diff --git a/crates/aiken-lang/src/ast.rs b/crates/aiken-lang/src/ast.rs
index 6c807bc9..63afd819 100644
--- a/crates/aiken-lang/src/ast.rs
+++ b/crates/aiken-lang/src/ast.rs
@@ -326,11 +326,21 @@ pub struct DefinitionLocation<'module> {
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum Constant {
-    Int { location: Span, value: String },
+    Int {
+        location: Span,
+        value: String,
+    },
 
-    String { location: Span, value: String },
+    String {
+        location: Span,
+        value: String,
+    },
 
-    ByteArray { location: Span, bytes: Vec<u8> },
+    ByteArray {
+        location: Span,
+        bytes: Vec<u8>,
+        preferred_format: ByteArrayFormatPreference,
+    },
 }
 
 impl Constant {
@@ -748,6 +758,13 @@ impl<A, B> Pattern<A, B> {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Copy)]
+pub enum ByteArrayFormatPreference {
+    HexadecimalString,
+    ArrayOfBytes,
+    Utf8String,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Copy)]
 pub enum AssignmentKind {
     Let,
diff --git a/crates/aiken-lang/src/expr.rs b/crates/aiken-lang/src/expr.rs
index 2ce99d3b..8f6ac7c9 100644
--- a/crates/aiken-lang/src/expr.rs
+++ b/crates/aiken-lang/src/expr.rs
@@ -4,9 +4,9 @@ use vec1::Vec1;
 
 use crate::{
     ast::{
-        Annotation, Arg, AssignmentKind, BinOp, CallArg, Clause, DefinitionLocation, IfBranch,
-        Pattern, RecordUpdateSpread, Span, TraceKind, TypedRecordUpdateArg, UnOp,
-        UntypedRecordUpdateArg,
+        Annotation, Arg, AssignmentKind, BinOp, ByteArrayFormatPreference, CallArg, Clause,
+        DefinitionLocation, IfBranch, Pattern, RecordUpdateSpread, Span, TraceKind,
+        TypedRecordUpdateArg, UnOp, UntypedRecordUpdateArg,
     },
     builtins::void,
     tipo::{ModuleValueConstructor, PatternConstructor, Type, ValueConstructor},
@@ -361,6 +361,7 @@ pub enum UntypedExpr {
     ByteArray {
         location: Span,
         bytes: Vec<u8>,
+        preferred_format: ByteArrayFormatPreference,
     },
 
     PipeLine {
diff --git a/crates/aiken-lang/src/format.rs b/crates/aiken-lang/src/format.rs
index ffeeca5d..8c5a82ba 100644
--- a/crates/aiken-lang/src/format.rs
+++ b/crates/aiken-lang/src/format.rs
@@ -5,12 +5,12 @@ use vec1::Vec1;
 
 use crate::{
     ast::{
-        Annotation, Arg, ArgName, AssignmentKind, BinOp, CallArg, ClauseGuard, Constant, DataType,
-        Definition, Function, IfBranch, ModuleConstant, Pattern, RecordConstructor,
-        RecordConstructorArg, RecordUpdateSpread, Span, TraceKind, TypeAlias, TypedArg, UnOp,
-        UnqualifiedImport, UntypedArg, UntypedClause, UntypedClauseGuard, UntypedDefinition,
-        UntypedFunction, UntypedModule, UntypedPattern, UntypedRecordUpdateArg, Use, Validator,
-        CAPTURE_VARIABLE,
+        Annotation, Arg, ArgName, AssignmentKind, BinOp, ByteArrayFormatPreference, CallArg,
+        ClauseGuard, Constant, DataType, Definition, Function, IfBranch, ModuleConstant, Pattern,
+        RecordConstructor, RecordConstructorArg, RecordUpdateSpread, Span, TraceKind, TypeAlias,
+        TypedArg, UnOp, UnqualifiedImport, UntypedArg, UntypedClause, UntypedClauseGuard,
+        UntypedDefinition, UntypedFunction, UntypedModule, UntypedPattern, UntypedRecordUpdateArg,
+        Use, Validator, CAPTURE_VARIABLE,
     },
     docvec,
     expr::{UntypedExpr, DEFAULT_ERROR_STR, DEFAULT_TODO_STR},
@@ -326,7 +326,11 @@ impl<'comments> Formatter<'comments> {
 
     fn const_expr<'a>(&mut self, value: &'a Constant) -> Document<'a> {
         match value {
-            Constant::ByteArray { bytes, .. } => self.bytearray(bytes),
+            Constant::ByteArray {
+                bytes,
+                preferred_format,
+                ..
+            } => self.bytearray(bytes, preferred_format),
             Constant::Int { value, .. } => value.to_doc(),
             Constant::String { value, .. } => self.string(value),
         }
@@ -635,18 +639,43 @@ impl<'comments> Formatter<'comments> {
         }
     }
 
-    pub fn bytearray<'a>(&mut self, bytes: &'a [u8]) -> Document<'a> {
-        "#".to_doc()
-            .append("\"")
-            .append(Document::String(hex::encode(bytes)))
-            .append("\"")
+    pub fn bytearray<'a>(
+        &mut self,
+        bytes: &'a [u8],
+        preferred_format: &ByteArrayFormatPreference,
+    ) -> Document<'a> {
+        match preferred_format {
+            ByteArrayFormatPreference::HexadecimalString => "#"
+                .to_doc()
+                .append("\"")
+                .append(Document::String(hex::encode(bytes)))
+                .append("\""),
+            ByteArrayFormatPreference::ArrayOfBytes => "#"
+                .to_doc()
+                .append(
+                    flex_break("[", "[")
+                        .append(join(bytes.iter().map(|b| b.to_doc()), break_(",", ", ")))
+                        .nest(INDENT)
+                        .append(break_(",", ""))
+                        .append("]"),
+                )
+                .group(),
+            ByteArrayFormatPreference::Utf8String => nil()
+                .append("\"")
+                .append(Document::String(String::from_utf8(bytes.to_vec()).unwrap()))
+                .append("\""),
+        }
     }
 
     pub fn expr<'a>(&mut self, expr: &'a UntypedExpr) -> Document<'a> {
         let comments = self.pop_comments(expr.start_byte_index());
 
         let document = match expr {
-            UntypedExpr::ByteArray { bytes, .. } => self.bytearray(bytes),
+            UntypedExpr::ByteArray {
+                bytes,
+                preferred_format,
+                ..
+            } => self.bytearray(bytes, preferred_format),
 
             UntypedExpr::If {
                 branches,
@@ -741,7 +770,7 @@ impl<'comments> Formatter<'comments> {
     }
 
     fn string<'a>(&self, string: &'a String) -> Document<'a> {
-        let doc = string.to_doc().surround("\"", "\"");
+        let doc = "@".to_doc().append(string.to_doc().surround("\"", "\""));
         if string.contains('\n') {
             doc.force_break()
         } else {
diff --git a/crates/aiken-lang/src/parser.rs b/crates/aiken-lang/src/parser.rs
index fabdec17..abd82341 100644
--- a/crates/aiken-lang/src/parser.rs
+++ b/crates/aiken-lang/src/parser.rs
@@ -7,7 +7,10 @@ pub mod lexer;
 pub mod token;
 
 use crate::{
-    ast::{self, BinOp, Span, TraceKind, UnOp, UntypedDefinition, CAPTURE_VARIABLE},
+    ast::{
+        self, BinOp, ByteArrayFormatPreference, Span, TraceKind, UnOp, UntypedDefinition,
+        CAPTURE_VARIABLE,
+    },
     expr,
 };
 
