Does OpenCode suffer from memory leaks? A single window is consuming over 20 GB of memory. #20626

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1. silent-night-no-trace

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   bugSomething isn't workingSomething isn't working

   on Apr 2, 2026
2. github-actions

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   rekram1-node

   on Apr 2, 2026
3. github-actions

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   perfIndicates a performance issue or need for optimizationIndicates a performance issue or need for optimization

   on Apr 2, 2026
4. github-actions commented on Apr 2, 2026

   

   github-actionsBot

   on Apr 2, 2026 – with GitHub Actions

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   This issue might be a duplicate of existing issues. Please check:

   • [Bug]: Massive memory leak (60GB+ OOM crash) on Server #17908: Massive memory leak (60GB+ OOM crash) — similar high memory consumption symptom
   • Opencode (1.2.24) leaks memory (until it's killed) #17237: Opencode leaks memory (until it's killed) — similar long-running memory leak behavior
   • Possible memory leak on OpenCode 1.2.15 #15920: Possible memory leak on OpenCode 1.2.15 — similar memory leak report

   If your issue is distinct from the above, please add context explaining how it differs.
5. silent-night-no-trace commented on Apr 2, 2026

   

   silent-night-no-trace

   on Apr 2, 2026

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   I am using version 1.3.2 and am still encountering this issue. How can I resolve it?
6. max-flizpay commented on Apr 2, 2026

   

   max-flizpay

   on Apr 2, 2026

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   Lets just rewrite OpenCode in Rust?

   👍React with 👍2Reacted by Krzyś and senlinjun
7. jwcrystal commented on Apr 2, 2026

   

   jwcrystal

   on Apr 2, 2026

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   This looks like a real long-running memory growth issue rather than a single one-off allocation.

   The most likely root causes are:

   1. Unbounded SSE/event buffering for long-lived windows

      • The app keeps long-lived event streams open.
      • If a client/window becomes slow or disconnect cleanup does not happen promptly, queued events can keep accumulating in memory.
      • This is especially bad for high-frequency events (message deltas, tool updates, etc.), and is much more likely to produce multi-GB growth than heartbeats alone.

   2. Shell/tool output retained in memory

      • Large stdout/stderr from bash/tool execution was being accumulated in memory instead of being capped/spilled early.
      • In a long-running session, a few large commands or repeated tool usage can compound badly.

   3. Session prompt subprocess output also had the same accumulation pattern

      • There was a second output-retention path in prompt/session execution, so the problem was not limited to one tool path.

   Why this matches the symptom: if one OpenCode window owns those queues/buffers, closing that single window would immediately release a very large amount of memory, which is exactly what was reported here.

   So the short version is: likely a combination of unbounded event queue growth + unbounded shell output retention over time.
8. thdxr commented on Apr 2, 2026

   

   thdxr

   on Apr 2, 2026

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   Closing in favor of #20695 where we're collecting all memory-related problems. Please follow that issue for updates.
9. thdxr

   closed this as completedon Apr 2, 2026