diff --git a/circuits/test/http/codegen.test.ts b/circuits/test/http/codegen.test.ts
index 9a872f2..1d08884 100644
--- a/circuits/test/http/codegen.test.ts
+++ b/circuits/test/http/codegen.test.ts
@@ -78,7 +78,7 @@ describe("HTTP :: Codegen :: Request", async () => {
         const lockData = await readLockFile<Request>(`${lockfile}.json`);
         console.log("lockData: ", JSON.stringify(lockData));
 
-        const input = await readHTTPInputFile(`${inputfile}`).input
+        const input = await readHTTPInputFile(`${inputfile}`).input;
 
         const headers = getHeaders(lockData);
         const params = [input.length, lockData.method.length, lockData.target.length, lockData.version.length];
@@ -154,7 +154,7 @@ describe("HTTP :: Codegen :: Request", async () => {
 });
 
 describe("HTTP :: Codegen :: Response", async () => {
-    let circuit: WitnessTester<["data", "version", "status", "message", "header1", "value1", "header2", "value2"], []>;
+    let circuit: WitnessTester<["data", "version", "status", "message", "header1", "value1", "header2", "value2"], ["body"]>;
 
     it("(valid) GET:", async () => {
         let lockfile = "response.lock";
@@ -166,10 +166,12 @@ describe("HTTP :: Codegen :: Response", async () => {
         const lockData = await readLockFile<Response>(`${lockfile}.json`);
         console.log("lockData: ", JSON.stringify(lockData));
 
-        const input = await readHTTPInputFile(`${inputfile}`).input
+        const http = await readHTTPInputFile(`${inputfile}`);
+        const input = http.input;
 
         const headers = getHeaders(lockData);
-        const params = [input.length, lockData.version.length, lockData.status.length, lockData.message.length];
+
+        const params = [input.length, parseInt(http.headers["Content-Length"]), lockData.version.length, lockData.status.length, lockData.message.length];
         headers.forEach(header => {
             params.push(header[0].length);
             params.push(header[1].length);
@@ -195,7 +197,9 @@ describe("HTTP :: Codegen :: Response", async () => {
             circuitInput[`header${index + 1}`] = toByte(header[0]);
             circuitInput[`value${index + 1}`] = toByte(header[1]);
         });
-        await circuit.expectPass(circuitInput, {});
+
+
+        await circuit.expectPass(circuitInput, { body: http.bodyBytes });
     });
 
     it("(invalid) GET:", async () => {
@@ -207,10 +211,12 @@ describe("HTTP :: Codegen :: Response", async () => {
 
         const lockData = await readLockFile<Response>(`${lockfile}.json`);
 
-        const input = await readHTTPInputFile(`${inputfile}`).input
+        const http = await readHTTPInputFile(`${inputfile}`);
+        const input = http.input;
 
         const headers = getHeaders(lockData);
-        const params = [input.length, lockData.version.length, lockData.status.length, lockData.message.length];
+
+        const params = [input.length, parseInt(http.headers["Content-Length"]), lockData.version.length, lockData.status.length, lockData.message.length];
         headers.forEach(header => {
             params.push(header[0].length);
             params.push(header[1].length);
diff --git a/src/http.rs b/src/http.rs
index 5470446..f0cbb65 100644
--- a/src/http.rs
+++ b/src/http.rs
@@ -99,7 +99,7 @@ fn build_http_circuit(
             }
             HttpData::Response(_) => {
                 circuit_buffer +=
-                    "template LockHTTPResponse(DATA_BYTES, versionLen, statusLen, messageLen";
+                    "template LockHTTPResponse(DATA_BYTES, maxContentLength, versionLen, statusLen, messageLen";
             }
         }
 
@@ -155,6 +155,19 @@ fn build_http_circuit(
         }
     }
 
+    // Create an output if circuit is for `Response`
+    {
+        if let HttpData::Response(_) = data {
+            circuit_buffer += r#"
+    // Set up mask bits for where the body of response lies
+    signal output body[maxContentLength];
+
+    signal bodyMask[DATA_BYTES];
+    bodyMask[0] <== 0;
+"#;
+        }
+    }
+
     // Setup for parsing the start line
     {
         match data {
@@ -233,6 +246,16 @@ fn build_http_circuit(
 "#;
     }
 
+    // If parsing a `Response`, create a mask of the body bytes
+    {
+        if let HttpData::Response(_) = data {
+            circuit_buffer += r#"
+        // Mask if parser is in the body of response
+        bodyMask[data_idx] <== data[data_idx] * State[data_idx].next_parsing_body;
+"#;
+        }
+    }
+
     // Start line matches
     {
         match data {
@@ -320,6 +343,34 @@ fn build_http_circuit(
 "#;
     }
 
+    // Get the output body bytes
+    {
+        if let HttpData::Response(_) = data {
+            circuit_buffer += r#" 
+    signal bodyStartingIndex[DATA_BYTES];
+    signal isZeroMask[DATA_BYTES];
+    signal isPrevStartingIndex[DATA_BYTES];
+    bodyStartingIndex[0] <== 0;
+    isZeroMask[0] <== IsZero()(bodyMask[0]);
+    for (var i=1 ; i < DATA_BYTES; i++) {
+        isZeroMask[i] <== IsZero()(bodyMask[i]);
+        isPrevStartingIndex[i] <== IsZero()(bodyStartingIndex[i-1]);
+        bodyStartingIndex[i] <== bodyStartingIndex[i-1] + i * (1-isZeroMask[i]) * isPrevStartingIndex[i];
+    }
+
+    body <== SelectSubArray(DATA_BYTES, maxContentLength)(bodyMask, bodyStartingIndex[DATA_BYTES-1]+1, DATA_BYTES - bodyStartingIndex[DATA_BYTES-1]);
+"#;
+        }
+    }
+
+    if debug {
+        circuit_buffer += r#"
+    for(var i = 0; i < maxContentLength; i++) {
+        log("body[", i, "] = ", body[i]);
+    }
+"#;
+    }
+
     // Verify all start line has matched
     {
         match data {