@@ -402,9 +405,12 @@ fn constant_value_parser() -> impl Parser<Token, ast::Constant, Error = ParseErr
         });
 
     let constant_bytearray_parser =
-        bytearray_parser().map_with_span(|bytes, span| ast::Constant::ByteArray {
-            location: span,
-            bytes,
+        bytearray_parser().map_with_span(|(preferred_format, bytes), span| {
+            ast::Constant::ByteArray {
+                location: span,
+                bytes,
+                preferred_format,
+            }
         });
 
     choice((
@@ -414,42 +420,54 @@ fn constant_value_parser() -> impl Parser<Token, ast::Constant, Error = ParseErr
     ))
 }
 
-pub fn bytearray_parser() -> impl Parser<Token, Vec<u8>, Error = ParseError> {
-    let bytearray_list_parser = just(Token::Hash).ignore_then(
-        select! {Token::Int {value} => value}
-            .validate(|value, span, emit| {
-                let byte: u8 = match value.parse() {
-                    Ok(b) => b,
-                    Err(_) => {
-                        emit(ParseError::expected_input_found(
-                            span,
-                            None,
-                            Some(error::Pattern::Byte),
-                        ));
+pub fn bytearray_parser(
+) -> impl Parser<Token, (ByteArrayFormatPreference, Vec<u8>), Error = ParseError> {
+    let bytearray_list_parser = just(Token::Hash)
+        .ignore_then(
+            select! {Token::Int {value} => value}
+                .validate(|value, span, emit| {
+                    let byte: u8 = match value.parse() {
+                        Ok(b) => b,
+                        Err(_) => {
+                            emit(ParseError::expected_input_found(
+                                span,
+                                None,
+                                Some(error::Pattern::Byte),
+                            ));
 
-                        0
-                    }
-                };
+                            0
+                        }
+                    };
 
-                byte
-            })
-            .separated_by(just(Token::Comma))
-            .allow_trailing()
-            .delimited_by(just(Token::LeftSquare), just(Token::RightSquare)),
-    );
+                    byte
+                })
+                .separated_by(just(Token::Comma))
+                .allow_trailing()
+                .delimited_by(just(Token::LeftSquare), just(Token::RightSquare)),
+        )
+        .map(|token| (ByteArrayFormatPreference::ArrayOfBytes, token));
 
     let bytearray_hexstring_parser =
-        just(Token::Hash).ignore_then(select! {Token::String {value} => value}.validate(
-            |value, span, emit| match hex::decode(value) {
-                Ok(bytes) => bytes,
-                Err(_) => {
-                    emit(ParseError::malformed_base16_string_literal(span));
-                    vec![]
-                }
-            },
-        ));
+        just(Token::Hash)
+            .ignore_then(select! {Token::ByteString {value} => value}.validate(
+                |value, span, emit| match hex::decode(value) {
+                    Ok(bytes) => bytes,
+                    Err(_) => {
+                        emit(ParseError::malformed_base16_string_literal(span));
+                        vec![]
+                    }
+                },
+            ))
+            .map(|token| (ByteArrayFormatPreference::HexadecimalString, token));
 
-    choice((bytearray_list_parser, bytearray_hexstring_parser))
+    let bytearray_utf8_parser = select! {Token::ByteString {value} => value.into_bytes() }
+        .map(|token| (ByteArrayFormatPreference::Utf8String, token));
+
+    choice((
+        bytearray_list_parser,
+        bytearray_hexstring_parser,
+        bytearray_utf8_parser,
+    ))
 }
 
 pub fn fn_param_parser() -> impl Parser<Token, ast::UntypedArg, Error = ParseError> {
@@ -515,6 +533,25 @@ pub fn anon_fn_param_parser() -> impl Parser<Token, ast::UntypedArg, Error = Par
     })
 }
 
+// Interpret bytearray string literals written as utf-8 strings, as strings.
+//
+// This is mostly convenient so that todo & error works with either @"..." or plain "...".
+// In this particular context, there's actually no ambiguity about the right-hand-side, so
+// we can provide this syntactic sugar.
+fn flexible_string_literal(expr: expr::UntypedExpr) -> expr::UntypedExpr {
+    match expr {
+        expr::UntypedExpr::ByteArray {
+            preferred_format: ByteArrayFormatPreference::Utf8String,
+            bytes,
+            location,
+        } => expr::UntypedExpr::String {
+            location,
+            value: String::from_utf8(bytes).unwrap(),
+        },
+        _ => expr,
+    }
+}
+
 pub fn expr_seq_parser() -> impl Parser<Token, expr::UntypedExpr, Error = ParseError> {
     recursive(|r| {
         choice((
@@ -525,14 +562,18 @@ pub fn expr_seq_parser() -> impl Parser<Token, expr::UntypedExpr, Error = ParseE
                     kind: TraceKind::Trace,
                     location: span,
                     then: Box::new(then_),
-                    text: Box::new(text),
+                    text: Box::new(flexible_string_literal(text)),
                 }),
             just(Token::ErrorTerm)
                 .ignore_then(expr_parser(r.clone()).or_not())
-                .map_with_span(|reason, span| expr::UntypedExpr::error(span, reason)),
+                .map_with_span(|reason, span| {
+                    expr::UntypedExpr::error(span, reason.map(flexible_string_literal))
+                }),
             just(Token::Todo)
                 .ignore_then(expr_parser(r.clone()).or_not())
-                .map_with_span(|reason, span| expr::UntypedExpr::todo(span, reason)),
+                .map_with_span(|reason, span| {
+                    expr::UntypedExpr::todo(span, reason.map(flexible_string_literal))
+                }),
             expr_parser(r.clone())
                 .then(r.repeated())
                 .foldl(|current, next| current.append_in_sequence(next)),
@@ -816,11 +857,13 @@ pub fn expr_parser(
                 elems,
             });
 
-        let bytearray =
-            bytearray_parser().map_with_span(|bytes, span| expr::UntypedExpr::ByteArray {
+        let bytearray = bytearray_parser().map_with_span(|(preferred_format, bytes), span| {
+            expr::UntypedExpr::ByteArray {
                 location: span,
                 bytes,
-            });
+                preferred_format,
+            }
+        });
 
         let list_parser = just(Token::LeftSquare)
             .ignore_then(r.clone().separated_by(just(Token::Comma)))
@@ -904,14 +947,18 @@ pub fn expr_parser(
                             .then_ignore(one_of(Token::RArrow).not().rewind())
                             .or_not(),
                     )
-                    .map_with_span(|reason, span| expr::UntypedExpr::todo(span, reason)),
+                    .map_with_span(|reason, span| {
+                        expr::UntypedExpr::todo(span, reason.map(flexible_string_literal))
+                    }),
                 just(Token::ErrorTerm)
                     .ignore_then(
                         r.clone()
                             .then_ignore(just(Token::RArrow).not().rewind())
                             .or_not(),
                     )
-                    .map_with_span(|reason, span| expr::UntypedExpr::error(span, reason)),
+                    .map_with_span(|reason, span| {
+                        expr::UntypedExpr::error(span, reason.map(flexible_string_literal))
+                    }),
             )))
             .map_with_span(
                 |(((patterns, alternative_patterns_opt), guard), then), span| ast::UntypedClause {
diff --git a/crates/aiken-lang/src/parser/error.rs b/crates/aiken-lang/src/parser/error.rs
index 4b2d1055..639ce3cc 100644
--- a/crates/aiken-lang/src/parser/error.rs
+++ b/crates/aiken-lang/src/parser/error.rs
@@ -102,15 +102,18 @@ impl<T: Into<Pattern>> chumsky::Error<T> for ParseError {
 pub enum ErrorKind {
     #[error("I arrived at the end of the file unexpectedly.")]
     UnexpectedEnd,
+
     #[error("{0}")]
     #[diagnostic(help("{}", .0.help().unwrap_or_else(|| Box::new(""))))]
     Unexpected(Pattern),
+
     #[error("I discovered an invalid tuple index.")]
     #[diagnostic()]
     InvalidTupleIndex {
         #[help]
         hint: Option<String>,
     },
+
     #[error("I tripped over a malformed base16-encoded string literal.")]
     #[diagnostic(help("{}", formatdoc! {
         r#"You can declare literal bytearrays from base16-encoded (a.k.a. hexadecimal) string literals.
@@ -123,6 +126,7 @@ pub enum ErrorKind {
         "#
     , "pub const".bright_blue(), "=".yellow(), "\"f4c9f9c4252d86702c2f4c2e49e6648c7cffe3c8f2b6b7d779788f50\"".bright_purple()}))]
     MalformedBase16StringLiteral,
+
     #[error("I failed to understand a when clause guard.")]
     #[diagnostic(url("https://aiken-lang.org/language-tour/control-flow#checking-equality-and-ordering-in-patterns"))]
     #[diagnostic(help("{}", formatdoc! {
diff --git a/crates/aiken-lang/src/parser/lexer.rs b/crates/aiken-lang/src/parser/lexer.rs
index 9797cbe1..895533d8 100644
--- a/crates/aiken-lang/src/parser/lexer.rs
+++ b/crates/aiken-lang/src/parser/lexer.rs
@@ -77,13 +77,21 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = ParseError> {
             .or(just('t').to('\t')),
     );
 
