diff --git a/examples/10-generic-struct.sx b/examples/10-generic-struct.sx
index 6123f49..0e21584 100644
--- a/examples/10-generic-struct.sx
+++ b/examples/10-generic-struct.sx
@@ -1,4 +1,5 @@
 #import "modules/std.sx";
+#import "modules/math";
 
 Vec :: struct($N: u32, $T:Type) {
     // <N x T> (LLVM Vector)
diff --git a/examples/modules/compiler.sx b/examples/modules/compiler.sx
index 6a3cf38..bf1ab32 100644
--- a/examples/modules/compiler.sx
+++ b/examples/modules/compiler.sx
@@ -6,14 +6,8 @@ ARCH : Architecture = .unknown;
 POINTER_SIZE : s64 = 8;
 
 BuildOptions :: struct {
-    add_link_flag :: (self: BuildOptions, flag: [:0]u8) {
-        // Compiler builtin — intercepted at compile time
-    }
-    set_output_path :: (self: BuildOptions, path: [:0]u8) {
-        // Compiler builtin — intercepted at compile time
-    }
+    add_link_flag :: (self: BuildOptions, flag: [:0]u8) #compiler;
+    set_output_path :: (self: BuildOptions, path: [:0]u8) #compiler;
 }
 
-build_options :: () -> BuildOptions {
-    return BuildOptions.{};
-}
+build_options :: () -> BuildOptions #compiler;
diff --git a/src/ast.zig b/src/ast.zig
index 0a52db7..6a34b65 100644
--- a/src/ast.zig
+++ b/src/ast.zig
@@ -67,6 +67,7 @@ pub const Node = struct {
         undef_literal: void,
         inferred_type: void,
         builtin_expr: void,
+        compiler_expr: void,
         foreign_expr: ForeignExpr,
         library_decl: LibraryDecl,
         function_type_expr: FunctionTypeExpr,
diff --git a/src/ir/compiler_hooks.zig b/src/ir/compiler_hooks.zig
new file mode 100644
index 0000000..a27393d
--- /dev/null
+++ b/src/ir/compiler_hooks.zig
@@ -0,0 +1,101 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const interp_mod = @import("interp.zig");
+const Value = interp_mod.Value;
+const Interpreter = interp_mod.Interpreter;
+
+// ── BuildConfig ─────────────────────────────────────────────────────────
+// Mutable build configuration accumulated by #run blocks via #compiler methods.
+
+pub const BuildConfig = struct {
+    link_flags: std.ArrayList([]const u8) = .empty,
+    output_path: ?[]const u8 = null,
+
+    pub fn deinit(self: *BuildConfig, alloc: Allocator) void {
+        self.link_flags.deinit(alloc);
+    }
+};
+
+// ── Hook system ─────────────────────────────────────────────────────────
+
+pub const HookError = error{
+    CannotEvalComptime,
+    TypeError,
+};
+
+/// Hook function signature. Receives the interpreter (for heap/string access),
+/// resolved argument values, and the mutable build config.
+pub const HookFn = *const fn (
+    interp: *const Interpreter,
+    args: []const Value,
+    bc: *BuildConfig,
+    alloc: Allocator,
+) HookError!Value;
+
+pub const Registry = struct {
+    hooks: std.StringHashMap(HookFn),
+
+    pub fn init(alloc: Allocator) Registry {
+        return .{ .hooks = std.StringHashMap(HookFn).init(alloc) };
+    }
+
+    pub fn deinit(self: *Registry) void {
+        self.hooks.deinit();
+    }
+
+    pub fn get(self: *const Registry, name: []const u8) ?HookFn {
+        return self.hooks.get(name);
+    }
+
+    /// Register all built-in compiler hooks.
+    pub fn registerDefaults(self: *Registry) void {
+        self.hooks.put("build_options", &hookBuildOptions) catch {};
+        self.hooks.put("BuildOptions.add_link_flag", &hookAddLinkFlag) catch {};
+        self.hooks.put("BuildOptions.set_output_path", &hookSetOutputPath) catch {};
+    }
+};
+
+// ── build_options() hook ────────────────────────────────────────────────
+
+fn hookBuildOptions(
+    _: *const Interpreter,
+    _: []const Value,
+    _: *BuildConfig,
+    _: Allocator,
+) HookError!Value {
+    // build_options() returns a sentinel value; the real work happens
+    // when methods like add_link_flag/set_output_path are called on it.
+    return .void_val;
+}
+
+// ── BuildOptions hooks ──────────────────────────────────────────────────
+
+fn hookAddLinkFlag(
+    interp: *const Interpreter,
+    args: []const Value,
+    bc: *BuildConfig,
+    alloc: Allocator,
+) HookError!Value {
+    // args: [self (BuildOptions value), flag_string]
+    if (args.len < 2) return .void_val;
+    const str_val = args[1];
+    if (str_val.asString(interp)) |s| {
+        bc.link_flags.append(alloc, alloc.dupe(u8, s) catch return error.CannotEvalComptime) catch return error.CannotEvalComptime;
+    }
+    return .void_val;
+}
+
+fn hookSetOutputPath(
+    interp: *const Interpreter,
+    args: []const Value,
+    bc: *BuildConfig,
+    alloc: Allocator,
+) HookError!Value {
+    // args: [self (BuildOptions value), path_string]
+    if (args.len < 2) return .void_val;
+    const str_val = args[1];
+    if (str_val.asString(interp)) |s| {
+        bc.output_path = alloc.dupe(u8, s) catch return error.CannotEvalComptime;
+    }
+    return .void_val;
+}
diff --git a/src/ir/emit_llvm.zig b/src/ir/emit_llvm.zig
index a756229..9eee79c 100644
--- a/src/ir/emit_llvm.zig
+++ b/src/ir/emit_llvm.zig
@@ -1454,6 +1454,10 @@ pub const LLVMEmitter = struct {
                     },
                 }
             },
+            .compiler_call => {
+                // Compiler hooks are comptime-only; if one reaches emission, produce undef
+                self.mapRef(c.LLVMGetUndef(self.toLLVMType(instruction.ty)));
+            },
             .call_closure => |call_op| {
                 // Closure: { fn_ptr, env } — extract fn_ptr, prepend env as first arg
                 const closure = self.resolveRef(call_op.callee);
diff --git a/src/ir/inst.zig b/src/ir/inst.zig
index 17bec08..b2985f3 100644
--- a/src/ir/inst.zig
+++ b/src/ir/inst.zig
@@ -177,6 +177,7 @@ pub const Op = union(enum) {
     call_indirect: CallIndirect,
     call_closure: CallIndirect,
     call_builtin: BuiltinCall,
+    compiler_call: CompilerCall,
 
