Chapter 4: API Interface Specifications

Modern temporal research systems comprise numerous interconnected software components that must communicate reliably and efficiently. The WIA-TIME-001 Phase 2 specification defines standardized Application Programming Interfaces (APIs) that enable this communication, establishing common patterns for requesting calculations, submitting displacement operations, verifying causality, and exchanging temporal data. This chapter provides comprehensive coverage of these API specifications, demonstrating how software systems interact within the WIA-TIME-001 framework.

The API design philosophy emphasizes simplicity, security, and reliability. All APIs use RESTful conventions with JSON payloads, ensuring compatibility with virtually any programming environment. Authentication and authorization mechanisms protect against unauthorized access, while comprehensive error handling ensures that failures are detected and reported appropriately. The APIs are versioned to support evolution while maintaining backward compatibility for existing implementations.

REST API Architecture

The WIA-TIME-001 REST API follows standard HTTP conventions, using appropriate methods (GET, POST, PUT, DELETE) for different operation types. All endpoints require HTTPS to ensure transport security. The base URL for production systems is standardized as https://api.wia-time.org/v1/, though facilities may deploy local instances with different base URLs while maintaining API compatibility.

Request and response bodies use JSON format exclusively. All timestamps in API communications use ISO 8601 format with explicit timezone specification. Numeric values use standard JSON number representation with sufficient precision for temporal calculations. The API supports content negotiation through Accept headers, though JSON is the only currently specified format.

Base URL: https://api.wia-time.org/v1/

Common Headers:
  Content-Type: application/json
  Authorization: Bearer {token}
  X-Request-ID: {unique-request-identifier}
  X-Temporal-Signature: {hmac-signature}

Temporal Calculation Endpoints

The calculation endpoints provide access to the computational capabilities required for temporal displacement planning. These endpoints accept displacement parameters and return calculated results including energy requirements, feasibility assessments, and risk evaluations. All calculations are performed server-side to ensure consistency and to leverage high-performance computing resources.

Calculate Displacement

The displacement calculation endpoint accepts origin and destination coordinates along with traveler parameters, returning comprehensive displacement metrics. This endpoint performs the fundamental calculations required to plan any temporal displacement operation.

POST /calculate/displacement

Request:
{
  "origin": {
    "time": "2025-01-01T00:00:00Z",
    "coordinates": { "x": 0, "y": 0, "z": 0 },
    "referenceFrame": "earth"
  },
  "destination": {
    "time": "2020-01-01T00:00:00Z",
    "coordinates": { "x": 0, "y": 0, "z": 0 },
    "referenceFrame": "earth"
  },
  "travelerMass": 75
}

Response 200:
{
  "displacementId": "TD-2025-001-ALPHA",
  "deltaTime": -157766400,
  "energyRequired": 6.75e18,
  "causalityRisk": "low",
  "feasibility": "possible"
}

Table 4.1: Displacement Calculation Response Fields

Field	Type	Description
displacementId	string	Unique identifier for referencing this calculation
deltaTime	number	Temporal displacement in seconds (negative = past)
energyRequired	number	Total energy requirement in joules
causalityRisk	enum	Risk level: none, low, medium, high, critical
feasibility	enum	Assessment: possible, marginal, infeasible

Calculate Energy Requirements

The energy calculation endpoint provides detailed breakdown of energy requirements for a specific displacement method. Different temporal displacement mechanisms have vastly different energy profiles, and this endpoint enables comparison between available methods.

POST /calculate/energy

Request:
{
  "displacementId": "TD-2025-001-ALPHA",
  "method": "wormhole"
}

Response 200:
{
  "totalEnergy": 6.75e18,
  "exoticMatter": -1e15,
  "powerDuration": 3.5,
  "sources": [
    { "type": "antimatter", "amount": 75, "unit": "kg" },
    { "type": "vacuum_energy", "amount": 1e12, "unit": "J" }
  ]
}

Causality Verification Endpoints

The causality endpoints enable verification of temporal operations against paradox risk thresholds. These endpoints analyze planned actions within the context of known timeline structure and return risk assessments that inform operational decisions. Causality verification is mandatory before any displacement operation proceeds.

