diff --git a/package-lock.json b/package-lock.json
index 11c8f9f..928096b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@archiewood/markdoc",
-  "version": "0.0.0-evidence.17",
+  "version": "0.0.0-evidence.29",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@archiewood/markdoc",
-      "version": "0.0.0-evidence.17",
+      "version": "0.0.0-evidence.29",
       "license": "MIT",
       "devDependencies": {
         "@types/jasmine": "^3.10.2",
diff --git a/package.json b/package.json
index 8cf3c28..d580bd7 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
-  "name": "@hughess/markdoc",
+  "name": "@archiewood/markdoc",
   "author": "Ryan Paul",
-  "version": "0.0.0-evidence.28",
+  "version": "0.0.0-evidence.29",
   "description": "A text markup language for documentation",
   "main": "dist/index.js",
   "module": "dist/index.mjs",
diff --git a/spec/marktest/tests.yaml b/spec/marktest/tests.yaml
index 15aa1e8..9ef20ef 100644
--- a/spec/marktest/tests.yaml
+++ b/spec/marktest/tests.yaml
@@ -2302,3 +2302,141 @@
       children:
         - tag: p
           children: [This is a test]
+
+- name: Triple-quoted string attribute
+  config:
+    tags:
+      test:
+        render: test
+        attributes:
+          bar:
+            type: String
+            render: true
+  code: |
+    {% test bar="""simple string""" /%}
+  expected:
+    - tag: test
+      attributes:
+        bar: 'simple string'
+
+- name: Triple-quoted string with quotes inside
+  config:
+    tags:
+      test:
+        render: test
+        attributes:
+          bar:
+            type: String
+            render: true
+  code: |
+    {% test bar="""He said "hello" and 'goodbye'""" /%}
+  expected:
+    - tag: test
+      attributes:
+        bar: 'He said "hello" and ''goodbye'''
+
+- name: Triple-quoted string with newlines
+  config:
+    tags:
+      test:
+        render: test
+        attributes:
+          query:
+            type: String
+            render: true
+  code: |
+    {% test query="""
+    SELECT *
+    FROM users
+    WHERE active = true
+    """ /%}
+  expected:
+    - tag: test
+      attributes:
+        query: "\nSELECT *\nFROM users\nWHERE active = true\n"
+
+- name: Triple-quoted string with SQL CASE statement
+  config:
+    tags:
+      table:
+        render: table
+        attributes:
+          series:
+            type: String
+            render: true
+  code: |
+    {% table series="""
+        case
+            when total_sales > 18000 then 'High'
+            when total_sales > 9000 then 'Medium'
+            else 'Low'
+        end
+    """ /%}
+  expected:
+    - tag: table
+      attributes:
+        series: "\n    case\n        when total_sales > 18000 then 'High'\n        when total_sales > 9000 then 'Medium'\n        else 'Low'\n    end\n"
+
+- name: Mixed regular and triple-quoted strings
+  config:
+    tags:
+      test:
+        render: test
+        attributes:
+          foo:
+            type: String
+            render: true
+          bar:
+            type: String
+            render: true
+          baz:
+            type: Boolean
+            render: true
+  code: |
+    {% test foo="regular" bar="""triple
+    quoted""" baz=true /%}
+  expected:
+    - tag: test
+      attributes:
+        foo: 'regular'
+        bar: "triple\nquoted"
+        baz: true
+
+- name: Empty triple-quoted string
+  config:
+    tags:
+      test:
+        render: test
+        attributes:
+          bar:
+            type: String
+            render: true
+  code: |
+    {% test bar="""""" /%}
+  expected:
+    - tag: test
+      attributes:
+        bar: ''
+
+- name: Triple-quoted string with interpolation
+  config:
+    variables:
+      condition: "status = 'active'"
+    tags:
+      test:
+        render: test
+        attributes:
+          query:
+            type: String
+            render: true
+  code: |
+    {% test query="""
+    SELECT *
+    FROM users
+    WHERE {{$condition}}
+    """ /%}
+  expected:
+    - tag: test
+      attributes:
+        query: "\nSELECT *\nFROM users\nWHERE status = 'active'\n"
+
diff --git a/src/grammar/tag.js b/src/grammar/tag.js
index 67ab2c3..6e0ca5f 100644
--- a/src/grammar/tag.js
+++ b/src/grammar/tag.js
@@ -168,11 +168,12 @@ function peg$parse(input, options) {
   var peg$c12 = '{';
   var peg$c13 = '}';
   var peg$c14 = '-';
-  var peg$c15 = '"';
-  var peg$c16 = '\\';
-  var peg$c17 = 'n';
-  var peg$c18 = 'r';
-  var peg$c19 = 't';
+  var peg$c15 = '"""';
+  var peg$c16 = '"';
+  var peg$c17 = '\\';
+  var peg$c18 = 'n';
+  var peg$c19 = 'r';
+  var peg$c20 = 't';
 
