Defines storage, endpoints, events, error handling, monitoring, and support procedures for multi-factor authentication. It fixes adoption boundaries and observable failure evidence while keeping environment-specific limits configurable.
Package status: reference context ready for human review. The contract and test scenarios are complete, but no claim is made that an adopting implementation has passed them.
Decision
For Multi-factor authentication, adopt a server-side credential and session lifecycle with explicit assurance. Expose a resource or event contract with stable identity, authorization, validation, idempotency, compatibility, and explicit errors. This package is a reference contract: the adopting team must choose numeric limits, providers, jurisdictions, and operational owners from evidence in its own environment.
Scope
- The Multi-factor authentication actors, inputs, outputs, states, policy or schema versions, and externally visible outcomes described by this api block.
- Primary and alternate interfaces, background work, caches, integrations, support paths, and evidence that can exercise the same boundary.
- Adoption-specific configuration, rollout, recovery, and verification responsibilities needed to apply the reference safely.
Outside this block
- Choosing a universal vendor, framework, jurisdiction, numeric threshold, retention period, or service-level objective for every adopter.
- Claiming that packaged scenarios have run against a downstream implementation or that this reference grants legal, security, or accessibility certification.
Contract
- Store only protected credential material, rotate signing and recovery secrets, and keep credentials out of URLs, logs, analytics, and support views.
- Bind issuance, use, expiry, revocation, recovery, and replay handling to a named subject and intended action.
- Return enumeration-resistant public responses while retaining sufficient internal reason and correlation data for support and abuse response.
- Re-evaluate sensitive actions after subject, device, authenticator, risk, or session state changes instead of trusting a stale login forever.
- Document method or event semantics, required fields, conditional behavior, limits, and a machine-readable error vocabulary.
- Reject unknown security-sensitive fields and preserve forward compatibility for explicitly extensible data.
- Model factor enrollment, verification, naming, replacement, recovery, step-up, revocation, and assurance level independently and require recent authenticated intent for factor changes.
- Prefer phishing-resistant factors for high-impact actions, prevent replay and downgrade, protect recovery codes, notify through a trusted channel, and never count two instances of one weak channel as independent factors.
Implementation guidance
- Publish contract fixtures and consumer tests before routing production traffic to a new version.
- Model Multi-factor authentication inputs, outputs, actors, states, invariants, side effects, and evidence before selecting framework or vendor details.
- Store the applicable Multi-factor authentication contract or policy version with material state so migrations, replay, and support decisions remain attributable.
- Introduce the path behind controlled rollout, compare expected and observed outcomes, and keep a tested recovery route until adoption evidence is complete.
Failure handling and safeguards
- Missing, expired, replayed, or contradictory authentication evidence denies the action and follows a rate-bounded recovery path.
- Invalid or contradictory Multi-factor authentication state is rejected or quarantined; the implementation never guesses a value that broadens authority or duplicates an effect.
- Retries are bounded and use durable identity; after exhaustion, work reaches an inspectable terminal state with an accountable owner.
Verification and operations
- Test retries, duplicate requests, conditional updates, pagination or resumption, invalid credentials, limits, and dependency timeout.
- Monitor Multi-factor authentication success, denial, validation failure, dependency failure, retry exhaustion, and recovery by contract version without sensitive payload dimensions.
- Re-run paired positive and negative fixtures after policy, schema, dependency, migration, or boundary changes and preserve the resulting evidence.
Adoption assumptions
- Names and values in the example are a concrete fixture, not universal defaults; adopters replace them through documented evidence and ownership.
- The adopting system can provide authenticated identity, durable operation or record versions, bounded telemetry, and a controlled path for change.
The executable-looking examples in this package are fixtures and acceptance contracts. Run the collection validator to check structure and metadata, then translate and execute the scenarios in the target repository before recording implementation evidence.
References
- NIST SP 800-63B-4, Authentication and Authenticator Management (applies as of 2026-09-08)