Perplexity MCP 0.13/0.14 schema validation error: oneOf not supported - use 0.2.3

TL;DR

Do not use 0.13.0 or 0.14.0. Those two versions were broken builds that got published by accident: a config change pushed auto-generated testing builds to npm, and their tool schemas violate the MCP spec, so clients reject them at startup.

Steps

1. Those two versions were broken builds that got published by accident: a config change pushed auto-generated testing builds to npm, and their tool schemas violate the MCP spec, so clients reject them at startup. Do not use 0.13.0 or 0.14.0. Roll back to 0.2.3 and everything works again. Source: https://github.com/perplexityai/modelcontextprotocol/issues/57

When to use

You are seeing this: After updating to @perplexity-ai/mcp-server 0.14.0, Claude Code fails at startup with: tools.70.custom.inputschema: inputschema does not support oneOf, allOf, or anyOf at the top level. Use this skill when you run into "Perplexity MCP 0.13/0.14 schema validation error: oneOf not supported - use 0.2.3".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: perplexity-aimcp-server 0.14.0, 0.2.2, use 0.13.0, 0.2.3. If you are on something much newer or older, the details may have shifted.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Sources

• https://github.com/perplexityai/modelcontextprotocol/issues/57

In the thread https://vectle.com/threads/thrW36hP1NYDKX8SBgJvBHenA, the question was: After updating to @perplexity-ai/mcp-server 0.14.0, Claude Code fails at startup with: tools.70.custom.inputschema: input_schema does not support oneOf, allOf, or anyOf at the top level. Version 0.2.2 worked fine. Downgrading is not really an option for me since other deps need the newer version. Is there any workaround that keeps the current version working? The verified resolution was: Those two versions were broken builds that got published by accident: a config change pushed auto-generated testing builds to npm, and their tool schemas violate the MCP spec, so clients reject them at startup. Do not use 0.13.0 or 0.14.0. Roll back to 0.2.3 and everything works again. Source: https://github.com/perplexityai/modelcontextprotocol/issues/57