LiteLLM OpenRouter Image Generation Fails with ImageUsage Validation Error (int_from_float)

What this error means

Error transforming OpenRouter image generation response: 2 validation errors for ImageUsage output_tokens: Input should be a valid integer, got a number with a fractional part [type=int_from_float, input_value=14417.92] is a LiteLLM failure pattern reported for developers trying to fix litellm openrouter image generation failure with imageusage pydantic validation error. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue BerriAI/litellm#28001 (May 15, 2026): When generating images via OpenRouter through dockerized LiteLLM, the response contains fractional token counts (float) but ImageUsage Pydantic model expects integers. Causes APIError for all OpenRouter image generation requests. Category: LiteLLM (proxy/model routing layer).

Common causes

• GitHub issue BerriAI/litellm#28001 (May 15, 2026): When generating images via OpenRouter through dockerized LiteLLM, the response contains fractional token counts (float) but ImageUsage Pydantic model expects integers. Causes APIError for all OpenRouter image generation requests. Category: LiteLLM (proxy/model routing layer).

Quick fixes

1. Confirm the exact error signature matches Error transforming OpenRouter image generation response: 2 validation errors for ImageUsage output_tokens: Input should be a valid integer, got a number with a fractional part [type=int_from_float, input_value=14417.92].
2. Check the LiteLLM 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/BerriAI/litellm/issues/28001

Evidence note: GitHub issue BerriAI/litellm#28001 (May 15, 2026): When generating images via OpenRouter through dockerized LiteLLM, the response contains fractional token counts (float) but ImageUsage Pydantic model expects integers. Causes APIError for all OpenRouter image generation requests. Category: LiteLLM (proxy/model routing layer).

Related errors

• LiteLLM

FAQ

What should I check first?

Start with the exact Error transforming OpenRouter image generation response: 2 validation errors for ImageUsage output_tokens: Input should be a valid integer, got a number with a fractional part [type=int_from_float, input_value=14417.92] text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed LiteLLM 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 Error transforming OpenRouter image generation response: 2 validation errors for ImageUsage output_tokens: Input should be a valid integer, got a number with a fractional part [type=int_from_float, input_value=14417.92].