---
title: "Add up to 500 people to a campaign"
method: POST
path: "/campaigns/{id}/leads"
tags: ["Campaigns"]
---

# Add up to 500 people to a campaign

`POST /campaigns/{id}/leads`

## Request

- Base URL: `https://mcp.senders.ai/api/v1`
- URL: `https://mcp.senders.ai/api/v1/campaigns/{id}/leads`
- Auth: HTTP bearer

Scope: leads:write. Active campaign: step 1 is scheduled immediately. People already known to the account are skipped with a reason (never moved or re-contacted). 2,000 per account per UTC day.

## Path parameters

- `id` integer, required

## Headers

- `Idempotency-Key` string, required

## Request body

- LeadsBody
  - `leads` LeadInput[], required
    - `email` string, email: Required for campaigns
    - `first_name` string
    - `last_name` string
    - `title` string
    - `organization` string
    - `linkedin_url` string
    - `timezone` string: IANA name, campaigns only
    - `custom_fields` object: Up to 50 keys ([A-Za-z0-9_]{1,64}), scalar values, 16 KB total

## Response `200`

OK

- EnrollResult
  - `data` object
    - `campaign_id` integer
    - `added` integer
    - `scheduled` integer
    - `skipped_count` integer
    - `skipped_reasons` object
    - `skipped` object[]
      - `email` string
      - `reason` 'already_in_campaign' | 'in_other_campaign' | 'previously_contacted' | 'previously_replied' | 'on_hold' | 'suppressed' | 'do_not_prospect' | 'personal_domain' | 'duplicate_in_request'
    - `note` string

## Other responses

- `400`: Invalid body or missing Idempotency-Key (bad_request, idempotency_key_required)
- `401`: Missing, wrong or revoked token
- `403`: Missing write permission, inactive account, or feature not enabled
- `404`: No such campaign on this account
- `409`: busy, conflict, idempotency_in_progress (retry) or a final conflict such as campaign_closed
- `413`: Body over 1 MB
- `415`: Body not JSON
- `422`: Idempotency-Key reused for a different request
- `429`: Rate or daily limit
- `503`: Writes paused because rate limiting is unavailable; retry after Retry-After

---

[API](https://skmtc.dev/senders/apis/senders-rest-api.md) · [All operations](https://skmtc.dev/senders/apis/senders-rest-api/llms.txt) · [OpenAPI document](https://skmtc.dev/senders/apis/senders-rest-api/revisions/3cd9960bc0af?raw)