i got this error on a long context paste.

[Oculto54]

• Keep only last N charse Go ~/Opencode
  707 | */▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
  708 | function keepLast(text: string, maxChars: number): string { tab agents ctrl+p commands • OpenCode 1.2.20
  709 | if (text.length <= maxChars) {
  ^
  TypeError: undefined is not an object (evaluating 'text.length')
  at keepLast (/Users/Paulo/.cache/opencode/node_modules/opencode-working-memory/index.ts:709:7)
  at (/Users/Paulo/.cache/opencode/node_modules/opencode-working-memory/index.ts:1641:35)

[katana-hydra]

Bug: crash during pruning when cached tool output is missing fullOutput

Summary

I hit a crash in opencode-working-memory that made the OpenCode session effectively unusable.

The failure happens during pruning / compacted old tool-output replay when a cached tool-output record is missing fullOutput.

Observed error:

TypeError: undefined is not an object (evaluating 'text.length')
at keepLast (...opencode-working-memory\index.ts:709:7)
at <anonymous> (...opencode-working-memory\index.ts:1641:35)

What I found

The crash path appears to be:

1. some openalex_* tool calls are persisted as cache JSON without a fullOutput field
2. later, pruning / replay loads that cache record
3. cached.fullOutput is passed into applySmartPruning(...)
4. keepLast(text, maxChars) receives undefined
5. the code crashes on text.length

Relevant code path:

function keepLast(text: string, maxChars: number): string {
  if (text.length <= maxChars) {
    return text;
  }
}

and:

const smartPruned = applySmartPruning(cached.fullOutput, rule, pruningConfig);

Evidence

I found 13 malformed cache files in one session.

Tool breakdown:

• openalex_search_works: 9
• openalex_search_works_in_venue: 3
• openalex_get_top_venues_for_field: 1

Malformed cache example:

{
  "callID": "<call_id>",
  "sessionID": "<session_id>",
  "tool": "openalex_search_works_in_venue",
  "timestamp": 1773038098683
}

Healthy cache files in the same session did include fullOutput as a string.

Environment

• Windows
• @opencode-ai/plugin 1.2.22
• opencode-working-memory 1.1.2

Local workaround

I restored the session by quarantining only the malformed cache files. I did not modify working-memory source code.

Suggested fix

I think there are two guardrails needed:

1. normalize tool output before caching
   • string -> store directly
   • object / array -> JSON stringify
   • null / undefined -> store a placeholder instead of omitting the field
2. validate cached records before pruning
   • skip records with missing fullOutput, or replace with a safe placeholder
   • do not allow non-string values to reach keepLast()

Attachments

• I also prepared a redacted detailed report and sanitized manifest locally.
• If useful, I can share the exact malformed-cache shape and timing distribution in follow-up.

[Sathvik-1007]

Hit the same bug. My crash was in applySmartPruning at line 643:

TypeError: undefined is not an object (evaluating 'result.split')
    at applySmartPruning (.../opencode-working-memory/index.ts:643:19)
    at <anonymous> (.../opencode-working-memory/index.ts:1641:35)

Same root cause — hookOutput.output can be undefined for some tool calls. Gets cached without fullOutput, then applySmartPruning / keepLast crashes on the undefined value.

I have a fix ready and will open a PR shortly.

[sdwolf4103]

This appears to be fixed by architectural removal in v1.2 rather than a narrow patch on top of 1.1.x, but I still want to verify whether any equivalent undefined-output path remains in the current codebase.