> ## Documentation Index > Fetch the complete documentation index at: https://docs.upsolve.ai/llms.txt > Use this file to discover all available pages before exploring further. # API Connectors > Connect your product's REST API from its OpenAPI spec, so the agent and rules can look things up and make changes in it, for each user's own account. > [!NOTE] > > API connectors are a **Beta** feature. Your database tells the agent what happened. Your product's API lets it **do** something about it: flag a transaction, update a record, open a ticket. An **API connector** turns the endpoints of your REST API into tools the agent can call in chat, and that [rules](https://docs.upsolve.ai/ai-agent-builder/interact/rules-and-actions.md) can call as their action. You add it from your API's OpenAPI spec and approve, endpoint by endpoint, what the agent may call. A change from chat, or from a rule someone sends by hand, waits for that person to confirm it. Scheduled rules and alerts make their changes automatically once they're switched on, without asking each time. Every change is recorded in [API activity](https://docs.upsolve.ai/ai-agent-builder/api-activity.md). ![Project settings, Connectors tab: the MCP servers section above the APIs section, with its Add API button](https://mintcdn.com/upsolve/Nurc8hPkBODmwDS1/images/ai-agent-builder/workspaces/api-connectors.png?fit=max\&auto=format\&n=Nurc8hPkBODmwDS1\&q=85\&s=da747f3db120077f4d02661df6f7d23b) ## Add an API API connectors belong to the project, so every workspace in it can use them. 1. Open **Project settings → Connectors** and, in the **APIs** section, click **Add API**. 2. **Spec**: choose **From a URL** or **Upload a file** (.json, .yaml or .yml, up to 2 MB), then click **Read spec**. Upsolve shows the spec's title, its version and how many endpoints it found. It reads OpenAPI 3.0 and 3.1; a Swagger 2.0 spec is refused with a message saying so. 3. **Who is calling**: give the API a **Name**, check the **Base URL**, and optionally say **When should the agent use this?** Then choose how Upsolve calls the API for each user (below). 4. **Endpoints**: approve the endpoints the agent may call (below), then **Save connection**. For **As the signed-in user**, a fourth step, **Check**, confirms your API accepts Upsolve's token before you save. ![The Add an API dialog on its first step, Spec, with From a URL and Upload a file, the OpenAPI spec field and Read spec](https://mintcdn.com/upsolve/Nurc8hPkBODmwDS1/images/ai-agent-builder/workspaces/api-connectors-add.png?fit=max\&auto=format\&n=Nurc8hPkBODmwDS1\&q=85\&s=233a1bed88081c16218a2896e407ba51) ### How Upsolve calls your API for each user | Option | How it works | | - | - | | **As the signed-in user** | Upsolve sends a short-lived token naming the user, and your API checks it. Works for your embedded users. | | **With one API key** | Every call uses one key. Add a **binding** to tie each call to the user's own account, or let each person add their own key. | | **Each person signs in** | Each user connects their own account once, with OAuth. | | **Your backend hands out tokens** | Your endpoint returns a short-lived token for each user. | | **No authentication** | For a public API. | A **binding** fills a header, query or path parameter from one of the user's or organization's properties, the ones you send when you sign a user in. The model can never set it, so each user only ever reaches their own account. [Let Upsolve act as your users](https://docs.upsolve.ai/act-as-your-users.md) explains each option and binding in detail. ### Approve endpoints Every endpoint starts unapproved, and the agent can only call the ones you approve (up to 200). * Each endpoint is marked **Read** or **Write**. GET and HEAD start as reads; everything else starts as a write. Change the marking if your API differs. * **Select all reads** approves every read at once. Writes are never approved for you: approve a write only if you'd let the agent and your rules make that change. * With bindings, an endpoint that doesn't take the bound parameter is hidden from end users unless you mark it **Global** (available to everyone). * Endpoints Upsolve can't call (for example, one whose request body isn't JSON) say why and can't be approved. ## Test the connection Open the API from the list and use the test panel: pick a read **Endpoint to call**, who to **Test as**, and any **Arguments**. It calls the endpoint once and shows the status and time (for example *Connected · 200 in 182 ms*). Nothing is saved. ## Keep it up to date Click the API in the list to open it. From there: * **Re-import spec** when your API changes. **Compare with current** shows what was **Added**, **Removed** and **Changed**; **Apply** takes it. Your approvals and Read/Write markings are kept, and an approved tool is never renamed, so the prompts and rules that use it keep working. * **Replace key** to rotate a server key. * **Delete** to remove the API from the project. ## How the agent uses it In a conversation, the agent calls approved **reads** as it needs them, to look things up in your product. A **write** is never sent by the agent on its own. The agent prepares the request and shows it as a card, and nothing happens until the person clicks **Confirm**. **Cancel** drops it. A request that isn't confirmed within 30 minutes expires, and if anything about it changed since it was shown, nothing is sent. ## How rules use it A rule's action can be any approved **write**, and its condition can look things up with approved **reads**. A scheduled rule or an alert calls the API as the rule's owner; a button calls it as the person who pressed it, with their own credentials. A write someone sends by hand (a button press, a test or a retry) waits for them to confirm it. A scheduled rule or an alert sends its writes without asking, once its owner switches it on, so approve a write only for rules you'd trust to run on their own. Writes are never retried automatically. See [Rules & Actions](https://docs.upsolve.ai/ai-agent-builder/interact/rules-and-actions.md). ## Next steps > [card] [Let Upsolve act as your users](https://docs.upsolve.ai/act-as-your-users.md) > > Each way of authenticating, and how bindings work. > [card] [API activity](https://docs.upsolve.ai/ai-agent-builder/api-activity.md) > > Every write the agent and your rules sent. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.