   var peg$r0 = /^[$@]/;
   var peg$r1 = /^[0-9]/;
@@ -302,16 +303,19 @@ function peg$parse(input, options) {
   var peg$f28 = function (value) {
     return value.join('');
   };
-  var peg$f29 = function () {
-    return '\n';
+  var peg$f29 = function (char) {
+    return char;
   };
   var peg$f30 = function () {
-    return '\r';
+    return '\n';
   };
   var peg$f31 = function () {
+    return '\r';
+  };
+  var peg$f32 = function () {
     return '\t';
   };
-  var peg$f32 = function (sequence) {
+  var peg$f33 = function (sequence) {
     return sequence;
   };
 
@@ -1646,7 +1650,7 @@ function peg$parse(input, options) {
   }
 
   function peg$parseValueString() {
-    var s0, s1, s2, s3;
+    var s0;
 
     var rule$expects = function (expected) {
       if (peg$silentFails === 0) peg$expect(expected);
@@ -1654,9 +1658,112 @@ function peg$parse(input, options) {
 
     rule$expects(peg$e16);
     peg$silentFails++;
+    s0 = peg$parseValueTripleQuotedString();
+    if (s0 === peg$FAILED) {
+      s0 = peg$parseValueQuotedString();
+    }
+    peg$silentFails--;
+
+    return s0;
+  }
+
+  function peg$parseValueTripleQuotedString() {
+    var s0, s1, s2, s3;
+
+    var rule$expects = function (expected) {
+      if (peg$silentFails === 0) peg$expect(expected);
+    };
+
     s0 = peg$currPos;
-    if (input.charCodeAt(peg$currPos) === 34) {
+    if (input.substr(peg$currPos, 3) === peg$c15) {
       s1 = peg$c15;
+      peg$currPos += 3;
+    } else {
+      s1 = peg$FAILED;
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = [];
+      s3 = peg$parseValueTripleQuotedChars();
+      while (s3 !== peg$FAILED) {
+        s2.push(s3);
+        s3 = peg$parseValueTripleQuotedChars();
+      }
+      if (input.substr(peg$currPos, 3) === peg$c15) {
+        s3 = peg$c15;
+        peg$currPos += 3;
+      } else {
+        s3 = peg$FAILED;
+      }
+      if (s3 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s0 = peg$f28(s2);
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    return s0;
+  }
+
+  function peg$parseValueTripleQuotedChars() {
+    var s0, s1, s2;
+
+    var rule$expects = function (expected) {
+      if (peg$silentFails === 0) peg$expect(expected);
+    };
+
+    s0 = peg$currPos;
+    s1 = peg$currPos;
+    peg$begin();
+    if (input.substr(peg$currPos, 3) === peg$c15) {
+      s2 = peg$c15;
+      peg$currPos += 3;
+    } else {
+      s2 = peg$FAILED;
+    }
+    peg$end(true);
+    if (s2 === peg$FAILED) {
+      s1 = undefined;
+    } else {
+      peg$currPos = s1;
+      s1 = peg$FAILED;
+    }
+    if (s1 !== peg$FAILED) {
+      if (input.length > peg$currPos) {
+        s2 = input.charAt(peg$currPos);
+        peg$currPos++;
+      } else {
+        s2 = peg$FAILED;
+      }
+      if (s2 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s0 = peg$f29(s2);
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    return s0;
+  }
+
+  function peg$parseValueQuotedString() {
+    var s0, s1, s2, s3;
+
+    var rule$expects = function (expected) {
+      if (peg$silentFails === 0) peg$expect(expected);
+    };
+
+    s0 = peg$currPos;
+    if (input.charCodeAt(peg$currPos) === 34) {
+      s1 = peg$c16;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
@@ -1669,7 +1776,7 @@ function peg$parse(input, options) {
         s3 = peg$parseValueStringChars();
       }
       if (input.charCodeAt(peg$currPos) === 34) {
-        s3 = peg$c15;
+        s3 = peg$c16;
         peg$currPos++;
       } else {
         s3 = peg$FAILED;
@@ -1685,7 +1792,6 @@ function peg$parse(input, options) {
       peg$currPos = s0;
       s0 = peg$FAILED;
     }
-    peg$silentFails--;
 
