Dureach

MCP SQL reader

Write read-only SQL for contacts.query and trade.query: allowed views, columns, grammar, pagination, and error handling.

dureach.contacts.query and dureach.trade.query accept read-only SQL over the documented contacts and shipment datasets. Use one SELECT with approved columns; joins and writes are not supported.

Which views and columns are allowed?

ToolViewColumns
dureach.contacts.querycontactsid, full_name, job_title, company_name, company_domain, city, country
dureach.trade.querybol_shipmentsid, source_type, trade_flow, bol_number, actual_arrival_date, shipper_name, consignee_name, product_desc

Query only these columns. Unknown tables, columns, or database prefixes return a validation error. product_desc is truncated to 300 characters in results.

What SQL shape is accepted?

  • Single SELECT with optional WHERE, GROUP BY, HAVING, and ORDER BY. Aliases are allowed.
  • Comparisons, boolean operators, arithmetic, literal IN, and LIKE are supported.
  • Aggregate and scalar functions: count, sum, avg, min, max, uniqExact, lower, upper, length, coalesce, toDate, toYear, toMonth.
  • Rejected: joins, subqueries, CTEs, window functions, SETTINGS, FORMAT, SQL LIMIT/OFFSET, SELECT SETTINGS, GROUP BY WITH TOTALS, global IN, and positional ORDER BY.
  • SQL must be at most 16 KiB UTF-8. Larger statements return a validation error before execution.
{
  "sql": "SELECT company_name, city, country FROM contacts WHERE country = 'DE' AND company_domain LIKE '%gmbh%' ORDER BY company_name, city",
  "page": 1,
  "limit": 25
}

Page 2 and higher require ORDER BY. Use ordering supported by the tool schema and add a permitted tie breaker where available. Ties and source updates can move rows between pages; bounded results are not a complete export.

How does pagination work?

Use page (1–20) and limit (1–50). Do not append SQL LIMIT/OFFSET. Results return column names, ClickHouse types, and ordered row arrays without a total count:

{
  "columns": [{"name": "company_name", "type": "String"}],
  "rows": [["Example GmbH"]],
  "page": 1,
  "limit": 25
}

UUID, date, decimal, and integers outside the JSON-safe range arrive as strings; non-finite floats arrive as strings. A result larger than 1 MiB returns result_too_large; narrow the column list or filters and retry.

How should errors be handled?

CodeMeaningFix
validation error on sqlDisallowed keyword, table, column, or shape.Keep one SELECT on the listed view and columns; remove joins, subqueries, CTEs, SETTINGS, FORMAT, and SQL LIMIT.
SQL exceeds 16 KiBStatement too large.Shorten predicates or split the question into smaller queries.
missing ORDER BY on page 2+Offset page is not deterministic.Add ORDER BY with a unique tie breaker.
quota_exceeded (contacts_daily)Daily contacts budget spent.Wait until reset or ask an admin about plan limits.
result_too_largeWire result over 1 MiB.Select fewer columns, add filters, or lower limit.

Log the request_id and error code. Never log full SQL with customer identifiers alongside tokens.