fix: set x-initiator header for compaction and synthetic messages

Author: aklajnert

packages/opencode/src/plugin/github-copilot/copilot.ts

@@ -324,7 +324,7 @@ export async function CopilotAuthPlugin(input: PluginInput): Promise<Hooks> {
         output.headers["anthropic-beta"] = "interleaved-thinking-2025-05-14"
       }
 
-      const parts = await sdk.session
+      const msg = await sdk.session
         .message({
           path: {
             id: incoming.message.sessionID,
@@ -337,24 +337,30 @@ export async function CopilotAuthPlugin(input: PluginInput): Promise<Hooks> {
         })
         .catch(() => undefined)
 
-      if (parts?.data.parts?.some((part) => part.type === "compaction")) {
+      if (
+        msg?.data?.parts?.some(
+          (p) =>
+            p.type === "compaction" ||
+            (p.type === "text" && p.text === "[auto-compaction-followup]" && p.synthetic && p.ignored),
+        )
+      ) {
         output.headers["x-initiator"] = "agent"
         return
       }
 
       const session = await sdk.session
         .get({
           path: {
-            id: incoming.sessionID,
+            id: incoming.message.sessionID,
           },
           query: {
             directory: input.directory,
           },
-          throwOnError: true,
         })
         .catch(() => undefined)
-      if (!session || !session.data.parentID) return
-      // mark subagent sessions as agent initiated matching standard that other copilot tools have
+      if (!session?.data?.parentID) return
+      const perms = (session.data as typeof session.data & { permission?: Array<{ permission: string }> }).permission
+      if (perms?.some((r) => r.permission === "user_slash_command")) return
       output.headers["x-initiator"] = "agent"
     },
   }

packages/opencode/src/session/compaction.ts

@@ -318,6 +318,15 @@ When constructing the summary, try to stick to this template:
               agent: userMessage.agent,
               model: userMessage.model,
             })
+            yield* session.updatePart({
+              id: PartID.ascending(),
+              messageID: continueMsg.id,
+              sessionID: input.sessionID,
+              type: "text",
+              synthetic: true,
+              ignored: true,
+              text: "[auto-compaction-followup]",
+            })
             const text =
               (input.overflow
                 ? "The previous request exceeded the provider's size limit due to large media attachments. The conversation was compacted and media files were removed from context. If the user was asking about attached images or files, explain that the attachments were too large to process and suggest they try again with smaller or fewer files.\n\n"

packages/opencode/src/tool/task.ts

@@ -70,6 +70,15 @@ export const TaskTool = Tool.defineEffect(
             parentID: ctx.sessionID,
             title: params.description + ` (@${next.name} subagent)`,
             permission: [
+              ...(params.command
+                ? [
+                    {
+                      permission: "user_slash_command" as const,
+                      pattern: params.command,
+                      action: "allow" as const,
+                    },
+                  ]
+                : []),
               ...(canTodo
                 ? []
                 : [