-    let string = just('"')
+    let string = just('@')
+        .ignore_then(just('"'))
         .ignore_then(filter(|c| *c != '\\' && *c != '"').or(escape).repeated())
         .then_ignore(just('"'))
         .collect::<String>()
         .map(|value| Token::String { value })
         .labelled("string");
 
+    let bytestring = just('"')
+        .ignore_then(filter(|c| *c != '\\' && *c != '"').or(escape).repeated())
+        .then_ignore(just('"'))
+        .collect::<String>()
+        .map(|value| Token::ByteString { value })
+        .labelled("bytestring");
+
     let keyword = text::ident().map(|s: String| match s.as_str() {
         "trace" => Token::Trace,
         "error" => Token::ErrorTerm,
@@ -158,16 +166,18 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = ParseError> {
         comment_parser(Token::ModuleComment),
         comment_parser(Token::DocComment),
         comment_parser(Token::Comment),
-        choice((ordinal, keyword, int, op, newlines, grouping, string))
-            .or(any().map(Token::Error).validate(|t, span, emit| {
-                emit(ParseError::expected_input_found(
-                    span,
-                    None,
-                    Some(t.clone()),
-                ));
-                t
-            }))
-            .map_with_span(|token, span| (token, span)),
+        choice((
+            ordinal, keyword, int, op, newlines, grouping, bytestring, string,
+        ))
+        .or(any().map(Token::Error).validate(|t, span, emit| {
+            emit(ParseError::expected_input_found(
+                span,
+                None,
+                Some(t.clone()),
+            ));
+            t
+        }))
+        .map_with_span(|token, span| (token, span)),
     ))
     .padded_by(one_of(" \t").ignored().repeated())
     .recover_with(skip_then_retry_until([]))
diff --git a/crates/aiken-lang/src/parser/token.rs b/crates/aiken-lang/src/parser/token.rs
index 933944f8..bb836faa 100644
--- a/crates/aiken-lang/src/parser/token.rs
+++ b/crates/aiken-lang/src/parser/token.rs
@@ -8,6 +8,7 @@ pub enum Token {
     UpName { name: String },
     DiscardName { name: String },
     Int { value: String },
+    ByteString { value: String },
     String { value: String },
     // Groupings
     NewLineLeftParen, // ↳(
@@ -97,6 +98,7 @@ impl fmt::Display for Token {
             Token::DiscardName { name } => name,
             Token::Int { value } => value,
             Token::String { value } => value,
+            Token::ByteString { value } => value,
             Token::NewLineLeftParen => "↳(",
             Token::LeftParen => "(",
             Token::RightParen => ")",
diff --git a/crates/aiken-lang/src/tests/check.rs b/crates/aiken-lang/src/tests/check.rs
index 6a17c816..40227927 100644
--- a/crates/aiken-lang/src/tests/check.rs
+++ b/crates/aiken-lang/src/tests/check.rs
@@ -235,12 +235,12 @@ fn list_pattern_6() {
 fn trace_strings() {
     let source_code = r#"
         fn bar() {
-            "BAR"
+            @"BAR"
         }
 
         test foo() {
-            let msg1 = "FOO"
-            trace("INLINE")
+            let msg1 = @"FOO"
+            trace(@"INLINE")
             trace(msg1)
             trace(bar())
             True
@@ -305,3 +305,17 @@ fn trace_if_false_ko() {
         Err((_, Error::CouldNotUnify { .. }))
     ))
 }
+
+#[test]
+fn utf8_hex_literal_warning() {
+    let source_code = r#"
+        pub const policy_id = "f43a62fdc3965df486de8a0d32fe800963589c41b38946602a0dc535"
+    "#;
+
+    let (warnings, _) = check(parse(source_code)).unwrap();
+
+    assert!(matches!(
+        warnings[0],
+        Warning::Utf8ByteArrayIsValidHexString { .. }
+    ))
+}
diff --git a/crates/aiken-lang/src/tests/format.rs b/crates/aiken-lang/src/tests/format.rs
index 12d21276..0e3b82a1 100644
--- a/crates/aiken-lang/src/tests/format.rs
+++ b/crates/aiken-lang/src/tests/format.rs
@@ -311,22 +311,6 @@ fn test_block_logical_expr() {
     assert_fmt(src, expected);
 }
 
-#[test]
-fn test_format_bytearray_literals() {
-    let src = indoc! {r#"
-        const foo = #"ff00"
-        const bar = #[0, 255]
-    "#};
-
-    let expected = indoc! { r#"
-        const foo = #"ff00"
-
-        const bar = #"00ff"
-    "#};
-
-    assert_fmt(src, expected);
-}
-
 #[test]
 fn test_nested_function_calls() {
     let src = indoc! {r#"
@@ -360,7 +344,7 @@ fn test_nested_function_calls() {
             ),
             when output.datum is {
               InlineDatum(_) -> True
-              _ -> error "expected inline datum"
+              _ -> error @"expected inline datum"
             },
           ]
           |> list.and
@@ -398,7 +382,33 @@ fn format_trace_todo_error() {
         }
     "#};
 
-    assert_fmt(src, src);
+    let out = indoc! {r#"
+        fn foo_1() {
+          todo
+        }
+
+        fn foo_2() {
+          todo @"my custom message"
+        }
+
+        fn foo_3() {
+          when x is {
+            Foo -> True
+            _ -> error
+          }
+        }
+
+        fn foo_4() {
+          if 14 == 42 {
+            error @"I don't think so"
+          } else {
+            trace @"been there"
+            True
+          }
+        }
+    "#};
+
+    assert_fmt(src, out);
 }
 
