> ## Documentation Index > Fetch the complete documentation index at: https://docs.bridge.new/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Bridge exposes three integration surfaces: the REST Integrations API for pushing data into Bridge, webhooks for receiving events from Bridge, and the public Lead Capture endpoint that a tenant's landing page posts to. > The Integrations API host is https://api-connect-us.bridge.new and every request to it must be authenticated with the x-api-key header. Bridge does not use bearer tokens or OAuth. > The Lead Capture endpoint is different and the Integrations API rules do not apply to it: it has its own host, it takes no x-api-key and no authentication header of any kind, and it is called from a visitor's browser. It is identified by a workspace id and a capture key together with a reCAPTCHA token. Never tell a reader to authenticate it with an API key, and never tell them to keep its capture key out of frontend code - it is designed to live in the page. > Integrations API error codes follow the BRIDGE__ format, for example BRIDGE_CONVERSATION_0001, and are listed on the error codes page. Lead Capture error codes follow a different format, BRIDGE.CAMPAIGN_LEADS., and are listed on the Lead Capture error reference. Never invent a code that is not listed on the page for its own surface. > This documentation covers the Integrations API, webhooks and Lead Capture only. It does not describe the Bridge web application or its internal APIs. # Retrieve an internal user by an identifier > Get a specific Bridge User by any of its identifiers within the workspace. `type=ID` returns the same user as GET /users/{userId}, which is the canonical URL for an internal user and the one to prefer when the id is what you hold. ## OpenAPI ````yaml /api-reference/openapi.yaml get /bridge/api/v1/workspaces/{workspaceId}/users/lookup openapi: 3.1.0 info: title: Bridge API summary: Bridge API specification for chat system management. description: >- Bridge API specification including webhook receiver endpoints, Contact CRUD operations, and comprehensive chat system. This API includes: 1. Webhook Receiver API - for CRM clients to receive event notifications from Bridge 2. Contact CRUD API - for clients to manage contacts in Bridge 3. Conversations API - for managing conversations with flexible user identification and participant management 4. Messages API - for sending messages and files to a conversation 5. Files API - for managing files in a message 6. Custom attributes API - for consult custom attributes of an specific workspace **Multi-Tenant Architecture**: All operations are scoped to a specific workspace using workspaceId. termsOfService: https://www.sainapsis.com/legal/terms-of-service contact: name: Bridge Support url: https://app.bridge.new/ email: support@sainapsis.com license: name: MIT License url: https://spdx.org/licenses/MIT.html version: 1.0.0 servers: - url: https://api-connect-us.bridge.new description: Production server security: [] paths: /bridge/api/v1/workspaces/{workspaceId}/users/lookup: get: tags: - Internal Users API summary: Retrieve an internal user by an identifier description: >- Get a specific Bridge User by any of its identifiers within the workspace. `type=ID` returns the same user as GET /users/{userId}, which is the canonical URL for an internal user and the one to prefer when the id is what you hold. operationId: >- retrieve_internal_user_by_identifier_bridge_api_v1_workspaces__workspaceId__users_lookup_get parameters: - name: workspaceId in: path required: true schema: type: string format: uuid description: Unique identifier of the workspace (UUID v4). examples: - b6cf1c4a-2b1e-4e63-8f3e-0f9d1a2a1234 title: Workspaceid description: Unique identifier of the workspace (UUID v4). - name: type in: query required: true schema: $ref: '#/components/schemas/InternalParticipantIdentifierType' description: >- Identifier the value is given as. An internal user's cellphone is not one. description: >- Identifier the value is given as. An internal user's cellphone is not one. - name: value in: query required: true schema: type: string minLength: 1 maxLength: 320 description: >- The identifier itself, in the form named by `type`. An `EMAIL` has its domain lowercased, but its local part is matched exactly as sent. title: Value description: >- The identifier itself, in the form named by `type`. An `EMAIL` has its domain lowercased, but its local part is matched exactly as sent. examples: email: summary: An email address description: >- Send with `type=EMAIL`. `John.Doe@example.com` and `john.doe@example.com` are different identifiers and do not resolve to the same