Agents and RAG systems amplify whatever they sit on, including the silent failures and undocumented assumptions in your warehouse. Limen fixes the layer underneath: contracts define what each table means, and certificates prove every batch met that definition before a model sees it. When the model answers, you can show why the answer holds.
All your agents: analysts, copilots, retrieval, and autonomous workflows.
OpenAI
Claude
Gemini
Every batch is verified against its contract before any model reads it. The certificate is the receipt.
A machine-readable definition of what each table is supposed to mean. Schema, freshness, ownership, semantics.
contract customers { pk customer_id freshness <= 4h email unique & rfc5322 tier in [free, pro, ent] }
Whatever you've got: Snowflake, BigQuery, Databricks, Postgres. The bytes underneath everything else.
Snowflake
Databricks
BigQuery
Postgres
Four failure modes get amplified the moment a model reads the warehouse and none of them show up in a dashboard until something downstream is already wrong.
A nightly job double-ran. Half the rows in orders_fact are
duplicates. The model dutifully reports revenue up 84%.
A vendor renamed customer_id to cust_id.
The retrieval index still queries by the old name. The agent answers with stale joins.
The employee who built churn_signal left in 2024. The definition
lives in someone's head. The agent has no way to know what it actually measures.
The warehouse has seven tables with revenue in the name.
Finance trusts exactly one. Nothing is broken; the agent just answers from the wrong table.
Contracts capture what a table is supposed to mean: schema, freshness, allowed values, ownership, semantic descriptions agents and humans both read.
Every materialization is validated against its contract before the data is exposed. A passing run emits a signed, timestamped certificate.
Models and retrieval read through Limen, which only returns batches with a valid certificate. Stale or failed batches are quarantined automatically.
When an answer is questioned, the certificate chain is the answer's defense: this run, this contract, this dataset, this verdict. Auditable on demand.
We'll instrument the three or four tables your most-used model reads from, generate baseline contracts, and run them for a week. You'll see exactly which batches your agents would have been served bad data on.