baml_language: packaging and running

baml_language/Cargo.toml

@@ -43,6 +43,7 @@ baml_compiler_lexer = { path = "crates/baml_compiler_lexer" }
 baml_compiler_parser = { path = "crates/baml_compiler_parser" }
 baml_compiler_syntax = { path = "crates/baml_compiler_syntax" }
 bex_project = { path = "crates/bex_project" }
+baml_exec = { path = "crates/baml_exec" }
 bex_engine = { path = "crates/bex_engine" }
 sys_llm = { path = "crates/sys_llm" }
 sys_ops = { path = "crates/sys_ops" }
@@ -139,6 +140,8 @@ quote = { version = "1" }
 ratatui = "0.29"
 regex = { version = "1.10.2" }
 base64 = "0.22"
+bitcode = { version = "0.6", features = [ "serde" ] }
+libsui = { version = "0.14" }
 reqwest = { version = "0.13.1", default-features = false, features = [
   "json",
   "stream",
@@ -154,13 +157,13 @@ salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "cdd0b85516a52c18
 serde = { version = "1.0.197", features = [ "derive" ] }
 serde_json = { version = "1.0.113", features = [ "preserve_order" ] }
 similar = { version = "2.4.0", features = [ "inline" ] }
-smol_str = { version = "0.3" }
+smol_str = { version = "0.3", features = [ "serde" ] }
 strsim = { version = "0.11.1" }
 syn = { version = "2", features = [ "full" ] }
 taplo = { version = "0.13" }
 tempfile = { version = "3" }
 time = { version = "0.3", features = [ "formatting", "macros" ] }
-text-size = { version = "1.1" }
+text-size = { version = "1.1", features = [ "serde" ] }
 thiserror = { version = "2.0.0" }
 toml = { version = "0.8" }
 toml_edit = { version = "0.22" }

baml_language/crates/baml_base/Cargo.toml

@@ -19,6 +19,7 @@ workspace = true
 [dependencies]
 ariadne = { workspace = true }
 salsa = { workspace = true }
+serde = { workspace = true }
 smol_str = { workspace = true }
 text-size = { workspace = true }
 

baml_language/crates/baml_base/src/attr.rs

@@ -6,13 +6,17 @@
 //! These live in `baml_base` b/c they're shared by `baml_compiler_tir::Ty`
 //! (TIR) and `baml_type::Ty` (VIR+).
 
+use serde::{Deserialize, Serialize};
+
 use crate::core_types::Span;
 
 /// Binary present/absent flag for SAP attributes.
 ///
 /// Used instead of `bool` for extensibility — future attributes may
 /// need additional states (e.g., `Inherited`, `Explicit`).
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
+#[derive(
+    Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Default, Serialize, Deserialize,
+)]
 pub enum TyAttrValue {
     #[default]
     Unset,
@@ -34,7 +38,7 @@ impl TyAttrValue {
 }
 
 /// A single `@assert` attached to a type expression.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub struct TyAssert {
     /// Index into the program's function table — the assertion body
     /// compiled to a `(value) -> bool` function.
@@ -67,7 +71,7 @@ impl Ord for TyAssert {
 ///
 /// BEP-006 v12 defines three binary (present/absent) SAP attributes
 /// that control how the schema-aligned parser handles each streaming state.
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Default, Serialize, Deserialize)]
 pub struct TyAttr {
     /// `@sap.parse_without_null`: during parsing (both in-progress and done
     /// states), exclude `null` from the type's parse candidates.

baml_language/crates/baml_base/src/core_types.rs

@@ -3,6 +3,7 @@
 use std::fmt;
 
 use ariadne;
+use serde::{Deserialize, Serialize};
 use smol_str::SmolStr;
 use text_size::{TextRange, TextSize};
 
@@ -32,7 +33,7 @@ use text_size::{TextRange, TextSize};
 ///
 /// - **Roslyn** (C#): synthetic `SyntaxTree`s constructed with a virtual file path.
 /// - **Clang**: bit 31 of `SourceLocation` distinguishes file vs macro-expansion locs.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default, Serialize, Deserialize)]
 pub struct FileId(u32);
 
 impl FileId {
@@ -84,7 +85,7 @@ impl fmt::Display for FileId {
 }
 
 /// A span in source code, tracking both file and position
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub struct Span {
     pub file_id: FileId,
     pub range: TextRange,
@@ -142,7 +143,7 @@ impl ariadne::Span for Span {
 pub type Name = SmolStr;
 
 /// The types of media we support
-#[derive(Debug, Clone, PartialEq, Eq, Hash, Copy)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Copy, Serialize, Deserialize)]
 pub enum MediaKind {
     Image,
     Audio,
@@ -163,7 +164,7 @@ impl fmt::Display for MediaKind {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
 pub enum Literal {
     Int(i64),
     Float(String),
@@ -183,7 +184,7 @@ impl fmt::Display for Literal {
 }
 
 /// Module identifier (for multi-file support)
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub struct ModuleId(u32);
 
 impl ModuleId {
@@ -197,7 +198,7 @@ impl ModuleId {
 }
 
 /// Severity level for diagnostics
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub enum Severity {
     Error,
     Warning,

baml_language/crates/baml_builtins2/baml_std/baml/ns_panics/panics.baml

@@ -28,11 +28,20 @@ class UserPanic {
   message string
 }
 
+/// A clean process-termination request from `baml.sys.exit(code)`.
+///
+/// Catchable like any other panic; if left unhandled, the engine
+/// terminates the process with this code. Patterned after Python's
+/// `SystemExit`.
+class Exit {
+  code int
+}
+
 /// Memory allocation failure. This happens when an operation would have caused an unrecoverable
 /// Out-Of-Memory error so we panic instead. Note that not all memory allocation failures are
 /// guaranteed to panic; some may cause a hard failure.
 class AllocFailure {
   message string
 }
 
