Update a lead
Update mutable fields on a lead
Only the fields you provide are updated. custom_fields uses merge patch
semantics: existing keys are preserved, the keys you send are added/updated,
and keys explicitly set to null are removed.
Updatable fields: first_name, last_name, company, custom_fields.
Example
import requests
campaign_id = "550e8400-e29b-41d4-a716-446655440000"
lead_id = "650e8400-e29b-41d4-a716-446655440000"
response = requests.put(
f"https://api.coldsend.io/api/public/v1/campaigns/{campaign_id}/leads/{lead_id}",
headers={"X-API-Key": "your-api-key"},
json={
"first_name": "Jane",
"custom_fields": {"industry": "SaaS", "old_field": None} # removes old_field
}
)
print(response.json())
Authorizations
API key with format cs_live_xxx
Body
Response
Lead updated successfully
Response schema for individual lead.
Lead ID
Batch ID this lead belongs to
Lead email address
First name
Last name
Company name
Lead status
Last contact timestamp
Email opened timestamp
Reply timestamp
Lead creation timestamp
Custom lead fields
Current sequence step
Whether email was opened
Whether lead replied
Whether lead unsubscribed
Delivery status from Azure (latest email)
Latest INTENT-group thread tag across the lead's threads (rollup)