     // ── Protocol dispatch ───────────────────────────────────────────
     protocol_call_dynamic: ProtocolCall, // vtable/inline dispatch
@@ -302,9 +303,11 @@ pub const BuiltinId = enum(u16) {
     type_of,
     alloc,
     dealloc,
-    build_options,
-    build_options_add_link_flag,
-    build_options_set_output_path,
+};
+
+pub const CompilerCall = struct {
+    name: u32, // StringPool id for qualified name (e.g. "BuildOptions.add_link_flag")
+    args: []const Ref,
 };
 
 pub const ProtocolCall = struct {
diff --git a/src/ir/interp.zig b/src/ir/interp.zig
index 1708cb1..a406ef8 100644
--- a/src/ir/interp.zig
+++ b/src/ir/interp.zig
@@ -106,17 +106,8 @@ pub const InterpError = error{
     Unreachable,
 };
 
-// ── BuildConfig ─────────────────────────────────────────────────────────
-// Mutable build configuration accumulated by #run blocks via BuildOptions methods.
-
-pub const BuildConfig = struct {
-    link_flags: std.ArrayList([]const u8) = .empty,
-    output_path: ?[]const u8 = null,
-
-    pub fn deinit(self: *BuildConfig, alloc: Allocator) void {
-        self.link_flags.deinit(alloc);
-    }
-};
+const compiler_hooks = @import("compiler_hooks.zig");
+pub const BuildConfig = compiler_hooks.BuildConfig;
 
 // ── Interpreter ─────────────────────────────────────────────────────────
 
@@ -136,13 +127,19 @@ pub const Interpreter = struct {
     // Mutable build configuration — set by LLVMEmitter, written by #run blocks
     build_config: ?*BuildConfig = null,
 
+    // Compiler hook registry for #compiler methods
+    hooks: compiler_hooks.Registry,
+
     pub fn init(module: *const Module, alloc: Allocator) Interpreter {
+        var hooks = compiler_hooks.Registry.init(alloc);
+        hooks.registerDefaults();
         return .{
             .module = module,
             .alloc = alloc,
             .output = std.ArrayList(u8).empty,
             .heap = std.ArrayList([]u8).empty,
             .global_values = std.AutoHashMap(u32, Value).init(alloc),
+            .hooks = hooks,
         };
     }
 
