Update campaign lead

Updates one lead inside a campaign you own — its fields, send status, labels, or scheduled send time. The campaign-scoped counterpart to Update lead, which only reaches leads that aren't in a campaign.

Stablescope: write API KeyLearn about API scopes →

Field updates merge, they don't replace

Only the keys you send inside fields are changed — every other field on the lead keeps its value. Labels are the opposite: the labels array you send replaces the lead's current labels.

Flat shape also accepted

Instead of fields, you can send firstName, lastName, email, company, phone, keyword, and customFields at the top level — they're merged into fields the same way. Don't mix the two shapes in one request.

Request

Authorization	Bearer YOUR_API_KEY
Content-Type	application/json

Parameters

Field	Type	Required	Description
id	string	Required	Campaign ID.
leadId	string	Required	Lead ID (lead_...) from List campaign leads.
fields	object	Optional	Field values to set, e.g. { company: "Acme Corp" } — up to 100 entries, each value up to 2,000 characters.
status	enum	Optional	PENDING \| QUEUED \| DRAFTED \| SENT \| FAILED \| CANCELLED \| IGNORED.
labels	object[]	Optional	{ labelId, name, color }[] — up to 50; color must be a hex code like #7C3AED. Replaces the lead's current labels.
scheduledAt	string	Optional	ISO 8601 timestamp for when this lead's email should send.

curl -X PUT "https://api.stynar.com/v2/campaigns/cmp_abc123/leads/lead_1a2b3c" \
  -H "Authorization: Bearer esk_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"fields":{"company":"Acme Corp"},"labels":[{"labelId":"lbl_1","name":"Hot lead","color":"#7C3AED"}]}'

Response

✓ 200 OK

200 response

{
  "lead": {
    "leadId": "lead_1a2b3c",
    "campaignId": "cmp_abc123",
    "status": "PENDING",
    "fields": {
      "email": "jane@acme.com",
      "firstName": "Jane",
      "company": "Acme Corp"
    },
    "labels": [
      {
        "labelId": "lbl_1",
        "name": "Hot lead",
        "color": "#7C3AED"
      }
    ],
    "updatedAt": "2026-10-03T09:12:00.000Z"
  }
}

Response fields

Errors

Status	Code	Meaning
✕ 400 Bad Request	VALIDATION_FAILED	Empty body (nothing to update), an unknown status, or a malformed field.
✕ 404 Not Found	NOT_FOUND	Campaign or lead doesn't exist or isn't yours.
✕ 401 Unauthorized	UNAUTHORIZED	Missing, malformed, unknown, revoked, or expired key.
✕ 403 Forbidden	API_ACCESS_DISABLED	API access is turned off for your account.
✕ 403 Forbidden	INSUFFICIENT_SCOPE	The key doesn't have the scope this endpoint requires.
✕ 409 Conflict	CONFLICT	The action can't be applied to the resource's current state.
✕ 429 Too Many Requests	RATE_LIMIT_EXCEEDED	Per-minute or per-second limit hit.
✕ 429 Too Many Requests	QUOTA_EXCEEDED	Monthly quota exhausted.
✕ 500 Internal Server Error	INTERNAL_ERROR	Something broke on Stynar's end.

Full error reference →

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