compaction.auto=false ignored: isOverflow called without cfg parameter #20249

Bug

compaction.auto: false in opencode.json is ignored. Auto-compaction still triggers.

Root Cause

In packages/opencode/src/session/prompt.ts, isOverflow is called without the cfg parameter:

// prompt.ts line ~549
if (lastFinished && lastFinished.summary !== true && (await SessionCompaction.isOverflow({ tokens: lastFinished.tokens, model }))) {

But isOverflow in compaction.ts expects input.cfg:

export async function isOverflow(input: { tokens: MessageV2.Assistant["tokens"]; model: Provider.Model }) {
    const config = await Config.get()
    if (config.compaction?.auto === false) return false  // <-- cfg not in input

Wait — actually isOverflow calls Config.get() internally, so it should work regardless. Let me re-check...

Environment

• OpenCode version: 1.3.9
• OS: Linux
• Model: groq/llama-3.1-8b-instant (but likely affects all models)

Steps to Reproduce

1. Add "compaction": { "auto": false } to opencode.json
2. Start a new session with any model
3. Send a message — compaction still triggers

Additional Context

The issue is especially visible with Groq models because Groq returns tokens: {input:0, output:0} in streaming responses, causing the compaction loop to never resolve. But compaction.auto: false should prevent this regardless of the model.