@@ -154,6 +151,7 @@ pub const Interpreter = struct {
         self.heap.deinit(self.alloc);
         self.output.deinit(self.alloc);
         self.global_values.deinit();
+        self.hooks.deinit();
     }
 
     // ── Heap operations ────────────────────────────────────────────
@@ -618,6 +616,25 @@ pub const Interpreter = struct {
                 return self.execBuiltin(bi, frame, instruction.ty);
             },
 
+            // ── Compiler hook calls (#compiler methods) ────────
+            .compiler_call => |cc| {
+                const name = self.module.types.getString(@enumFromInt(cc.name));
+                if (self.hooks.get(name)) |hook| {
+                    // Resolve args from Ref to Value
+                    var resolved_args = std.ArrayList(Value).empty;
+                    defer resolved_args.deinit(self.alloc);
+                    for (cc.args) |arg| {
+                        resolved_args.append(self.alloc, frame.getRef(arg)) catch return error.CannotEvalComptime;
+                    }
+                    if (self.build_config) |bc| {
+                        const result = hook(self, resolved_args.items, bc, self.alloc) catch return error.CannotEvalComptime;
+                        return .{ .value = result };
+                    }
+                    return .{ .value = .void_val };
+                }
+                return error.CannotEvalComptime;
+            },
+
             // ── Struct GEP (field pointer) ─────────────────────
             .struct_gep => |fa| {
                 const base = frame.getRef(fa.base);
@@ -1257,30 +1274,6 @@ pub const Interpreter = struct {
                 const f = val.asFloat() orelse return error.TypeError;
                 return .{ .value = .{ .float = @floor(f) } };
             },
-            .build_options => {
-                // Returns a void sentinel — the "handle" to BuildConfig
-                return .{ .value = .void_val };
-            },
-            .build_options_add_link_flag => {
-                // args: [opts_handle, flag_string]
-                const str_val = frame.getRef(bi.args[1]);
-                if (str_val.asString(self)) |s| {
-                    if (self.build_config) |bc| {
-                        bc.link_flags.append(self.alloc, self.alloc.dupe(u8, s) catch return error.CannotEvalComptime) catch return error.CannotEvalComptime;
-                    }
-                }
-                return .{ .value = .void_val };
-            },
-            .build_options_set_output_path => {
-                // args: [opts_handle, path_string]
-                const str_val = frame.getRef(bi.args[1]);
-                if (str_val.asString(self)) |s| {
-                    if (self.build_config) |bc| {
-                        bc.output_path = self.alloc.dupe(u8, s) catch return error.CannotEvalComptime;
-                    }
-                }
-                return .{ .value = .void_val };
-            },
             .cast, .type_of, .alloc, .dealloc => {
                 return error.CannotEvalComptime;
             },
diff --git a/src/ir/ir.zig b/src/ir/ir.zig
index 58ad440..bdb870c 100644
--- a/src/ir/ir.zig
+++ b/src/ir/ir.zig
@@ -31,6 +31,7 @@ pub const Interpreter = interp.Interpreter;
 pub const Value = interp.Value;
 pub const Lowering = lower.Lowering;
 
+pub const compiler_hooks = @import("compiler_hooks.zig");
 pub const emit_llvm = @import("emit_llvm.zig");
 pub const LLVMEmitter = emit_llvm.LLVMEmitter;
 
diff --git a/src/ir/lower.zig b/src/ir/lower.zig
index 537d22e..2f2f1b9 100644
--- a/src/ir/lower.zig
+++ b/src/ir/lower.zig
@@ -534,7 +534,7 @@ pub const Lowering = struct {
         // No AST? (builtins, foreign functions, or imported functions not in this file)
         const fd = self.fn_ast_map.get(name) orelse return;
         // Check builtin/foreign/generic — these stay as extern stubs
-        if (fd.body.data == .builtin_expr or fd.body.data == .foreign_expr) return;
+        if (fd.body.data == .builtin_expr or fd.body.data == .foreign_expr or fd.body.data == .compiler_expr) return;
         if (fd.type_params.len > 0) return; // generics handled by monomorphization (Step 3.13)
 
         // Defer functions with type-category matches until all types are registered.
@@ -685,7 +685,7 @@ pub const Lowering = struct {
         }
 
