# Instasent Docs

> Developer documentation for the Instasent APIs. Product API manages organizations, projects and audiences. Ingest API streams contacts and events. Transactional API sends SMS over HTTP and SMPP. Legacy API is kept alive for existing integrations. Each API has a machine-readable dump under /{api}/llms-full.txt.

## Getting Started

- [Introduction](https://docs.instasent.com/getting-started/introduction): Instasent is a customer messaging platform with four public APIs.
- [Create an account](https://docs.instasent.com/getting-started/create-an-account): Sign up for Instasent with a magic link, complete the onboarding wizard, and issue your first API token — all from the dashboard, no passwords involved..
- [Choose your API](https://docs.instasent.com/getting-started/choose-your-api): Decide exactly which Instasent API fits the job in front of you: Product, Ingest, Transactional or Legacy.

## Product API

- [Guide](https://docs.instasent.com/product-api/guide): The Product API is Instasent's primary management API: organizations, projects, data sources, unified audiences, events, segments, campaigns, automations and direct messaging, all under one token..
- [Quickstart](https://docs.instasent.com/product-api/quickstart): Find a contact in the unified audience, read their recent events and send a direct SMS — end to end in under five minutes..
- [Authentication](https://docs.instasent.com/product-api/authentication): The Product API authenticates each request with a bearer token carrying specific scopes.
- [Rate limits](https://docs.instasent.com/product-api/rate-limits): The Product API is rate-limited per organization and per endpoint class.
- [Errors](https://docs.instasent.com/product-api/errors): The Product API uses standard HTTP status codes.
- [Audience query filter](https://docs.instasent.com/product-api/audience-query-filter): Search and segment the unified audience with a structured JSON filter.
- [Audience event query filter](https://docs.instasent.com/product-api/audience-event-query-filter): Search and aggregate audience events with a structured JSON filter.
- [Webhooks](https://docs.instasent.com/product-api/webhooks): Webhooks for the Product API..
- [MCP](https://docs.instasent.com/product-api/mcp): Model Context Protocol server for the Product API..
- [API Reference](https://docs.instasent.com/product-api/reference): scaffolding
- [OpenAPI spec](https://docs.instasent.com/openapi/product.openapi.yaml): machine-readable spec for Product API.
- [Full docs dump](https://docs.instasent.com/product-api/llms-full.txt): every page under /product-api concatenated for LLM context.

## Ingest API

- [Guide](https://docs.instasent.com/ingest-api/guide): The Ingest API imports contacts and events into an Instasent project so every downstream surface — audiences, campaigns, analytics — sees the same source of truth..
- [Quickstart](https://docs.instasent.com/ingest-api/quickstart): Load a contact and record an event in under five minutes.
- [Authentication](https://docs.instasent.com/ingest-api/authentication): The Ingest API authenticates each request with a bearer token scoped to a datasource.
- [Rate limits](https://docs.instasent.com/ingest-api/rate-limits): Ingest traffic is rate-limited per datasource and per endpoint.
- [Errors](https://docs.instasent.com/ingest-api/errors): The Ingest API uses standard HTTP status codes plus a partial-success body for batched writes.
- [API Reference](https://docs.instasent.com/ingest-api/reference): scaffolding
- [OpenAPI spec](https://docs.instasent.com/openapi/ingest.openapi.yaml): machine-readable spec for Ingest API.
- [Full docs dump](https://docs.instasent.com/ingest-api/llms-full.txt): every page under /ingest-api concatenated for LLM context.

## Transactional API

- [Overview](https://docs.instasent.com/transactional-api/overview): The Transactional API is Instasent's SMS wholesale surface: single send, bulk send, delivery reports, inbound, HLR lookup, balance and pricing, over HTTP (REST) or SMPP.
- **HTTP**
  - [Quickstart](https://docs.instasent.com/transactional-api/http/quickstart): Send your first SMS over the Transactional API in under five minutes.
  - [Bulk sending](https://docs.instasent.com/transactional-api/http/bulk): Send many SMS in a single request via POST /sms/bulk — the Transactional API's throughput endpoint for campaigns, notification fan-outs and wholesale dispatch.
  - [Authentication](https://docs.instasent.com/transactional-api/http/authentication): The Transactional API authenticates each request with a bearer token.
  - [Rate limits](https://docs.instasent.com/transactional-api/http/rate-limits): Transactional HTTP traffic is rate-limited per organization and per endpoint.
  - [Errors](https://docs.instasent.com/transactional-api/http/errors): The Transactional HTTP API uses standard HTTP status codes.
  - [DLRs](https://docs.instasent.com/transactional-api/http/dlrs): Delivery reports (DLRs) are POSTed to a webhook URL configured per API token.
  - [API Reference](https://docs.instasent.com/transactional-api/http/reference): scaffolding
- **SMPP**
  - [Authentication](https://docs.instasent.com/transactional-api/smpp/authentication): The Transactional API over SMPP authenticates each session with a system_id and password carried on the bind PDU.
  - [Integration](https://docs.instasent.com/transactional-api/smpp/integration): Supported PDUs, submit_sm fields, message concatenation, DLRs over deliver_sm and inbound handling for the Transactional API over SMPP..
- **SDKs**
  - [Node.js](https://docs.instasent.com/transactional-api/sdks/node): Official Node.js client for the Instasent Transactional API.
  - [PHP](https://docs.instasent.com/transactional-api/sdks/php): Official PHP client for the Instasent Transactional API.
  - [Python](https://docs.instasent.com/transactional-api/sdks/python): Official Python client for the Instasent Transactional API.
  - [Ruby](https://docs.instasent.com/transactional-api/sdks/ruby): Official Ruby client for the Instasent Transactional API.
  - [Java](https://docs.instasent.com/transactional-api/sdks/java): Official Java client for the Instasent Transactional API.
- [OpenAPI spec](https://docs.instasent.com/openapi/transactional.openapi.yaml): machine-readable spec for Transactional API.
- [Full docs dump](https://docs.instasent.com/transactional-api/llms-full.txt): every page under /transactional-api concatenated for LLM context.

## Legacy API

- [Overview](https://docs.instasent.com/legacy-api/overview): The Legacy API is Instasent's first-generation SMS surface.
- [Authentication](https://docs.instasent.com/legacy-api/authentication): The Legacy API authenticates each request with a bearer token issued in the dashboard.
- [API Reference](https://docs.instasent.com/legacy-api/reference): scaffolding
- [OpenAPI spec](https://docs.instasent.com/openapi/legacy.openapi.yaml): machine-readable spec for Legacy API.
- [Full docs dump](https://docs.instasent.com/legacy-api/llms-full.txt): every page under /legacy-api concatenated for LLM context.

## Further reading

- [Query Filter](https://docs.instasent.com/further-reading/query-filter): Shared syntax for filtering, sorting, paginating and grouping results on index endpoints across every Instasent API.
- [Use with AI](https://docs.instasent.com/further-reading/use-with-ai): These docs are published as machine-readable artifacts alongside the HTML.