From 9ff2bb133a1764ed01ef2091247c35ec3657d8fc Mon Sep 17 00:00:00 2001
From: Kannav02 <kannavsethi02@gmail.com>
Date: Wed, 1 Oct 2025 23:11:04 -0400
Subject: [PATCH 1/4] fix: added condition for message delta to be included for
 anthropic

---
 packages/providers/anthropic/src/llm.ts | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/packages/providers/anthropic/src/llm.ts b/packages/providers/anthropic/src/llm.ts
index c01904c329..6b953cb58a 100644
--- a/packages/providers/anthropic/src/llm.ts
+++ b/packages/providers/anthropic/src/llm.ts
@@ -604,6 +604,15 @@ export class Anthropic extends ToolCallLLM<
           ? part.delta.signature
           : undefined;
 
+      if (part.type === "message_delta") {
+        yield {
+          raw: part,
+          delta: "",
+          options: {},
+        };
+        continue;
+      }
+
       if (
         part.type === "content_block_start" &&
         part.content_block.type === "tool_use"

From 1f16e084f84f84271552dde95d21cd1564277f04 Mon Sep 17 00:00:00 2001
From: Kannav02 <kannavsethi02@gmail.com>
Date: Wed, 1 Oct 2025 23:12:09 -0400
Subject: [PATCH 2/4] fix: raw field included in AgentStep and AgentResultData
 types, so usage is visible in downstream tasks

---
 packages/workflow/src/agent/agent-workflow.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/workflow/src/agent/agent-workflow.ts b/packages/workflow/src/agent/agent-workflow.ts
index 4fe66418b6..83698767f3 100644
--- a/packages/workflow/src/agent/agent-workflow.ts
+++ b/packages/workflow/src/agent/agent-workflow.ts
@@ -64,6 +64,7 @@ export type AgentResultData<O = JSONObject> = {
   message: ChatMessage;
   state?: AgentWorkflowState | undefined;
   object?: O | undefined;
+  raw?: unknown;
 };
 export const stopAgentEvent = workflowEvent<AgentResultData, "llamaindex-stop">(
   {
@@ -88,6 +89,7 @@ export type AgentStep = {
   agentName: string;
   response: ChatMessage;
   toolCalls: AgentToolCall[];
+  raw: unknown;
 };
 export const agentStepEvent = workflowEvent<AgentStep>();
 
@@ -426,6 +428,7 @@ export class AgentWorkflow implements Workflow {
         agentName: agent.name,
         response: output.response,
         toolCalls: output.toolCalls,
+        raw: output.raw,
       }),
     );
 
@@ -436,7 +439,7 @@ export class AgentWorkflow implements Workflow {
     context: StatefulContext<AgentWorkflowState>,
     event: WorkflowEventData<AgentStep>,
   ) => {
-    const { agentName, response, toolCalls } = event.data;
+    const { agentName, response, toolCalls, raw } = event.data;
     const agent = this.agents.get(agentName);
     if (!agent) {
       throw new Error(
@@ -453,7 +456,7 @@ export class AgentWorkflow implements Workflow {
       const agentOutput = {
         response,
         toolCalls: [],
-        raw: response,
+        raw,
         currentAgentName: agentName,
       };
       const content = await agent.finalize(context.state, agentOutput);
@@ -472,6 +475,7 @@ export class AgentWorkflow implements Workflow {
         result: content.response.content,
         state: context.state,
         object,
+        raw: content.raw ?? raw,
       });
     }
 
@@ -594,6 +598,7 @@ export class AgentWorkflow implements Workflow {
         message: responseMessage,
         result: output,
         state: context.state,
+        raw,
       });
     }
 

From ddbbfaaa1ad72e5b925f0b335f80b09f86a125d3 Mon Sep 17 00:00:00 2001
From: Kannav02 <kannavsethi02@gmail.com>
Date: Wed, 1 Oct 2025 23:13:03 -0400
Subject: [PATCH 3/4] fix: last chunk fixed from always being undefined to
 having the lastChunk value

---
 packages/workflow/src/agent/function-agent.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/workflow/src/agent/function-agent.ts b/packages/workflow/src/agent/function-agent.ts
index d7fd9e1073..c5de7fab40 100644
--- a/packages/workflow/src/agent/function-agent.ts
+++ b/packages/workflow/src/agent/function-agent.ts
@@ -197,6 +197,7 @@ export class FunctionAgent implements BaseWorkflowAgent {
     let lastChunk: ChatResponseChunk | undefined;
     const toolCalls: Map<string, AgentToolCall> = new Map();
     for await (const chunk of responseStream) {
+      lastChunk = chunk;
       response += chunk.delta;
       ctx.sendEvent(
         agentStreamEvent.with({

From 92d840a7ef136b9136ae6f7eeaa3b4017dd884de Mon Sep 17 00:00:00 2001
From: Marcus Schiesser <marcus.schiesser@googlemail.com>
Date: Thu, 2 Oct 2025 11:43:58 +0800
Subject: [PATCH 4/4] Create wild-bananas-sip.md

---
 .changeset/wild-bananas-sip.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 .changeset/wild-bananas-sip.md

diff --git a/.changeset/wild-bananas-sip.md b/.changeset/wild-bananas-sip.md
new file mode 100644
index 0000000000..59b744445c
--- /dev/null
+++ b/.changeset/wild-bananas-sip.md
@@ -0,0 +1,6 @@
+---
+"@llamaindex/workflow": patch
+"@llamaindex/anthropic": patch
+---
+
+fix: message delta visibility for anthropic