SuperSaaS slots MCP server
This is a read-only MCP server that reports which slots are free on public SuperSaaS schedules without needing an account or API key.
find_available_slotsis the only tool: given a SuperSaaS/schedule/URL (or a business page linking to one), afrom_date, and athrough_date, it lists available slots for up to 366 days.Resource schedules (appointments): returns
unit: "slot"withduration_minutesand start/end wall-clock times.Date-only schedules (rentals): returns
unit: "night"withcheck_in/check_out, per-nightslots, plus mergedstaysranges.Capacity schedules (classes): returns
unit: "class"with per-classid,title,location,capacity,booked,waiting, andavailableseats.Options: cap output with
max_results(default 500, max 2000); setrespect_booking_windowtofalseto see historical data.URL flexibility: accepts
supersaas.nl,.com,.co.ukwithwww.,m., ord.hosts, and can scan a business page (including its JS files) to find the linked schedule, reportinglinked_from.Errors are descriptive: covers resource-selection needed, multiple schedules linked, login-protected, service schedules, multi-day units, missing start-time grids, and other unsupported rules.
Read-only and credential-free: never books or changes anything; only reads pages an anonymous browser can load.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@SuperSaaS slots MCP serverFind free slots for https://www.supersaas.nl/schedule/downthehatch/SLEEP 2026-10-19 to 2026-10-25"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
SuperSaaS slots MCP server
A read-only MCP server that reports which slots are free on a public SuperSaaS schedule. It covers intraday appointments, date-only schedules such as nightly rentals, and capacity schedules with seats per class. Give it a SuperSaaS schedule URL, or a business page that links to one, such as https://www.down-the-hatch.nl/reserveren/. No account or API key is needed.
Not the official SuperSaaS MCP server. SuperSaaS offers its own server at
https://www.supersaas.com/mcp, which authenticates as your account — via OAuth or a per-account bearer token — and can read and change anything the account can: bookings, users, prices, credit balances. Use that one when the goal is managing your own schedules with an AI assistant. This package answers a different question: what is available on someone else's public schedule, or on your own as a visitor sees it, without credentials and without touching anything. It reads only pages an anonymous browser can already load, never books, and has no account of any kind. Pick by which side of the counter you are on: SuperSaaS's server is the merchant's till, this one is the window display.
Licensed under the MIT License. How the schedule data is read is documented in INTERNALS.md.
Install
After publication, use Python 3.10+:
pip install supersaas-slots-mcpFor local development from the project directory:
python3 -m venv .venv
.venv/bin/python -m pip install -e .Dependencies are declared in pyproject.toml; FastMCP is pinned to version 4.0.10. Both supersaas-slots and supersaas-slots-mcp start the server.
Related MCP server: OpenSlot MCP
Connect
Configure a stdio MCP server in your MCP client:
{
"mcpServers": {
"supersaas-slots": {
"command": "/absolute/path/to/supersaas-mcp/.venv/bin/supersaas-slots"
}
}
}Replace the command path with the absolute path to your project directory. The client must allow this local process to make HTTPS requests to www.supersaas.nl, www.supersaas.com and www.supersaas.co.uk.
Or run it from PyPI with uvx:
{
"mcpServers": {
"supersaas-slots": {
"command": "uvx",
"args": ["supersaas-slots-mcp"]
}
}
}Tool
find_available_slots
{
"schedule_url": "https://www.supersaas.nl/schedule/downthehatch/SLEEP",
"from_date": "2026-10-19",
"through_date": "2026-10-25"
}Parameter | Default | Notes |
| required | A SuperSaaS |
| required |
|
| required |
|
|
| Caps the returned |
|
| Apply the schedule's minimum and maximum advance-booking limits. Set |
schedule_url may be a business page instead. The server scans it for a link to a SuperSaaS schedule, follows it, and reports the origin as linked_from. If the HTML names none — single-page sites keep the link in a bundled script — it also scans the page's own JS files, limited to the same origin and to the first ten scripts.
Response
{
"schedule_url": "https://www.supersaas.nl/schedule/downthehatch/SLEEP",
"from_date": "2026-10-19",
"through_date": "2026-10-25",
"time_basis": "schedule wall time; epoch values interpreted as UTC",
"unit": "slot",
"duration_minutes": 180,
"count": 1,
"truncated": false,
"slots": [{ "start": "2026-10-22 09:30", "end": "2026-10-22 12:30" }]
}Times are schedule wall-clock strings, YYYY-MM-DD HH:MM. truncated describes slots only, so compare it against count before treating a list as complete. Data is re-fetched on every call, so results change as other people book.
unit is slot, night, or class. Appointment schedules return slot with duration_minutes set to the appointment length. Date-only schedules such as rentals return night and add three fields:
{
"unit": "night",
"duration_minutes": 1440,
"check_in": "14:00",
"check_out": "12:00",
"slots": [{ "start": "2026-10-05 14:00", "end": "2026-10-06 12:00" }],
"stays": [{ "start": "2026-10-05", "end": "2026-10-10", "nights": 5 }]
}Each slots entry is one night, from check-in on a date to check-out on the next; duration_minutes is the nominal 1440-minute night. stays merges consecutive free nights into the ranges you can actually book, so four adjacent nights become one four-night stay. Use slots when pricing per night and stays when offering a date range to the customer.
Capacity schedules, such as Jazzercise, return unit: "class" and one entry per class with an ordinary seat available:
{
"unit": "class",
"slots": [{
"id": 101,
"start": "2026-10-01 19:00",
"end": "2026-10-01 20:00",
"title": "CardioSculpt",
"location": "Village Hall",
"capacity": 40,
"booked": 32,
"waiting": 0,
"available": 8
}]
}The class id is SuperSaaS's slot ID. A class with unlimited capacity has null for capacity and available. SuperSaaS includes waiting-list places in booked, so available is capacity - booked + waiting. Classes without an ordinary seat are excluded, even when the schedule offers a waiting list. Class lengths can vary, so there is no top-level duration_minutes in this mode.
