> ## Documentation Index > Fetch the complete documentation index at: https://docs.fuseai.com/llms.txt > Use this file to discover all available pages before exploring further. # Start an async duplicate-contact scan (returns a jobId) > Starts an async scan of the workspace's saved contacts (the whole team's pool, Fuse and custom) for duplicates: contacts that match EXACTLY on every field in `matchFields`. The selection must carry at least one unique identifier (`linkedinUrl`, `email`, `phone`) or at least 3 profile fields (`fullName`, `jobTitle`, `industry`, `location`, `companyName`, `companyDomain`) — anything weaker would group unrelated people and is rejected. Async: 202 returns a `jobId`; poll `GET /business/contacts/dedupe-jobs/{jobId}` until `status` is `completed`, then read `scanResult.groups`. Each group carries a `mergePreview` (what the surviving contact will look like) so the result can be reviewed before anything is merged; scanning changes nothing and spends no credits. The result stores at most 200 groups (`truncated` is true when more were found — merge and scan again), and a group larger than 50 contacts is skipped as a too-weak selection (`skippedOversizedGroups` counts them). Rate limit: 120 requests per minute, 10,000 per day on the contacts bucket, which every /business/contacts endpoint shares. Errors: - `422` `VALIDATION_FAILED` — matchFields is missing, carries an unknown field, or fails the selection-strength rule. - `429` `RATE_LIMITED` — More than 120 requests per minute or 10,000 per day on the contacts bucket, which every /business/contacts endpoint shares; retry after Retry-After. - `500` `UNEXPECTED_ERROR` — The request could not be completed; quote request_id to support. Requires one of the following token scopes: contacts. ## OpenAPI ````yaml /openapi.json post /business/contacts/dedupe-scan openapi: 3.1.0 info: title: Fuse Business API version: 1.0.0 description: >- External API for lists, campaigns, prospect search and contacts. Authenticate with your API token as HTTP Basic. All paths are under /api/v1. servers: - url: https://api.tryfuse.ai/api/v1 description: Production security: - basicAuth: [] tags: - name: Lists - name: Custom columns - name: Smart columns - name: Exports - name: Campaigns - name: Knowledge hubs - name: Analytics - name: Website intent - name: Account - name: Prospect search - name: Campaign steps - name: Scheduled sends - name: Campaign templates - name: Agents - name: Research - name: Company search - name: Saved searches - name: Folders - name: Contacts paths: /business/contacts/dedupe-scan: post: tags: - Contacts summary: Start an async duplicate-contact scan (returns a jobId) description: >- Starts an async scan of the workspace's saved contacts (the whole team's pool, Fuse and custom) for duplicates: contacts that match EXACTLY on every field in `matchFields`. The selection must carry at least one unique identifier (`linkedinUrl`, `email`, `phone`) or at least 3 profile fields (`fullName`, `jobTitle`, `industry`, `location`, `companyName`, `companyDomain`) — anything weaker would group unrelated people and is rejected. Async: 202 returns a `jobId`; poll `GET /business/contacts/dedupe-jobs/{jobId}` until `status` is `completed`, then read `scanResult.groups`. Each group carries a `mergePreview` (what the surviving contact will look like) so the result can be reviewed before anything is merged; scanning changes nothing and spends no credits. The result stores at most 200 groups (`truncated` is true when more were found — merge and scan again), and a group larger than 50 contacts is skipped as a too-weak selection (`skippedOversizedGroups` counts them). Rate limit: 120 requests per minute, 10,000 per day on the contacts bucket, which every /business/contacts endpoint shares. Errors: - `422` `VALIDATION_FAILED` — matchFields is missing, carries an unknown field, or fails the selection-strength rule. - `429` `RATE_LIMITED` — More than 120 requests per minute or 10,000 per day on the contacts bucket, which every /business/contacts endpoint shares; retry after Retry-After. - `500` `UNEXPECTED_ERROR` — The request could not be completed; quote request_id to support. Requires one of the following token scopes: contacts. operationId: startDedupeScan requestBody: required: true content: application/json: schema: type: object properties: matchFields: type: array items: type: string enum: - linkedinUrl - email - phone - fullName - jobTitle - industry - location - companyName - companyDomain minItems: 1 maxItems: 9 description: >- Fields duplicates must match exactly on: any combination of linkedinUrl, email, phone, fullName, jobTitle, industry, location, companyName, companyDomain. The selection must include at least one unique identifier (linkedinUrl, email or phone) OR at least 3 of the profile fields — a weaker selection would group unrelated people and is rejected. required: - matchFields responses: '202': description: Success headers: RateLimit-Limit: schema: type: integer description: Requests permitted in the current window. RateLimit-Remaining: schema: type: integer description: Requests remaining in the current window. RateLimit-Reset: schema: type: integer description: Seconds until the current window resets. content: application/json: schema: type: object required: - jobId properties: jobId: type: string description: >- Id of the scan job; poll GET /business/contacts/dedupe-jobs/{jobId} and pass it to POST /business/contacts/dedupe-merge. example: jobId: 68a1f5209c41d20014b3eb11 '400': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '402': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '404': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '409': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '422': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' '500': description: Error content: application/json: schema: $ref: '#/components/schemas/Error' security: - basicAuth: [] components: schemas: Error: type: object properties: error: type: object properties: code: type: string message: type: string param: type: - string - 'null' doc_url: type: - string - 'null' request_id: type: - string - 'null' required: - code - message required: - error securitySchemes: basicAuth: type: http scheme: basic description: >- Your API token (`af_…`) as the Basic-auth username, with an empty password. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.