Plan agent loops forever after auto-compaction (opencode run never exits) #62628

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1. opencodejr commented on Nov 7, 2026

   

   opencodejrBot

   on Nov 7, 2026

   Contributor

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   Thanks for the detailed report! I reproduced this on 2.2.6, and it still happens on the latest dev (c33eaa170).

   Setup: a local OpenAI-compatible mock model (no real provider), with the model's context limit set small enough that the system prompt alone triggers auto-compaction.

   • opencode run --agent plan "reply with exactly: ok" never exits. In 40 seconds the mock got about 3,000 requests, alternating compaction and answer, until timeout killed it.
   • --agent build with the same small limit exits after one compaction and one answer.
   • --agent plan with a large context limit exits normally.

   The script below reproduces it with a mock model, so no credentials are needed. The likely cause is that the Plan-mode reminder is added back after every compaction, which seems to start another turn that compacts again. That has not been confirmed yet.

   Related: #52697 and #48827 (earlier auto-compaction loops, not specific to the plan agent) and #58395 (when the Plan reminder is saved).

   Reproduction script (repro.sh)

   #!/usr/bin/env bash
   # Repro for #62628: `opencode run --agent plan` never exits once auto-compaction triggers.
   # Uses a local OpenAI-compatible mock model (no credentials). Requires bun.
   # OC="opencode" by default; set OC to another command (e.g. a source checkout) to test it.
   # For a source checkout set OC to its CLI command and OC_SERVE=1.
   # CONTEXT (default 3000) is the model's context limit; small enough that the first request auto-compacts.
   set -u
   OC=${OC:-opencode}
   AGENT=${AGENT:-plan}
   CONTEXT=${CONTEXT:-3000}
   PORT=${PORT:-4567}
   WORK=$(mktemp -d)
   mkdir -p "$WORK/proj" "$WORK/home"
   cat > "$WORK/mock.ts" <<'EOF'
   let n = 0
   const SUMMARY = "## Objective\n- Reply with exactly: ok\n\n## Requirements\n- (none)\n\n## Decisions\n- (none)\n\n## Work State\n### Completed\n- (none)\n\n### Active\n- Reply ok\n\n### Blocked\n- (none)\n\n## Next Move\n1. Reply ok\n\n## Relevant Files\n- (none)\n\n## Important Context\n- (none)\n"
   Bun.serve({
     port: Number(process.env.PORT),
     async fetch(req) {
       if (!new URL(req.url).pathname.endsWith("/chat/completions")) return new Response("{}", { status: 404 })
       const body: any = await req.json()
       n++
       const size = JSON.stringify(body.messages).length
       const last = body.messages.at(-1)
       const lastText = typeof last.content === "string" ? last.content : (last.content ?? []).map((p: any) => p.text ?? "").join("")
       const title = /first message of the conversation/.test(lastText)
       const compaction = /^(You MUST summarize|Update the existing checkpoint|The previous response did not fill in the required summary template)/.test(lastText)
       const kind = title ? "title" : compaction ? "COMPACTION" : "answer"
       console.log(`request #${n} ${kind}`)
       const text = compaction ? SUMMARY : title ? "Reply ok" : "ok"
       const enc = new TextEncoder()
       const base = { id: "c" + n, object: "chat.completion.chunk", created: 0, model: "m" }
       const chunk = (o: any) => enc.encode(`data: ${JSON.stringify({ ...base, ...o })}\n\n`)
       return new Response(new ReadableStream({ start(c) {
         c.enqueue(chunk({ choices: [{ index: 0, delta: { role: "assistant", content: text } }] }))
         c.enqueue(chunk({ choices: [{ index: 0, delta: {}, finish_reason: "stop" }] }))
         c.enqueue(chunk({ choices: [], usage: { prompt_tokens: Math.ceil(size / 4), completion_tokens: 2, total_tokens: Math.ceil(size / 4) + 2 } }))
         c.enqueue(enc.encode("data: [DONE]\n\n")); c.close()
       } }), { headers: { "content-type": "text/event-stream" } })
     },
   })
   EOF
   PORT=$PORT bun "$WORK/mock.ts" > "$WORK/mock.log" 2>&1 &
   MOCK=$!
   trap 'kill $MOCK 2>/dev/null' EXIT
   sleep 1
   cat > "$WORK/proj/opencode.json" <<EOF
   {
     "\$schema": "https://opencode.ai/config.json",
     "model": "mock/m",
     "provider": { "mock": {
       "npm": "@ai-sdk/openai-compatible",
       "options": { "baseURL": "http://127.0.0.1:$PORT/v1", "apiKey": "x" },
       "models": { "m": { "name": "m", "limit": { "context": $CONTEXT, "output": 2048 } } }
     } }
   }
   EOF
   cd "$WORK/proj" && git init -q
   echo "== $($OC --version) agent=$AGENT context=$CONTEXT"
   if [ -n "${OC_SERVE:-}" ]; then
     # Source checkouts: start the server separately (the --standalone child lacks bun's preload/conditions).
     OPENCODE_PASSWORD=repro HOME="$WORK/home" $OC serve --port $((PORT+1)) > "$WORK/serve.log" 2>&1 &
     SERVE=$!; trap 'kill $MOCK $SERVE 2>/dev/null' EXIT; sleep 8
     CONN="--server http://127.0.0.1:$((PORT+1))"
   else
     CONN="--standalone"
   fi
   OPENCODE_PASSWORD=repro HOME="$WORK/home" timeout 40 $OC run $CONN --agent "$AGENT" "reply with exactly: ok" > "$WORK/run.out" 2>&1
   code=$?; [ -n "${SHOW_OUT:-}" ] && tail -c 2000 "$WORK/run.out"
   [ $code = 124 ] && echo "RESULT: opencode run did NOT exit within 40s (killed)" || echo "RESULT: opencode run exited with code $code"
   echo "== model requests ($(grep -c '^request' "$WORK/mock.log") total), first 15:"
   head -15 "$WORK/mock.log"

   Run it: bash repro.sh
2. opencodejr

   added

   reproduced

   on Nov 7, 2026
3. tomwangcn commented on Nov 7, 2026

   

   tomwangcn

   on Nov 7, 2026

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   I've picked this up and opened #62633.

   Root cause, confirmed locally with the mock-model repro from @opencodejr[bot]'s comment (latest dev, ~2,000 requests in 40s before the fix): the Plan plugin's context hook persists the re-injected reminder via ctx.session.synthetic, which admits a pending steer item; the next idle boundary promotes it into a fresh turn answering the reminder, and with auto-compaction stripping the reminder every turn the cycle never ends.

   The fix records the reminder straight onto the durable log instead (same path as instruction-file injection), so it stays in history and in the current request without spawning answer turns. Repro now exits after 3 requests; plan plugin tests and typecheck pass.
4. vijaym2k6 commented on Nov 8, 2026

   

   vijaym2k6

   on Nov 8, 2026

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   Thanks for the quick fix in #62633. A cheap backstop for this whole class: cap compactions per turn (say 3) and end the turn with an error after that. A turn that compacts more than a few times is not making progress.