Errors
Every error names a cause, and most have a remedy:
Error | What to do |
Page asks the visitor to pick a resource | Pass one resource URL, such as |
Page links to several schedules | The message lists them; pass the intended one directly. |
Schedule is kept behind a login | Nothing to do — the schedule is not public. |
Capacity schedule publishes no public slots | The schedule does not expose class data without a login. |
This is a service schedule | A catalogue of services booked across shared staff. Nothing to do. |
Schedule declares no start-time grid | Visitors pick their own start and end times, so there is no fixed grid. Nothing to do. |
Schedule books in multi-day units | A two-day-or-more product. Nothing to do. |
Schedule publishes opening hours but no start times | Nothing to do — slots are generated per request. |
URL is not a public SuperSaaS HTTPS page | Use |
Scope
Supported: public resource schedules with a single resource, fixed appointment duration, weekly opening hours with per-day exceptions and blocked ranges, booked appointments, buffer time, advance-booking limits, and both slot and night units. Public capacity schedules list classes with available seats, including each class's title, location, capacity, booked and waiting counts, and remaining seats.
SuperSaaS offers three schedule types; service schedules are reported as unsupported. Also not modeled: recurring rules, per-user limits, minimum-stay rules, and payment-dependent availability. An available slot is a calculated candidate, not a booking guarantee — the booking page remains authoritative at reservation time.
Development
.venv/bin/python -m unittest -v test_supersaas_mcp.py
.venv/bin/python check_release.pyThe tests run offline against saved copies of three real resource schedules and a Jazzercise capacity response, so they do not drift as customers book. See INTERNALS.md for what each fixture pins.
Release
Releases use PyPI Trusted Publishing and MCP Registry GitHub OIDC. Before the first release:
Create a
pypienvironment in this GitHub repository and allow deployment from version tags. In PyPI, register a pending trusted publisher for ownerRichieB2B, repositorysupersaas-slots-mcp, workflowrelease.yml, and environmentpypi. The PyPI project does not need to exist yet.Create an
mcp-registryGitHub environment and allow deployment from version tags. The Registry uses GitHub OIDC, so it needs no registry token.Keep the version in
pyproject.toml,server.json(both version fields), and the FastMCP server constructor in sync.check_release.pyverifies this and accepts the candidate tag with--tag v0.3.1. Commit the release before tagging it.Push a matching tag, for example
git tag v0.3.1 && git push origin v0.3.1.
The release workflow tests and builds the distribution, publishes it to PyPI, then submits server.json to the MCP Registry. The CI workflow runs tests and package checks on pushes and pull requests. A pushed release tag publishes externally; review its commit and environment settings first.
Available Tools
1 toolfind_available_slotsFind Available SlotsARead-only
List available slots in a public, single-resource SuperSaaS schedule.
Supports explicit numeric start times, fixed duration, weekly opening hours, exceptions, booked appointments, and booking-window limits. Unsupported schedule rules are reported as errors.
| Name | Required | Description | Default |
|---|---|---|---|
| from_date | Yes | First date, YYYY-MM-DD | |
| max_results | No | Maximum number of slots returned | |
| schedule_url | Yes | Public HTTPS SuperSaaS /schedule/ URL | |
| through_date | Yes | Last date, inclusive, YYYY-MM-DD | |
| respect_booking_window | No | Apply minimum and maximum advance-booking limits |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds real behavioral context beyond that: the schedule features it honors, and crucially that unsupported schedule rules surface as errors rather than silently degrading, which tells the agent how to react to failures.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Front-loaded with the core purpose in the first sentence, followed by supported capabilities and error behavior. Four short lines with little waste, though the feature list is somewhat dense and could be tightened.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
An output schema exists, so return values need not be re-explained. Combined with annotations, the description covers scope, supported rules, and failure behavior; only pagination/result-volume nuance is left implicit.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the baseline is 3 and the schema already documents all five parameters. The description's references to 'explicit numeric start times' and 'booking-window limits' loosely map to the booking-window parameter but add no format or boundary detail beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb (List) and resource (available slots) along with the scope constraint (public, single-resource SuperSaaS schedule). An agent immediately knows this is an availability-read tool and the kind of schedule it targets.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There are no sibling tools to disambiguate against, and the description implies its use case (find bookable slots in a public schedule) rather than stating when to reach for it or when not to. The mention of booking-window limits hints at a precondition but is not framed as guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Tool Schema Changelog
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
1 tool update
v0.1.1- First observed
find_available_slots
TDQS
Scored across 1 tool
There is only one tool, so there is no possibility of confusion or misselection between tools. Its purpose to find available slots is unambiguous.
The single tool name find_available_slots follows a clear snake_case verb_noun convention. With only one tool, there are no inconsistent naming patterns to compare against.
A single tool is thin for an MCP server, even a narrowly focused one. It earns its place for read-only slot lookup, but the count is borderline given the typical 3-15 tool range.
The tool comprehensively supports listing available slots, including durations, opening hours, exceptions, booked appointments, and booking-window limits. It lacks write or booking operations, which may be acceptable if the server is strictly read-only for slots.
Maintenance
Related MCP Connectors
Find open slots on any appty link and book solo providers. Providers manage bookings by API key.
Find available slots and manage bookings, users, and forms in the SuperSaaS scheduling service
Merged free/busy, find mutual time, propose bookings with human approval. Never event contents.
Read appointments, types, calendars and availability; create, cancel or reschedule bookings.
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