 #[test]
@@ -503,3 +513,37 @@ fn test_newline_module_comments() {
 
     assert_fmt(src, out);
 }
+
+#[test]
+fn test_bytearray_literals() {
+    let src = indoc! {r#"
+        const foo_const_array = #[102, 111, 111]
+
+        const foo_const_hex = #"666f6f"
+
+        const foo_const_utf8 = "foo"
+
+        fn foo() {
+          let foo_const_array = #[102, 111, 111]
+
+          let foo_const_hex = #"666f6f"
+
+          let foo_const_utf8 = "foo"
+        }
+    "#};
+
+    assert_fmt(src, src);
+}
+
+#[test]
+fn test_string_literal() {
+    let src = indoc! {r#"
+        const foo_const: String = @"foo"
+
+        fn foo() {
+          let foo_var: String = @"foo"
+        }
+    "#};
+
+    assert_fmt(src, src);
+}
diff --git a/crates/aiken-lang/src/tests/parser.rs b/crates/aiken-lang/src/tests/parser.rs
index 0a945fb9..159873e0 100644
--- a/crates/aiken-lang/src/tests/parser.rs
+++ b/crates/aiken-lang/src/tests/parser.rs
@@ -1343,7 +1343,7 @@ fn call() {
 #[test]
 fn record_update() {
     let code = indoc! {r#"
-        fn update_name(user: User, name: String) -> User {
+        fn update_name(user: User, name: ByteArray) -> User {
           User { ..user, name: "Aiken", age }
         }
     "#};
@@ -1373,60 +1373,61 @@ fn record_update() {
                         name: "name".to_string(),
                         location: Span::new((), 27..31),
                     },
-                    location: Span::new((), 27..39),
+                    location: Span::new((), 27..42),
                     annotation: Some(ast::Annotation::Constructor {
-                        location: Span::new((), 33..39),
+                        location: Span::new((), 33..42),
                         module: None,
-                        name: "String".to_string(),
+                        name: "ByteArray".to_string(),
                         arguments: vec![],
                     }),
                     tipo: (),
                 },
             ],
             body: expr::UntypedExpr::RecordUpdate {
-                location: Span::new((), 53..88),
+                location: Span::new((), 56..91),
                 constructor: Box::new(expr::UntypedExpr::Var {
-                    location: Span::new((), 53..57),
+                    location: Span::new((), 56..60),
                     name: "User".to_string(),
                 }),
                 spread: ast::RecordUpdateSpread {
                     base: Box::new(expr::UntypedExpr::Var {
-                        location: Span::new((), 62..66),
+                        location: Span::new((), 65..69),
                         name: "user".to_string(),
                     }),
-                    location: Span::new((), 60..66),
+                    location: Span::new((), 63..69),
                 },
                 arguments: vec![
                     ast::UntypedRecordUpdateArg {
                         label: "name".to_string(),
-                        location: Span::new((), 68..81),
-                        value: expr::UntypedExpr::String {
-                            location: Span::new((), 74..81),
-                            value: "Aiken".to_string(),
+                        location: Span::new((), 71..84),
+                        value: expr::UntypedExpr::ByteArray {
+                            location: Span::new((), 77..84),
+                            bytes: String::from("Aiken").into_bytes(),
+                            preferred_format: ast::ByteArrayFormatPreference::Utf8String,
                         },
                     },
                     ast::UntypedRecordUpdateArg {
                         label: "age".to_string(),
-                        location: Span::new((), 83..86),
+                        location: Span::new((), 86..89),
                         value: expr::UntypedExpr::Var {
-                            location: Span::new((), 83..86),
+                            location: Span::new((), 86..89),
                             name: "age".to_string(),
                         },
                     },
                 ],
             },
             doc: None,
-            location: Span::new((), 0..48),
+            location: Span::new((), 0..51),
             name: "update_name".to_string(),
             public: false,
             return_annotation: Some(ast::Annotation::Constructor {
-                location: Span::new((), 44..48),
+                location: Span::new((), 47..51),
                 module: None,
                 name: "User".to_string(),
                 arguments: vec![],
             }),
             return_type: (),
-            end_position: 89,
+            end_position: 92,
         })],
     )
 }
@@ -1448,9 +1449,10 @@ fn record_create_labeled() {
                     ast::CallArg {
                         label: Some("name".to_string()),
                         location: Span::new((), 23..36),
-                        value: expr::UntypedExpr::String {
+                        value: expr::UntypedExpr::ByteArray {
                             location: Span::new((), 29..36),
-                            value: "Aiken".to_string(),
+                            bytes: String::from("Aiken").into_bytes(),
+                            preferred_format: ast::ByteArrayFormatPreference::Utf8String,
                         },
                     },
                     ast::CallArg {
@@ -1504,9 +1506,10 @@ fn record_create_labeled_with_field_access() {
                     ast::CallArg {
                         label: Some("name".to_string()),
                         location: Span::new((), 35..48),
-                        value: expr::UntypedExpr::String {
+                        value: expr::UntypedExpr::ByteArray {
                             location: Span::new((), 41..48),
-                            value: "Aiken".to_string(),
+                            bytes: String::from("Aiken").into_bytes(),
+                            preferred_format: ast::ByteArrayFormatPreference::Utf8String,
                         },
                     },
                     ast::CallArg {
@@ -1785,6 +1788,7 @@ fn plain_bytearray_literals() {
             value: Box::new(Constant::ByteArray {
                 location: Span::new((), 25..39),
                 bytes: vec![0, 170, 255],
+                preferred_format: ast::ByteArrayFormatPreference::ArrayOfBytes,
             }),
             tipo: (),
         })],
@@ -1813,6 +1817,7 @@ fn base16_bytearray_literals() {
                 value: Box::new(Constant::ByteArray {
                     location: Span::new((), 25..34),
                     bytes: vec![0, 170, 255],
+                    preferred_format: ast::ByteArrayFormatPreference::HexadecimalString,
                 }),
                 tipo: (),
             }),
@@ -1828,6 +1833,7 @@ fn base16_bytearray_literals() {
                     right: Box::new(expr::UntypedExpr::ByteArray {
                         location: Span::new((), 71..80),
                         bytes: vec![0, 170, 255],
+                        preferred_format: ast::ByteArrayFormatPreference::HexadecimalString,
                     }),
                 },
                 doc: None,
@@ -2489,9 +2495,10 @@ fn clause_guards() {
                                     )),
                                 }),
                             }),
-                            right: Box::new(ast::ClauseGuard::Constant(ast::Constant::String {
+                            right: Box::new(ast::ClauseGuard::Constant(ast::Constant::ByteArray {
                                 location: Span::new((), 178..183),
-                                value: "str".to_string(),
+                                bytes: String::from("str").into_bytes(),
+                                preferred_format: ast::ByteArrayFormatPreference::Utf8String,
                             })),
                         }),
                         then: expr::UntypedExpr::Var {
@@ -2669,10 +2676,10 @@ fn scope_logical_expression() {
 fn trace_expressions() {
     let code = indoc! {r#"
           fn foo() {
-            let msg1 = "FOO"
-            trace "INLINE"
+            let msg1 = @"FOO"
+            trace @"INLINE"
             trace msg1
-            trace string.concat(msg1, "BAR")
+            trace string.concat(msg1, @"BAR")
             trace ( 14 + 42 * 1337 )
             Void
           }
@@ -2682,12 +2689,12 @@ fn trace_expressions() {
         vec![ast::Definition::Fn(Function {
             arguments: vec![],
             body: expr::UntypedExpr::Sequence {
-                location: Span::new((), 13..128),
+                location: Span::new((), 13..131),
                 expressions: vec![
                     expr::UntypedExpr::Assignment {
-                        location: Span::new((), 13..29),
+                        location: Span::new((), 13..30),
                         value: Box::new(expr::UntypedExpr::String {
-                            location: Span::new((), 24..29),
+                            location: Span::new((), 24..30),
                             value: "FOO".to_string(),
                         }),
                         pattern: ast::Pattern::Var {
@@ -2699,36 +2706,36 @@ fn trace_expressions() {
                     },
                     expr::UntypedExpr::Trace {
                         kind: ast::TraceKind::Trace,
-                        location: Span::new((), 32..128),
+                        location: Span::new((), 33..131),
                         then: Box::new(expr::UntypedExpr::Trace {
                             kind: ast::TraceKind::Trace,
-                            location: Span::new((), 49..128),
+                            location: Span::new((), 51..131),
                             then: Box::new(expr::UntypedExpr::Trace {
                                 kind: ast::TraceKind::Trace,
-                                location: Span::new((), 62..128),
+                                location: Span::new((), 64..131),
                                 then: Box::new(expr::UntypedExpr::Trace {
                                     kind: ast::TraceKind::Trace,
-                                    location: Span::new((), 97..128),
+                                    location: Span::new((), 100..131),
                                     then: Box::new(expr::UntypedExpr::Var {
-                                        location: Span::new((), 124..128),
+                                        location: Span::new((), 127..131),
                                         name: "Void".to_string(),
                                     }),
                                     text: Box::new(expr::UntypedExpr::BinOp {
-                                        location: Span::new((), 105..119),
+                                        location: Span::new((), 108..122),
                                         name: ast::BinOp::AddInt,
                                         left: Box::new(expr::UntypedExpr::Int {
-                                            location: Span::new((), 105..107),
+                                            location: Span::new((), 108..110),
                                             value: "14".to_string(),
                                         }),
                                         right: Box::new(expr::UntypedExpr::BinOp {
-                                            location: Span::new((), 110..119),
+                                            location: Span::new((), 113..122),
                                             name: ast::BinOp::MultInt,
                                             left: Box::new(expr::UntypedExpr::Int {
-                                                location: Span::new((), 110..112),
+                                                location: Span::new((), 113..115),
                                                 value: "42".to_string(),
                                             }),
                                             right: Box::new(expr::UntypedExpr::Int {
-                                                location: Span::new((), 115..119),
+                                                location: Span::new((), 118..122),
                                                 value: "1337".to_string(),
                                             }),
                                         }),
@@ -2738,39 +2745,39 @@ fn trace_expressions() {
                                     arguments: vec![
                                         ast::CallArg {
                                             label: None,
-                                            location: Span::new((), 82..86),
+                                            location: Span::new((), 84..88),
                                             value: expr::UntypedExpr::Var {
-                                                location: Span::new((), 82..86),
+                                                location: Span::new((), 84..88),
                                                 name: "msg1".to_string(),
                                             },
                                         },
                                         ast::CallArg {
                                             label: None,
-                                            location: Span::new((), 88..93),
+                                            location: Span::new((), 90..96),
                                             value: expr::UntypedExpr::String {
-                                                location: Span::new((), 88..93),
+                                                location: Span::new((), 90..96),
                                                 value: "BAR".to_string(),
                                             },
                                         },
                                     ],
                                     fun: Box::new(expr::UntypedExpr::FieldAccess {
-                                        location: Span::new((), 68..81),
+                                        location: Span::new((), 70..83),
                                         label: "concat".to_string(),
                                         container: Box::new(expr::UntypedExpr::Var {
-                                            location: Span::new((), 68..74),
+                                            location: Span::new((), 70..76),
                                             name: "string".to_string(),
                                         }),
                                     }),
-                                    location: Span::new((), 68..94),
+                                    location: Span::new((), 70..97),
                                 }),
                             }),
                             text: Box::new(expr::UntypedExpr::Var {
-                                location: Span::new((), 55..59),
+                                location: Span::new((), 57..61),
                                 name: "msg1".to_string(),
                             }),
                         }),
                         text: Box::new(expr::UntypedExpr::String {
-                            location: Span::new((), 38..46),
+                            location: Span::new((), 39..48),
                             value: "INLINE".to_string(),
                         }),
                     },
@@ -2782,7 +2789,7 @@ fn trace_expressions() {
             public: false,
             return_annotation: None,
             return_type: (),
-            end_position: 129,
+            end_position: 132,
         })],
     )
 }
@@ -2791,7 +2798,7 @@ fn trace_expressions() {
 fn parse_keyword_error() {
     let code = indoc! {r#"
           fn foo() {
-            error "not implemented"
+            error @"not implemented"
           }
 