-type Panic = DivisionByZero | IndexOutOfBounds | MapKeyNotFound | StackOverflow | AssertionFailed | Unreachable | UserPanic | AllocFailure
+type Panic = DivisionByZero | IndexOutOfBounds | MapKeyNotFound | StackOverflow | AssertionFailed | Unreachable | UserPanic | Exit | AllocFailure

baml_language/crates/baml_builtins2/baml_std/baml/ns_sys/sys.baml

@@ -10,6 +10,10 @@ function panic(message: string) -> never {
   $rust_function
 }
 
+function exit(code: int) -> never {
+  $rust_function
+}
+
 function now_ms() -> int {
   $rust_function
 }

baml_language/crates/baml_builtins2_codegen/src/codegen.rs

@@ -26,6 +26,7 @@ fn is_fallible(path: &str) -> bool {
         || matches!(
             path,
             "baml.sys.panic"
+                | "baml.sys.exit"
                 | "baml.Uint8Array.zeroes"
                 | "baml.Uint8Array.from_array"
                 | "baml.Uint8Array.from_hex"

baml_language/crates/baml_builtins2_codegen/src/codegen_io.rs

@@ -592,7 +592,7 @@ pub fn generate_sys_op_enum(io_builtins: &[NativeBuiltin]) -> String {
         .collect();
 
     let tokens = quote! {
-        #[derive(Clone, Copy, Debug, PartialEq, Eq)]
+        #[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
         pub enum SysOp {
             #(#variant_idents,)*
         }

baml_language/crates/baml_cli/Cargo.toml

@@ -19,6 +19,7 @@ workspace = true
 [dependencies]
 baml_codegen_python = { workspace = true }
 baml_db = { workspace = true }
+baml_exec = { workspace = true }
 baml_fmt = { workspace = true }
 baml_lsp2_actions = { workspace = true }
 baml_lsp_server = { workspace = true }
@@ -30,9 +31,11 @@ bex_events_native = { workspace = true }
 bex_vm_types = { workspace = true }
 sys_native = { workspace = true }
 anyhow = { workspace = true }
+bitcode = { workspace = true }
 clap = { workspace = true, features = [ "color", "env" ] }
 clap-cargo = { workspace = true }
 ctrlc = { workspace = true }
+libsui = { workspace = true }
 regex = { workspace = true }
 serde_json = { workspace = true }
 strsim = { workspace = true }

baml_language/crates/baml_cli/src/commands.rs

@@ -72,6 +72,9 @@ pub(crate) enum Commands {
     #[command(about = "Run a BAML function or script", disable_help_flag = true)]
     Run(crate::run_command::RunArgs),
 
+    #[command(about = "Package a BAML program into a standalone executable")]
+    Pack(crate::pack_command::PackArgs),
+
     #[command(about = "Starts a language server", name = "lsp")]
     LanguageServer(crate::lsp::LanguageServerArgs),
     // #[command(about = "Start an interactive REPL for BAML expressions", hide = true)]
@@ -140,6 +143,7 @@ impl RuntimeCli {
                 }
             },
             Commands::Format(args) => args.run(),
+            Commands::Pack(args) => args.run(),
         }
     }
 }

baml_language/crates/baml_cli/src/lib.rs

@@ -15,6 +15,7 @@ pub(crate) mod format;
 pub(crate) mod generate;
 pub(crate) mod grep_command;
 pub(crate) mod lsp;
+pub(crate) mod pack_command;
 pub(crate) mod project_load;
 pub(crate) mod run_command;
 pub(crate) mod test_command;
@@ -39,6 +40,9 @@ pub enum ExitCode {
     TestFailure,
     TestCancelled,
     NoTestsRun,
+    /// User code requested a specific exit code via `baml.sys.exit(n)`.
+    /// Already narrowed to i32 (the `std::process::exit` contract).
+    Exit(i32),
 }
 
 impl From<ExitCode> for i32 {
@@ -56,25 +60,8 @@ impl From<ExitCode> for i32 {
             ExitCode::Other | ExitCode::InvalidArgs => 4,
             // No tests were found
             ExitCode::NoTestsRun => 5,
-        }
-    }
-}
-
-impl From<ExitCode> for u32 {
-    fn from(exit_code: ExitCode) -> Self {
-        match exit_code {
-            // All tests passed
-            ExitCode::Success => 0,
-            // All tests completed, but some required human evaluation
-            ExitCode::HumanEvalRequired => 1,
-            // Some tests failed
-            ExitCode::TestFailure => 2,
-            // Execution was interrupted
-            ExitCode::TestCancelled => 3,
-            // Some internal error occurred
-            ExitCode::Other | ExitCode::InvalidArgs => 4,
-            // No tests were found
-            ExitCode::NoTestsRun => 5,
+            // `baml.sys.exit(n)` — the user's exact code, already narrowed.
+            ExitCode::Exit(n) => n,
         }
     }
 }

baml_language/crates/baml_cli/src/main.rs

@@ -10,6 +10,12 @@ fn main() -> Result<()> {
 
     let argv: Vec<String> = std::env::args().collect();
 
+    // `run_cli` returns an `ExitCode` variant describing how the verb
+    // finished. The real process exit is deferred here so `run_cli` and
+    // its callees stay testable (no inline `std::process::exit`).
     let exit_code = baml_cli::run_cli(argv)?;
-    std::process::exit(exit_code.into());
+    match exit_code {
+        baml_cli::ExitCode::Success => Ok(()),
+        other => std::process::exit(other.into()),
+    }
 }