diff --git a/lib/auth/join.go b/lib/auth/join.go
index 5aea611bafdea..6cb33b176a1d9 100644
--- a/lib/auth/join.go
+++ b/lib/auth/join.go
@@ -207,14 +207,12 @@ func (a *Server) handleJoinFailure(
 // will be checked.
 func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsingTokenRequest) (certs *proto.Certs, err error) {
 	attrs := &workloadidentityv1pb.JoinAttrs{}
-	// rawJoinAttrs typically holds the raw metadata sourced from a join.
-	// E.g the claims from a JWT token. This is used for auditing purposes.
-	var rawJoinAttrs any
+	var rawClaims any
 	var provisionToken types.ProvisionToken
 	defer func() {
 		// Emit a log message and audit event on join failure.
 		if err != nil {
-			a.handleJoinFailure(err, provisionToken, rawJoinAttrs, req)
+			a.handleJoinFailure(err, provisionToken, rawClaims, req)
 		}
 	}()
 
@@ -236,7 +234,7 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodGitHub:
 		claims, err := a.checkGitHubJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
 			attrs.Github = claims.JoinAttrs()
 		}
 		if err != nil {
@@ -245,7 +243,7 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodGitLab:
 		claims, err := a.checkGitLabJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
 			attrs.Gitlab = claims.JoinAttrs()
 		}
 		if err != nil {
@@ -254,7 +252,7 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodCircleCI:
 		claims, err := a.checkCircleCIJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
 			attrs.Circleci = claims.JoinAttrs()
 		}
 		if err != nil {
@@ -263,7 +261,7 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodKubernetes:
 		claims, err := a.checkKubernetesJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
 		}
 		if err != nil {
 			return nil, trace.Wrap(err)
@@ -271,7 +269,7 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodGCP:
 		claims, err := a.checkGCPJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
 		}
 		if err != nil {
 			return nil, trace.Wrap(err)
@@ -279,7 +277,8 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodSpacelift:
 		claims, err := a.checkSpaceliftJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
+			attrs.Spacelift = claims.JoinAttrs()
 		}
 		if err != nil {
 			return nil, trace.Wrap(err)
@@ -287,7 +286,8 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodTerraformCloud:
 		claims, err := a.checkTerraformCloudJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
+			attrs.TerraformCloud = claims.JoinAttrs()
 		}
 		if err != nil {
 			return nil, trace.Wrap(err)
@@ -295,7 +295,7 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 	case types.JoinMethodBitbucket:
 		claims, err := a.checkBitbucketJoinRequest(ctx, req)
 		if claims != nil {
-			rawJoinAttrs = claims
+			rawClaims = claims
 			attrs.Bitbucket = claims.JoinAttrs()
 		}
 		if err != nil {
@@ -323,12 +323,12 @@ func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsin
 			ctx,
 			provisionToken,
 			req,
-			rawJoinAttrs,
+			rawClaims,
 			attrs,
 		)
 		return certs, trace.Wrap(err)
 	}
-	certs, err = a.generateCerts(ctx, provisionToken, req, rawJoinAttrs)
+	certs, err = a.generateCerts(ctx, provisionToken, req, rawClaims)
 	return certs, trace.Wrap(err)
 }
 
diff --git a/lib/spacelift/spacelift.go b/lib/spacelift/spacelift.go
index ddaba2f11cfd2..289e074fcb3b0 100644
--- a/lib/spacelift/spacelift.go
+++ b/lib/spacelift/spacelift.go
@@ -21,6 +21,8 @@ package spacelift
 import (
 	"github.com/gravitational/trace"
 	"github.com/mitchellh/mapstructure"
+
+	workloadidentityv1pb "github.com/gravitational/teleport/api/gen/proto/go/teleport/workloadidentity/v1"
 )
 
 // IDTokenClaims
@@ -49,6 +51,21 @@ type IDTokenClaims struct {
 	Scope string `json:"scope"`
 }
 
+// JoinAttrs returns the protobuf representation of the attested identity.
+// This is used for auditing and for evaluation of WorkloadIdentity rules and
+// templating.
+func (c *IDTokenClaims) JoinAttrs() *workloadidentityv1pb.JoinAttrsSpacelift {
+	return &workloadidentityv1pb.JoinAttrsSpacelift{
+		Sub:        c.Sub,
+		SpaceId:    c.SpaceID,
+		CallerType: c.CallerType,
+		CallerId:   c.CallerID,
+		RunType:    c.RunType,
+		RunId:      c.RunID,
+		Scope:      c.Scope,
+	}
+}
+
 // JoinAuditAttributes returns a series of attributes that can be inserted into
 // audit events related to a specific join.
 func (c *IDTokenClaims) JoinAuditAttributes() (map[string]interface{}, error) {
diff --git a/lib/terraformcloud/terraform.go b/lib/terraformcloud/terraform.go
index ded2340c2e5d1..c9db802130ae2 100644
--- a/lib/terraformcloud/terraform.go
+++ b/lib/terraformcloud/terraform.go
@@ -19,8 +19,7 @@
 package terraformcloud
 
 import (
-	"github.com/gravitational/trace"
-	"github.com/mitchellh/mapstructure"
+	workloadidentityv1pb "github.com/gravitational/teleport/api/gen/proto/go/teleport/workloadidentity/v1"
 )
 
 // IDTokenClaims
@@ -52,20 +51,17 @@ type IDTokenClaims struct {
 	RunPhase string `json:"terraform_run_phase"`
 }
 
-// JoinAuditAttributes returns a series of attributes that can be inserted into
-// audit events related to a specific join.
-func (c *IDTokenClaims) JoinAuditAttributes() (map[string]interface{}, error) {
-	res := map[string]interface{}{}
-	d, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
-		TagName: "json",
-		Result:  &res,
-	})
-	if err != nil {
-		return nil, trace.Wrap(err)
+// JoinAttrs returns the protobuf representation of the attested identity.
+// This is used for auditing and for evaluation of WorkloadIdentity rules and
+// templating.
+func (c *IDTokenClaims) JoinAttrs() *workloadidentityv1pb.JoinAttrsTerraformCloud {
+	return &workloadidentityv1pb.JoinAttrsTerraformCloud{
+		Sub:              c.Sub,
+		OrganizationName: c.OrganizationName,
+		ProjectName:      c.ProjectName,
+		WorkspaceName:    c.WorkspaceName,
+		FullWorkspace:    c.FullWorkspace,
+		RunId:            c.RunID,
+		RunPhase:         c.RunPhase,
 	}
-
-	if err := d.Decode(c); err != nil {
-		return nil, trace.Wrap(err)
-	}
-	return res, nil
 }