diff --git a/lib/trailblazer/pro/debugger.rb b/lib/trailblazer/pro/debugger.rb
index 168741b..45822f0 100644
--- a/lib/trailblazer/pro/debugger.rb
+++ b/lib/trailblazer/pro/debugger.rb
@@ -6,7 +6,7 @@ module Pro
     def self.invoke_debugger(**kws)
       _, (ctx, _) = Activity::TaskWrap.invoke(Debugger, [{now: DateTime.now, **kws, output: []}, {}])
 
-      return ctx[:output], [ctx[:session], ctx[:id], ctx[:debugger_url], ctx[:data_to_store], ctx[:session_updated]]
+      return ctx[:output], ctx#[:session], ctx[:id], ctx[:debugger_url], ctx[:data_to_store], ctx[:session_updated]]
     end
 
     # This is the {:render_method} implementation (for Trace::Present)
diff --git a/lib/trailblazer/pro/trace/wtf.rb b/lib/trailblazer/pro/trace/wtf.rb
index a084a64..86f0e5c 100644
--- a/lib/trailblazer/pro/trace/wtf.rb
+++ b/lib/trailblazer/pro/trace/wtf.rb
@@ -21,7 +21,9 @@ def call(*args, present_options: {}, **options)
           **options
         )
 
-        (session, _trace_id, _debugger_url, _trace_envelope, session_updated) = returned[-1]
+        returned_ctx = returned[-1]
+
+        session, session_updated = returned_ctx[:session], returned_ctx[:session_updated]
 
         update_session!(session) if session_updated # DISCUSS: this is a hook for pro-rails, not a massive fan.
 
diff --git a/test/debugger_test.rb b/test/debugger_test.rb
index a708291..75adb4d 100644
--- a/test/debugger_test.rb
+++ b/test/debugger_test.rb
@@ -115,7 +115,7 @@ def self.call(ctx, **)
     assert_equal ctx[:session].trailblazer_pro_host, "https://testbackend-pro.trb.to"
   end
 
-  it "what" do
+  it "{Pro.invoke_debugger}" do
     class Create < Trailblazer::Activity::Railway
       step :model
 
@@ -138,8 +138,9 @@ def model(ctx, **)
     debugger_trace = returned_args
 
     # NOTE: this tests private internals and hence looks a bit clumsy (especially retrieving the {debugger_trace}).
-    signal, (ctx, _) = Trailblazer::Developer.wtf?(Trailblazer::Pro::Debugger, [
-      {
+    # signal, (ctx, _) = Trailblazer::Developer.wtf?(Trailblazer::Pro::Debugger, [
+    output, ctx = Trailblazer::Pro.invoke_debugger(
+      **{
         debugger_trace: debugger_trace,
         activity: Create,
         renderer: Trailblazer::Developer::Trace::Present.method(:default_renderer),
@@ -149,7 +150,10 @@ def model(ctx, **)
         # http: stubbed_http,
         # data_to_store: {fields: {a: 1}},
         # firestore_fields_template: session_static_options[:firestore_fields_template],
-      }, {}])
+      }
+    )
+
+    assert_equal output.split(".to")[0], %(\e[1m[TRB PRO] view trace (DebuggerAPITest::Create) at \e[22mhttps://ide.trailblazer)
 
     assert_equal ctx[:session].class, Trailblazer::Pro::Session # initialized session.
     assert_equal ctx[:session_updated], true
diff --git a/test/present_options_test.rb b/test/present_options_test.rb
index ea5c55d..3652e27 100644
--- a/test/present_options_test.rb
+++ b/test/present_options_test.rb
@@ -14,7 +14,7 @@ def model(ctx, **)
   it "with {render_wtf: true}" do
     ctx = {}
 
