[Bug]: Ollama integration fails - streaming NDJSON response not parsed correctly

[rooftop-Owl]

Prerequisites

• I have searched existing issues to avoid duplicates
• I am using the latest version of oh-my-opencode
• I have read the documentation

Bug Description

Ollama-based agents fail with JSON Parse error: Unexpected EOF when attempting tool calls. The root cause is that oh-my-opencode uses stream: true when calling Ollama API, but Ollama returns NDJSON (newline-delimited JSON) for streaming responses which cannot be parsed as a single JSON object.

Steps to Reproduce

1. Configure oh-my-opencode to use Ollama provider with a local model (e.g., qwen3-coder, ministral-3:14b)
2. Invoke any agent that uses tools (e.g., explore agent)
3. Agent attempts a tool call
4. Error occurs during response parsing

Direct reproduction with curl:

# This works (stream: false)
curl -s http://localhost:11434/api/chat -d '{"model": "qwen3-coder", "messages": [{"role": "user", "content": "Read file README.md"}], "stream": false, "tools": [{"type": "function", "function": {"name": "read", "description": "Read a file", "parameters": {"type": "object", "properties": {"filePath": {"type": "string"}}, "required": ["filePath"]}}}]}'

# This fails when parsed as single JSON (stream: true returns NDJSON)
curl -s http://localhost:11434/api/chat -d '{"model": "qwen3-coder", "messages": [{"role": "user", "content": "Read file README.md"}], "stream": true, "tools": [...]}'

Expected Behavior

Ollama agents should work the same as cloud agents - tool calls should be parsed correctly regardless of streaming mode.

Actual Behavior

Agent invocation fails with:

JSON Parse error: Unexpected EOF

The streaming response returns multiple NDJSON lines:

{"message":{"tool_calls":[{"function":{"name":"read","arguments":{"filePath":"README.md"}}}]}, "done":false}
{"message":{"content":""}, "done":true}

This cannot be parsed as a single JSON object.

Doctor Output

# Unable to run doctor - this is a development/testing environment
# The issue is reproducible with direct Ollama API calls

Error Logs

JSON Parse error: Unexpected EOF

Configuration

{
  "provider": "ollama",
  "model": "qwen3-coder"
}

Additional Context

Suggested fixes:

1. Simple fix: Use stream: false for Ollama provider
2. Better fix: Parse NDJSON properly by splitting on newlines and merging tool_calls

Related:

• Ollama API docs: https://github.com/ollama/ollama/blob/main/docs/api.md

Operating System

Linux (Ubuntu 22.04)

OpenCode Version

Latest (tested with oh-my-opencode plugin)

[rooftop-Owl]

Related Issues

After investigating, this appears to be part of a broader JSON parsing/streaming issue affecting multiple providers:

Directly Related (Same Root Cause)

• [Bug]: Librarian agent fails with JSON Parse error: Unexpected EOF #683 - Librarian agent fails with JSON Parse error: Unexpected EOF (Gemini models)
• [Bug] look_at tool fails with JSON Parse error #564 - look_at tool fails with JSON Parse error
• background agents queued and finished immediately with no output #480 - Background agents finish immediately with no output

Local Model Issues (Compounding Factors)

• [Bug]: Subagent prompts exceed 24K tokens, breaking local models with limited context windows #951 - Subagent prompts exceed 24K tokens, breaking local models with limited context windows
• Ollama/llama.cpp support? #491 - Ollama/llama.cpp support discussion
• [Question]: how to use local llm. Sisyphus always reports configured model is not valid #940 - Local LLM configuration issues

Pattern Observed

The JSON Parse error: Unexpected EOF occurs across:

• Ollama models (this issue) - NDJSON streaming not parsed
• Gemini models ([Bug]: Librarian agent fails with JSON Parse error: Unexpected EOF #683) - Same error with Antigravity wrapper
• Multimodal agents ([Bug] look_at tool fails with JSON Parse error #564) - Same error pattern

This suggests the issue is in the agent response parsing layer, not provider-specific. The streaming response handler may not be correctly:

1. Accumulating chunked responses before parsing
2. Handling NDJSON (newline-delimited JSON) format
3. Waiting for done: true before attempting parse

Suggested Investigation

The fix likely needs to be in the shared response parsing code, not per-provider handling.

[justsisyphus]

Investigation Summary

Status: ✅ Confirmed valid bug

Findings:

1. No Ollama integration found - Codebase search shows no existing Ollama provider implementation
2. Root cause confirmed - Issue accurately describes the NDJSON streaming problem:
   • Ollama returns newline-delimited JSON when stream: true
   • Current code likely treats response as single JSON object → parse failure
3. Impact - Affects any Ollama-based agent attempting tool calls

Codebase Analysis:

• Provider system exists in src/config/schema.ts and src/plugin-handlers/config-handler.ts
• Model resolution logic in src/shared/model-resolver.ts
• No Ollama-specific handling detected

Suggested Implementation Path:

1. Add Ollama provider to config schema
2. Implement NDJSON parser for streaming responses
3. Merge tool_calls from multiple NDJSON lines
4. Add tests for Ollama streaming scenarios

Label: bug ✅