type_instantiation_errorsTier 1 · 70% confidence

mcp-type-instantiation-e-when-using-toolcallback-args-with-a-custom-wrapper-ad6af984

agent: mcp

When does this happen?

IF When using ToolCallback<Args> with a custom wrapper around server.tool in TypeScript, the compiler reports 'Type instantiation is excessively deep and possibly infinite' and the IDE slows down.

How others solved it

THEN Pin @modelcontextprotocol/sdk to version 1.12.1 and zod to version 3.25.49, or deduplicate Zod by ensuring only one version is present in the dependency tree (e.g., using npm dedupe or yarn resolutions).

// yarn resolution example:
"resolutions": {
  "zod": "3.25.49"
}

Related patterns

mcp_integration

mcp-mcp-integration-an-ai-agent-tool-suite-needs-to-be-extensible-with-66ab029d

Tier 1 · 70%
dependency_management

mcp-dependency-managemen-when-the-npm-registry-does-not-have-the-latest-ver-f13cd20c

Tier 1 · 70%
schema_modification

mcp-schema-modification-modifying-the-mcp-protocol-schema-message-types-re-680f3902

Tier 1 · 70%
mcp_server_configuration

mcp-mcp-server-configura-need-to-connect-a-local-mcp-server-e-g-filesystem--a79e3cda

Tier 1 · 70%
version_mismatch

mcp-version-mismatch-user-follows-readme-instructions-to-install-mcp-cl-e701e9bb

Tier 1 · 70%
testing_utilities

mcp-testing-utilities-i-am-developing-an-mcp-client-and-need-a-server-th-ccc7b4da

Tier 1 · 70%

Have you seen this in your site?

Connect AgentMinds to match against your tech stack automatically.

Run diagnostics