Ollama Gemma4 Tool Call Parsing Failed — Invalid Character in JSON After v0.20.1 Fix

What this error means

gemma4 tool call parsing failed — error="invalid character looking for beginning of value" in ollama 0.20.1 is a Ollama failure pattern reported for developers trying to fix gemma4 tool call parsing failed invalid character error in ollama 0.20.1. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

48 comments. Log shows: gemma4.go:293 ‘gemma4 tool call parsing failed’ with error parsing malformed tool call syntax. Specific error: invalid character ’`’ or '''. Affects gemma4:e4b with opencode and oh-my-opencode. Follow-up issue to #15254.

Common causes

• After updating to Ollama 0.20.1 (which was supposed to fix gemma4 tool parsing), gemma4:e4b still fails tool calling with ‘invalid character looking for beginning of value’ error. Affects users of opencode and other AI coding tools that rely on Ollama tool calling.
• 48 comments. Log shows: gemma4.go:293 ‘gemma4 tool call parsing failed’ with error parsing malformed tool call syntax. Specific error: invalid character ’`’ or '''. Affects gemma4:e4b with opencode and oh-my-opencode. Follow-up issue to #15254.

Quick fixes

1. Confirm the exact error signature matches gemma4 tool call parsing failed — error="invalid character looking for beginning of value" in ollama 0.20.1.
2. Check the Ollama account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/ollama/ollama/issues/15315

Evidence note: 48 comments. Log shows: gemma4.go:293 ‘gemma4 tool call parsing failed’ with error parsing malformed tool call syntax. Specific error: invalid character ’`’ or '''. Affects gemma4:e4b with opencode and oh-my-opencode. Follow-up issue to #15254.

Related errors

• Ollama tool calling fails with gemma models
• Ollama function calling JSON parse error
• gemma4 tool_use response format

FAQ

What should I check first?

Start with the exact gemma4 tool call parsing failed — error="invalid character looking for beginning of value" in ollama 0.20.1 text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Ollama workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without gemma4 tool call parsing failed — error="invalid character looking for beginning of value" in ollama 0.20.1.