Add up to 1,000 people. A person is identified by their phone number (all formats of one number collapse to it: +91 98765 43210, 919876543210, national + countryCode) or, without a phone, by email — someone already in the segment is updated instead of added twice.

Phone numbers must be E.164 or come with countryCode; numbers that are not possible for their country are rejected per item in invalid (the rest are still added). Members are linked to your existing contact with the same phone / email, so contact fields work in templates. A segment holds at most 200,000 people.

Security:

• The organisationId in the URL must match the organisation your JWT was issued for — requests for a different organisation fail with 401.
• Requires CRM_ADMIN, ACCOUNT_OWNER, or CRM_BOT role; other roles receive 403.