Show orchestrator-chosen subagent names on agent groups

A subagent_start whose payload data carries a name (the orchestrator's new
name trigger parameter) now labels the agent group with that mission name —
the agent-type icon stays. The name flows through the live stream path, the
turn model (AgentNode.displayName) and its serialize/rebuild round-trip, and
persisted transcripts (PersistedContentBlock.name), so reloads keep the label.

Author: Sg312

apps/sim/app/workspace/[workspaceId]/home/components/message-content/message-content.tsx

@@ -380,6 +380,7 @@ function parseBlocksWithSpanTree(blocks: ContentBlock[]): MessageSegment[] {
       const dispatchToolName = SUBAGENT_DISPATCH_TOOLS[block.content]
       if (dispatchToolName) absorbDispatchTool(dispatchToolName, block.parentSpanId)
       const g = ensureSpanGroup(block.content, block.spanId, block.parentSpanId)
+      if (block.subagentName) g.agentLabel = block.subagentName
       if (block.endedAt !== undefined) {
         // Persisted backend path: the lane was stamped closed (endedAt) without
         // a separate subagent_end block (the Sim backend stamps endedAt only;
@@ -623,6 +624,7 @@ function parseBlocksLegacy(blocks: ContentBlock[]): MessageSegment[] {
       }
       groupsByKey.delete(groupKey('mothership', undefined))
       const { group: g } = ensureGroup(key, block.parentToolCallId)
+      if (block.subagentName) g.agentLabel = block.subagentName
       if (inheritedDelegation) g.isDelegating = true
       g.isOpen = true
       activeGroupKey = resolveGroupKey(key, block.parentToolCallId)

apps/sim/app/workspace/[workspaceId]/home/hooks/stream/turn-model-serialize.ts

@@ -167,6 +167,7 @@ export function modelToContentBlocks(model: TurnModel): ContentBlock[] {
       block: {
         type: 'subagent',
         content: node.agentId,
+        ...(node.displayName ? { subagentName: node.displayName } : {}),
         spanId: node.spanId,
         parentSpanId: node.parentSpanId,
         ...(node.triggerToolCallId ? { parentToolCallId: node.triggerToolCallId } : {}),
@@ -267,7 +268,10 @@ export function contentBlocksToModel(blocks: ContentBlock[]): TurnModel {
             kind: 'subagent',
             event: 'start',
             agent: block.content,
-            data: block.parentToolCallId ? { tool_call_id: block.parentToolCallId } : {},
+            data: {
+              ...(block.parentToolCallId ? { tool_call_id: block.parentToolCallId } : {}),
+              ...(block.subagentName ? { name: block.subagentName } : {}),
+            },
           },
           scopeFor(block),
           block.timestamp

apps/sim/app/workspace/[workspaceId]/home/hooks/stream/turn-model.test.ts

@@ -237,6 +237,29 @@ describe('reduceEvent — subagent lifecycle', () => {
     expect(agent(m, 'S1').parentSpanId).toBe(MAIN_SPAN)
   })
 
+  it('captures the orchestrator-chosen display name from span start data', () => {
+    const m = apply([
+      envelope(
+        1,
+        'span',
+        {
+          kind: 'subagent',
+          event: 'start',
+          agent: 'research',
+          data: { tool_call_id: 'tc-r', name: 'Pricing research' },
+        },
+        {
+          lane: 'subagent',
+          spanId: 'S1',
+          parentSpanId: MAIN_SPAN,
+          parentToolCallId: 'tc-r',
+          agentId: 'research',
+        }
+      ),
+    ])
+    expect(agent(m, 'S1').displayName).toBe('Pricing research')
+  })
+
   it('settles an agent error when span end carries an error', () => {
     const m = apply([
       spanStart(1, 'S1', 'file', 'tc-file'),

apps/sim/app/workspace/[workspaceId]/home/hooks/stream/turn-model.ts

@@ -85,6 +85,8 @@ export interface AgentNode extends NodeBase {
   agentId: string
   /** The outer delegation tool_use that triggered this run; links the trigger tool node. */
   triggerToolCallId?: string
+  /** Orchestrator-chosen display name for this delegation (falls back to the agent label). */
+  displayName?: string
   status: NodeStatus
   /** Wire seq at which the run terminated (span end), for ordering the close marker. */
   endSeq?: number
@@ -563,6 +565,7 @@ export function reduceEvent(model: TurnModel, envelope: PersistedStreamEventEnve
       const triggerToolCallId =
         scope?.parentToolCallId ?? asString(data?.tool_call_id) ?? asString(data?.toolCallId)
       const agentId = asString(payload.agent) ?? scope?.agentId ?? ''
+      const displayName = asString(data?.name)
       const resolvedSpanId =
         scope?.spanId ?? (triggerToolCallId ? `span:${triggerToolCallId}` : `span:${seq}`)
       const parentSpanId = scope?.parentSpanId ?? MAIN_SPAN
@@ -581,6 +584,7 @@ export function reduceEvent(model: TurnModel, envelope: PersistedStreamEventEnve
           // scope.agentId can name the forwarding caller (e.g. superagent),
           // while this start's payload.agent is the authoritative lane owner.
           if (agentId && existing.agentId !== agentId) existing.agentId = agentId
+          if (displayName && !existing.displayName) existing.displayName = displayName
           if (!existing.triggerToolCallId && triggerToolCallId) {
             existing.triggerToolCallId = triggerToolCallId
           }
@@ -602,6 +606,7 @@ export function reduceEvent(model: TurnModel, envelope: PersistedStreamEventEnve
           seq: seq,
           ...(tsMs !== undefined ? { startedAtMs: tsMs } : {}),
           ...(triggerToolCallId ? { triggerToolCallId } : {}),
+          ...(displayName ? { displayName } : {}),
         }
         model.nodes.set(node.id, node)
         model.order.push(node.id)

