diff --git a/integration/tests/assert_header.output.json b/integration/tests/assert_header.output.json
new file mode 100644
index 00000000000..1b67e7354e0
--- /dev/null
+++ b/integration/tests/assert_header.output.json
@@ -0,0 +1,71 @@
+[
+  {
+    "filename": "tests/assert_header.hurl",
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "http://localhost:8000/assert-header"
+        },
+        "response": {
+          "httpVersion": "HTTP/1.0",
+          "status": 200
+        },
+        "asserts": [
+          {
+            "line": 2,
+            "success": true
+          },
+          {
+            "line": 2,
+            "success": true
+          },
+          {
+            "line": 3,
+            "success": true
+          },
+          {
+            "line": 4,
+            "success": true
+          },
+          {
+            "line": 5,
+            "success": true
+          },
+          {
+            "line": 7,
+            "success": true
+          },
+          {
+            "line": 8,
+            "success": true
+          },
+          {
+            "line": 9,
+            "success": true
+          },
+          {
+            "line": 10,
+            "success": true
+          },
+          {
+            "line": 11,
+            "success": true
+          },
+          {
+            "line": 12,
+            "success": true
+          },
+          {
+            "line": 13,
+            "success": true
+          },
+          {
+            "line": 14,
+            "success": true
+          }
+        ]
+      }
+    ]
+  }
+]
\ No newline at end of file
diff --git a/integration/tests/error_assert_match_utf8.output.json b/integration/tests/error_assert_match_utf8.output.json
new file mode 100644
index 00000000000..97e8f039fc9
--- /dev/null
+++ b/integration/tests/error_assert_match_utf8.output.json
@@ -0,0 +1,32 @@
+[
+  {
+    "filename": "tests/error_assert_match_utf8.hurl",
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "http://localhost:8000/error-assert/match-utf8"
+        },
+        "response": {
+          "httpVersion": "HTTP/1.0",
+          "status": 200
+        },
+        "asserts": [
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": false,
+            "message": "Invalid Decoding\n  --> tests/error_assert_match_utf8.hurl:4:1\n   |\n 4 | body matches \".*\"\n   | ^^^^ The body can not be decoded with charset 'utf-8'\n   |",
+            "line": 4
+          }
+        ]
+      }
+    ]
+  }
+]
diff --git a/integration/tests/error_assert_status.output.json b/integration/tests/error_assert_status.output.json
new file mode 100644
index 00000000000..1a817de882b
--- /dev/null
+++ b/integration/tests/error_assert_status.output.json
@@ -0,0 +1,28 @@
+[
+  {
+    "filename": "tests/error_assert_status.hurl",
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "http://localhost:8000/not_found"
+        },
+        "response": {
+          "httpVersion": "HTTP/1.0",
+          "status": 404
+        },
+        "asserts": [
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": false,
+            "message": "Assert Status\n  --> tests/error_assert_status.hurl:2:10\n   |\n 2 | HTTP/1.0 200\n   |          ^^^ actual value is <404>\n   |",
+            "line": 2
+          }
+        ]
+      }
+    ]
+  }
+]
diff --git a/integration/tests/error_assert_template_variable_not_found.output.json b/integration/tests/error_assert_template_variable_not_found.output.json
new file mode 100644
index 00000000000..8cc145baeb3
--- /dev/null
+++ b/integration/tests/error_assert_template_variable_not_found.output.json
@@ -0,0 +1,32 @@
+[
+  {
+    "filename": "tests/error_assert_template_variable_not_found.hurl",
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "http://localhost:8000/error-assert-template-variable-not-found"
+        },
+        "response": {
+          "httpVersion": "HTTP/1.0",
+          "status": 200
+        },
+        "asserts": [
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": false,
+            "message": "Undefined Variable\n  --> tests/error_assert_template_variable_not_found.hurl:4:33\n   |\n 4 | header \"content-type\" equals \"{{content_type}}\"\n   |                                 ^^^^^^^^^^^^ You must set the variable content_type\n   |",
+            "line": 4
+          }
+        ]
+      }
+    ]
+  }
+]
diff --git a/integration/tests/error_assert_value_error.output.json b/integration/tests/error_assert_value_error.output.json
new file mode 100644
index 00000000000..94d5f01c289
--- /dev/null
+++ b/integration/tests/error_assert_value_error.output.json
@@ -0,0 +1,67 @@
+[
+  {
+    "filename": "tests/error_assert_value_error.hurl",
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "http://localhost:8000/error-assert-value"
+        },
+        "response": {
+          "httpVersion": "HTTP/1.0",
+          "status": 200
+        },
+        "asserts": [
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:4:0\n   |\n 4 | header \"content-type\" equals \"XXX\"\n   |   actual:   string <text/html; charset=utf-8>\n   |   expected: string <XXX>\n   |",
+            "line": 4
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:5:0\n   |\n 5 | header \"content-type\" notEquals \"text/html; charset=utf-8\"\n   |   actual:   string <text/html; charset=utf-8>\n   |   expected: string <text/html; charset=utf-8>\n   |",
