fix: preserve agent mode during noReply tool calls

When MCP tools call session.prompt({ noReply: true }), the agent mode was incorrectly switching from "plan" to "build" because the current executing agent wasn't tracked. Changes: - Add currentAgent field to Session schema to track active agent - Update loop() to set currentAgent before tool execution - Update createUserMessage() fallback chain to use currentAgent - Clear currentAgent on loop completion - Optimise to only update session when agent changes Fixes mode-switching bug during MCP tool execution.
anomalyco · arsham · Nov 22, 2025 · Nov 22, 2025 · Nov 22, 2025 · Nov 26, 2025
commit f123aa72db254964f31c5283a9557149f7ce0b56
diff --git a/packages/opencode/src/session/index.ts b/packages/opencode/src/session/index.ts
@@ -56,6 +56,7 @@ export namespace Session {
        })
        .optional(),
      title: z.string(),
+      currentAgent: z.string().optional(),
      version: z.string(),
      time: z.object({
        created: z.number(),

diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
@@ -91,7 +91,6 @@ export namespace SessionPrompt {
    noReply: z.boolean().optional(),
    tools: z.record(z.string(), z.boolean()).optional(),
    system: z.string().optional(),
-    variant: z.string().optional(),
    parts: z.array(
      z.discriminatedUnion("type", [
        MessageV2.TextPart.omit({
@@ -255,7 +254,13 @@ export namespace SessionPrompt {
    }

    using _lock = lock(sessionID)
-    using _ = defer(() => cancel(sessionID))
+    using _ = defer(() => {
+      cancel(sessionID)
+      // Clear currentAgent when loop completes
+      Session.update(sessionID, (draft) => {
+        draft.currentAgent = undefined
+      }).catch(() => {})
+    })

    let step = 0
    while (true) {
@@ -478,7 +483,7 @@ export namespace SessionPrompt {
      if (
        lastFinished &&
        lastFinished.summary !== true &&
-        (await SessionCompaction.isOverflow({ tokens: lastFinished.tokens, model }))
+        SessionCompaction.isOverflow({ tokens: lastFinished.tokens, model })
      ) {
        await SessionCompaction.create({
          sessionID,
@@ -491,6 +496,13 @@ export namespace SessionPrompt {

      // normal processing
      const agent = await Agent.get(lastUser.agent)
+      // Track current agent in session state (only if changed)
+      const session = await Session.get(sessionID)
+      if (session.currentAgent !== agent.name) {
+        await Session.update(sessionID, (draft) => {
+          draft.currentAgent = agent.name
+        })
+      }
      const maxSteps = agent.maxSteps ?? Infinity
      const isLastStep = step >= maxSteps
      msgs = insertReminders({
@@ -602,7 +614,7 @@ export namespace SessionPrompt {
      mergeDeep(await ToolRegistry.enabled(input.agent)),
      mergeDeep(input.tools ?? {}),
    )
-    for (const item of await ToolRegistry.tools(input.model.providerID, input.agent)) {
+    for (const item of await ToolRegistry.tools(input.model.providerID)) {
      if (Wildcard.all(item.id, enabledTools) === false) continue
      const schema = ProviderTransform.schema(input.model, z.toJSONSchema(item.parameters))
      tools[item.id] = tool({
@@ -734,7 +746,19 @@ export namespace SessionPrompt {
  }