internal user. value: john.doe@example.com id: summary: The internal user id description: >- Send with `type=ID`. Returns exactly what `GET /users/{userId}` returns, which stays the canonical URL for an internal user. value: 4e362e2b-67b2-4a7e-a9df-e9ecf9141be8 responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/InternalUserResponse' '403': description: Forbidden content: application/json: examples: FORBIDDEN: value: title: Forbidden status: 403 code: BRIDGE_CORE_0301 schema: $ref: '#/components/schemas/Problem' '404': description: Not Found content: application/json: examples: WORKSPACE_NOT_FOUND: value: title: Workspace Not Found status: 404 code: BRIDGE_WORKSPACE_0001 INTERNAL_USER_NOT_FOUND: value: title: Internal User Not Found status: 404 code: BRIDGE_INTERNAL_0001 schema: $ref: '#/components/schemas/Problem' '422': description: Unprocessable Content content: application/json: examples: INVALID_FIELD_FORMAT: value: title: Invalid Field Format status: 422 code: BRIDGE_CORE_0101 schema: $ref: '#/components/schemas/Problem' '429': description: Too Many Requests content: application/json: schema: $ref: '#/components/schemas/Problem' examples: WORKSPACE_BUDGET_EXHAUSTED: value: title: Too Many Requests status: 429 code: BRIDGE_RATE_LIMIT_0001 security: - x-api-key: [] components: schemas: InternalParticipantIdentifierType: type: string enum: - ID - EMAIL title: InternalParticipantIdentifierType InternalUserResponse: properties: id: type: string title: Identifier description: Unique identifier for the internal user (UUID v4). examples: - b6cf1c4a-2b1e-4e63-8f3e-0f9d1a2a1234 firstName: anyOf: - type: string - type: 'null' title: First Name description: Internal user's first name. examples: - John - null lastName: anyOf: - type: string - type: 'null' title: Last Name description: Internal user's last name. examples: - Doe - null email: anyOf: - type: string - type: 'null' title: Email description: Internal user's email address. examples: - john.doe@example.com - null cellphone: anyOf: - type: string - type: 'null' title: Cellphone description: Internal user's cellphone number. examples: - '+14084029292' - null languageCode: anyOf: - $ref: '#/components/schemas/LanguageCode' - type: 'null' title: Language Code description: Language code of the internal user. examples: - EN - null status: type: string enum: - active - disabled title: Status description: >- 'active' when the internal user is live, 'disabled' when the user has been removed. examples: - active - disabled createdAt: type: string title: Created At description: Timestamp when the internal user was created. examples: - '2003-04-10T08:00:00.000Z' updatedAt: type: string title: Updated At description: Timestamp when the internal user was last updated. examples: - '2003-04-10T08:00:00.000Z' type: object required: - id - status - createdAt - updatedAt title: InternalUserResponse description: Response body for internal-user (human agent) read operations. Problem: properties: title: type: string title: Title description: Short, summary of the problem type. status: type: integer title: Status description: >- HTTP status code generated by the origin server for this occurrence of the problem. detail: anyOf: - type: string - type: 'null' title: Detail description: Explanation specific to this occurrence of the problem. instance: anyOf: - type: string - type: 'null' title: Instance description: >- A URI reference that identifies the specific occurrence of the problem. traceId: anyOf: - type: string - type: 'null' title: Traceid description: Trace ID for debugging purposes. code: anyOf: - type: string - type: 'null' title: Code description: >- Error code for identification, view the error codes page for more details. errors: anyOf: - items: additionalProperties: true type: object type: array - type: 'null' title: Errors description: List of error details. extra: anyOf: - additionalProperties: true type: object - type: 'null' title: Extra description: Extra information about the problem. type: object required: - title - status title: Problem description: Object representing a Problem response body. LanguageCode: type: string enum: - ES - EN - AF - SQ - AR - AZ - BN - BG - CA - ZH_CN - HR - CS - DA - NL - ET - FIL - FI - FR - KA - DE - EL - GU - HA - HE - HI - HU - ID - GA - IT - JA - KN - KK - RW_RW - KO - KY_KG - LO - LV - LT - MK - MS - ML - MR - NB - FA - PL - PT_BR - PA - RO - RU - SR - SK - SL - SW - SV - TA - TE - TH - TR - UK - UR - UZ - VI - ZU title: LanguageCode securitySchemes: x-api-key: type: apiKey description: Copy the API key as provided by the Bridge Console. in: header name: x-api-key ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.