Bug: TypeError in session prompt handling and workflow timeout with free models

[bowen31337]

Bug Report: TypeError in session prompt handling and workflow timeout issues with free models

Summary

There are two critical issues affecting the OpenCode server's functionality:

1. TypeError in session prompt handling (src/session/prompt.ts:1597)
2. Workflow engine timeout with free models (e.g., minimax-m2.1-free)

Issue 1: TypeError in command handling

Description

When sending requests to the OpenCode server via REST API, certain command formats trigger a TypeError.

Error Message

TypeError: undefined is not an object (evaluating 'command3.agent')
    at command2 (src/session/prompt.ts:1597:23)
    at processTicksAndRejections (native:7:39)

Steps to Reproduce

1. Start the OpenCode server:

opencode serve --port 54321

2. Create a session:

curl -X POST http://localhost:54321/session \
  -H "Content-Type: application/json" \
  -d '{}'
# Response: {"id": "ses_xxx", ...}

3. Send a command request:

curl -X POST "http://localhost:54321/session/{SESSION_ID}/command" \
  -H "Content-Type: application/json" \
  -d '{
    "messageID": "msg-test-001",
    "model": "opencode/minimax-m2.1-free",
    "agent": "",
    "command": "bash",
    "arguments": "echo \"test\""
  }'

Expected Result

The command should be processed and executed.

Actual Result

{"name":"UnknownError","data":{"message":"TypeError: undefined is not an object (evaluating 'command3.agent')\n    at command2 (src/session/prompt.ts:1597:23)\n    at processTicksAndRejections (native:7:39)"}}

Environment

• OpenCode version: 1.1.25
• Platform: macOS (Darwin)
• Server port: 54321

Root Cause Analysis

The error occurs in src/session/prompt.ts at line 1597 when accessing the agent property. The code appears to be accessing a property on an undefined object, likely due to improper null checking or object structure validation.

---

Issue 2: Workflow timeout with free models

Description

The OpenCode workflow engine terminates prematurely when using free models (like minimax-m2.1-free) that have longer response times (90+ seconds).

Steps to Reproduce

1. Start the OpenCode server:

opencode serve --port 54321

2. Run a workflow with a free model:

uv run oac run ./project --model "opencode/minimax-m2.1-free" --spec templates/rest-api.md

Expected Result

The workflow should wait for the LLM response (up to the configured timeout, e.g., 600s) before proceeding.

Actual Result

[INFO] Waiting for LLM response... (15s elapsed, timeout: 600.0s)
[INFO] Waiting for LLM response... (30s elapsed, timeout: 600.0s)
[INFO] Waiting for LLM response... (45s elapsed, timeout: 600.0s)
[INFO] Workflow state: complete

The workflow completes at ~45 seconds even though:

• Timeout is configured for 600s
• The minimax-m2.1-free model takes 90+ seconds for responses
• The LLM is still processing

Environment

• Model: opencode/minimax-m2.1-free
• Timeout configured: 600s
• Actual completion time: ~45s
• Platform: macOS (Darwin)

Root Cause Analysis

The workflow engine appears to have a hardcoded or misconfigured short-circuit timeout that triggers before the LLM response is received. This may be related to the streaming response handling or the way the workflow engine tracks request progress.

---

Workarounds

For Issue 1 (TypeError)

Use the OpenCode CLI directly instead of REST API:

opencode run "Your request" --model "opencode/minimax-m2.1-free"

For Issue 2 (Timeout)

Use a faster (paid) model instead of free models:

uv run oac run ./project --model "anthropic/claude-sonnet-4-20250514"

---

Impact

• Issue 1: Blocks programmatic access via REST API, affecting SDK integrations
• Issue 2: Makes free models unusable for autonomous workflows
• Combined Impact: Users cannot build automated workflows using free models through the REST API

---

Suggested Fixes

For Issue 1

Add proper null checking and validation for the agent property in src/session/prompt.ts:1597:

// Before
const agent = command3.agent;

// After  
const agent = command3?.agent ?? "";

For Issue 2

• Review the workflow timeout configuration logic
• Ensure the timeout is based on the actual LLM response, not an internal stream timeout
• Consider adding model-specific timeout adjustments for known slow models

---

Additional Context

• Free models (minimax-m2.1-free, glm-4.7-free) are important for users without API keys
• These models are documented as having longer response times (up to 600s recommended timeout)
• The OpenCode CLI works correctly, suggesting the issue is specific to REST API handling

---

Related Files

• src/session/prompt.ts (line 1597)
• Workflow engine timeout configuration
• REST API command handler

---

Test Data

Session ID for Issue 1 Reproduction

ses_4221056f2ffeIrtlGp2cVyOrLK

LLM Response Time Data

• Simple query: ~90s (minimax-m2.1-free)
• Complex query: >120s (minimax-m2.1-free)

---

Severity

• Issue 1: High - Blocks programmatic access
• Issue 2: High - Makes free models unusable for automation

---

Contact

For questions or additional context, please reach out.

---

Bug Report Version: 1.0
Date: 2026-01-21
OpenCode Version: 1.1.25

[github-actions]

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

• Sessions hang indefinitely when Task tool spawns subagents via REST API (opencode serve) #6573: Sessions hang indefinitely when Task tool spawns subagents via REST API (opencode serve) - Similar REST API issue with command handling and session state
• Task Tool Timeouts & Early Termination in Multi-Agent Conductor Pattern #6792: Task Tool Timeouts & Early Termination in Multi-Agent Conductor Pattern - Similar timeout issue where tasks return session_id prematurely instead of completing
• Agent.get() returns undefined without error handling, causing crash #9437: Agent.get() returns undefined without error handling, causing crash - Related undefined handling issue that causes TypeError when accessing agent properties

Feel free to ignore if none of these address your specific case.

[wlioi]

Related: Another TypeError in prompt.ts (#12336)

I reported a similar TypeError issue (#12336) that also occurs in src/session/prompt.ts, but at a different location.

Comparison

Your Issue (#9733): Line 1597, command3.agent undefined
My Issue (#12336): Line 704, schema._zod.def undefined

Common Pattern

Both issues suggest src/session/prompt.ts has multiple locations missing defensive null checking.

Refs:

• Bug: Zod TypeError when loading custom tools from .opencode directory #12336: Bug: Zod TypeError when loading custom tools
• bug: tool.registry test fails on CI — custom tool import crashes registry when dependencies are missing #12269: tool.registry test fails on CI

[github-actions]

To stay organized issues are automatically closed after 90 days of no activity. If the issue is still relevant please open a new one.