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Use this when you have a list of business emails and need to know who each one belongs to — the person, their crustdata_person_id, and basic profile — at bulk scale. Submit a job, then poll or receive a webhook when it finishes. You pay only for the emails that resolve to a person.
Identify vs Enrich. Identify answers “who is this email?” — it returns the matched person’s crustdata_person_id and basic_profile (name, headline, title). If you also need contact data, full employment history, or company IDs per role, use Person Enrich (which also supports reverse lookup by business email).

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How it works

Reverse identify is an asynchronous, two-call flow — you submit a job, then fetch the results once it finishes:
1

Submit your emails

POST /batch/person/identify with your list of business_emails (or professional_network_profile_urls). You get a batch_id back immediately.
2

Poll, or wait for a webhook

GET /batch/{batch_id} to check the job status — or pass a webhook_url on submit and we call you when it finishes.
3

Download the results

Once status is completed, the status response includes a download_url: a gzipped JSONL file with one record per input, valid for 5 days.
Emails already known to Crustdata resolve in seconds. Emails that require real-time retrieval take longer, which is why this endpoint is asynchronous.
Replace YOUR_API_KEY in each example with your actual API key. All requests require the x-api-version: 2025-11-01 header.
Pricing: 1 credit per email that resolves to a person — unmatched emails are free. See Pricing for details. Limits: up to 300 identifiers per submission, and up to 5 active batch jobs per user at a time.

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1. Submit your emails

Send your emails in business_emails. The response returns a batch_id immediately — the job runs asynchronously. 
curl --request POST \
  --url https://api.crustdata.com/batch/person/identify \
  --header 'authorization: Bearer YOUR_API_KEY' \
  --header 'content-type: application/json' \
  --header 'x-api-version: 2025-11-01' \
  --data '{
    "business_emails": [
      "abhilash@crustdata.com",
      "ankit.harbhajanka@aequs.com"
    ]
  }'
You can submit professional_network_profile_urls instead of business_emails to resolve profile URLs to their crustdata_person_id. Submit exactly one identifier type per job. To be notified when the job finishes instead of polling, include a webhook_url in the request body.

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2. Get the results

Poll the status_url (or GET /batch/{batch_id}). While the job runs, status is pending or processing. When it is completed, the response includes a download_url. 
curl --request GET \
  --url https://api.crustdata.com/batch/61f537fc-e93d-4912-8d00-0ece6c7ecf9f \
  --header 'authorization: Bearer YOUR_API_KEY' \
  --header 'x-api-version: 2025-11-01'
The download_url points to gzipped JSONL (.jsonl.gz) with one record per submitted identifier. The link is valid for 5 days.

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Result format

Each line is one record for an input identifier: 
{
  "matched_on": "abhilash@crustdata.com",
  "match_type": "business_email",
  "matches": [
    {
      "confidence_score": 1.0,
      "person_data": {
        "crustdata_person_id": 1068035,
        "basic_profile": {
          "name": "Abhilash Chowdhary",
          "headline": "Co-founder at Crustdata (YC F24) | Real-time B2B data for AI agents",
          "current_title": "Co-Founder & CEO",
          "summary": "Love building things...",
          "languages": ["English", "Hindi"],
          "last_updated": "2026-06-22T00:11:06Z",
          "location": null
        },
        "updated_at": "2026-06-22T00:11:06Z"
      }
    }
  ]
}
An email with no match returns an empty matches array (and is not billed): 
{ "matched_on": "nobody@unknown-domain.com", "match_type": "business_email", "matches": [] }

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Request parameters

ParameterTypeRequiredDescription
business_emailsstring[]One identifier ofBusiness emails to reverse-lookup. Max 300 per submission.
professional_network_profile_urlsstring[]One identifier ofProfile URLs to resolve to a crustdata_person_id. Max 300 per submission.
webhook_urlstringNoURL to call when the job finishes, instead of polling.
Submit exactly one identifier type per job — either business_emails or professional_network_profile_urls, not both.

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Response fields

FieldDescription
matched_onThe input value this record resolved (the email or profile URL you submitted).
match_typebusiness_email or professional_network_profile_url.
matchesArray of matches. Empty when nothing resolved.
matches[].confidence_scoreMatch confidence, 0–1.
matches[].person_datacrustdata_person_id, basic_profile, and updated_at for the matched person.

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Job lifecycle

StatusMeaning
pendingJob accepted, not yet started.
processingJob is running.
completedJob finished — download_url is available.
failedJob failed. Nothing was billed.

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Errors

StatusMeaning
400Invalid request — missing identifier, both identifier types, or too many values.
401Invalid or missing API key.
403Permission denied or insufficient credits.
429Too many active batch jobs (max 5 per user).
500Internal server error. Retry with exponential backoff.

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API reference summary

DetailValue
SubmitPOST /batch/person/identify
PollGET /batch/{batch_id}
AuthBearer token + x-api-version: 2025-11-01
RequestOne of business_emails or professional_network_profile_urls (max 300). Optional: webhook_url.
ResponseSubmit returns batch_id + status; poll returns status and a download_url when complete.
OutputGzipped JSONL, one record per identifier, download link valid 5 days.
Billing1 credit per matched person; unmatched identifiers are free.
Errors400, 401, 403, 429, 500
For credit pricing, see Pricing. For throughput guidance, see Rate limits.

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What to do next

  • Need contact data or full employment history? Use Person Enrich — it reverse-looks-up by business email and returns the full profile, including each role’s crustdata_company_id.
  • Enrich contact info in bulk — Batch Contact Enrich returns emails and phone numbers for a list of profile URLs.
  • Find people first — use Person Search to build the list to identify.