diff --git a/packages/opencode/src/cli/cmd/logs.ts b/packages/opencode/src/cli/cmd/logs.ts
index 737a950555c2..a290c4ef7085 100644
--- a/packages/opencode/src/cli/cmd/logs.ts
+++ b/packages/opencode/src/cli/cmd/logs.ts
@@ -29,7 +29,9 @@ export const LogsCommand = effectCmd({
     const lines = text.split("\n")
     if (lines.at(-1) === "") lines.pop()
     const count = Math.max(0, Math.floor(args.tail))
-    for (const line of lines.slice(-count)) console.log(line)
+    // slice(-0) === slice(0) returns the whole array, so guard 0 explicitly to
+    // mean "print no history" (e.g. `logs --tail 0 --follow` to stream only new lines).
+    for (const line of count === 0 ? [] : lines.slice(-count)) console.log(line)
     if (!args.follow) return
     // Follow by re-reading appended bytes whenever the file changes; the log
     // is append-only so the previous size is always a valid resume offset.
diff --git a/packages/opencode/src/session/compaction.ts b/packages/opencode/src/session/compaction.ts
index d199ccf5965d..4d87716c358d 100644
--- a/packages/opencode/src/session/compaction.ts
+++ b/packages/opencode/src/session/compaction.ts
@@ -339,27 +339,6 @@ const layer = Layer.effect(
         cfg,
         model,
       })
-      // Remove old messages that have been summarized (head and hidden) to prevent context buildup
-      if (!input.overflow) {
-        const messageIDsToRemove = new Set<MessageID>()
-        const messageIDsToPreserve = new Set<MessageID>()
-        // Add head messages (to be summarized in this compaction)
-        for (const msg of selected.head) {
-          messageIDsToRemove.add(msg.info.id)
-        }
-        // Add previously summarized messages (hidden)
-        for (const index of hidden) {
-          messageIDsToRemove.add(history[index].info.id)
-        }
-        // Preserve the parent message (needed as parent of the new compaction message)
-        messageIDsToPreserve.add(input.parentID)
-        // Remove messages marked for removal but not preserved
-        for (const msgID of messageIDsToRemove) {
-          if (!messageIDsToPreserve.has(msgID)) {
-            yield* session.removeMessage({ sessionID: input.sessionID, messageID: msgID })
-          }
-        }
-      }
       // Allow plugins to inject context or replace compaction prompt.
       const compacting = yield* plugin.trigger(
         "experimental.session.compacting",
@@ -433,6 +412,32 @@ const layer = Layer.effect(
         return "stop"
       }
 
+      // Remove old messages that have been summarized (head and hidden) to prevent
+      // context buildup. This must run only after the summary has been generated
+      // and persisted above: deleting first would permanently lose the history if
+      // summarization failed or the session was too large to compact. A "stop"
+      // result with an errored message means no valid summary exists either, so
+      // the history must survive in that case too.
+      if (!input.overflow && !processor.message.error) {
+        const messageIDsToRemove = new Set<MessageID>()
+        const messageIDsToPreserve = new Set<MessageID>()
+        // Add head messages (summarized in this compaction)
+        for (const msg of selected.head) {
+          messageIDsToRemove.add(msg.info.id)
+        }
+        // Add previously summarized messages (hidden)
+        for (const index of hidden) {
+          messageIDsToRemove.add(history[index].info.id)
+        }
+        // Preserve the parent message (needed as parent of the new compaction message)
+        messageIDsToPreserve.add(input.parentID)
+        for (const msgID of messageIDsToRemove) {
+          if (!messageIDsToPreserve.has(msgID)) {
+            yield* session.removeMessage({ sessionID: input.sessionID, messageID: msgID })
+          }
+        }
+      }
+
       if (compactionPart && selected.tail_start_id && compactionPart.tail_start_id !== selected.tail_start_id) {
         yield* session.updatePart({
           ...compactionPart,
diff --git a/packages/opencode/src/session/reminders.ts b/packages/opencode/src/session/reminders.ts
index f5484b8e9ba4..5915f949e49a 100644
--- a/packages/opencode/src/session/reminders.ts
+++ b/packages/opencode/src/session/reminders.ts
@@ -35,7 +35,7 @@ export const apply = Effect.fn("SessionReminders.apply")(function* (input: {
       })
     }
     const wasPlan = input.messages.some((msg) => msg.info.role === "assistant" && msg.info.agent === "plan")
-    if (wasPlan && input.agent.name === "build") {
+    if (wasPlan && input.agent.name === "code") {
       userMessage.parts.push({
         id: PartID.ascending(),
         messageID: userMessage.info.id,
diff --git a/packages/opencode/test/session/compaction.test.ts b/packages/opencode/test/session/compaction.test.ts
index 4a4210cf08bc..22b6b558e049 100644
--- a/packages/opencode/test/session/compaction.test.ts
+++ b/packages/opencode/test/session/compaction.test.ts
@@ -195,7 +195,7 @@ function createCompactionMarker(sessionID: SessionID) {
 
