The API your
agents call
before writing
to a calendar.
When sales-bot, cal.ai, recruiting-bot, and your focus-time agent all want the same Tuesday 9 AM — Openavail picks one (by your rules, not last-write-wins) and writes the receipt.
◇ one slot · five agents · one winner · five audit rows
One POST.
One decision.
One audit row.
No client SDK required. If your agent speaks HTTP, it speaks Openavail. MCP server lands in v1.5.
▸ REQUEST
curl -X POST https://api.openavail.com/v1/availability \
-H "Authorization: Bearer ak_01HXYZ..." \
-H "Idempotency-Key: lead-12345-attempt-1" \
-d '{
"agent_id": "sales-bot",
"meeting_class": "external_customer_call",
"owner": "[email protected]",
"slot": {
"start": "2026-06-04T09:00:00Z",
"end": "2026-06-04T09:30:00Z"
}
}'◂ RESPONSE
{
"decision": "reject",
"reason": "sacred_meeting_conflict",
"conflicts": [
{
"booking_id": "bk_ceo_1on1_q2",
"class": "internal_1_on_1",
"priority": 100
}
],
"audit_id": "dec_8XnPq7r3",
"arbiter_p99_ms": 188
}Three primitives.
That's the whole product.
Ask before you book
Every agent points at one URL — Openavail. Before it writes to Google or Outlook, it asks us: "is this slot really free?" We answer yes, no, or try-this-instead — against rules you set.
Priority, not chaos
When two agents want the same slot in the same millisecond, Openavail picks one — by the rules you wrote, not by whoever was faster to commit. Deterministic. Same inputs always produce the same winner.
A receipt for every decision
Every accept, reject, preempt, and counter-propose is an audit row. Which agent. Which key. Which rule fired. Queryable forever, exportable as JSONL.
Many agents in.
One decision out.
Your agents stop talking to Google directly. They talk to Openavail. We hold the only real token — and own the only writes to the calendar.
"Which agent
booked over my
CEO 1:1?"
Five-second answer. By agent identity, by API key, by rule fired, by calendar owner. Exportable as JSONL. Indexed forever. The artifact your security team asks for in week one of any procurement review.
AUDIT_ROW · SAMPLE
GOOGLE WORKSPACE REQUIRED · MICROSOFT 365 WHEN A CUSTOMER ASKS · PRICING SUBJECT TO CHANGE DURING PUBLIC BETA