         // Check if the function body is a builtin or foreign declaration (no body needed)
-        if (fd.body.data == .builtin_expr or fd.body.data == .foreign_expr) {
+        if (fd.body.data == .builtin_expr or fd.body.data == .foreign_expr or fd.body.data == .compiler_expr) {
             // Already declared by scanDecls/declareFunction (which handles #foreign renames)
             return;
         }
@@ -3707,6 +3707,14 @@ pub const Lowering = struct {
                         return self.lowerGenericCall(fd, func_name, c, args.items);
                     }
                 }
+                // Check for #compiler free functions
+                if (self.fn_ast_map.get(func_name)) |fd_check| {
+                    if (fd_check.body.data == .compiler_expr) {
+                        const ret_ty = if (fd_check.return_type) |rt| type_bridge.resolveAstType(rt, &self.module.types) else TypeId.void;
+                        return self.builder.compilerCall(func_name, args.items, ret_ty);
+                    }
+                }
+
                 // Look up declared/extern function — try lazy lowering if not yet lowered
                 {
                     // First attempt: function may already be declared (from scanDecls)
@@ -3960,18 +3968,16 @@ pub const Lowering = struct {
                 // Try to resolve the method by struct type name
                 const struct_name = self.getStructTypeName(obj_ty);
                 if (struct_name) |sname| {
-                    // Intercept BuildOptions compiler builtins
-                    if (std.mem.eql(u8, sname, "BuildOptions")) {
-                        if (std.mem.eql(u8, fa.field, "add_link_flag")) {
-                            return self.builder.callBuiltin(.build_options_add_link_flag, method_args.items, .void);
-                        } else if (std.mem.eql(u8, fa.field, "set_output_path")) {
-                            return self.builder.callBuiltin(.build_options_set_output_path, method_args.items, .void);
-                        }
-                    }
-
                     // Try direct qualified name: StructName.method
                     const qualified = std.fmt.allocPrint(self.alloc, "{s}.{s}", .{ sname, fa.field }) catch fa.field;
 
+                    // Generic #compiler method dispatch
+                    if (self.fn_ast_map.get(qualified)) |method_fd| {
+                        if (method_fd.body.data == .compiler_expr) {
+                            return self.builder.compilerCall(qualified, method_args.items, .void);
+                        }
+                    }
+
                     // Check for generic struct template method
                     if (self.struct_instance_template.get(sname)) |tmpl_name| {
                         // This is an instantiated generic struct — look up template method
@@ -7595,13 +7601,14 @@ pub const Lowering = struct {
                             const oi = self.module.types.get(obj_ty);
                             if (oi == .@"struct") {
                                 const struct_name = self.module.types.getString(oi.@"struct".name);
-                                // Intercept BuildOptions compiler builtins
-                                if (std.mem.eql(u8, struct_name, "BuildOptions")) {
-                                    if (std.mem.eql(u8, cfa.field, "add_link_flag") or std.mem.eql(u8, cfa.field, "set_output_path")) {
+                                const qualified = std.fmt.allocPrint(self.alloc, "{s}.{s}", .{ struct_name, cfa.field }) catch cfa.field;
+                                // Generic #compiler method dispatch — return type from declaration
+                                if (self.fn_ast_map.get(qualified)) |method_fd| {
+                                    if (method_fd.body.data == .compiler_expr) {
+                                        if (method_fd.return_type) |rt| return type_bridge.resolveAstType(rt, &self.module.types);
                                         return .void;
                                     }
                                 }
-                                const qualified = std.fmt.allocPrint(self.alloc, "{s}.{s}", .{ struct_name, cfa.field }) catch cfa.field;
                                 if (self.resolveFuncByName(qualified)) |fid| {
                                     return self.module.functions.items[@intFromEnum(fid)].ret;
                                 }
diff --git a/src/ir/module.zig b/src/ir/module.zig
index 1a8c905..fe92b24 100644
--- a/src/ir/module.zig
+++ b/src/ir/module.zig
@@ -362,6 +362,12 @@ pub const Builder = struct {
         return self.emit(.{ .call_builtin = .{ .builtin = builtin, .args = owned } }, ret_ty);
     }
 
+    pub fn compilerCall(self: *Builder, name: []const u8, args: []const Ref, ret_ty: TypeId) Ref {
+        const name_id = self.module.types.strings.intern(self.module.alloc, name);
+        const owned = self.module.alloc.dupe(Ref, args) catch unreachable;
+        return self.emit(.{ .compiler_call = .{ .name = @intFromEnum(name_id), .args = owned } }, ret_ty);
+    }
+
     // ── Protocol ────────────────────────────────────────────────────
 
     pub fn protocolCallDynamic(self: *Builder, receiver: Ref, method_index: u32, args: []const Ref, ret_ty: TypeId) Ref {
diff --git a/src/ir/print.zig b/src/ir/print.zig
index 7697026..74e37de 100644
--- a/src/ir/print.zig
+++ b/src/ir/print.zig
@@ -316,6 +316,12 @@ fn printInst(instruction: *const Inst, ref_idx: u32, tt: *const TypeTable, write
             try writeArgs(c.args, writer);
             try writer.writeAll(") : ");
         },
+        .compiler_call => |cc| {
+            const name = tt.getString(@enumFromInt(cc.name));
+            try writer.print("compiler_call \"{s}\"(", .{name});
+            try writeArgs(cc.args, writer);
+            try writer.writeAll(") : ");
+        },
 
