---
ref: tool:heyreach/send-message
name: Send a message
company: company:heyreach
workflows: [workflow:outbound-demo-engine]
access: [api]
tags: [capability:send-linkedin-messages, category:sales-engagement, has:api]
docs: https://documenter.getpostman.com/view/23808049/2sA2xb5F75
updated: 2026-09-28
---

# Send a message

Sends a LinkedIn message into an existing conversation from one of the workspace's LinkedIn sender accounts.

Note: Sends a real LinkedIn message: confirm the text first. It takes a conversation id and the sender account id that owns the conversation; it replies to existing conversations rather than starting new ones.

## Set up

Use the first option your agent supports.

### API (official)

- Base URL: https://api.heyreach.io
- Endpoint: `POST /api/public/inbox/SendMessage`
- Auth: send the header `X-API-KEY: $HEYREACH_API_KEY`
- Docs: https://documenter.getpostman.com/view/23808049/2sA2xb5F75

Note: Create the key in the HeyReach app under Settings, API keys. Every request counts toward one workspace limit of 300 requests per minute, and read endpoints use POST with a JSON body of filters.

Before anything else, confirm access with the cheapest read-only call, like a list or a search. Never send or change anything to test access.

## Rules

- Ask the user before anything that sends messages, costs money, or changes data, and say how many records it touches. One approval covers a batch the user has seen.
- Never print API keys.