-    signal, (ctx, _), _, output, (token, trace_id, debugger_url, trace_envelope) = Trailblazer::Developer.wtf?(
+    signal, (ctx, _), _, output, returned_ctx = Trailblazer::Developer.wtf?(
       Create,
       [ctx, {}],
       present_options: {render_method: Trailblazer::Pro.method(:invoke_debugger), session: uninitialized_session, render_wtf: true}, # FIXME:  why do we have to pass {:session} here?
@@ -24,34 +24,35 @@ def model(ctx, **)
 |-- \e[32mStart.default\e[0m
 |-- \e[32mmodel\e[0m
 `-- End.success
-\e[1m[TRB PRO] view trace (PresentOptionsTest::Create) at \e[22mhttps://ide.trailblazer.to/#{trace_id})
+\e[1m[TRB PRO] view trace (PresentOptionsTest::Create) at \e[22mhttps://ide.trailblazer.to/#{returned_ctx[:id]})
   end
 
   it "with {render_wtf: false}" do
     ctx = {}
 
-    signal, (ctx, _), _, output, (token, trace_id, debugger_url, trace_envelope) = Trailblazer::Developer.wtf?(
+    signal, (ctx, _), _, output, returned_ctx = Trailblazer::Developer.wtf?(
       Create,
       [ctx, {}],
       present_options: {render_method: Trailblazer::Pro.method(:invoke_debugger), session: uninitialized_session, render_wtf: false}, # FIXME:  why do we have to pass {:session} here?
     )
 
-    assert_equal output, %(\e[1m[TRB PRO] view trace (PresentOptionsTest::Create) at \e[22mhttps://ide.trailblazer.to/#{trace_id})
+    assert_equal output, %(\e[1m[TRB PRO] view trace (PresentOptionsTest::Create) at \e[22mhttps://ide.trailblazer.to/#{returned_ctx[:id]})
   end
 
   # test if trace has expected elements
   it "returned trace data is correct" do
     ctx = {}
 
-    signal, (ctx, _), _, output, (token, trace_id, debugger_url, trace_envelope) = Trailblazer::Developer.wtf?(
+    signal, (ctx, _), _, output, returned_ctx = Trailblazer::Developer.wtf?(
       Create,
       [ctx, {}],
       present_options: {render_method: Trailblazer::Pro.method(:invoke_debugger), session: uninitialized_session},
     )
 
-    assert_equal trace_id.size, 20
-    assert_equal debugger_url, "https://ide.trailblazer.to/#{trace_id}"
+    assert_equal returned_ctx[:id].size, 20
+    assert_equal returned_ctx[:debugger_url], "https://ide.trailblazer.to/#{returned_ctx[:id]}"
 
+    trace_envelope = returned_ctx[:data_to_store]
     assert_equal trace_envelope[:fields].keys, [:activity_name, :trace, :created_at]
     assert_equal trace_envelope[:fields][:activity_name], {:stringValue=>PresentOptionsTest::Create}
     assert trace_envelope[:fields][:created_at][:timestampValue] < DateTime.now
diff --git a/test/wtf_test.rb b/test/wtf_test.rb
index 6207535..6532ce6 100644
--- a/test/wtf_test.rb
+++ b/test/wtf_test.rb
@@ -28,8 +28,11 @@ def model(ctx, **)
   # Uninitialized session.
     assert_equal Trailblazer::Pro::Session.session.to_h, {api_key: api_key, trailblazer_pro_host: trailblazer_pro_host}
 
-    signal, (ctx, _), _, output, (session, trace_id, debugger_url, _trace_envelope) = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
+    signal, (ctx, _), _, output, returned_ctx = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
 
+    trace_id = returned_ctx[:id]
+    session = returned_ctx[:session]
+    debugger_url = returned_ctx[:debugger_url]
 
     assert_equal trace_id.size, 20
     assert_equal debugger_url, "https://ide.trailblazer.to/#{trace_id}"
@@ -38,7 +41,11 @@ def model(ctx, **)
     session_1_hash = assert_session({session: session}, **session_static_options)
 
