diff --git a/cue/interpreter/wasm/builtin.go b/cue/interpreter/wasm/builtin.go
index a8b9cc84647..31ad0e307a6 100644
--- a/cue/interpreter/wasm/builtin.go
+++ b/cue/interpreter/wasm/builtin.go
@@ -55,7 +55,9 @@ func generateCallThatReturnsBuiltin(name string, scope adt.Value, args []string,
 	call := &adt.CallExpr{Fun: &adt.Builtin{
 		Result: adt.TopKind,
 		Name:   name,
-		Func: func(opctx *adt.OpContext, _ []adt.Value) adt.Expr {
+		Func: func(call *adt.CallContext) adt.Expr {
+			opctx := call.OpContext()
+
 			scope := value.Make(opctx, scope)
 			sig := compileStringsInScope(args, scope)
 			args, result := splitLast(sig)
diff --git a/internal/core/adt/call.go b/internal/core/adt/call.go
index 0e69682f310..a95ecb35296 100644
--- a/internal/core/adt/call.go
+++ b/internal/core/adt/call.go
@@ -29,6 +29,10 @@ type CallContext struct {
 	isValidator bool
 }
 
+func (c *CallContext) OpContext() *OpContext {
+	return c.ctx
+}
+
 func (c *CallContext) Pos() token.Pos {
 	var src ast.Node
 	switch {
@@ -57,3 +61,17 @@ func (c *CallContext) AddPositions(err *ValueError) {
 		err.AddPosition(v)
 	}
 }
+
+// Args return the pre-evaluated arguments. This function is only used for
+// transitioning and will be removed at some point. Use [CallContext.Value]
+// instead.
+func (c *CallContext) Args() []Value {
+	return c.args
+}
+
+// Exprs return the unevaluated argument expressions. This function is only used
+// for transitioning and will be removed at some point. Use [CallContext.Expr]
+// instead. (TODO)
+func (c *CallContext) Exprs() []Expr {
+	return c.call.Args
+}
diff --git a/internal/core/adt/expr.go b/internal/core/adt/expr.go
index 7aa9789f7ba..59e10d234ad 100644
--- a/internal/core/adt/expr.go
+++ b/internal/core/adt/expr.go
@@ -1544,7 +1544,7 @@ func (x *CallExpr) evaluate(c *OpContext, state combinedFlags) Value {
 			if !call.builtin.checkArgs(c, pos(x), len(x.Args)) {
 				return nil
 			}
-			return f.RawFunc(c, x.Args)
+			return f.RawFunc(call)
 		}
 
 	case *BuiltinValidator:
@@ -1637,7 +1637,7 @@ type Builtin struct {
 	// arguments. By default, all arguments are checked to be concrete.
 	NonConcrete bool
 
-	Func func(c *OpContext, args []Value) Expr
+	Func func(call *CallContext) Expr
 
 	// RawFunc gives low-level control to CUE's internals for builtins.
 	// It should be used when fine control over the evaluation process is
@@ -1645,7 +1645,9 @@ type Builtin struct {
 	// gives them fine control over how exactly such value gets evaluated.
 	// A RawFunc may pass CycleInfo, errors and other information through
 	// the Context.
-	RawFunc func(c *OpContext, args []Expr) Value
+	//
+	// TODO: consider merging Func and RawFunc into a single field again.
+	RawFunc func(call *CallContext) Value
 
 	Package Feature
 	Name    string
@@ -1773,7 +1775,7 @@ func (x *Builtin) call(call *CallContext) Expr {
 
 	saved := c.IsValidator
 	c.IsValidator = call.isValidator
-	ret := x.Func(c, call.args)
+	ret := x.Func(call)
 	c.IsValidator = saved
 
 	return ret
diff --git a/internal/core/compile/builtin.go b/internal/core/compile/builtin.go
index 79e5bbca477..3ebe42efd4a 100644
--- a/internal/core/compile/builtin.go
+++ b/internal/core/compile/builtin.go
@@ -35,7 +35,10 @@ var lenBuiltin = &adt.Builtin{
 	Name:   "len",
 	Params: []adt.Param{{Value: &adt.BasicType{K: supportedByLen}}},
 	Result: adt.IntKind,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		v := args[0]
 		if x, ok := v.(*adt.Vertex); ok {
 			x.LockArcs = true
@@ -82,7 +85,10 @@ var closeBuiltin = &adt.Builtin{
 	Name:   "close",
 	Params: []adt.Param{structParam},
 	Result: adt.StructKind,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		s, ok := args[0].(*adt.Vertex)
 		if !ok {
 			return c.NewErrf("struct argument must be concrete")
@@ -110,7 +116,10 @@ var andBuiltin = &adt.Builtin{
 	Name:   "and",
 	Params: []adt.Param{listParam},
 	Result: adt.IntKind,
-	RawFunc: func(c *adt.OpContext, args []adt.Expr) adt.Value {
+	RawFunc: func(call *adt.CallContext) adt.Value {
+		c := call.OpContext()
+		args := call.Exprs()
+
 		// Pass through the cycle information from evaluating the first argument.
 		v := c.EvaluateKeepState(args[0])
 		list := c.RawElems(v)
@@ -130,7 +139,10 @@ var orBuiltin = &adt.Builtin{
 	Params:      []adt.Param{listParam},
 	Result:      adt.IntKind,
 	NonConcrete: true,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		d := []adt.Disjunct{}
 		for _, c := range c.RawElems(args[0]) {
 			d = append(d, adt.Disjunct{Val: c, Default: false})
@@ -165,7 +177,10 @@ var divBuiltin = &adt.Builtin{
 	Name:   "div",
 	Params: []adt.Param{intParam, intParam},
 	Result: adt.IntKind,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		const name = "argument to div builtin"
 
