diff --git a/.github/workflows/scripts/setup-go-workspace.sh b/.github/workflows/scripts/setup-go-workspace.sh
index 517d6b7f5a..bc9a4d2854 100755
--- a/.github/workflows/scripts/setup-go-workspace.sh
+++ b/.github/workflows/scripts/setup-go-workspace.sh
@@ -18,9 +18,6 @@ if [ -f "go.work" ]; then
   return 0 2>/dev/null || exit 0
 fi
 go work init
-# Bump workspace go directive so GOTOOLCHAIN=auto switches to >= 1.26.2
-# (required by published core@v1.4.19 which is referenced from transports/go.mod).
-go work edit -go=1.26.2 -toolchain=go1.26.2
 go work use ./core
 go work use ./framework
 go work use ./plugins/governance
diff --git a/core/version b/core/version
index 771411b02f..dae2f141cd 100644
--- a/core/version
+++ b/core/version
@@ -1 +1 @@
-1.4.20
+1.4.21
\ No newline at end of file
diff --git a/transports/go.mod b/transports/go.mod
index 046f8e586e..3125ce242a 100644
--- a/transports/go.mod
+++ b/transports/go.mod
@@ -12,7 +12,7 @@ require (
 	github.com/google/uuid v1.6.0
 	github.com/klauspost/compress v1.18.2
 	github.com/mark3labs/mcp-go v0.43.2
-	github.com/maximhq/bifrost/core v1.4.19
+	github.com/maximhq/bifrost/core v1.4.20
 	github.com/maximhq/bifrost/framework v1.2.38
 	github.com/maximhq/bifrost/plugins/governance v1.4.38
 	github.com/maximhq/bifrost/plugins/litellmcompat v0.0.27
diff --git a/transports/go.sum b/transports/go.sum
index d9770c4540..491bef44a1 100644
--- a/transports/go.sum
+++ b/transports/go.sum
@@ -215,6 +215,8 @@ github.com/mattn/go-sqlite3 v1.14.32 h1:JD12Ag3oLy1zQA+BNn74xRgaBbdhbNIDYvQUEuuE
 github.com/mattn/go-sqlite3 v1.14.32/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/maximhq/bifrost/core v1.4.19 h1:RY6n8O1upUo/W05whsLO2OJtJpCpTFzplyq+6pk4NaY=
 github.com/maximhq/bifrost/core v1.4.19/go.mod h1:iOh2p1qEKVolMG8l84LWcn1CseUL2Kl5c/iXFMiZI84=
+github.com/maximhq/bifrost/core v1.4.20 h1:irEnW4oenNN4q8wiERa0Oa2D3UYnOQiF77UDMjqr1rc=
+github.com/maximhq/bifrost/core v1.4.20/go.mod h1:IaGSRlCgvy6Nr7Xiyu44sJJo9JbK188EL4QPXIcvURA=
 github.com/maximhq/bifrost/framework v1.2.38 h1:uWITpE+PilOwo1CQCXhZ8iQ98hH7VOBroJlTMWGL8As=
 github.com/maximhq/bifrost/framework v1.2.38/go.mod h1:S7vc+M9QOAj7RYK6pA0uauWHMxLxGRvlhHlZGArNsPw=
 github.com/maximhq/bifrost/plugins/governance v1.4.38 h1:B9rYAYWo5hO57XGRmb5nNMyj8FAdN8rcRtBTl4SLDXQ=