           fn bar() {
@@ -2808,12 +2815,12 @@ fn parse_keyword_error() {
                 arguments: vec![],
                 body: expr::UntypedExpr::Trace {
                     kind: ast::TraceKind::Error,
-                    location: Span::new((), 13..36),
+                    location: Span::new((), 13..37),
                     then: Box::new(expr::UntypedExpr::ErrorTerm {
-                        location: Span::new((), 13..36),
+                        location: Span::new((), 13..37),
                     }),
                     text: Box::new(expr::UntypedExpr::String {
-                        location: Span::new((), 19..36),
+                        location: Span::new((), 19..37),
                         value: "not implemented".to_string(),
                     }),
                 },
@@ -2823,22 +2830,22 @@ fn parse_keyword_error() {
                 public: false,
                 return_annotation: None,
                 return_type: (),
-                end_position: 37,
+                end_position: 38,
             }),
             ast::Definition::Fn(Function {
                 arguments: vec![],
                 body: expr::UntypedExpr::When {
-                    location: Span::new((), 53..109),
+                    location: Span::new((), 54..110),
                     subjects: vec![expr::UntypedExpr::Var {
-                        location: Span::new((), 58..59),
+                        location: Span::new((), 59..60),
                         name: "x".to_string(),
                     }],
                     clauses: vec![
                         ast::Clause {
-                            location: Span::new((), 71..88),
+                            location: Span::new((), 72..89),
                             pattern: vec![ast::Pattern::Constructor {
                                 is_record: false,
-                                location: Span::new((), 71..80),
+                                location: Span::new((), 72..81),
                                 name: "Something".to_string(),
                                 arguments: vec![],
                                 module: None,
@@ -2849,26 +2856,26 @@ fn parse_keyword_error() {
                             alternative_patterns: vec![],
                             guard: None,
                             then: expr::UntypedExpr::Var {
-                                location: Span::new((), 84..88),
+                                location: Span::new((), 85..89),
                                 name: "Void".to_string(),
                             },
                         },
                         ast::Clause {
-                            location: Span::new((), 95..105),
+                            location: Span::new((), 96..106),
                             pattern: vec![ast::Pattern::Discard {
                                 name: "_".to_string(),
-                                location: Span::new((), 95..96),
+                                location: Span::new((), 96..97),
                             }],
                             alternative_patterns: vec![],
                             guard: None,
                             then: expr::UntypedExpr::Trace {
                                 kind: ast::TraceKind::Error,
-                                location: Span::new((), 100..105),
+                                location: Span::new((), 101..106),
                                 then: Box::new(expr::UntypedExpr::ErrorTerm {
-                                    location: Span::new((), 100..105),
+                                    location: Span::new((), 101..106),
                                 }),
                                 text: Box::new(expr::UntypedExpr::String {
-                                    location: Span::new((), 100..105),
+                                    location: Span::new((), 101..106),
                                     value: "aiken::error".to_string(),
                                 }),
                             },
@@ -2876,12 +2883,12 @@ fn parse_keyword_error() {
                     ],
                 },
                 doc: None,
-                location: Span::new((), 40..48),
+                location: Span::new((), 41..49),
                 name: "bar".to_string(),
                 public: false,
                 return_annotation: None,
                 return_type: (),
-                end_position: 110,
+                end_position: 111,
             }),
         ],
     )
@@ -2891,7 +2898,7 @@ fn parse_keyword_error() {
 fn parse_keyword_todo() {
     let code = indoc! {r#"
           fn foo() {
-            todo "not implemented"
+            todo @"not implemented"
           }
 
