> ## Documentation Index > Fetch the complete documentation index at: https://www.worldmonitor.app/docs/llms.txt > Use this file to discover all available pages before exploring further. # GetPopulationExposure > GetPopulationExposure returns country population data or estimates population within a radius. ## OpenAPI ````yaml /api/DisplacementService.openapi.yaml get /api/displacement/v1/get-population-exposure openapi: 3.1.0 info: title: DisplacementService API version: 1.0.0 servers: - url: https://api.worldmonitor.app security: - WorldMonitorKey: [] - ApiKeyHeader: [] paths: /api/displacement/v1/get-population-exposure: get: tags: - DisplacementService summary: GetPopulationExposure description: >- GetPopulationExposure returns country population data or estimates population within a radius. operationId: GetPopulationExposure parameters: - name: mode in: query description: 'Mode: "countries" (default) or "exposure".' required: false example: countries schema: type: string - name: lat in: query description: Latitude (required for exposure mode). required: false example: 40.7128 schema: type: number format: double - name: lon in: query description: Longitude (required for exposure mode). required: false example: -74.006 schema: type: number format: double - name: radius in: query description: Radius in km (required for exposure mode, defaults to 50). required: false example: 1.5 schema: type: number format: double - name: jmespath in: query description: >- Optional JMESPath expression applied server-side to project or reduce the JSON response before it is returned (mirrors the MCP jmespath argument). Invalid expressions, expressions larger than 1024 UTF-8 bytes, or projections that exceed the 256 KB output cap return HTTP 400 with a {_jmespath_error, original_keys} envelope. Grammar and worked examples: https://www.worldmonitor.app/docs/mcp-jmespath. required: false example: keys(@) schema: type: string responses: '200': description: Successful response content: application/json: example: countries: - code: US densityPerKm2: 1 name: WorldMonitor Analyst population: 1 exposure: densityPerKm2: 1 exposedPopulation: 1 exposureRadiusKm: 1.5 nearestCountry: US success: true schema: $ref: '#/components/schemas/GetPopulationExposureResponse' '400': description: Validation error content: application/json: schema: oneOf: - $ref: '#/components/schemas/ValidationError' - $ref: '#/components/schemas/JmespathProjectionError' '401': description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/UnauthorizedError' '403': description: >- API access requires an active subscription (the API key's subscription is inactive or expired). content: application/json: schema: $ref: '#/components/schemas/ForbiddenError' '429': description: Rate limit exceeded. headers: X-RateLimit-Limit: description: Maximum requests allowed in the active rate-limit window. schema: type: string X-RateLimit-Remaining: description: Requests remaining in the active rate-limit window. schema: type: string X-RateLimit-Reset: description: >- Unix epoch milliseconds when the active rate-limit window resets. schema: type: string Retry-After: description: Seconds to wait before retrying the request. schema: type: string content: application/json: schema: oneOf: - $ref: '#/components/schemas/Error' - $ref: '#/components/schemas/RateLimitError' default: description: Gateway or handler error response. content: application/json: schema: oneOf: - $ref: '#/components/schemas/Error' - $ref: '#/components/schemas/GatewayError' components: schemas: GetPopulationExposureResponse: type: object properties: success: type: boolean description: True if the request succeeded. countries: type: array items: $ref: '#/components/schemas/CountryPopulationEntry' exposure: $ref: '#/components/schemas/ExposureResult' description: >- GetPopulationExposureResponse returns either a countries list or an exposure estimate. ValidationError: type: object properties: violations: type: array items: $ref: '#/components/schemas/FieldViolation' description: List of validation violations required: - violations description: >- ValidationError is returned when request validation fails. It contains a list of field violations describing what went wrong. JmespathProjectionError: description: >- Returned when a REST jmespath projection is invalid or exceeds the expression/output byte limits. properties: _jmespath_error: description: Projection error discriminator and details. type: string original_keys: description: Top-level keys or shape of the unprojected response. items: type: string type: array required: - _jmespath_error - original_keys type: object UnauthorizedError: type: object properties: error: type: string description: Human-readable error message. required: - error description: >- Returned when the API key is missing, malformed, or lacks current API access. ForbiddenError: type: object properties: error: type: string description: Human-readable entitlement failure reason. requiredTier: type: integer format: int32 description: Minimum entitlement tier required for this endpoint. currentTier: type: integer format: int32 description: Caller entitlement tier when known. planKey: type: string description: Caller plan key when known. required: - error description: >- Returned when a PRO-gated endpoint denies access because the caller has no resolved authenticated user, entitlements cannot be verified, or the caller lacks the required entitlement tier. Error: type: object properties: message: type: string description: Error message (e.g., 'user not found', 'database connection failed') description: >- Error is returned when a handler encounters an error. It contains a simple error message that the developer can customize. RateLimitError: type: object description: Returned when a gateway or handler rate limit rejects the request. properties: error: type: string description: Human-readable rate-limit failure reason. required: - error GatewayError: type: object description: >- Returned by gateway infrastructure errors before an RPC handler runs, such as origin, routing, method, authentication, or quota checks. properties: error: oneOf: - type: string - type: object additionalProperties: true description: Gateway error reason or structured gateway failure details. required: - error CountryPopulationEntry: type: object properties: code: type: string description: ISO 3166-1 alpha-3 country code. name: type: string description: Country name. population: type: integer format: int64 description: >- Total population.. Warning: Values > 2^53 may lose precision in JavaScript densityPerKm2: type: integer format: int32 description: Population density per square kilometer. description: CountryPopulationEntry represents a country with population data. ExposureResult: type: object properties: exposedPopulation: type: integer format: int64 description: >- Estimated exposed population.. Warning: Values > 2^53 may lose precision in JavaScript exposureRadiusKm: type: number format: double description: Radius used for the estimate in km. nearestCountry: type: string description: ISO3 code of nearest priority country. densityPerKm2: type: integer format: int32 description: Population density used for the estimate. description: ExposureResult contains the population exposure estimate. FieldViolation: type: object properties: field: type: string description: >- The field path that failed validation (e.g., 'user.email' for nested fields). For header validation, this will be the header name (e.g., 'X-API-Key') description: type: string description: >- Human-readable description of the validation violation (e.g., 'must be a valid email address', 'required field missing') required: - field - description description: FieldViolation describes a single validation error for a specific field. securitySchemes: WorldMonitorKey: type: apiKey in: header name: X-WorldMonitor-Key description: User-issued WorldMonitor API key. ApiKeyHeader: type: apiKey in: header name: X-Api-Key description: Alias header for the WorldMonitor API key (X-WorldMonitor-Key). ````