ADR-003 — Runtime Contracts

Status: Accepted
Date: 2026-06-28
Phase: 12-1A
Deciders: Platform Architect
Related: ERP v1.0 contracts/runtime-contracts.md

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Context

ERP v1.0 defined eight Runtime Contracts between Platform Core and adapters. Adapters (IDEs) change frequently; contract stability is the integration surface products depend on.

ZEP must freeze contract semantics for contracts@1 across platform 1.x releases.

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Decision

1. Runtime Contracts are the only stable interface between platform and adapters
2. Eight component contracts + RuntimeAdapterContract meta — unchanged obligations at platform 1.0.0
3. Contract major version increments only on obligation change — not on adapter implementation
4. Products pin contractMajor in platform.lock
5. Adapter certification proves implementedContracts against contract major
6. Contract text lives in platform contracts/ — products reference, never fork

Contract inventory (contracts@1):

Contract	Component
RuntimeConstraintContract	Constraints
RuntimeProcedureContract	Procedures
RuntimeWorkflowContract	Workflows
RuntimeDelegationContract	Delegation
RuntimeEnforcementContract	Enforcement
RuntimeContextProviderContract	Context Providers
RuntimeExecutionContract	Execution
RuntimeAdapterContract	Adapters (meta)

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Consequences

Positive

• Replace Cursor with future IDE without product migration
• PHPUnit contract compliance tests are portable
• Clear breaking change boundary (contract major)

Negative

• Contract amendments require formal process
• Adapter authors must implement full contract set

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Alternatives considered

Alternative	Rejected because
Adapter-specific contracts per IDE	Product N×M matrix
Informal "best effort" adapter parity	Not CI-enforceable
Merge contracts into adapter profiles	Leaks vendor into stable surface

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Compliance

Phase 12-1A does not amend ERP v1.0 contract obligations — only relocates authority to platform package.

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ADR-003 — Runtime Contracts are the stable platform surface.