diff --git a/package.json b/package.json
index 2828c60..acc1446 100644
--- a/package.json
+++ b/package.json
@@ -108,6 +108,16 @@
           "light": "./icons/fauna.svg",
           "dark": "./icons/fauna-light.svg"
         }
+      },
+      {
+        "id": "fsl",
+        "extensions": [
+          ".fsl"
+        ],
+        "icon": {
+          "light": "./icons/fauna.svg",
+          "dark": "./icons/fauna-light.svg"
+        }
       }
     ],
     "grammars": [
@@ -115,6 +125,11 @@
         "language": "fql",
         "scopeName": "source.fql",
         "path": "./syntax/fql.tmGrammar.json"
+      },
+      {
+        "language": "fsl",
+        "scopeName": "source.fsl",
+        "path": "./syntax/fsl.tmGrammar.json"
       }
     ],
     "keybindings": [
diff --git a/syntax/fsl.tmGrammar.json b/syntax/fsl.tmGrammar.json
new file mode 100644
index 0000000..437c434
--- /dev/null
+++ b/syntax/fsl.tmGrammar.json
@@ -0,0 +1,155 @@
+{
+  "name": "fsl",
+  "scopeName": "source.fsl",
+  "patterns": [
+    {
+      "comment": "Single-line comment",
+      "name": "comment.line.double-slash.fsl",
+      "begin": "//",
+      "end": "$"
+    },
+    {
+      "include": "#block_comment"
+    },
+    {
+      "comment": "Function body",
+      "name": "constant.function.fsl",
+      "begin": "\\b(function)\\s+([a-zA-Z_][a-zA-Z0-9_]*)\\s*\\([\\S\\s]*\\)\\s*(:[\\S\\s]*)?\\s*{",
+      "end": "}",
+      "captures": {
+        "1": {
+          "name": "keyword.control.fsl"
+        },
+        "2": {
+          "name": "entity.name.function.fsl"
+        }
+      },
+      "patterns": [
+        {
+          "include": "source.fql"
+        }
+      ]
+    },
+    {
+      "comment": "Schema block",
+      "name": "constant.block.fsl",
+      "match": "\\b(collection|role|index|privileges|membership|(access\\s+provider))\\b(\\s+[a-zA-Z_][a-zA-Z0-9_]*)?",
+      "captures": {
+        "1": {
+          "name": "keyword.control.fsl"
+        },
+        "3": {
+          "name": "entity.name.type.fsl"
+        }
+      }
+    },
+    {
+      "comment": "Keyword",
+      "name": "keyword.control.fsl",
+      "match": "\\b(collection|function|role|access|provider|index|privileges|membership)\\b"
+    },
+    {
+      "comment": "Action keyword",
+      "name": "variable.other.constant.property",
+      "match": "\\b(create|delete|read|write|call|history_read|history_write|unrestricted_read)\\b"
+    },
+    {
+      "comment": "Field keyword",
+      "name": "variable.other.property",
+      "match": "\\b(terms|values|unique|predicate|history_days|ttl_days|issuer|jwks_uri)\\b"
+    },
+    {
+      "include": "#single_string_literal"
+    },
+    {
+      "include": "#double_string_literal"
+    },
+    {
+      "comment": "Floating point literal (fraction)",
+      "name": "constant.numeric.float.fsl",
+      "match": "\\b[+-]?[0-9][0-9_]*\\.[0-9][0-9_]*([eE][+-]?[0-9][0-9_]*)?\\b"
+    },
+    {
+      "comment": "Floating point literal (exponent)",
+      "name": "constant.numeric.float.fsl",
+      "match": "\\b[+-]?[0-9][0-9_]*(\\.[0-9][0-9_]*)?[eE][+-]?[0-9][0-9_]*\\b"
+    },
+    {
+      "comment": "Integer literal (decimal)",
+      "name": "constant.numeric.integer.decimal.fsl",
+      "match": "\\b[+-]?[0-9][0-9_]*\\b"
+    },
+    {
+      "comment": "Integer literal (hexadecimal)",
+      "name": "constant.numeric.integer.hexadecimal.fsl",
+      "match": "\\b[+-]?0[xX][0-9a-fA-F_]+\\b"
+    },
+    {
+      "comment": "Integer literal (octal)",
+      "name": "constant.numeric.integer.octal.fsl",
+      "match": "\\b[+-]?0[oO][0-7_]+\\b"
+    },
+    {
+      "comment": "Integer literal (binary)",
+      "name": "constant.numeric.integer.binary.fsl",
+      "match": "\\b[+-]?0[bB][01_]+\\b"
+    },
+    {
+      "comment": "Boolean constant",
+      "name": "constant.language.boolean.fsl",
+      "match": "\\b(true|false)\\b"
+    },
+    {
+      "comment": "Null constant",
+      "name": "constant.language.null.fsl",
+      "match": "\\bnull\\b"
+    }
+  ],
+  "repository": {
+    "block_comment": {
+      "comment": "Block comment",
+      "name": "comment.block.fsl",
+      "begin": "/\\*",
+      "end": "\\*/",
+      "patterns": [
+        {
+          "include": "#block_comment"
+        }
+      ]
+    },
+    "escaped_character": {
+      "name": "constant.character.escape.fsl",
+      "match": "\\\\([\\\\0'\"`nrvtbf#]|x[0-9a-fA-F]{2}|u[0-9a-fA-F]{2}|u\\{[01]0[0-9a-fA-F]{0,4}\\}|u\\{[0-9a-fA-F]{1,4}\\})"
+    },
+    "interpolated_value": {
+      "name": "constant.character.escape.fsl",
+      "begin": "#{",
+      "end": "}"
+    },
+    "single_string_literal": {
+      "comment": "String literal (single quotes)",
+      "name": "string.quoted.single.fsl",
+      "begin": "'",
+      "end": "'",
+      "patterns": [
+        {
+          "include": "#escaped_character"
+        }
+      ]
+    },
+    "double_string_literal": {
+      "comment": "String literal (double quotes)",
+      "name": "string.quoted.double.fsl",
+      "begin": "\"",
+      "end": "\"",
+      "patterns": [
+        {
+          "include": "#escaped_character"
+        },
+        {
+          "include": "#interpolated_value"
+        }
+      ]
+    }
+  }
+}