Check Paradox Risk

The paradox check endpoint accepts a displacement identifier and a list of planned actions, returning detailed risk assessment including probability estimates and specific warnings. This endpoint must be called before any displacement operation and the response must indicate approval before proceeding.

POST /causality/check

Request:
{
  "displacementId": "TD-2025-001-ALPHA",
  "plannedActions": [
    { "type": "observation", "target": "historical_event" },
    { "type": "sample_collection", "target": "geological" }
  ]
}

Response 200:
{
  "paradoxRisk": "low",
  "probability": 0.001,
  "warnings": [],
  "approved": true,
  "validUntil": "2025-01-15T12:00:00Z"
}

Verify Timeline Integrity

The timeline integrity endpoint provides real-time assessment of timeline stability. This endpoint is used both before operations to verify baseline stability and after operations to confirm that no unintended modifications occurred.

GET /causality/timeline/{timelineId}/integrity

Response 200:
{
  "timelineId": "TL-PRIME-A1-001",
  "integrity": 0.9999,
  "anomalies": 0,
  "lastVerified": "2025-01-15T10:00:00Z",
  "status": "stable"
}

Table 4.2: Timeline Integrity Status Values

Status	Integrity Range	Operational Impact
stable	≥ 0.999	Normal operations permitted
minor_variance	0.99 - 0.999	Enhanced monitoring required
significant_variance	0.9 - 0.99	New operations suspended
critical	< 0.9	Emergency protocols activated

Navigation Endpoints

Navigation endpoints support worldline calculation and trajectory optimization. These endpoints accept origin and destination coordinates along with navigational constraints, returning optimized paths through spacetime that minimize risk while respecting physical limitations.

POST /navigation/worldline

Request:
{
  "origin": { /* SpacetimeCoordinate */ },
  "destination": { /* SpacetimeCoordinate */ },
  "constraints": {
    "maxAcceleration": 10,
    "avoidMassive": true,
    "preferredMethod": "wormhole"
  }
}

Response 200:
{
  "worldlineId": "WL-2025-001",
  "segments": [ /* array of path segments */ ],
  "totalProperTime": 3600,
  "waypoints": [ /* critical navigation points */ ],
  "hazards": []
}

Authentication and Authorization

The WIA-TIME-001 API implements multiple authentication mechanisms to accommodate different operational contexts. All mechanisms require TLS 1.3 or higher for transport security. API keys provide simple authentication for automated systems, while OAuth 2.0 supports interactive applications with user-specific permissions.

Temporal signatures provide an additional security layer that binds requests to specific times, preventing replay attacks. The signature is computed as HMAC-SHA256 over the concatenation of timestamp and request hash, using the facility's secret key. Requests with temporal signatures more than five minutes old are rejected.

Table 4.3: Authentication Methods

Method	Header Format	Use Case
API Key	Authorization: Bearer {api_key}	Automated systems
OAuth 2.0	Authorization: Bearer {access_token}	Interactive applications
Temporal Signature	X-Temporal-Signature: {hmac}	High-security operations

Rate Limiting and Quotas

To ensure fair resource allocation and prevent abuse, the API implements rate limiting and quota systems. Limits vary by subscription tier, with higher tiers receiving greater allocation. Rate limit status is returned in response headers, enabling clients to implement appropriate backoff strategies.

Table 4.4: Rate Limits by Tier

Tier	Requests/Hour	Calculations/Day	Displacement Ops/Month
Free	100	10	0
Basic	1,000	100	1
Professional	10,000	1,000	10
Enterprise	Unlimited	Unlimited	Unlimited

Error Handling

The API uses standard HTTP status codes augmented with detailed error responses. All error responses include a machine-readable error code, human-readable message, and when applicable, specific field-level details. Clients should implement robust error handling that appropriately responds to different error categories.

Error Response Format:
{
  "error": {
    "code": "CAUSALITY_VIOLATION",
    "message": "Proposed action would create grandfather paradox",
    "details": {
      "paradoxType": "grandfather",
      "probability": 0.87,
      "affectedEntities": ["traveler_ancestor_3"]
    }
  }
}