Zen Upgrade: All models getting stuck/unable to complete sessions #10088

Issue Description

After upgrading to OpenCode Zen, every single model is getting stuck and unable to complete sessions. Models become unresponsive and hang indefinitely without completing coding tasks.

Expected Behavior

Models should respond and complete sessions normally as they did before the Zen upgrade.

Actual Behavior

All Zen models freeze/hang and cannot complete tasks. Sessions hang indefinitely with no resolution.

Steps to Reproduce

1. Upgrade to OpenCode Zen (version 1.1.31)
2. Attempt to use any Zen model (GPT-5.2, Claude Sonnet, GLM, etc.)
3. Models become unresponsive and cannot complete sessions

System Information

• OS: macOS 15.6.1 (Darwin 24.6.0, arm64)
• OpenCode Version: 1.1.31
• Node Version: v25.2.1
• Shell: /bin/zsh
• Architecture: arm64 (Apple Silicon)
• Install Location: /Users/iamjohndass/.bun/bin/opencode
• Config Location: ~/.opencode/
• Provider: OpenCode Zen

Additional Context

• Issue affects ALL Zen models, not specific to one model
• OpenCode installed via bun: /Users/iamjohndass/.bun/bin/opencode
• Using OpenCode Zen provider with API key
• Previously working fine before Zen upgrade

Related Issues

This appears related to several existing issues about Zen hanging/freezing:

• How does OpenCode Zen report rate limit errors to the user? #2839 - Rate limit errors causing stuck in "Generating..."
• Unable to login with zen provider. #3335 - Login with zen provider freezes entirely
• OpenCode hangs indefinitely when sending requests to Anthropic via Oauth login #1618 - Hangs indefinitely when sending to Anthropic API
• [BUG] OpenCode just hangs randomly after receiving instructions #2940 - Random hanging after receiving instructions
• Critical Stability Issues: App Freezing & Hanging Analysis #731 - Critical Stability Issues: App Freezing & Hanging

Debugging Attempts

I'm happy to provide additional debug logs if needed. I can run with --print-logs --log-level DEBUG to capture more details.

Questions

1. Are there known rate limits on Zen that might be causing this?
2. Is this a recent regression in a specific version?
3. Are there specific debugging steps or workarounds I should try?
4. Should I try clearing the cache (~/.opencode/cache)?