inFlow Inventory API: which plans include it, what it exposes and its limits

Does inFlow Inventory have an API?

Yes, inFlow Inventory has a public REST API that reads and writes JSON, plus an MCP server for AI agents. The pricing page lists inFlow API and MCP as a $49 a month add-on on the Lite and Core plans and as included on Pro and Max, as read on 3 October 2026. The API documentation adds that an inFlow trial account can also generate a key, so you can test before paying.

So the cheapest paid route to the API is Lite plus the add-on, $148 a month on annual billing.

What the inFlow API exposes

The published specification groups its endpoints by record type. They cover the same objects staff work with in the app:

• Catalog: products, product groups, categories, pricing schemes, custom fields
• Orders: sales orders, purchase orders, manufacturing orders
• Stock: stock adjustments, stock transfers, stock counts, lot numbers, locations, product cost adjustments, Stockroom scans
• Contacts: customers, vendors, team members
• Settings: tax codes, taxing schemes, payment terms, currencies, adjustment reasons
• Output: reports and webhooks

The help center gives two typical uses: building custom reports and connecting software that inFlow does not integrate with, such as pulling customers from a CRM or sending orders to a shipping service.

How access works, per the official documentation

1. Subscribe to a plan that includes the API, add the add-on from the Account page, or start a trial.
2. As an administrator, open the Integrations page in inFlow and select Add new API key. Give it a name.
3. Copy the key and the companyId shown beside it. The key grants access until revoked, so store it like a password.
4. Send requests to the base URL at cloudapi.inflowinventory.com over HTTPS with the key as a Bearer token, a JSON content type and an Accept header that names the API version.
5. Use GET to read. Writes typically use PUT, which inserts or updates depending on whether the record's GUID already exists.

Reads return 20 results by default. A count parameter raises that, and an include parameter pulls related data. For example, a products request can include cost, default price, vendor items and inventory lines, which returns quantity on hand by location in one call.

Limits to design around

• Rate limit: 60 requests a minute, with a burst of up to 300 in one minute from unused allowance. Beyond that the API returns a 429 status. The docs recommend retrying with exponential backoff.
• No browser calls: the API does not support CORS, so requests must come from a server or script, not front-end code.
• Negative stock: picks that would push a location below zero fail with a 422 error unless you send an override header.
• Versioning: the version is set in the Accept header. The vendor says it emails account administrators before breaking changes and does not guarantee stability.
• Support: the support team cannot help with specific API questions, though it can forward them to developers.

A worked example of the rate limit: syncing 1,000 products one request each takes about 12 minutes after the first 300. Fetching 50 per page takes 20 requests and fits in the first minute.

The MCP server for AI agents

The same key works with inFlow's MCP server, which the documentation says exposes all public API operations as tools for AI assistants. The docs include configuration examples for Claude Desktop, Claude Code and Cursor. In practice this lets an assistant look up stock or draft an order in plain language. Treat it like any write-capable integration: use a separate named key and revoke it when testing ends.

What to use if you do not want to pay for or build on the API

If you only need to move records between inFlow and another app, Zapier is the no-code route. inFlow's Zapier connection has triggers for new or updated orders, products, customers and stock movements, and actions that create or update them. The native connections for Shopify, QuickBooks Online and Xero also need no API work. The integrations overview lists them all.

The API is worth the add-on when you need bulk reads for reporting or logic Zapier cannot express. If API access on an entry plan with no extra fee is the deciding factor, Katana lists API access on its free plan, limited to 30 SKUs. See the alternatives comparison and decide where each system's responsibility ends with the integration boundaries guide.