# Governed BigQuery access for AI agents > Give AI agents governed access to BigQuery: per-role service accounts, preserved row and column policies, billed-byte allowances and no SQL from agents. Canonical URL: https://sembric.app.arelis.digital/integrations/bigquery Integration · Google Cloud data warehouse Discover a BigQuery dataset and serve certified aggregates and governed views to agents, with each Sembric role impersonating its own customer service account. [Request a pilot](https://sembric.app.arelis.digital/contact) · [Setup steps](#setup) Identity ## How Sembric connects to BigQuery ### Per-role identity Each Sembric role maps to its own customer service account. The Sembric runtime holds Token Creator on those target accounts only and impersonates the account mapped to the acting role. ### Your policies stay in force BigQuery row-level and column-level policies stay in force because every query runs as the mapped account. Curated datasets or authorized views keep raw and regulated tables out of reach. Enforcement ## What Sembric checks and refuses - Discovery pages through the entire dataset and commits a new catalog only after every metadata call succeeds. - Nested STRUCT and repeated ARRAY fields keep their full type in the reviewed fingerprint, start sensitive when a nested field name looks personal, and can never be measures or dimensions. - Every result page is read; repeated or missing page tokens are refused, so a partial page is never treated as the whole answer. - NUMERIC, BIGNUMERIC and wide integers return as exact strings; timestamps return as ISO strings. - Each job reserves from a workspace UTC-day billed-byte allowance (10 GB by default) before it starts and carries a matching maximumBytesBilled and a 30-second timeout. Limits ## What these controls don’t do - The billed-byte allowance is an on-demand query control, not an invoice limit: capacity reservations, storage and other Google Cloud charges are outside it. Keep project budgets and billing alerts. - Only confirmed billed bytes return unused allowance; failed or uncertain jobs keep their full reservation. Setup ## Connecting BigQuery 1. Create one service account per Sembric role with metadata and data read on the chosen dataset or authorized views, plus BigQuery Job User on the billing project. 2. Grant the Sembric runtime identity Token Creator on those service accounts only. In an isolated customer plane, the connection form shows the exact identity to grant. 3. An owner enters the data project, dataset, billing project, location, per-query billed-byte cap and the account for each role, then tests every mapping before saving. 4. Discover the dataset, have the asset’s steward review classifications, then define and independently certify products and views. FAQ ## BigQuery questions Something else? [Ask us directly](https://sembric.app.arelis.digital/contact). ### Does Sembric need access to all of our BigQuery data? No. Each role’s service account should read only a curated dataset or authorized views. Sembric discovers what that account can see, and agents can reach only certified surfaces built on reviewed, non-sensitive fields. ### Can an agent run up a large BigQuery bill? Agents cannot send SQL. Every job reserves from a workspace daily billed-byte allowance and carries maximumBytesBilled. That bounds on-demand query bytes, but it is not an invoice limit, so keep project budgets and alerts too. More sources ## Other integrations - Cloud data platform ### [Snowflake](https://sembric.app.arelis.digital/integrations/snowflake) Connect a Snowflake schema over the SQL API with one key-pair user and role per Sembric role, and let agents query only certified surfaces. - Federated SQL engine and lakehouse catalogs ### [Trino](https://sembric.app.arelis.digital/integrations/trino) Discover one Trino catalog and schema, including a lakehouse catalog you operate, and serve certified surfaces through role-specific read-only users. - Databricks SQL warehouse with Unity Catalog ### [Databricks](https://sembric.app.arelis.digital/integrations/databricks) Connect a Databricks SQL warehouse and one Unity Catalog schema with a separate OAuth service principal per Sembric role. - Native PostgreSQL ### [PostgreSQL](https://sembric.app.arelis.digital/integrations/postgresql) Connect an existing PostgreSQL schema over verified TLS with a restricted login per Sembric role, keeping row-level security in force. - MySQL 8.0 and 8.4 ### [MySQL](https://sembric.app.arelis.digital/integrations/mysql) Connect a MySQL 8.0 or 8.4 database over mandatory verified TLS with direct read-only grants per Sembric role. ## Put your first certified data product in front of an agent. Tell us which warehouse you run and what your agents need to answer. We will help you connect a source, certify a first surface and query it over MCP. [Request a pilot](https://sembric.app.arelis.digital/contact) · [Email us](mailto:contact@arelis.digital?subject=Sembric%20pilot%20request&body=Hello%20Sembric%20team%2C%0D%0A%0D%0AWe%20would%20like%20to%20discuss%20a%20pilot.%0D%0A%0D%0A-%20Which%20warehouse%20or%20engine%20holds%20the%20data%3A%20BigQuery%2C%20Snowflake%2C%20Trino%2C%20Databricks%2C%20PostgreSQL%20or%20MySQL%3A%0D%0A%0D%0A-%20The%20first%20questions%20your%20agents%20should%20answer%2C%20and%20who%20owns%20that%20data%20today%3A%0D%0A%0D%0A-%20Which%20agents%20or%20clients%20you%20use%2C%20such%20as%20Claude%20Code%20or%20your%20own%20MCP%20client%3A%0D%0A%0D%0A-%20Any%20security%20or%20compliance%20review%20the%20pilot%20needs%20to%20pass%3A%0D%0A%0D%0A\(Please%20do%20not%20include%20credentials%20or%20customer%20data.\)) --- Last updated 2026-10-14. Published by Arelis AI (https://arelis.digital).