           fn bar() {
@@ -2909,12 +2916,12 @@ fn parse_keyword_todo() {
                 arguments: vec![],
                 body: expr::UntypedExpr::Trace {
                     kind: ast::TraceKind::Todo,
-                    location: Span::new((), 13..35),
+                    location: Span::new((), 13..36),
                     then: Box::new(expr::UntypedExpr::ErrorTerm {
-                        location: Span::new((), 13..35),
+                        location: Span::new((), 13..36),
                     }),
                     text: Box::new(expr::UntypedExpr::String {
-                        location: Span::new((), 18..35),
+                        location: Span::new((), 18..36),
                         value: "not implemented".to_string(),
                     }),
                 },
@@ -2924,22 +2931,22 @@ fn parse_keyword_todo() {
                 public: false,
                 return_annotation: None,
                 return_type: (),
-                end_position: 36,
+                end_position: 37,
             }),
             ast::Definition::Fn(Function {
                 arguments: vec![],
                 body: expr::UntypedExpr::When {
-                    location: Span::new((), 52..120),
+                    location: Span::new((), 53..121),
                     subjects: vec![expr::UntypedExpr::Var {
-                        location: Span::new((), 57..58),
+                        location: Span::new((), 58..59),
                         name: "x".to_string(),
                     }],
                     clauses: vec![
                         ast::Clause {
-                            location: Span::new((), 70..81),
+                            location: Span::new((), 71..82),
                             pattern: vec![ast::Pattern::Constructor {
                                 is_record: false,
-                                location: Span::new((), 70..73),
+                                location: Span::new((), 71..74),
                                 name: "Foo".to_string(),
                                 arguments: vec![],
                                 module: None,
@@ -2951,21 +2958,21 @@ fn parse_keyword_todo() {
                             guard: None,
                             then: expr::UntypedExpr::Trace {
                                 kind: ast::TraceKind::Todo,
-                                location: Span::new((), 77..81),
+                                location: Span::new((), 78..82),
                                 then: Box::new(expr::UntypedExpr::ErrorTerm {
-                                    location: Span::new((), 77..81),
+                                    location: Span::new((), 78..82),
                                 }),
                                 text: Box::new(expr::UntypedExpr::String {
-                                    location: Span::new((), 77..81),
+                                    location: Span::new((), 78..82),
                                     value: "aiken::todo".to_string(),
                                 }),
                             },
                         },
                         ast::Clause {
-                            location: Span::new((), 88..99),
+                            location: Span::new((), 89..100),
                             pattern: vec![ast::Pattern::Constructor {
                                 is_record: false,
-                                location: Span::new((), 88..91),
+                                location: Span::new((), 89..92),
                                 name: "Bar".to_string(),
                                 arguments: vec![],
                                 module: None,
@@ -2976,32 +2983,32 @@ fn parse_keyword_todo() {
                             alternative_patterns: vec![],
                             guard: None,
                             then: expr::UntypedExpr::Var {
-                                location: Span::new((), 95..99),
+                                location: Span::new((), 96..100),
                                 name: "True".to_string(),
                             },
                         },
                         ast::Clause {
-                            location: Span::new((), 106..116),
+                            location: Span::new((), 107..117),
                             pattern: vec![ast::Pattern::Discard {
                                 name: "_".to_string(),
-                                location: Span::new((), 106..107),
+                                location: Span::new((), 107..108),
                             }],
                             alternative_patterns: vec![],
                             guard: None,
                             then: expr::UntypedExpr::Var {
-                                location: Span::new((), 111..116),
+                                location: Span::new((), 112..117),
                                 name: "False".to_string(),
                             },
                         },
                     ],
                 },
                 doc: None,
-                location: Span::new((), 39..47),
+                location: Span::new((), 40..48),
                 name: "bar".to_string(),
                 public: false,
                 return_annotation: None,
                 return_type: (),
-                end_position: 121,
+                end_position: 122,
             }),
         ],
     )
diff --git a/crates/aiken-lang/src/tipo/error.rs b/crates/aiken-lang/src/tipo/error.rs
index 878aee77..87b3c6c7 100644
--- a/crates/aiken-lang/src/tipo/error.rs
+++ b/crates/aiken-lang/src/tipo/error.rs
@@ -1244,6 +1244,31 @@ pub enum Warning {
         #[label("unused")]
         location: Span,
     },
+
+    #[error(
+        "I noticed a suspicious {type_ByteArray} UTF-8 literal which resembles a hash digest.",
+        type_ByteArray = "ByteArray".bold().bright_blue()
+    )]
+    #[diagnostic(help("{}", formatdoc! {
+        r#"When you specify a {type_ByteArray} literal using plain double-quotes, it's interpreted as an array of UTF-8 bytes. For example, the literal {literal_foo} is interpreted as the byte sequence {foo_bytes}.
+
+           However here, you have specified a literal that resembles a hash digest encoded as an hexadecimal string. This is a common case, but you probably want to capture the raw bytes represented by this sequence, and not the hexadecimal sequence. Fear not! Aiken provides a convenient syntax for that: just prefix the literal with {symbol_hash}. This will decode the hexadecimal string for you and capture the non-encoded bytes as a {type_ByteArray}.
+
+           ╰─▶ {symbol_hash}{value}
+        "#,
+        type_ByteArray = "ByteArray".bold().bright_blue(),
+        literal_foo = "\"foo\"".purple(),
+        foo_bytes = "#[102, 111, 111]".purple(),
+        value = "\"{value}\"".purple(),
+        symbol_hash = "#".purple(),
+    }))]
+    #[diagnostic(code("syntax::bytearray_literal_is_hex_string"))]
+    #[diagnostic(url("https://aiken-lang.org/language-tour/primitive-types#bytearray"))]
+    Utf8ByteArrayIsValidHexString {
+        #[label("missing '#' to decode hex string")]
+        location: Span,
+        value: String,
+    },
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
diff --git a/crates/aiken-lang/src/tipo/expr.rs b/crates/aiken-lang/src/tipo/expr.rs
index 8bb97739..695ff653 100644
--- a/crates/aiken-lang/src/tipo/expr.rs
+++ b/crates/aiken-lang/src/tipo/expr.rs
@@ -4,11 +4,11 @@ use vec1::Vec1;
 
 use crate::{
     ast::{
-        Annotation, Arg, ArgName, AssignmentKind, BinOp, CallArg, Clause, ClauseGuard, Constant,
-        IfBranch, RecordUpdateSpread, Span, TraceKind, Tracing, TypedArg, TypedCallArg,
-        TypedClause, TypedClauseGuard, TypedIfBranch, TypedMultiPattern, TypedRecordUpdateArg,
-        UnOp, UntypedArg, UntypedClause, UntypedClauseGuard, UntypedIfBranch, UntypedMultiPattern,
-        UntypedPattern, UntypedRecordUpdateArg,
+        Annotation, Arg, ArgName, AssignmentKind, BinOp, ByteArrayFormatPreference, CallArg,
+        Clause, ClauseGuard, Constant, IfBranch, RecordUpdateSpread, Span, TraceKind, Tracing,
+        TypedArg, TypedCallArg, TypedClause, TypedClauseGuard, TypedIfBranch, TypedMultiPattern,
+        TypedRecordUpdateArg, UnOp, UntypedArg, UntypedClause, UntypedClauseGuard, UntypedIfBranch,
+        UntypedMultiPattern, UntypedPattern, UntypedRecordUpdateArg,
     },
     builtins::{bool, byte_array, function, int, list, string, tuple},
     expr::{TypedExpr, UntypedExpr},
@@ -350,9 +350,11 @@ impl<'a, 'b> ExprTyper<'a, 'b> {
                 ..
             } => self.infer_tuple_index(*tuple, index, location),
 
-            UntypedExpr::ByteArray { location, bytes } => {
-                Ok(self.infer_byte_array(bytes, location))
-            }
+            UntypedExpr::ByteArray {
+                bytes,
+                preferred_format,
+                location,
+            } => self.infer_bytearray(bytes, preferred_format, location),
 
             UntypedExpr::RecordUpdate {
                 location,
@@ -373,12 +375,27 @@ impl<'a, 'b> ExprTyper<'a, 'b> {
         }
     }
 
