LiteLLM / LiteLLM

[Bug]: Fireworks AI rejects MCP tool schemas with unsupported JSON Schema fields triggered by Coralogix DevRev MCP integrations

Fix LiteLLM proxy passing invalid JSON Schema fields (title, default) to Fireworks AI when bridging MCP tools, causing API rejections for Coralogix/DevRev integration users Includes evidence for LiteLLM troubleshooting demand.

Source-backed Last updated May 18, 2026 1 source Needs local verification

Category: LiteLLM
Error signature: Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 18, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for LiteLLM, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm is a LiteLLM failure pattern reported for developers trying to fix litellm proxy passing invalid json schema fields (title, default) to fireworks ai when bridging mcp tools, causing api rejections for coralogix/devrev integration users. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub Issue #28149 opened by apshada on May 18, 2026 (today). Fresh proxy-to-model compatibility bug. MCP tool schemas contain fields Fireworks AI doesn't accept. Affects enterprise integration users spending money on both LiteLLM proxy and Fireworks AI. Maps to 'LiteLLM' per approved mapping.

Common causes

GitHub Issue #28149 opened by apshada on May 18, 2026 (today). Fresh proxy-to-model compatibility bug. MCP tool schemas contain fields Fireworks AI doesn't accept. Affects enterprise integration users spending money on both LiteLLM proxy and Fireworks AI. Maps to 'LiteLLM' per approved mapping.

Quick fixes

Confirm the exact error signature matches Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm.
Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
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

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

Diagnostic flow for this page

Match Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm exactly before applying the quick fix.
Compare the failing environment with LiteLLM versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm mean in LiteLLM?

Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm indicates the workflow described by "[Bug]: Fireworks AI rejects MCP tool schemas with unsupported JSON Schema fields triggered by Coralogix DevRev MCP integrations" failed in a LiteLLM context. Start by confirming the exact signature and the component that emitted it.

What should I check first for Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm?

Check whether this cause matches your environment: GitHub Issue #28149 opened by apshada on May 18, 2026 (today). Fresh proxy-to-model compatibility bug. MCP tool schemas contain fields Fireworks AI doesn't accept. Affects enterprise integration users spending money on both LiteLLM proxy and Fireworks AI. Maps to 'LiteLLM' per approved mapping.

Is the Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm guidance source-backed?

The "[Bug]: Fireworks AI rejects MCP tool schemas with unsupported JSON Schema fields triggered by Coralogix DevRev MCP integrations" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm?

For "[Bug]: Fireworks AI rejects MCP tool schemas with unsupported JSON Schema fields triggered by Coralogix DevRev MCP integrations", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging Fireworks AI rejects MCP tool schemas unsupported JSON Schema title default litellm?

For "[Bug]: Fireworks AI rejects MCP tool schemas with unsupported JSON Schema fields triggered by Coralogix DevRev MCP integrations", collect the failing LiteLLM command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.