[API-03] Define partner credentials, webhooks, usage, entitlements, and operations contracts

[jaavid]

Background

CoreLink is managed as one product across multiple implementation repositories. This work is the executable feature owned by api-contracts under EPIC-07.

Problem

The current repository state does not yet provide verified, release-ready evidence to define partner credentials, webhooks, usage, entitlements, and operations contracts.

Goal

Define partner credentials, webhooks, usage, entitlements, and operations contracts with observable acceptance evidence and no divergence from the product-level contract.

Parent

• Primary Product Epic: EPIC-07
• Backlog ID: API-03

Scope

• Deliver the outcome stated in the title within the api-contracts implementation boundary.
• Reconcile affected contracts, tests, documentation, security, tenancy, observability, migration and release behavior.
• Retain acceptance evidence suitable for the Partner Platform product gate.

Out of Scope

• Creating a separate repository roadmap.
• Expanding into adjacent product domains without an accepted Product Epic or decision record.
• Claiming completion based only on code merge when operational or customer validation is required.

Acceptance Criteria

• The stated outcome is implemented or documented at the correct repository boundary.
• Expected, failure and recovery paths are covered by repeatable checks or retained evidence.
• Tenant isolation, authorization and sensitive-data behavior are reviewed where applicable.
• Public/internal contract and compatibility impacts are reconciled.
• Documentation, observability, migration/rollback and release notes are updated where applicable.
• Evidence is attached or linked and the parent Epic exit criteria are measurably advanced.

Technical Notes

Preserve canonical identifiers, provider-neutral public behavior, idempotency and backward compatibility. Prefer the existing modular-monolith boundary unless measured scale, security isolation or ownership requires extraction.

Dependencies

• Prerequisite completed: API-01 established the initial public contract baseline.
• Active blockers: PLAT-06 through PLAT-09.
• Blocks: Partner credentials, webhook, usage, entitlement, and operations contract readiness for the Partner Platform gate.
• Cross-repository work: Link concrete Issues during refinement; do not duplicate their implementation here.
• Current dependency state: See the CoreLink Product organization Project.

Planning Metadata

• Type: Feature
• Priority: P0
• Product milestone: Partner Platform
• Domains: api, billing
• Area: contract
• Complexity: L
• Created in status: Triage
• Current status and DRI: See the CoreLink Product organization Project.
• Intended repository labels: type:feature

Definition of Done

• Acceptance criteria demonstrated.
• Required tests and evidence pass.
• Contracts are updated or confirmed unaffected.
• Security and tenant boundaries are reviewed.
• Migration and rollback paths are verified where applicable.
• Observability and runbooks are updated where applicable.
• Documentation and release notes are updated.
• Pull request(s) are merged and linked.