---
ref: tool:segment/send-batch
name: Send a batch of calls
company: company:segment
workflows: []
access: [api]
tags: [capability:track-product-usage, category:cdp, has:api]
docs: https://www.twilio.com/docs/segment/connections/sources/catalog/libraries/server/http-api#batch
updated: 2026-09-27
---

# Send a batch of calls

Sends up to 2,500 identify, group, track, page and screen calls to a source in one request.

Put each call in `batch[]` with its `type`. A request can be up to 500 KB and
each call up to 32 KB. Segment still answers 200 but drops the events when a
batch holds more than 2,500 of them, so split large imports. `SEGMENT_API_KEY`
holds the base64 of the source's write key followed by a colon.

## Set up

Use the first option your agent supports.

### API (official)

- Base URL: https://api.segment.io
- Endpoint: `POST /v1/batch`
- Auth: send the header `Authorization: Basic $SEGMENT_API_KEY`
- Get a key: https://www.twilio.com/docs/segment/connections/find-writekey
- Docs: https://www.twilio.com/docs/segment/connections/sources/catalog/libraries/server/http-api

Before doing anything else, make one read-only call to confirm access.

## Rules

- Ask the user before anything that sends messages, costs money, or changes data.
- Never print API keys.