Assign a key card in 60 seconds
One Access Grant creates the credential. The last step is a call: pass the card number of a card the system already knows, and Seam attaches the credential to it.
Build it with your AI agent
Install the Seam plugin and your coding agent picks up three integration skills: Reservation Automations, Access Grants and Access Codes. It then writes the calls the way we would. Paste the prompt below and let it build.
1. Install the plugin
The Claude Code install also adds our documentation MCP server, so the agent can look up endpoints and device capabilities while it works. Cursor, Codex and other agents get the skills through npx skills add and can add the MCP server there separately.
2. Paste this prompt
How it works
Connect the lock and confirm support
Your user links their lock or access system account through Seam Connect Webview. Seam returns the doors behind it as devices and entrances. There is no device flag for assigned plastic cards: Seam publishes eight boolean capability flags and this is not one of them. Check the device's capabilities_supported array, or ask for { mode: "card" } in requested_access_methods and handle what Seam reports back.
Create an Access Grant
Name the person, the doors and the window, then ask for a key card in requested_access_methods. Seam works out how to satisfy that on the specific hardware, so the call is the same for a battery deadbolt and a wired reader. Swap acs_entrance_ids for space_ids to cover a group of doors, or device_ids when the door is a standalone lock. The credential's schedule ends at ends_at. Deleting the grant requests removal of its credentials from the connected device or access system.
Assign the registered card
List the access methods and read is_assignment_required. Call /access_methods/assign_card with the access method and the card_number printed on, or stored for, the card. is_issued flips to true once the system accepts the assignment, and the card opens the doors on the grant from starts_at.
Frequently asked questions
Which smart locks support assigned plastic cards?
Seam supports assigned plastic cards on 54 smart lock models from 1 manufacturer, including Salto. The table on this page comes from Seam's device database, and each model links to its own page with the per-system status and any hardware requirements.
How do I check whether a system can assign a card for a door?
Not with a device flag. can_assign_plastic_cards is a device database capability, not one of the eight booleans on the API's device object. Read capabilities_supported, or request { mode: "card" } on the Access Grant and read is_assignment_required on the access method.
Do I need a card encoder?
No. Assignment attaches the credential to a card the access system has already registered. Systems that write blank cards need an encoder; that is the plastic card encoding page.
Where does the card number come from?
From the access system. Cards are registered there first, usually by scanning them in the system's own software, and the number Seam expects is the one the system reports for the card.
Can the same card open several doors?
Yes. Put every entrance on the Access Grant, or pass a space that covers them, and the card is assigned for all of them at once. Adding a door later updates the credential.
What happens to a card when a stay or membership ends?
The credential expires with the grant, so the card stops opening doors at ends_at whether or not it comes back to the desk. Revoking early is a deletion, not a trip to the lock.
Related
- Implement key card assignmentIssue a card credential and attach it to a registered card by its card number.
- Every smart lock capabilityAll capability pages side by side, with live model, brand and system counts.
- Features per industryOne table per industry: each system's status for every capability, from remote unlock to key cards.
- Smart locks that support online access codesEvery model, with the status of each system that issues online access codes.
- Smart locks that support mobile keysEvery model, with the status of each system that issues mobile keys.
- Smart locks that support encoded plastic cardsEvery model, with the status of each system that issues encoded plastic cards.
- Smart locks that support remote unlockEvery model, with the status of each system that supports remote unlock.
- Smart locks that support remote lockEvery model, with the status of each system that supports remote lock.
- Smart locks that support offline access codesEvery model, with the status of each system that issues offline access codes.
- Every device and system Seam supportsSearch the whole device database by brand, device type and capability.
- Access control systemsThe wired systems behind the entrances in these grants: Salto, dormakaba, Brivo, ASSA ABLOY and more.
- Smart lock API overviewHow Seam's smart lock API works, from device connection to access automation.