   #@ while session is valid, do another call.
-    signal, (ctx, _), _, output, (session_2, trace_id_2, debugger_url_2, _trace_envelope) = Trailblazer::Pro::Trace::Wtf.call(Create, [ctx, {}])
+    signal, (ctx, _), _, output, returned_ctx_2 = Trailblazer::Pro::Trace::Wtf.call(Create, [ctx, {}])
+
+    trace_id_2 = returned_ctx_2[:id]
+    session_2 = returned_ctx_2[:session]
+    debugger_url_2 = returned_ctx_2[:debugger_url]
 
     assert_equal trace_id_2.size, 20
     assert_equal debugger_url_2, "https://ide.trailblazer.to/#{trace_id_2}"
@@ -50,9 +57,13 @@ def model(ctx, **)
     assert_equal session_1_hash[:id_token], session_2_hash[:id_token]
 
   #@ simulate time out, new token required.
-    signal, (ctx, _), _, output, (session_3, trace_id_3, debugger_url_3, _trace_envelope) =
+    signal, (ctx, _), _, output, returned_ctx_3 =
       Trailblazer::Pro::Trace::Wtf.call(Create, [ctx, {}], present_options: {now: DateTime.now + (60 * 1000)})
 
+    trace_id_3 = returned_ctx_3[:id]
+    session_3 = returned_ctx_3[:session]
+    debugger_url_3 = returned_ctx_3[:debugger_url]
+
     assert_equal trace_id_3.size, 20
     assert_equal debugger_url_3, "https://ide.trailblazer.to/#{trace_id_3}"
     assert trace_id != trace_id_3
@@ -73,7 +84,11 @@ def model(ctx, **)
 
     Trailblazer::Pro.initialize!(**session_4)
 
-    signal, (ctx, _), _, output, (session_5, trace_id_5, debugger_url_5, _trace_envelope) = Trailblazer::Pro::Trace::Wtf.call(Create, [ctx, {}])
+    signal, (ctx, _), _, output, returned_ctx_5 = Trailblazer::Pro::Trace::Wtf.call(Create, [ctx, {}])
+
+    trace_id_5 = returned_ctx_5[:id]
+    session_5 = returned_ctx_5[:session]
+    debugger_url_5 = returned_ctx_5[:debugger_url]
 
     assert_equal trace_id_5.size, 20
     assert_equal debugger_url_5, "https://ide.trailblazer.to/#{trace_id_5}"
@@ -91,7 +106,11 @@ def model(ctx, **)
       render_wtf: false,
     )
 
-    signal, (ctx, _), _, output, (session, trace_id, debugger_url, _trace_envelope) = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
+    signal, (ctx, _), _, output, returned_ctx = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
+
+    trace_id = returned_ctx[:id]
+    session = returned_ctx[:session]
+    debugger_url = returned_ctx[:debugger_url]
 
     assert_equal output, %(\e[1m[TRB PRO] view trace (WtfTest::Create) at \e[22mhttps://ide.trailblazer.to/#{trace_id})
     assert_equal trace_id.size, 20
@@ -105,7 +124,11 @@ def model(ctx, **)
       render_wtf: true,
     )
 
-    signal, (ctx, _), _, output, (session, trace_id, debugger_url, _trace_envelope) = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
+    signal, (ctx, _), _, output, returned_ctx = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
+
+    trace_id = returned_ctx[:id]
+    session = returned_ctx[:session]
+    debugger_url = returned_ctx[:debugger_url]
 
     assert_equal output, %(WtfTest::Create
 |-- \e[32mStart.default\e[0m
@@ -124,7 +147,7 @@ def model(ctx, **)
       # render_wtf: false,
     )
 
-    signal, (ctx, _), _, output, (session, trace_id, debugger_url, _trace_envelope) = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
+    signal, (ctx, _), _, output, _returned_ctx = Trailblazer::Pro::Trace::Wtf.call(Create, [{}, {}])
 
     assert_equal output, %(WtfTest::Create
 |-- \e[32mStart.default\e[0m