Cannot resume session when context exceeds limit - no way to compact before loading

[pnvoroshilov]

Description

When a session's context grows large and is stopped, resuming it becomes impossible if the total context exceeds the model's limit. The error "Prompt is too long" occurs immediately upon resume, before any user interaction.

Problem

1. Session runs normally, context grows over time
2. Session is stopped (user closes terminal, or programmatic stop via SDK)
3. User tries to resume session with --resume <session-id>
4. Immediate error: "Prompt is too long"
5. Cannot run /compact because the session must be loaded first to execute commands
6. Deadlock: Session is too large to load, but must be loaded to compact

Steps to Reproduce

1. Create a long-running session with many tool calls and large responses
2. Stop the session before auto-compaction triggers
3. Try to resume: claude --resume <session-id>
4. Observe "Prompt is too long" error

Evidence

Session file size: 5.4 MB (201 lines in .jsonl)

$ ls -lah ~/.claude/projects/.../f2270107-6417-4c38-8808-e52dc63c42f4.jsonl
-rw------- 1 user staff 5.4M Dec 18 16:37 f2270107-...jsonl

Error in session history:

{
  "type": "assistant",
  "message": {
    "content": [{"type": "text", "text": "Prompt is too long"}]
  },
  "error": "invalid_request",
  "isApiErrorMessage": true
}

Expected Behavior

One of the following:

1. Auto-compact on resume - If session exceeds limit, automatically compact before loading
2. Offline compact command - Allow claude compact --session <id> without loading the full session
3. Graceful degradation - Load only recent messages + summary when limit exceeded

Environment

• Claude Code version: 2.0.72
• OS: macOS
• Using: Claude Code SDK (Python) with resume parameter

Workaround Attempted

• Tried claude --resume <id> -p "/compact" - fails with same error because session must load first

Impact

Sessions that grow large become permanently inaccessible. Users lose all conversation history and must start fresh, losing context accumulated over potentially $7+ of API usage.

[github-actions]

Found 1 possible duplicate issue:

1. [Bug] Compaction fails with "Conversation too long" error despite available context #14342

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[oteronavarretericardo]

this happens to me as well, load a big file or paste a lot of text, you first get
⎿  API Error: 400 Input is too long for requested model.

and any further prompt, also gives you:
⎿  API Error: 400 Input is too long for requested model.

that's it, your session is cooked, relaunching with --resume doesn't work, you have to lose your session. I believe you can switch to larger models and recover but that's just a hack

[ilude]

Been having issues with auto compaction and manual compaction for the last few days 2.0.72 but issues seemed to start when instant compaction was added. On Max plan.

Windows 11

[blackholegalaxy]

It's becoming really annoying to pop complex tasks... You run sub-agents. Some run of context, you're basically doomed. No way to continue. You have to start a new long planning session cause claude is too dumb to deduct already changed files and retrieve a previous plan. Are we really paying for that?

[github-actions]

This issue has been inactive for 30 days. If the issue is still occurring, please comment to let us know. Otherwise, this issue will be automatically closed in 30 days for housekeeping purposes.