Dex 1.9.1 turns ClickHouse Cloud cost controls and query shape into an agent contract

What shipped

Exmergo released Dex 1.9.1 on August 31 with a ClickHouse Cloud connector and a self-describing query envelope. The release also includes fixes for seeded-schema exploration, tighter inventory payload caps, a warning for unrecognized dialects that would otherwise silently full-scan, and changes that let Dex skills run without depending on the caller’s Python project. The release notes list all ten merged changes.

The headline addition is not just another connection string. Dex now treats ClickHouse Cloud as a distinct guarded deployment rather than reusing its self-hosted ClickHouse accounting. In cloud mode it reports compute-seconds, derives approximate compute-unit hours from live replica memory and can translate that estimate into dollars when a real CU price is configured. If capacity information is missing, denied, partial or inconsistent, Dex refuses before billed work; self-hosted ClickHouse retains its database-load model. That behavior is documented in the merged connector change.

Why the guardrails matter

The connector work also adds a narrow live-cloud integration suite. The project says its test workflow checks usage before opening a SQL connection, uses a service-scoped API key plus read-only database credentials, and refuses once a protected daily threshold is reached. Query execution is still bounded with ClickHouse’s execution-time and bytes-read limits. The pull request and its CI changes describe the protected environment and preflight admission check.

For teams letting coding agents inspect warehouses, that separation is useful: “read only” does not mean “cost free.” A valid analytical query can still wake cloud capacity or scan more than intended. Dex’s design makes estimated consumption part of the confirmation and ledger path instead of leaving cost as an operational afterthought. That is an interpretation of the release’s documented controls, not a claim that the controls eliminate billing risk. Dex describes its connector budgets and local spend ledger in the project documentation updated by the same change.

A result that explains itself

The second change is smaller in code but directly relevant to agent integrations. Single-query responses, batch responses and each batch result now carry "shape": "columnar"; the existing columns, types and cells layout does not change. That lets a caller discover how to decode the payload from the response itself rather than relying on separate documentation or source inspection. The merged query-envelope change documents the contract and regression coverage.

This is the practical theme of Dex 1.9.1: make both sides of an automated warehouse action explicit. Before execution, the tool identifies the deployment’s cost model and can refuse when it cannot establish safe bounds. After execution, the result states its own data shape. Neither feature improves text-to-SQL accuracy by itself, but together they reduce two integration ambiguities that become expensive when software—not a person—is deciding the next step. Both changes ship in the v1.9.1 release.