-    fn infer_byte_array(&mut self, bytes: Vec<u8>, location: Span) -> TypedExpr {
-        TypedExpr::ByteArray {
+    fn infer_bytearray(
+        &mut self,
+        bytes: Vec<u8>,
+        preferred_format: ByteArrayFormatPreference,
+        location: Span,
+    ) -> Result<TypedExpr, Error> {
+        if let ByteArrayFormatPreference::Utf8String = preferred_format {
+            let value = String::from_utf8(bytes.clone()).unwrap();
+            let is_hex_string = hex::decode(&value).is_ok();
+            if bytes.len() >= 56 && is_hex_string {
+                self.environment
+                    .warnings
+                    .push(Warning::Utf8ByteArrayIsValidHexString { location, value });
+            }
+        }
+
+        Ok(TypedExpr::ByteArray {
             location,
             bytes,
             tipo: byte_array(),
-        }
+        })
     }
 
     fn infer_trace_if_false(
@@ -1353,7 +1370,18 @@ impl<'a, 'b> ExprTyper<'a, 'b> {
                 location, value, ..
             } => Ok(Constant::String { location, value }),
 
-            Constant::ByteArray { location, bytes } => Ok(Constant::ByteArray { location, bytes }),
+            Constant::ByteArray {
+                location,
+                bytes,
+                preferred_format,
+            } => {
+                let _ = self.infer_bytearray(bytes.clone(), preferred_format, location)?;
+                Ok(Constant::ByteArray {
+                    location,
+                    bytes,
+                    preferred_format,
+                })
+            }
         }?;
 
         // Check type annotation is accurate.
diff --git a/examples/acceptance_tests/032/lib/tests.ak b/examples/acceptance_tests/032/lib/tests.ak
index 2c2326b4..8ad32f16 100644
--- a/examples/acceptance_tests/032/lib/tests.ak
+++ b/examples/acceptance_tests/032/lib/tests.ak
@@ -10,10 +10,10 @@ fn concat(left: String, right: String) -> String {
 
 fn is_negative(i: Int) -> Bool {
   if i < 0 {
-    trace "is negative"
+    trace @"is negative"
     True
   } else {
-    trace concat("is", concat(" ", "non-negative"))
+    trace concat(@"is", concat(@" ", @"non-negative"))
     False
   }
 }
diff --git a/examples/acceptance_tests/036/aiken.lock b/examples/acceptance_tests/036/aiken.lock
index 550023f7..0423f31b 100644
--- a/examples/acceptance_tests/036/aiken.lock
+++ b/examples/acceptance_tests/036/aiken.lock
@@ -3,11 +3,11 @@
 
 [[requirements]]
 name = "aiken-lang/stdlib"
-version = "3b47c89006e7580c2213370d7426ed2a38d2836e"
+version = "main"
 source = "github"
 
 [[packages]]
 name = "aiken-lang/stdlib"
-version = "3b47c89006e7580c2213370d7426ed2a38d2836e"
+version = "main"
 requirements = []
 source = "github"
diff --git a/examples/acceptance_tests/036/aiken.toml b/examples/acceptance_tests/036/aiken.toml
index 32640c11..8147c157 100644
--- a/examples/acceptance_tests/036/aiken.toml
+++ b/examples/acceptance_tests/036/aiken.toml
@@ -1,6 +1,7 @@
 name = "aiken-lang/acceptance_test_036"
 version = "0.0.0"
 
-dependencies = [
-  { name = "aiken-lang/stdlib", version = "3b47c89006e7580c2213370d7426ed2a38d2836e", source = "github" },
-]
+[[dependencies]]
+name = 'aiken-lang/stdlib'
+version = 'main'
+source = 'github'
diff --git a/examples/acceptance_tests/054/aiken.lock b/examples/acceptance_tests/054/aiken.lock
index d9cf5aff..0423f31b 100644
--- a/examples/acceptance_tests/054/aiken.lock
+++ b/examples/acceptance_tests/054/aiken.lock
@@ -3,11 +3,11 @@
 
 [[requirements]]
 name = "aiken-lang/stdlib"
-version = "1cedbe85b7c7e9c4036d63d45cad4ced27b0d50b"
+version = "main"
 source = "github"
 
 [[packages]]
 name = "aiken-lang/stdlib"
-version = "1cedbe85b7c7e9c4036d63d45cad4ced27b0d50b"
+version = "main"
 requirements = []
 source = "github"
diff --git a/examples/acceptance_tests/054/aiken.toml b/examples/acceptance_tests/054/aiken.toml
index e2810ab2..17ae1181 100644
--- a/examples/acceptance_tests/054/aiken.toml
+++ b/examples/acceptance_tests/054/aiken.toml
@@ -1,6 +1,7 @@
 name = "aiken-lang/acceptance_test_054"
 version = "0.0.0"
 
-dependencies = [
-  { name = "aiken-lang/stdlib", version = "1cedbe85b7c7e9c4036d63d45cad4ced27b0d50b", source = "github" },
-]
+[[dependencies]]
+name = 'aiken-lang/stdlib'
+version = 'main'
+source = 'github'
diff --git a/examples/acceptance_tests/055/aiken.lock b/examples/acceptance_tests/055/aiken.lock
index 550023f7..0423f31b 100644
--- a/examples/acceptance_tests/055/aiken.lock
+++ b/examples/acceptance_tests/055/aiken.lock
@@ -3,11 +3,11 @@
 
 [[requirements]]
 name = "aiken-lang/stdlib"
-version = "3b47c89006e7580c2213370d7426ed2a38d2836e"
+version = "main"
 source = "github"
 
 [[packages]]
 name = "aiken-lang/stdlib"
-version = "3b47c89006e7580c2213370d7426ed2a38d2836e"
+version = "main"
 requirements = []
 source = "github"
diff --git a/examples/acceptance_tests/055/aiken.toml b/examples/acceptance_tests/055/aiken.toml
index 1a35f90d..97e0ed2e 100644
--- a/examples/acceptance_tests/055/aiken.toml
+++ b/examples/acceptance_tests/055/aiken.toml
@@ -1,6 +1,7 @@
 name = "aiken-lang/acceptance_test_055"
 version = "0.0.0"
 
-dependencies = [
-  { name = "aiken-lang/stdlib", version="3b47c89006e7580c2213370d7426ed2a38d2836e", source = "github" },
-]
+[[dependencies]]
+name = 'aiken-lang/stdlib'
+version = 'main'
+source = 'github'
diff --git a/examples/acceptance_tests/062/tmp b/examples/acceptance_tests/062/tmp
deleted file mode 100644
index 1f301610..00000000
--- a/examples/acceptance_tests/062/tmp
+++ /dev/null
@@ -1,2 +0,0 @@
-
-let foo = Module { name: "tests", docs: [], type_info: (), definitions: [Fn(Function { arguments: [Arg { arg_name: Named { name: "signatories", label: "signatories", location: 18..29 }, location: 18..29, annotation: None, tipo: () }], body: When { location: 35..154, subjects: [Var { location: 40..51, name: "signatories" }], clauses: [Clause { location: 61..115, pattern: [List { location: 61..63, elements: [], tail: None }], alternative_patterns: [], guard: None, then: Trace { kind: Trace, location: 75..109, then: Var { location: 104..109, name: "False" }, text: String { location: 81..97, value: "no signatories" } } }, Clause { location: 120..150, pattern: [List { location: 120..129, elements: [Var { location: 121..124, name: "sig" }], tail: Some(Discard { name: "_", location: 128..129 }) }], alternative_patterns: [], guard: None, then: TraceIfFalse { location: 133..150, value: BinOp { location: 134..148, name: Eq, left: Var { location: 134..137, name: "sig" }, right: String { location: 141..148, value: "#ffff" } } } }] }, doc: None, location: 0..30, name: "must_be_signed", public: false, return_annotation: None, return_type: (), end_position: 155 }), Fn(Function { arguments: [], body: Var { location: 182..186, name: "True" }, doc: None, location: 158..177, name: "must_say_hello", public: false, return_annotation: None, return_type: (), end_position: 187 }), Test(Function { arguments: [], body: BinOp { location: 205..260, name: Or, left: BinOp { location: 205..252, name: And, left: TraceIfFalse { location: 205..231, value: Call { arguments: [CallArg { label: None, location: 220..229, value: List { location: 220..229, elements: [String { location: 221..228, value: "#f000" }], tail: None } }], fun: Var { location: 205..219, name: "must_be_signed" }, location: 205..230 } }, right: TraceIfFalse { location: 235..252, value: Call { arguments: [], fun: Var { location: 235..249, name: "must_say_hello" }, location: 235..251 } } }, right: Var { location: 256..260, name: "True" } }, doc: None, location: 190..200, name: "foo", public: false, return_annotation: None, return_type: (), end_position: 261 })], kind: Lib };
diff --git a/examples/acceptance_tests/063/aiken.toml b/examples/acceptance_tests/063/aiken.toml
index 1b2e4d85..7ddf487c 100644
--- a/examples/acceptance_tests/063/aiken.toml
+++ b/examples/acceptance_tests/063/aiken.toml
@@ -1,4 +1,4 @@
-name = 'aiken-lang/acceptance_test_061'
+name = 'aiken-lang/acceptance_test_063'
 version = '0.0.0'
 description = ''
 
