+```
+
+Unsuccessful responses will include an explanatory `application/json` encoded message in the body of the response.
+
 ## Sample workflow
 If you want to manually test a locally running service pointed to the Fuji testnet you can do so with the following steps.