openclaw - 💡(How to fix) Fix Ajv 2020-12 schema compatibility: playwright-mcp tools fail to initialize [1 participants]

Error: no schema with key or ref "https://json-schema.org/draft/2020-12/schema"

TL;DR

Update the schema validator to support draft-2020-12 schemas by switching to require("ajv/dist/2020") or strip the $schema from MCP tool input schemas before validation.

Guidance

• Identify the version of ajv being used in OpenClaw and consider updating to a version that supports draft-2020-12 schemas.
• Verify that the error occurs during tool catalog initialization by checking the logs or debugging the code.
• Test the suggested fixes, Option A (switching to require("ajv/dist/2020")) or Option B (stripping $schema from MCP tool input schemas), to determine which one resolves the issue.
• Consider the broader impact of this issue on other MCP servers that may be sending 2020-12 schemas.

Example

// Option A: Switch to ajv/dist/2020
const Ajv2020 = require("ajv/dist/2020");
const ajv = new Ajv2020({ schemaId: "auto" });

// Option B: Strip $schema from MCP tool input schemas
const inputSchema = { ...inputSchema };
delete inputSchema.$schema;

Notes

The issue is specific to the combination of OpenClaw and @playwright/mcp v1.60+, and the suggested fixes may not apply to other versions or configurations.

Recommendation

Apply Option A (switch to require("ajv/dist/2020")) as it is the preferred solution, allowing for backward compatibility with draft-07 schemas.