Warehouse API and webhooks for your own integrations
A warehouse system that cannot talk to the rest of your stack ends up as a second place to retype orders. NextStock has a documented REST API with a public OpenAPI specification, listed on the integrations page, plus webhooks and CSV import, so orders flow in and stock updates flow out without copy and paste.
Highlights
REST API v1
Create orders, read stock and work with warehouse records over a versioned REST API.
Public OpenAPI spec
Generate a client in your language of choice and see every endpoint and field before you write code.
Safe retries
Idempotency keys on create requests mean a retried call does not create a duplicate order.
Webhooks
Receive events when things change in the warehouse instead of polling for them.
Why warehouse integrations go wrong
Most integration problems are not about missing endpoints. They come from retries and gaps. A store sends an order, the network drops, the store sends it again, and now the warehouse has two orders. Or a stock sync runs every hour, and in that hour you sell units you no longer have.
A good warehouse API makes those failure modes hard to hit. Writes should be safe to repeat. Lists should page reliably even while new records arrive. Changes should be pushed to you instead of discovered on the next poll.
How the NextStock API works
The API is versioned as v1 and described by a public OpenAPI specification, so you can read it, test against it and generate typed clients.
- Authenticate with an API key issued in your organization.
- Send an Idempotency-Key header on create requests. Repeating the same request with the same key returns the original result instead of creating a second record.
- Page through lists with cursor pagination, which stays stable while new records are added.
- Subscribe to webhooks so your system hears about warehouse changes without polling.
- Use CSV import for bulk data that does not need a live connection.
Typical integration patterns
Most setups follow one of a few patterns. A store or order management system pushes sales orders into NextStock, where order allocation reserves stock and the floor picks and packs. An ERP pushes purchase orders or ASNs so receiving knows what to expect. A storefront or marketplace reads stock levels to keep listings honest.
Webhooks close the loop. Instead of polling every few minutes, your system receives an event when something changes and fetches what it needs. If you are deciding which system should own orders and which should own stock, WMS vs OMS walks through the split.
Connectors: what exists and what is planned
Native connectors for Shopify, WooCommerce, Salla and FleetRunnr are on the roadmap and not available yet. Until they ship, those platforms connect through the REST API, webhooks or CSV. A small middleware service or an integration platform can map store orders to the NextStock order format.
For teams without developers, CSV import of orders through bulk import and export is a practical bridge. It is staged, validated and previewed before anything is committed.
Building a reliable integration
A few habits prevent most production incidents.
- Use a stable idempotency key, such as your store's order number, not a random value per attempt.
- Treat webhook deliveries as signals and make your receiver safe to run twice for the same event, as any webhook can arrive more than once.
- Store the NextStock ID next to your own ID so updates always hit the right record.
- Give each integration its own API key, so you can replace one without breaking the others.
- Test against the OpenAPI specification before going live.
Built for
Frequently asked questions
Short, direct answers to the questions warehouse teams ask most.
Is the NextStock API documentation public?
Yes. The REST API v1 is described by a public OpenAPI specification. You can read it before signing up, import it into an API client to explore requests, or generate a typed client library. It lists every endpoint, field and response shape, so your developers can estimate an integration before committing to it.
Does NextStock integrate with Shopify, WooCommerce or Salla?
Native connectors for Shopify, WooCommerce, Salla and FleetRunnr are planned but not available yet. Today you can connect those platforms through the REST API and webhooks, usually with a small service or an integration platform in between, or by importing order CSV files. When the native connectors ship, they will use the same order and stock model.
What happens if my system sends the same order twice?
If both requests carry the same Idempotency-Key header, NextStock treats the second as a repeat and returns the original result instead of creating a duplicate order. This is why a stable key matters: use something tied to the order itself, like the store's order number, so a retry after a timeout is always recognized.
Can a 3PL give API access to its clients?
API keys are issued at the organization level, not per client, so a key can reach every client's data in your account. For that reason, a 3PL should run client integrations itself, or through a trusted middleware service, rather than hand a key to a client. A dedicated client portal for 3PL clients is planned but not available yet.
A little more order. A lot more possibility.
Make space for a better way to run your warehouse.