deepseek-v4-flash-free stops the agent loop after nearly every tool call #39204

Description

When using deepseek-v4-flash-free, the Build agent frequently stops after a single tool call, even when the model says it is about to continue. This happens after tools such as read, grep, glob, and todowrite.

Typing continue resumes the task, but it usually stops again after the next tool call. There is no steps limit configured, no permission denial, and no visible tool error. The logs show OpenCode starting the next loop step, then exiting normally because the model does not emit another tool call.

This appears to be a model or provider-adapter issue where the response ends with a terminal stop reason after a tool result instead of continuing the agent loop.

Plugins

none

OpenCode version

1.18.7

Steps to reproduce

1. Open a repository in OpenCode.
2. Select the deepseek-v4-flash-free model and use the Build agent.
3. Give it a task that requires multiple tool calls, such as inspecting several files and making a change.
4. Wait for it to run a tool like read, grep, glob, or todowrite.
5. Observe that the agent stops immediately after the tool result instead of continuing.
6. Type continue.
7. Observe that it usually performs one more tool call and stops again.

Screenshot and/or share link

https://opncd.ai/share/nxPY1oQG

Operating System

Macos 27 beta 2

Terminal

Kitty