DE//AGENT
Explore
Tutorial Lesson 3 of 10 · The Data Quality Series community beginner

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.

At a glance

When A producer and its consumers keep arguing about what a column means; A dataset feeds multiple teams and needs a freshness or completeness SLA
Where Data Contracts
Why A contract with no enforcement is documentation, and documentation is not a contract — the sixth part is what makes the other five binding.

Learning objectives

  • Write all six parts of a contract for a real dataset
  • Specify freshness and completeness numbers in the SLA
  • Name the CI test that fails when the contract is violated

What you need

  • A producer dataset with at least one consumer
  • [object Object]
  • [object Object]

Steps

  1. Name an owner — a team, with an on-call. (from skill-data-contract-author )
  2. Define the schema, typed and versioned. (from skill-data-contract-author )
  3. Write the semantics: what each field means, units, nullability. (from skill-data-contract-author )
  4. Set the SLA — freshness and completeness. (from skill-data-contract-author )
  5. Agree the breaking-change policy — notice period and a deprecation path. (from skill-data-contract-author )
  6. Wire enforcement: name the CI test that fails on violation. (from skill-data-contract-author )

Check yourself

  • The contract names a team with an on-call as owner, not a distribution list.
  • Renaming a promised field in a test branch fails the CI test named in part six.

Worked example

Scaffold the contract repo — from tpl-data-contract 

amp template new de-agent/data-contract-template ./contracts

The six parts of a contract — from skill-data-contract-author 

1. Owner (a team, with an on-call).
2. Schema (typed, versioned).
3. Semantics (what each field *means*, units, nullability).
4. SLA (freshness, completeness).
5. Breaking-change policy (notice period, deprecation path).
6. Enforcement (which CI test fails on violation).

Template layout — contract, schema, CI gate, deprecation path — from tpl-data-contract 

data-contract-template/
  contract.yaml        # owner, sla, semantics, policy
  schema.avsc          # typed schema
  ci/check-compat.sh   # compatibility gate
  DEPRECATION.md       # dated deprecation path

Sourced from

Security scan

Last sweep 2026-10-24: 0 finding(s), 0 marked as examples.

Common gotchas

  • A contract with no enforcement is documentation. Documentation is not a contract.
  • The owner is a team with an on-call — a contract owned by nobody has no pager.
  • A rename + a new column with the old name looks compatible to a schema differ but breaks every consumer that read the old semantics — write the semantics section so the diff catches it.

Production considerations

  • Enforcement is part six — the contract must name the CI test that fails on violation.
  • Keep contract.yaml, schema.avsc, ci/check-compat.sh and DEPRECATION.md together; the template ships all four.

Diagram

contract authoring
   |
   |- owner + schema --> semantics (units, nullability)
   |
   |- SLA (freshness, completeness) --> breaking-change policy
   |
   |- enforcement --> CI test fails on violation --> contract, not documentation

Registry stats

Verification community · Oct 21, 2026
Completeness 81
Trust multiplier ×1.25
Composite 34.15 · adequate
Freshness 3 days since last source check
Difficulty beginner
Version 0.1.0
License CC-BY-4.0
Security flags none