         // ── Protocol ────────────────────────────────────────────
         .protocol_call_dynamic => |c| {
diff --git a/src/lexer.zig b/src/lexer.zig
index 4fcde1f..c2133c8 100644
--- a/src/lexer.zig
+++ b/src/lexer.zig
@@ -69,6 +69,7 @@ pub const Lexer = struct {
                 .{ "#insert", Tag.hash_insert },
                 .{ "#run", Tag.hash_run },
                 .{ "#builtin", Tag.hash_builtin },
+                .{ "#compiler", Tag.hash_compiler },
                 .{ "#foreign", Tag.hash_foreign },
                 .{ "#library", Tag.hash_library },
                 .{ "#using", Tag.hash_using },
diff --git a/src/lsp/server.zig b/src/lsp/server.zig
index ee10b77..318225c 100644
--- a/src/lsp/server.zig
+++ b/src/lsp/server.zig
@@ -1482,6 +1482,7 @@ pub const Server = struct {
             .hash_import,
             .hash_insert,
             .hash_builtin,
+            .hash_compiler,
             .hash_foreign,
             .hash_library,
             .hash_using,
diff --git a/src/parser.zig b/src/parser.zig
index b2a7c8e..e443f2d 100644
--- a/src/parser.zig
+++ b/src/parser.zig
@@ -1215,13 +1215,18 @@ pub const Parser = struct {
             return_type = try self.parseTypeExpr();
         }
 
-        // Body: block `{ ... }`, arrow `=> expr;`, #builtin, or #foreign marker
+        // Body: block `{ ... }`, arrow `=> expr;`, #builtin, #compiler, or #foreign marker
         var is_arrow = false;
         const body = if (self.current.tag == .hash_builtin) blk: {
             const bi_start = self.current.loc.start;
             self.advance();
             try self.expect(.semicolon);
             break :blk try self.createNode(bi_start, .{ .builtin_expr = {} });
+        } else if (self.current.tag == .hash_compiler) blk: {
+            const ci_start = self.current.loc.start;
+            self.advance();
+            try self.expect(.semicolon);
+            break :blk try self.createNode(ci_start, .{ .compiler_expr = {} });
         } else if (self.current.tag == .hash_foreign) blk: {
             const fi_start = self.current.loc.start;
             self.advance();
@@ -2351,7 +2356,7 @@ pub const Parser = struct {
 
     fn isFunctionDef(self: *Parser) bool {
         const tag = self.peekPastParens() orelse return false;
-        return tag == .l_brace or tag == .arrow or tag == .hash_builtin or tag == .hash_foreign or tag == .fat_arrow;
+        return tag == .l_brace or tag == .arrow or tag == .hash_builtin or tag == .hash_compiler or tag == .hash_foreign or tag == .fat_arrow;
     }
 
     fn isAssignOp(self: *const Parser) bool {
diff --git a/src/sema.zig b/src/sema.zig
index be42b54..0c36e9e 100644
--- a/src/sema.zig
+++ b/src/sema.zig
@@ -862,6 +862,7 @@ pub const Analyzer = struct {
             .undef_literal,
             .inferred_type,
             .builtin_expr,
+            .compiler_expr,
             .foreign_expr,
             .library_decl,
             .function_type_expr,
@@ -1264,6 +1265,7 @@ pub fn findNodeAtOffset(node: *Node, offset: u32) ?*Node {
         .undef_literal,
         .inferred_type,
         .builtin_expr,
+        .compiler_expr,
         .foreign_expr,
         .library_decl,
         .function_type_expr,
diff --git a/src/token.zig b/src/token.zig
index 87df06c..b3d832e 100644
--- a/src/token.zig
+++ b/src/token.zig
@@ -101,6 +101,7 @@ pub const Tag = enum {
     hash_import, // #import
     hash_insert, // #insert
     hash_builtin, // #builtin
+    hash_compiler, // #compiler
     hash_foreign, // #foreign
     hash_library, // #library
     hash_using, // #using