 function fake(
   input: Parameters<SessionProcessorModule.SessionProcessor.Interface["create"]>[0],
-  result: "continue" | "compact",
+  result: "continue" | "compact" | "stop",
 ) {
   const msg = input.assistantMessage
   return {
@@ -204,11 +204,21 @@ function fake(
     },
     updateToolCall: Effect.fn("TestSessionProcessor.updateToolCall")(() => Effect.succeed(undefined)),
     completeToolCall: Effect.fn("TestSessionProcessor.completeToolCall")(() => Effect.void),
-    process: Effect.fn("TestSessionProcessor.process")(() => Effect.succeed(result)),
+    process: Effect.fn("TestSessionProcessor.process")(() =>
+      Effect.sync(() => {
+        // The real processor returns "stop" after recording an error on the
+        // assistant message (aborted, provider failure, ...), so mirror that.
+        if (result === "stop") {
+          msg.error = new SessionV1.AbortedError({ message: "processor failed" }).toObject()
+          msg.finish = "error"
+        }
+        return result
+      }),
+    ),
   } satisfies SessionProcessorModule.SessionProcessor.Handle
 }
 
-function processorLayer(result: "continue" | "compact") {
+function processorLayer(result: "continue" | "compact" | "stop") {
   return Layer.succeed(
     SessionProcessorModule.SessionProcessor.Service,
     SessionProcessorModule.SessionProcessor.Service.of({
@@ -245,7 +255,7 @@ const compactionEnv = AppNodeBuilder.build(
 const itCompaction = testEffect(compactionEnv)
 
 type CompactionProcessOptions = {
-  result?: "continue" | "compact"
+  result?: "continue" | "compact" | "stop"
   llm?: Layer.Layer<LLM.Service>
   plugin?: Layer.Layer<Plugin.Service>
   provider?: ReturnType<typeof wide>
@@ -890,6 +900,74 @@ describe("session.compaction.process", () => {
     }).pipe(withCompaction({ result: "compact" })),
   )
 
+  itCompaction.instance(
+    "keeps summarized history when compaction fails",
+    Effect.gen(function* () {
+      const ssn = yield* SessionNs.Service
+      const session = yield* ssn.create({})
+      yield* createUserMessage(session.id, "first")
+      yield* createUserMessage(session.id, "second")
+      yield* createUserMessage(session.id, "third")
+      yield* createSummaryCompaction(session.id)
+
+      const msgs = yield* ssn.messages({ sessionID: session.id })
+      const parent = msgs.at(-1)?.info.id
+      expect(parent).toBeTruthy()
+      if (!parent) return
+
+      // Non-overflow auto compaction whose summarization fails ("compact"): the
+      // old head messages must survive, since deletion must happen only after a
+      // summary has been produced. Regression for history-loss on failed compaction.
+      const result = yield* SessionCompaction.use.process({
+        parentID: parent,
+        messages: msgs,
+        sessionID: session.id,
+        auto: true,
+      })
+
+      expect(result).toBe("stop")
+      const texts = (yield* ssn.messages({ sessionID: session.id }))
+        .flatMap((msg) => msg.parts)
+        .flatMap((part) => (part.type === "text" ? [part.text] : []))
+      expect(texts).toContain("first")
+      expect(texts).toContain("second")
+    }).pipe(withCompaction({ result: "compact", config: cfg({ tail_turns: 1, preserve_recent_tokens: 100 }) })),
+  )
+
+  itCompaction.instance(
+    "keeps summarized history when processing stops with an error",
+    Effect.gen(function* () {
+      const ssn = yield* SessionNs.Service
+      const session = yield* ssn.create({})
+      yield* createUserMessage(session.id, "first")
+      yield* createUserMessage(session.id, "second")
+      yield* createUserMessage(session.id, "third")
+      yield* createSummaryCompaction(session.id)
+
+      const msgs = yield* ssn.messages({ sessionID: session.id })
+      const parent = msgs.at(-1)?.info.id
+      expect(parent).toBeTruthy()
+      if (!parent) return
+
+      // Processing that stops with an errored assistant message ("stop" +
+      // message.error) produced no valid summary either, so the summarized
+      // head messages must survive. Regression for history-loss on errored stop.
+      const result = yield* SessionCompaction.use.process({
+        parentID: parent,
+        messages: msgs,
+        sessionID: session.id,
+        auto: true,
+      })
+
+      expect(result).toBe("stop")
+      const texts = (yield* ssn.messages({ sessionID: session.id }))
+        .flatMap((msg) => msg.parts)
+        .flatMap((part) => (part.type === "text" ? [part.text] : []))
+      expect(texts).toContain("first")
+      expect(texts).toContain("second")
+    }).pipe(withCompaction({ result: "stop", config: cfg({ tail_turns: 1, preserve_recent_tokens: 100 }) })),
+  )
+
   it.instance(
     "adds synthetic continue prompt when auto is enabled",
     Effect.gen(function* () {