+            "line": 5
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:6:0\n   |\n 6 | jsonpath \"$.id\" equals \"000001\"\n   |   actual:   none\n   |   expected: string <000001>\n   |",
+            "line": 6
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:7:0\n   |\n 7 | jsonpath \"$.values\" includes 100\n   |   actual:   [int <1>, int <2>, int <3>]\n   |   expected: includes int <100>\n   |",
+            "line": 7
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:8:0\n   |\n 8 | jsonpath \"$.values\" not contains \"Hello\"\n   |   actual:   [int <1>, int <2>, int <3>]\n   |   expected: not contains string <Hello>\n   |   >>> types between actual and expected are not consistent\n   |",
+            "line": 8
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:9:0\n   |\n 9 | jsonpath \"$.count\" greaterThan 5\n   |   actual:   int <2>\n   |   expected: greater than int <5>\n   |",
+            "line": 9
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:10:0\n   |\n10 | jsonpath \"$.count\" isFloat\n   |   actual:   int <2>\n   |   expected: float\n   |",
+            "line": 10
+          },
+          {
+            "success": false,
+            "message": "Assert Failure\n  --> tests/error_assert_value_error.hurl:11:0\n   |\n11 | bytes contains hex,00;\n   |   actual:   byte array <7b202276616c756573223a205b312c322c335d2c2022636f756e74223a20327d>\n   |   expected: contains byte array <00>\n   |",
+            "line": 11
+          }
+        ]
+      }
+    ]
+  }
+]
diff --git a/integration/tests/error_query_header_not_found.output.json b/integration/tests/error_query_header_not_found.output.json
new file mode 100644
index 00000000000..ad0ba9ee604
--- /dev/null
+++ b/integration/tests/error_query_header_not_found.output.json
@@ -0,0 +1,32 @@
+[
+  {
+    "filename": "tests/error_query_header_not_found.hurl",
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "http://localhost:8000/error-query-header-not-found"
+        },
+        "response": {
+          "httpVersion": "HTTP/1.0",
+          "status": 200
+        },
+        "asserts": [
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": false,
+            "message": "Header not Found\n  --> tests/error_query_header_not_found.hurl:3:1\n   |\n 3 | Custom: XXX\n   | ^^^^^^ This header has not been found in the response\n   |",
+            "line": 3
+          }
+        ]
+      }
+    ]
+  }
+]
diff --git a/integration/tests/hello.output.json b/integration/tests/hello.output.json
index fc2d532376a..dbee9543d69 100644
--- a/integration/tests/hello.output.json
+++ b/integration/tests/hello.output.json
@@ -13,11 +13,17 @@
         },
         "asserts": [
           {
-            "actual": "1.0",
-            "expected": "1.0"
+            "success": true,
+            "line": 2
           },
-          {},
-          {}
+          {
+            "success": true,
+            "line": 2
+          },
+          {
+            "success": true,
+            "line": 3
+          }
         ]
       },
       {
diff --git a/packages/hurl/src/json/result.rs b/packages/hurl/src/json/result.rs
index 95da7f5b3ca..3160d3a68fc 100644
--- a/packages/hurl/src/json/result.rs
+++ b/packages/hurl/src/json/result.rs
@@ -247,21 +247,21 @@ impl CaptureResult {
 }
 
 impl AssertResult {
-    fn to_json(&self, _lines: &[String], _filename: String) -> serde_json::Value {
+    fn to_json(&self, lines: &[String], filename: String) -> serde_json::Value {
         let mut map = serde_json::Map::new();
-        if let AssertResult::Version {
-            actual, expected, ..
-        } = self
-        {
-            map.insert(
-                "actual".to_string(),
-                serde_json::Value::String(actual.clone()),
-            );
-            map.insert(
-                "expected".to_string(),
-                serde_json::Value::String(expected.clone()),
-            );
-        };
+
+        let success = self.clone().error().is_none();
+        map.insert("success".to_string(), serde_json::Value::Bool(success));
+
+        if let Some(err) = self.clone().error() {
+            let message = crate::cli::error_string(lines, filename, &err);
+            map.insert("message".to_string(), serde_json::Value::String(message));
+        }
+        map.insert(
+            "line".to_string(),
+            serde_json::Value::Number(serde_json::Number::from(self.line())),
+        );
+
         serde_json::Value::Object(map)
     }
 }
diff --git a/packages/hurl/src/runner/assert.rs b/packages/hurl/src/runner/assert.rs
index fb3c6218fd9..224a6fd6468 100644
--- a/packages/hurl/src/runner/assert.rs
+++ b/packages/hurl/src/runner/assert.rs
@@ -126,6 +126,15 @@ impl AssertResult {
             _ => None,
         }
     }
+    pub fn line(&self) -> usize {
+        match self {
+            AssertResult::Version { source_info, .. } => source_info.start.line,
+            AssertResult::Status { source_info, .. } => source_info.start.line,
+            AssertResult::Header { source_info, .. } => source_info.start.line,
+            AssertResult::Body { source_info, .. } => source_info.start.line,
+            AssertResult::Explicit { source_info, .. } => source_info.start.line,
+        }
+    }
 }
 
 pub fn eval_assert(