     return s0;
   }
@@ -1719,21 +1825,21 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 92) {
-      s1 = peg$c16;
+      s1 = peg$c17;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
     }
     if (s1 !== peg$FAILED) {
       if (input.charCodeAt(peg$currPos) === 34) {
-        s2 = peg$c15;
+        s2 = peg$c16;
         peg$currPos++;
       } else {
         s2 = peg$FAILED;
       }
       if (s2 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 92) {
-          s2 = peg$c16;
+          s2 = peg$c17;
           peg$currPos++;
         } else {
           s2 = peg$FAILED;
@@ -1741,40 +1847,40 @@ function peg$parse(input, options) {
         if (s2 === peg$FAILED) {
           s2 = peg$currPos;
           if (input.charCodeAt(peg$currPos) === 110) {
-            s3 = peg$c17;
+            s3 = peg$c18;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s2;
-            s3 = peg$f29();
+            s3 = peg$f30();
           }
           s2 = s3;
           if (s2 === peg$FAILED) {
             s2 = peg$currPos;
             if (input.charCodeAt(peg$currPos) === 114) {
-              s3 = peg$c18;
+              s3 = peg$c19;
               peg$currPos++;
             } else {
               s3 = peg$FAILED;
             }
             if (s3 !== peg$FAILED) {
               peg$savedPos = s2;
-              s3 = peg$f30();
+              s3 = peg$f31();
             }
             s2 = s3;
             if (s2 === peg$FAILED) {
               s2 = peg$currPos;
               if (input.charCodeAt(peg$currPos) === 116) {
-                s3 = peg$c19;
+                s3 = peg$c20;
                 peg$currPos++;
               } else {
                 s3 = peg$FAILED;
               }
               if (s3 !== peg$FAILED) {
                 peg$savedPos = s2;
-                s3 = peg$f31();
+                s3 = peg$f32();
               }
               s2 = s3;
             }
@@ -1783,7 +1889,7 @@ function peg$parse(input, options) {
       }
       if (s2 !== peg$FAILED) {
         peg$savedPos = s0;
-        s0 = peg$f32(s2);
+        s0 = peg$f33(s2);
       } else {
         peg$currPos = s0;
         s0 = peg$FAILED;
diff --git a/src/grammar/tag.pegjs b/src/grammar/tag.pegjs
index 8db36f5..4432998 100644
--- a/src/grammar/tag.pegjs
+++ b/src/grammar/tag.pegjs
@@ -159,6 +159,16 @@ ValueNumber 'number' =
   '-'? [0-9]+ ('.'[0-9]+)? { return parseFloat(text()); }
 
 ValueString 'string' =
+  ValueTripleQuotedString /
+  ValueQuotedString
+
+ValueTripleQuotedString =
+  '"""' value:ValueTripleQuotedChars* '"""' { return value.join(''); }
+
+ValueTripleQuotedChars =
+  !'"""' char:. { return char; }
+
+ValueQuotedString =
   '"' value:ValueStringChars* '"' { return value.join(''); }
 
