> ## Documentation Index > Fetch the complete documentation index at: https://docs.cala.ai/llms.txt > Use this file to discover all available pages before exploring further. # Lookup Entity > Resolve one entity by an external identifier. Accepts exactly one of these schemes: `lei` (Legal Entity Identifier), `cik` (SEC Central Index Key), `rssd_id` (Federal Reserve RSSD ID), `companies_house_uk_company_number` (UK Companies House number), `siren` (French SIREN). Pass exactly one scheme in `id`, or as a top-level shorthand: `{"id": {"lei": "95980020140005017502"}}` `{"lei": "95980020140005017502"}` Returns an entity stub (`id`, `name`, `entity_type`, `description`). Feed the `id` into Retrieve Entity / Entity Introspection for a full profile. Use this when you have an external identifier and need the entity UUID. Use `retrieve_entity` when you already have the UUID. ## OpenAPI ````yaml POST /v1/entities/lookup openapi: 3.1.0 info: title: Cala AI summary: Verified, reliable knowledge one API call away description: > ### Knowledge Search Let's you search for verified knowledge to empower your AI Agent with the **right context**. ### Knowledge Entities Get information about entities, **structured** and reliable. version: Beta 1.0 servers: - url: https://api.cala.ai security: [] paths: /v1/entities/lookup: post: tags: - API v1 - Entities summary: Entity Lookup description: >- Resolve one Entity by an indexed Ontology identifier (LEI, CIK, SIREN, …). Pass exactly one scheme in `id`, or as a top-level shorthand: `{"id": {"lei": "95980020140005017502"}}` `{"lei": "95980020140005017502"}` Returns the same stub as `entity_search` (`id`, `name`, `entity_type`, `description`). Feed the `id` into `entity_retrieval` / `entity_introspection` for a full profile. Use this when: You have an external identifier and need the Entity id. For fuzzy name matching use `entity_search`; when you already have the UUID use `entity_retrieval`. operationId: entity_lookup requestBody: content: application/json: schema: $ref: '#/components/schemas/LookupRequest' required: true responses: '200': description: Entity stub matching Entity Search content: application/json: schema: $ref: '#/components/schemas/Entity' example: id: d1715183-1d00-42c9-81c3-be3da24cdcf2 name: MANGO MNG S.A. entity_type: Company description: >- Spanish fashion retailer headquartered in Palau-solità i Plegamans, Barcelona, founded in 1989. '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '429': description: Too many requests (rate limit exceeded) content: application/json: example: error: rate_limit_exceeded message: Rate limit exceeded. Too many requests. security: - APIKeyHeader: [] components: schemas: LookupRequest: properties: id: additionalProperties: type: string type: object title: Id description: >- Exactly one Ontology identifier scheme and its value, e.g. `{"lei": "95980020140005017502"}` or `{"cik": "320193"}` (CIK is zero-padded). Supported schemes: cik, companies_house_uk_company_number, lei, rssd_id, siren. examples: - lei: '95980020140005017502' additionalProperties: false type: object required: - id title: LookupRequest description: >- Resolve one Entity by an Ontology identifier scheme. ``id`` is a single-key object ``{ "": "" }`` (e.g. ``{"lei": "5493…"}``). A top-level shorthand ``{"lei": "5493…"}`` is accepted and normalised into ``id``. Integer values are coerced to strings (e.g. ``{"cik": 320193}``). example: id: lei: '95980020140005017502' Entity: properties: id: type: string format: uuid title: Id description: The ID of the entity examples: - e5bb591a-d308-4aa5-9672-96046d366cde name: type: string title: Name description: The name of the entity examples: - OpenAI entity_type: type: string enum: - Entity - Animal - Award - Organization - Company - EducationalInstitution - ResearchInstitution - GovernmentalInstitution - CulturalInstitution - NonprofitOrganization - IntergovernmentalOrganization - HealthcareEstablishment - Hospital - HealthcareNetwork - HealthcareMetric - Person - Event - GPE - Country - CountrySubdivision - DependentTerritory - Municipality - Continent - Currency - Industry - DomainName - FinancialMetric - CuratedFinancialMetric - Group - CorporateEvent - PrivateCompanyFundingRound - FundingRound - FundingRoundTranche - LoanFacilityComponent - Facility - Location - Organism - Plant - Fungus - Bacterium - Archaeon - Virus - Protist - Chromosome - Product - Medicine - ChemicalSubstance - SmallMolecule - Protein - ProteinComplex - Antibody - ProteinIsoform - Gene - Transcript - Oligonucleotide - Drug - SmallMoleculeDrug - AntibodyDrug - ProteinDrug - OligonucleotideDrug - ChemicalSubstanceDrug - CellTherapy - GeneTherapy - MechanismOfAction - Disease - Anatomy - Pathway - ClinicalTrial - ClinicalTrialArm - ClinicalIntervention - ClinicalOutcome - Sanction - WorkOfArt - Document - Patent - ResearchPaper - Law - Language - Exchange - Future - Commodity - PositioningMetric - MacroIndicatorPublication - MacroIndicator - ForeignExchangeRate - CountryRegion - AbstractFinancialMetric title: Entity Type description: The type of the entity examples: - Company description: anyOf: - type: string - type: 'null' title: Description description: A short description of the entity examples: - An American multinational technology company. type: object required: - id - name - entity_type title: Entity ErrorResponse: properties: response_type: type: string const: ERROR title: Response Type default: ERROR error: $ref: '#/components/schemas/Error' type: object required: - error title: ErrorResponse Error: properties: error_type: $ref: '#/components/schemas/ErrorType' message: type: string title: Message type: object required: - error_type - message title: Error ErrorType: type: string enum: - internal_server_error - service_unavailable_error - format_error - session_not_found_error - entity_not_found_error - request_not_found_error - bad_gateway_error - search_query_error title: ErrorType securitySchemes: APIKeyHeader: type: apiKey in: header name: X-API-KEY ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.