Data Contracts

Author your first data contract

Draft an enforceable contract for one real dataset by walking the six parts — owner, schema, semantics, SLA, breaking-change policy, enforcement — starting from the data-contract template, and finish with the CI test that makes it a contract instead of documentation.

Enforce contracts in CI with the schema change check

Install the Schema Change Check as a pre-commit gate over staged schema files so a breaking change exits non-zero unless a migration plan or deprecation annotation rides along with it — the producer-CI placement that catches breakage before merge.

Respond when a data contract breaks

Work the broken-contract runbook end to end: identify which clause broke, bound the consumer impact set from lineage before anything else, decide whether the producer reverts or the consumer adapts, and close with consumer-driven contract tests in the producer's pipeline.

Review a schema change against its contract

Run the Schema Reviewer's four-step pass over a producer's schema diff — classify each field change, resolve consumers from lineage, emit a dated migration plan — and use the schema-drift runbook to separate hard failures from silent nulls before anything merges.

Data Contract Author

• Specify a freshness and completeness SLA
• Encode a contract as executable tests

Schema Change Contract Review

• Apply backward/forward compatibility rules to a diff
• Detect a breaking change hidden behind a "safe" rename

Contract Kit

Authors data contracts, enforces them in CI, and classifies schema changes as compatible/risky/breaking for producers and consumers.

Schema Change Check

Block a commit that introduces a breaking schema change without a migration plan.

Schema Reviewer

Classify schema changes and prevent breaking changes from shipping.

Data Contract Template

A contract skeleton (ownership, schema, semantics, SLA, compatibility policy) with the CI check that enforces it and a deprecation checklist.

Data contract broken

A producer violated its contract and a consumer broke in production — bound the impact before fixing.

Schema drift

The upstream schema changed without notice and a cast broke or a column silently nulled.

Contracts as a Quality Gate

Producers change schemas and semantics with no notice; consumers break in production.