  async function createUserMessage(input: PromptInput) {
-    const agent = await Agent.get(input.agent ?? (await Agent.defaultAgent()))
+    const session = await Session.get(input.sessionID)
+
+    // If no agent specified, infer from last assistant message's mode
+    let agentName = input.agent
+    if (!agentName) {
+      const msgs = await MessageV2.filterCompacted(MessageV2.stream(input.sessionID))
+      const lastAssistant = msgs.findLast((m) => m.info.role === "assistant") as MessageV2.Assistant | undefined
+      // Updated fallback chain - add session.currentAgent before session.agent
+      agentName = lastAssistant?.mode ?? session.currentAgent ?? session.agent ?? "general"
+    }
+
+    const agent = (await Agent.get(agentName)) || (await Agent.get("general"))
+    if (!agent) throw new Error(`Agent not found: ${agentName}`)
    const info: MessageV2.Info = {
      id: input.messageID ?? Identifier.ascending("message"),
      role: "user",
@@ -746,7 +770,6 @@ export namespace SessionPrompt {
      agent: agent.name,
      model: input.model ?? agent.model ?? (await lastModel(input.sessionID)),
      system: input.system,
-      variant: input.variant,
    }

    const parts = await Promise.all(
@@ -847,7 +870,7 @@ export namespace SessionPrompt {
                    const result = await t.execute(args, {
                      sessionID: input.sessionID,
                      abort: new AbortController().signal,
-                      agent: input.agent!,
+                      agent: agent.name,
                      messageID: info.id,
                      extra: { bypassCwdCheck: true, model },
                      metadata: async () => {},
@@ -907,7 +930,7 @@ export namespace SessionPrompt {
                  t.execute(args, {
                    sessionID: input.sessionID,
                    abort: new AbortController().signal,
-                    agent: input.agent!,
+                    agent: agent.name,
                    messageID: info.id,
                    extra: { bypassCwdCheck: true },
                    metadata: async () => {},
@@ -1287,7 +1310,6 @@ export namespace SessionPrompt {
    model: z.string().optional(),
    arguments: z.string(),
    command: z.string(),
-    variant: z.string().optional(),
  })
  export type CommandInput = z.infer<typeof CommandInput>
  const bashRegex = /!`([^`]+)`/g
@@ -1303,22 +1325,20 @@ export namespace SessionPrompt {
  export async function command(input: CommandInput) {
    log.info("command", input)
    const command = await Command.get(input.command)
-    const agentName = command.agent ?? input.agent ?? (await Agent.defaultAgent())
+    const agentName = command.agent ?? input.agent ?? "build"

    const raw = input.arguments.match(argsRegex) ?? []
    const args = raw.map((arg) => arg.replace(quoteTrimRegex, ""))

-    const templateCommand = await command.template
-
-    const placeholders = templateCommand.match(placeholderRegex) ?? []
+    const placeholders = command.template.match(placeholderRegex) ?? []
    let last = 0
    for (const item of placeholders) {
      const value = Number(item.slice(1))
      if (value > last) last = value
    }

    // Let the final placeholder swallow any extra arguments so prompts read naturally
-    const withArgs = templateCommand.replaceAll(placeholderRegex, (_, index) => {
+    const withArgs = command.template.replaceAll(placeholderRegex, (_, index) => {
      const position = Number(index)
      const argIndex = position - 1
      if (argIndex >= args.length) return ""
@@ -1332,7 +1352,7 @@ export namespace SessionPrompt {
      const results = await Promise.all(
        shell.map(async ([, cmd]) => {
          try {
-            return await $`${{ raw: cmd }}`.quiet().nothrow().text()
+            return await $`${{ raw: cmd }}`.nothrow().text()
          } catch (error) {
            return `Error executing command: ${error instanceof Error ? error.message : String(error)}`
          }
@@ -1392,7 +1412,6 @@ export namespace SessionPrompt {
      model,
      agent: agentName,
      parts,
-      variant: input.variant,
    })) as MessageV2.WithParts

    Bus.publish(Command.Event.Executed, {
@@ -1449,7 +1468,7 @@ export namespace SessionPrompt {
              time: {
                created: Date.now(),
              },
-              agent: input.message.info.role === "user" ? input.message.info.agent : await Agent.defaultAgent(),
+              agent: input.message.info.role === "user" ? input.message.info.agent : "build",
              model: {
                providerID: input.providerID,
                modelID: input.modelID,