[Bug/Robustness] 400 Error: InternalError.Algo.InvalidParameter due to unclosed tool_calls after interruption

Description

[Bug/Robustness] 400 Error: `InternalError.Algo.InvalidParameter` due to unclosed `tool_calls` after interruption

Description

When using OpenCode with Alibaba DashScope (阿里云百炼) or similar providers, the session becomes permanently corrupted if an agent fails to provide a tool response following an assistant message that contains tool_calls.

This typically occurs in multi-agent workflows when:

An agent crashes or timed out after generating a tool call.
The system/process is interrupted or rebooted before the tool execution completes.

Upon restarting the session, the API returns a 400 Bad Request:
"An assistant message with 'tool_calls' must be followed by tool messages responding to each 'tool_call_id'."

Root Cause

Alibaba DashScope's inference engine (and OpenAI's strict mode) enforces a strict transactional sequence for tool calls. If the conversation history sent to the API ends with a "dangling" tool_calls without corresponding tool results, the API rejects the entire payload.

Proposed Solution: The "Tombstone" Pattern (Preferred)

I recommend implementing a Self-Healing/Auto-Completion mechanism within the framework's message persistence or pre-request layer.

Logic:
Before dispatching the messages array to the LLM API, the framework should validate the integrity of the tool-call chain. If a dangling tool_call_id is detected, OpenCode should automatically inject a "Tombstone" (placeholder) message to close the loop.

Example Injected Payload:

{
  "role": "tool",
  "tool_call_id": "the_interrupted_call_id",
  "content": "{\"error\": \"System interruption: The agent/tool failed to return a result in the previous session.\"}"
}

Plugins

No response

OpenCode version

1.4.6

Steps to reproduce

interrupt opencode when it is calling tool. (actually, I do not interrupt it,maybe the internal tool interrupt)

Screenshot and/or share link

"<400> InternalError.Algo.InvalidParameter: An assistant message with "tool_calls" must be followed by tool messages responding to each "tool_call_id"."

Operating System

windows10

Terminal

git bash

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Please edit this issue to address the above within 2 hours, or it will be automatically closed.

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

Interrupted tool calls permanently corrupt session history (orphaned tool_use without tool_result) #21326: Interrupted tool calls permanently corrupt session history (orphaned tool_use without tool_result) — describes the same root cause and proposes the same synthetic tool_result fix

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[Bug/Robustness] 400 Error: InternalError.Algo.InvalidParameter due to unclosed tool_calls after interruption #22808

Description