apps/sim/app/workspace/[workspaceId]/home/types.ts

@@ -114,6 +114,8 @@ export interface ContentBlock {
   type: ContentBlockType
   content?: string
   subagent?: string
+  /** Orchestrator-chosen display name for a `subagent` start block (shown instead of the generic agent label). */
+  subagentName?: string
   toolCall?: ToolCallInfo
   options?: OptionItem[]
   timestamp?: number

apps/sim/lib/copilot/chat/display-message.ts

@@ -92,7 +92,11 @@ function toDisplayBlockBody(block: PersistedContentBlock): ContentBlock | undefi
       if (block.lifecycle === MothershipStreamV1SpanLifecycleEvent.end) {
         return { type: ContentBlockType.subagent_end }
       }
-      return { type: ContentBlockType.subagent, content: block.content }
+      return {
+        type: ContentBlockType.subagent,
+        content: block.content,
+        ...(block.name ? { subagentName: block.name } : {}),
+      }
     case MothershipStreamV1EventType.complete:
       if (block.status === MothershipStreamV1CompletionStatus.cancelled) {
         return { type: ContentBlockType.stopped }

apps/sim/lib/copilot/chat/persisted-message.ts

@@ -53,6 +53,8 @@ export interface PersistedContentBlock {
   lifecycle?: MothershipStreamV1SpanLifecycleEvent
   status?: MothershipStreamV1CompletionStatus
   content?: string
+  /** Orchestrator-chosen display name on a subagent start block. */
+  name?: string
   toolCall?: PersistedToolCall
   timestamp?: number
   endedAt?: number
@@ -245,6 +247,7 @@ function mapContentBlockBody(block: ContentBlock): PersistedContentBlock {
         kind: MothershipStreamV1SpanPayloadKind.subagent,
         lifecycle: MothershipStreamV1SpanLifecycleEvent.start,
         content: block.content,
+        ...(block.subagentName ? { name: block.subagentName } : {}),
       }
     case 'subagent_text':
       return {
@@ -436,6 +439,9 @@ interface RawBlock {
   type: string
   lane?: string
   agent?: string
+  /** Orchestrator-chosen subagent display name (legacy blocks store it as `subagentName`). */
+  name?: string
+  subagentName?: string
   content?: string
   /** Go persists text blocks with key "text" instead of "content" */
   text?: string
@@ -503,6 +509,7 @@ function normalizeCanonicalBlock(block: RawBlock): PersistedContentBlock {
     result.lane = block.lane
   }
   if (block.agent) result.agent = block.agent
+  if (block.name) result.name = block.name
   const blockContent = block.content ?? block.text
   if (blockContent !== undefined) result.content = blockContent
   if (block.channel) result.channel = block.channel as MothershipStreamV1TextChannel
@@ -584,6 +591,7 @@ function normalizeLegacyBlock(block: RawBlock): PersistedContentBlock {
       kind: MothershipStreamV1SpanPayloadKind.subagent,
       lifecycle: MothershipStreamV1SpanLifecycleEvent.start,
       content: block.content,
+      ...(block.subagentName ? { name: block.subagentName } : {}),
     }
   }
 

apps/sim/lib/copilot/request/go/stream.ts

@@ -436,9 +436,17 @@ export async function runStreamLoop(
               const openParents = (context.openSubagentParents ??= new Set<string>())
               if (!openParents.has(toolCallId)) {
                 openParents.add(toolCallId)
+                const payloadData = streamEvent.payload.data
+                const displayName =
+                  payloadData && typeof payloadData === 'object' && !Array.isArray(payloadData)
+                    ? (payloadData as Record<string, unknown>).name
+                    : undefined
                 context.contentBlocks.push({
                   type: 'subagent',
                   content: subagentName,
+                  ...(typeof displayName === 'string' && displayName
+                    ? { subagentName: displayName }
+                    : {}),
                   parentToolCallId: toolCallId,
                   ...(spanId ? { spanId } : {}),
                   ...(parentSpanId ? { parentSpanId } : {}),

apps/sim/lib/copilot/request/types.ts

@@ -80,6 +80,8 @@ export interface ContentBlock {
    * `subagent` start block is missing (resume legs re-emit text without start).
    */
   subagent?: string
+  /** Orchestrator-chosen display name for a `subagent` start block. */
+  subagentName?: string
   /**
    * Deterministic agent-run identity. `spanId` is the stable per-invocation id
    * of the subagent that produced the block; `parentSpanId` links it to the run