 ValueStringChars = 
diff --git a/src/grammar/tag.test.ts b/src/grammar/tag.test.ts
index 4b71474..08d4c6b 100644
--- a/src/grammar/tag.test.ts
+++ b/src/grammar/tag.test.ts
@@ -356,5 +356,67 @@ describe('Markdoc tag parser', function () {
       for (const example of examples)
         expect(() => parse(example)).toThrowError(SyntaxError);
     });
+
+    describe('with triple-quoted strings', function () {
+      it('with a simple triple-quoted string', function () {
+        const example = parse('foo="""bar"""');
+        expect(example.meta.attributes).toDeepEqual([
+          { type: 'attribute', name: 'foo', value: 'bar' },
+        ]);
+      });
+
+      it('with multi-line triple-quoted string', function () {
+        const example = parse('foo="""line1\nline2\nline3"""');
+        expect(example.meta.attributes).toDeepEqual([
+          { type: 'attribute', name: 'foo', value: 'line1\nline2\nline3' },
+        ]);
+      });
+
+      it('with quotes inside triple-quoted string', function () {
+        const example = parse('foo="""He said "hello"!"""');
+        expect(example.meta.attributes).toDeepEqual([
+          { type: 'attribute', name: 'foo', value: 'He said "hello"!' },
+        ]);
+      });
+
+      it('with SQL case statement', function () {
+        const example = parse(`series="""
+        case
+            when total_sales > 18000 then 'High'
+            when total_sales > 9000 then 'Medium'
+            else 'Low'
+        end
+    """`);
+        expect(example.meta.attributes).toDeepEqual([
+          {
+            type: 'attribute',
+            name: 'series',
+            value: `
+        case
+            when total_sales > 18000 then 'High'
+            when total_sales > 9000 then 'Medium'
+            else 'Low'
+        end
+    `,
+          },
+        ]);
+      });
+
+      it('with multiple attributes including triple-quoted', function () {
+        const example = parse('foo="bar" baz="""multi\nline""" test=true');
+        expect(example.meta.attributes).toDeepEqual([
+          { type: 'attribute', name: 'foo', value: 'bar' },
+          { type: 'attribute', name: 'baz', value: 'multi\nline' },
+          { type: 'attribute', name: 'test', value: true },
+        ]);
+      });
+
+      it('with empty triple-quoted string', function () {
+        const example = parse('foo=""""""');
+        expect(example.meta.attributes).toDeepEqual([
+          { type: 'attribute', name: 'foo', value: '' },
+        ]);
+      });
+    });
   });
 });
diff --git a/src/utils.test.ts b/src/utils.test.ts
index b39301e..ecabd20 100644
--- a/src/utils.test.ts
+++ b/src/utils.test.ts
@@ -182,6 +182,67 @@ describe('Templating', function () {
         },
       ]);
     });
+
+    describe('triple-quoted strings', function () {
+      it('with simple triple-quoted string', function () {
+        const example = '{% foo bar="""test""" %}';
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(22);
+        expect(example[end]).toEqual('%');
+      });
+
+      it('with multi-line triple-quoted string', function () {
+        const example = '{% foo bar="""line1\nline2\nline3""" %}';
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(35);
+        expect(example[end]).toEqual('%');
+      });
+
+      it('with quotes inside triple-quoted string', function () {
+        const example = '{% foo bar="""He said "hello"!""" %}';
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(34);
+        expect(example[end]).toEqual('%');
+      });
+
+      it('with multi-line SQL case statement', function () {
+        const example = `{% table
+    data="demo_daily_orders"
+    date="date"
+    series="""
+        case
+            when total_sales > 18000 then 'High'
+            when total_sales > 9000 then 'Medium'
+            else 'Low'
+        end
+    """
+/%}`;
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(example.length - 2);
+        expect(example[end]).toEqual('%');
+      });
+
+      it('with multiple attributes including triple-quoted', function () {
+        const example = '{% foo bar="test" baz="""multi\nline""" test=true %}';
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(49);
+        expect(example[end]).toEqual('%');
+      });
+
+      it('with empty triple-quoted string', function () {
+        const example = '{% foo bar="""""" %}';
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(18);
+        expect(example[end]).toEqual('%');
+      });
+
+      it('with triple-quoted and regular quoted strings', function () {
+        const example = '{% foo a="first" b="""second""" c="third" %}';
+        const end = findTagEnd(example, 2);
+        expect(end).toEqual(42);
+        expect(example[end]).toEqual('%');
+      });
+    });
   });
 
   describe('interpolateString', function () {
diff --git a/src/utils.ts b/src/utils.ts
index 5b3c81b..aaebce4 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -8,6 +8,7 @@ enum STATES {
   normal,
   string,
   escape,
+  triple_string,
 }
 
 export const OPEN = '{%';
@@ -154,9 +155,21 @@ export function findTagEnd(content: string, start = 0) {
       case STATES.escape:
         state = STATES.string;
         break;
+      case STATES.triple_string:
+        if (char === '"' && content[pos + 1] === '"' && content[pos + 2] === '"') {
+          state = STATES.normal;
+          pos += 2; // Skip the next two quotes
+        }
+        break;
       case STATES.normal:
-        if (char === '"') state = STATES.string;
-        else if (content.startsWith(CLOSE, pos)) return pos;
+        if (char === '"' && content[pos + 1] === '"' && content[pos + 2] === '"') {
+          state = STATES.triple_string;
+          pos += 2; // Skip the next two quotes
+        } else if (char === '"') {
+          state = STATES.string;
+        } else if (content.startsWith(CLOSE, pos)) {
+          return pos;
+        }
     }
   }