Troubleshooting the ATTOM MCP Server

This page covers the most common issues encountered when connecting to the ATTOM MCP Server, along with steps to resolve them.

Unauthorized

API key missing

Your request did not include an Authorization header.
Add:
Authorization: Bearer YOUR_API_KEY

Header incorrectly formatted

The header must follow this exact structure:
Authorization: Bearer <your_api_key>

Check for extra spaces, missing "Bearer", or hidden characters.

Trial key expired

Trial access expires automatically.
Contact your account representative or support to request an extension or production key.

Wrong key type used

Ensure you are using an ATTOM MCP key, not an API key.

Too Many Requests

Monthly MCP request quota exceeded

Your API key has hit its monthly request cap.
You may need a higher-volume plan or quota reset.

Burst rate limit exceeded

MCP enforces rate limits to ensure stability.
Try reducing concurrency or adding retry/backoff logic.

n8n Connection Errors

Transport type set incorrectly

Ensure the HTTP Request or AI Agent node is using the correct transport type (typically POST, JSON body).

Bearer token missing

Add the Authorization header inside your n8n node configuration.

SSL / HTTPS validation failures

If running n8n self-hosted, ensure CA certificates are installed.
Try enabling "Ignore SSL Issues" temporarily to confirm the root cause.

Make.com Connection Errors

Incomplete module configuration

Make requires both the HTTP Header and Request Body fields to be configured.
Ensure JSON mode is enabled.

Incorrect Content-Type header

Make sometimes defaults to form-encoded.
Set Content-Type: application/json.

Missing Bearer token

Add the Authorization header in “Headers” for the module.

Request Body Errors

Invalid JSON format

Common issues:

• missing commas

• trailing commas

• mismatched brackets
  Validate JSON before sending.

Required parameters missing

Check the MCP tool documentation to ensure all required fields are included.

Data Access Errors

Property not found

The address or APN may not exist in ATTOM’s dataset.
Try searching with more general parameters.

No results returned from search

Ensure you are using valid search filters as defined by the tool’s schema.

Unexpected Errors

Temporary service interruption

Retry after a short delay with exponential backoff.

Gateway or proxy issues

If using corporate VPNs or proxies, ensure they allow outbound HTTPS to the MCP Server.