 		return intDivOp(c, (*adt.OpContext).IntDiv, name, args)
@@ -176,7 +191,10 @@ var modBuiltin = &adt.Builtin{
 	Name:   "mod",
 	Params: []adt.Param{intParam, intParam},
 	Result: adt.IntKind,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		const name = "argument to mod builtin"
 
 		return intDivOp(c, (*adt.OpContext).IntMod, name, args)
@@ -187,7 +205,10 @@ var quoBuiltin = &adt.Builtin{
 	Name:   "quo",
 	Params: []adt.Param{intParam, intParam},
 	Result: adt.IntKind,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		const name = "argument to quo builtin"
 
 		return intDivOp(c, (*adt.OpContext).IntQuo, name, args)
@@ -198,7 +219,10 @@ var remBuiltin = &adt.Builtin{
 	Name:   "rem",
 	Params: []adt.Param{intParam, intParam},
 	Result: adt.IntKind,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		const name = "argument to rem builtin"
 
 		return intDivOp(c, (*adt.OpContext).IntRem, name, args)
diff --git a/internal/core/compile/validator.go b/internal/core/compile/validator.go
index 2bdd1a35e4c..fd09478cb60 100644
--- a/internal/core/compile/validator.go
+++ b/internal/core/compile/validator.go
@@ -30,7 +30,10 @@ var matchNBuiltin = &adt.Builtin{
 	Params:      []adt.Param{topParam, intParam, listParam}, // varargs
 	Result:      adt.BoolKind,
 	NonConcrete: true,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		if !c.IsValidator {
 			return c.NewErrf("matchN is a validator and should not be used as a function")
 		}
@@ -89,7 +92,10 @@ var matchIfBuiltin = &adt.Builtin{
 	Params:      []adt.Param{topParam, topParam, topParam, topParam},
 	Result:      adt.BoolKind,
 	NonConcrete: true,
-	Func: func(c *adt.OpContext, args []adt.Value) adt.Expr {
+	Func: func(call *adt.CallContext) adt.Expr {
+		c := call.OpContext()
+		args := call.Args()
+
 		if !c.IsValidator {
 			return c.NewErrf("matchIf is a validator and should not be used as a function")
 		}
diff --git a/internal/core/runtime/extern_test.go b/internal/core/runtime/extern_test.go
index f66e4199a28..0d410449a77 100644
--- a/internal/core/runtime/extern_test.go
+++ b/internal/core/runtime/extern_test.go
@@ -119,7 +119,9 @@ func (c *compilerFake) Compile(name string, scope adt.Value, a *internal.Attr) (
 
 	call := &adt.CallExpr{Fun: &adt.Builtin{
 		Result: adt.TopKind,
-		Func: func(opctx *adt.OpContext, args []adt.Value) adt.Expr {
+		Func: func(call *adt.CallContext) adt.Expr {
+			opctx := call.OpContext()
+
 			cuectx := (*cue.Context)(c.runtime)
 			scope := value.Make(opctx, scope)
 
diff --git a/internal/pkg/builtin.go b/internal/pkg/builtin.go
index 6795df32c2d..88b75755f7b 100644
--- a/internal/pkg/builtin.go
+++ b/internal/pkg/builtin.go
@@ -126,7 +126,10 @@ func ToBuiltin(b *Builtin) *adt.Builtin {
 		Package:     b.Pkg,
 		Name:        b.Name,
 	}
-	x.Func = func(ctx *adt.OpContext, args []adt.Value) (ret adt.Expr) {
+	x.Func = func(call *adt.CallContext) (ret adt.Expr) {
+		ctx := call.OpContext()
+		args := call.Args()
+
 		// call, _ := ctx.Source().(*ast.CallExpr)
 		c := &CallCtxt{
 			ctx:     ctx,