diff --git a/examples/acceptance_tests/063/lib/tests.ak b/examples/acceptance_tests/063/lib/tests.ak
index e6175dd0..60afb373 100644
--- a/examples/acceptance_tests/063/lib/tests.ak
+++ b/examples/acceptance_tests/063/lib/tests.ak
@@ -1,7 +1,7 @@
 fn must_be_signed(signatories) {
   when signatories is {
     [] -> {
-      trace "no signatories"
+      trace @"no signatories"
       False
     }
     [sig, ..] -> (sig == "#ffff")?
diff --git a/examples/acceptance_tests/script_context/validators/basic.ak b/examples/acceptance_tests/script_context/validators/basic.ak
index a2575c42..57b3f37a 100644
--- a/examples/acceptance_tests/script_context/validators/basic.ak
+++ b/examples/acceptance_tests/script_context/validators/basic.ak
@@ -28,7 +28,7 @@ fn assert_purpose(purpose) {
       ref.transaction_id == TransactionId(
         #"0000000000000000000000000000000000000000000000000000000000000000",
       ) && ref.output_index == 0
-    _ -> error "script purpose isn't 'Spend'"
+    _ -> error @"script purpose isn't 'Spend'"
   }
 }
 
@@ -49,6 +49,6 @@ fn assert_outputs(transaction) {
         output.reference_script == None,
       ]
       |> list.and
-    _ -> error "unexpected number of outputs"
+    _ -> error @"unexpected number of outputs"
   }
 }
diff --git a/examples/acceptance_tests/script_context/validators/deploy.ak b/examples/acceptance_tests/script_context/validators/deploy.ak
index c753b45f..dd7f9ae5 100644
--- a/examples/acceptance_tests/script_context/validators/deploy.ak
+++ b/examples/acceptance_tests/script_context/validators/deploy.ak
@@ -40,7 +40,7 @@ fn assert_outputs(outputs) {
   when outputs is {
     [output_1, output_2, ..] ->
       assert_first_output(output_1) && assert_second_output(output_2)
-    _ -> error "expected transaction to have (at least) 2 outputs"
+    _ -> error @"expected transaction to have (at least) 2 outputs"
   }
 }
 
@@ -67,7 +67,7 @@ fn assert_second_output(output) {
     ),
     when output.datum is {
       InlineDatum(_) -> True
-      _ -> error "expected inline datum"
+      _ -> error @"expected inline datum"
     },
   ]
   |> list.and
diff --git a/examples/acceptance_tests/script_context/validators/mint.ak b/examples/acceptance_tests/script_context/validators/mint.ak
index 734c80a4..d55a5fb5 100644
--- a/examples/acceptance_tests/script_context/validators/mint.ak
+++ b/examples/acceptance_tests/script_context/validators/mint.ak
@@ -29,7 +29,7 @@ fn assert_mint(purpose, transaction) {
   let tokens = value.tokens(transaction.mint, policy_id)
 
   when dict.get(tokens, #"666f6f") is {
-    None -> error "token not found"
+    None -> error @"token not found"
     Some(quantity) -> quantity == 1337
   }
 }
diff --git a/examples/acceptance_tests/script_context/validators/withdrawals.ak b/examples/acceptance_tests/script_context/validators/withdrawals.ak
index 1c8ce18b..8c19e01e 100644
--- a/examples/acceptance_tests/script_context/validators/withdrawals.ak
+++ b/examples/acceptance_tests/script_context/validators/withdrawals.ak
@@ -23,11 +23,11 @@ validator spend {
 
     [
       when dict.get(ctx.transaction.withdrawals, alice) is {
-        None -> error "alice's withdrawal not found"
+        None -> error @"alice's withdrawal not found"
         Some(value) -> value == 42
       },
       when dict.get(ctx.transaction.withdrawals, bob) is {
-        None -> error "bob's withdrawal not found"
+        None -> error @"bob's withdrawal not found"
         Some(value) -> value == 14
       },
       dict.keys(ctx.transaction.withdrawals) == [alice, bob],
diff --git a/examples/hello_world/aiken.lock b/examples/hello_world/aiken.lock
index 36ae1dc8..0423f31b 100644
--- a/examples/hello_world/aiken.lock
+++ b/examples/hello_world/aiken.lock
@@ -3,11 +3,11 @@
 
 [[requirements]]
 name = "aiken-lang/stdlib"
-version = "43d8e740ffdf5febc59e51b7f0d5f8506115340c"
+version = "main"
 source = "github"
 
 [[packages]]
 name = "aiken-lang/stdlib"
-version = "43d8e740ffdf5febc59e51b7f0d5f8506115340c"
+version = "main"
 requirements = []
 source = "github"
diff --git a/examples/hello_world/aiken.toml b/examples/hello_world/aiken.toml
index f8495550..3b523f22 100644
--- a/examples/hello_world/aiken.toml
+++ b/examples/hello_world/aiken.toml
@@ -2,6 +2,8 @@ name = "aiken-lang/hello_world"
 version = "1.0.0"
 licences = ["Apache-2.0"]
 description = "Aiken contracts for project 'aiken-lang/hello_world'"
-dependencies = [
-  { name = "aiken-lang/stdlib", version = "43d8e740ffdf5febc59e51b7f0d5f8506115340c", source = "github" },
-]
+
+[[dependencies]]
+name = "aiken-lang/stdlib"
+version = "main"
+source = "github"
diff --git a/examples/hello_world/validators/hello_world.ak b/examples/hello_world/validators/hello_world.ak
index 1fe1b788..1d4066b4 100644
--- a/examples/hello_world/validators/hello_world.ak
+++ b/examples/hello_world/validators/hello_world.ak
@@ -1,6 +1,5 @@
 use aiken/hash.{Blake2b_224, Hash}
 use aiken/list
-use aiken/string
 use aiken/transaction.{ScriptContext}
 use aiken/transaction/credential.{VerificationKey}
 
@@ -14,7 +13,7 @@ type Redeemer {
 
 validator spend {
   fn(datum: Datum, redeemer: Redeemer, context: ScriptContext) -> Bool {
-    let must_say_hello = string.from_bytearray(redeemer.msg) == "Hello, World!"
+    let must_say_hello = redeemer.msg == "Hello, World!"
 
     let must_be_signed =
       list.has(context.transaction.extra_signatories, datum.owner)
@@ -22,4 +21,3 @@ validator spend {
     must_say_hello && must_be_signed
   }
 }
-