Teamup Calendar MCP by usefulapi
REMOTE · TEAMUP-CALENDAR.USEFULAPI.IO
Read and search Teamup Calendar events and sub-calendars; create, update, delete and undo events.
Available components
Last scanned (4 hours ago)
Scores higher than 46% of remote servers
Reachable. Last reached 17 Oct 2026.
Category Productivity and Notes
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security78
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation is enforced on tool calls, advertised via RFC 9728 protected-resource metadata. Discovery is public, which costs nothing: no tool can be invoked without a token. View diagnostics → Pass
- HTTPS enforcement could not be verified: the plaintext port redirected somewhere other than https, so enforcement is unproven. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
- The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents. View diagnostics → Partial
Transport & Reachability0
- Transport check failed: declared streamable-http, but the endpoint redirected instead of responding directly. See how to fix → View diagnostics → Fail
Schema Quality & AI Usability78
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 2540 tokens (~169/item across 15 items; 15 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management17
- Stability observed for 5 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage93
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 80% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 16 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 16 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Oct 26 +3
- The server rewrote its instructions, which are the text every model session reads security
- The server now declares the “prompts” capability functional
- First check of Schema quality: 100 functional
- New prompt “getting_started” functional
- Server version: 1.0.0 → 1.1.0 functional
- 13 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 12 Oct 26 59
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 17 Oct 2026 · Probed https://teamup-calendar.usefulapi.io/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=usefulapi.io | CN=WE1,O=Google Trust Services,C=US | 13 Sept 2026 | 12 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | d9be3287b0fde9630e825ba1f79bff3f |
| SANs: usefulapi.io, *.usefulapi.io | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of teamup-calendar.usefulapi.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| io. | present | 57355 | 8 | Verified |
| usefulapi.io. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Enforced and verified
The endpoint asked for a token and published valid RFC 9728 metadata describing how to get one.
| Result | Enforced and verified |
|---|---|
| Enforced | On tool calls |
| HTTP status | 302 |
WWW-Authenticate challenge Bearer realm="OAuth", resource_metadata="https://teamup-calendar.usefulapi.io/.well-known/oauth-protected-resource/mcp"
Bearer realm="OAuth", resource_metadata="https://teamup-calendar.usefulapi.io/.well-known/oauth-protected-resource/mcp"Protected resource metadata
| Document | https://teamup-calendar.usefulapi.io/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://teamup-calendar.usefulapi.io/mcp |
| Authorisation server | https://teamup-calendar.usefulapi.io |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://teamup-calendar.usefulapi.io/mcp | Redirected | 302 | https://usefulapi.io/teamup-calendar/ |
| http (plaintext) | http://teamup-calendar.usefulapi.io/mcp | Inconclusive | 302 | http://teamup-calendar.usefulapi.io/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
teamup_create_event Create event ~382
WRITE: create an event. Needs a calendar key with add or modify permission. Give at least subcalendar_ids, start and end. Not idempotent: a repeated call creates a second event. The reply holds the new event and an undo_id; teamup_undo_event_action removes the event again within one hour. POST /{calendarKey}/events.
| Name | Type | Req | Description |
|---|---|---|---|
| all_day | boolean | – | True for an all-day event (default false). |
| comments_enabled | boolean | – | Allow comments (default false). |
| comments_visibility | string | – | Who sees the comments: all_users or users_with_modify_permission. |
| custom | object | – | Values of custom fields, keyed by field id (see teamup_get_calendar -> fields). |
| end | string | yes | End, same format as start. Must not be before start. |
| location | string | – | – |
| notes | string | – | Notes, in markdown. |
| rrule | string | – | Recurrence rule (iCalendar RRULE, e.g. FREQ=WEEKLY;COUNT=10). Omit for a single event. |
| signup_enabled | boolean | – | Let people sign up (default false). |
| signup_limit | integer | – | Maximum signups; required by Teamup when signup_enabled is true. |
| signup_visibility | string | – | Who sees the signups: all_users or users_with_modify_permission. |
| start | string | yes | Start, e.g. 2026-10-14T09:00:00 (calendar timezone) or with an offset such as +02:00. For an all-day event: yyyy-mm-dd. |
| subcalendar_ids | array | yes | Sub-calendar ids the event belongs to (from teamup_list_subcalendars). |
| title | string | – | Event title. |
| who | string | – | The "who" field. |
No output schema declared.
No examples provided.
teamup_create_subcalendar Create sub-calendar ~113
WRITE: create a sub-calendar. Needs a calendar key with admin permission, and the plan may limit how many exist. Not idempotent: a repeated call creates a second one. POST /{calendarKey}/subcalendars.
| Name | Type | Req | Description |
|---|---|---|---|
| active | boolean | – | Active (default true). |
| color | integer | – | Color number from Teamup's palette (default 17). |
| name | string | yes | Sub-calendar name. |
| overlap | boolean | – | Allow overlapping events on it (default true). |
No output schema declared.
No examples provided.
teamup_delete_event Delete event ~185
WRITE, DESTRUCTIVE: delete an event, or for a recurring event the chosen occurrences. Needs modify permission. Not retried. The reply holds an undo_id; teamup_undo_event_action restores the event within one hour, after that the deletion is permanent. For one occurrence use the occurrence id (123-rid-<unix start>) and redit single (the default); redit all deletes the whole series. DELETE /{calendarKey}/events/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| event_id | string | yes | Event id (occurrence id for one occurrence of a recurring event). |
| redit | string | – | For a recurring event: single (default), future or all. With all the whole series is deleted. |
| version | string | – | The event's version (from teamup_get_event). If set, the delete is refused when the event changed since. |
No output schema declared.
No examples provided.
teamup_get_calendar Get calendar ~76
The calendar this connection points at: title, timezone and date settings, custom event fields, sub-calendars, the permission of the calendar key in use and the plan's features. Call this first to learn the sub-calendar ids and the timezone. The calendar key itself is never returned. GET /{calendarKey}/configuration.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
teamup_get_event Get event ~95
One event by id: title, times, sub-calendars, location, who, notes (markdown), recurrence rule, custom fields, signups, comments, attachments (metadata), version, change history and reminders. Use the occurrence id (123-rid-<unix start>) for one occurrence of a recurring event. GET /{calendarKey}/events/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| event_id | string | yes | Event id. |
No output schema declared.
No examples provided.
teamup_get_subcalendar Get sub-calendar ~58
One sub-calendar by id: name, color, overlap rule, active state and which links may use it. GET /{calendarKey}/subcalendars/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| subcalendar_id | integer | yes | Sub-calendar id. |
No output schema declared.
No examples provided.
teamup_list_access_keys List access keys ~149
List the calendar's access keys (sharing links and user accesses) with name, role, active state and per-sub-calendar permission. Needs a key with admin permission. The secret key values are never returned (they are secrets); use the id and name to tell links apart. GET /{calendarKey}/keys.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Results per page, 1-200 (default 50). |
| name_contains | string | – | Only keys whose link, user or group name matches this text. |
| offset | integer | – | Number of results to skip (default 0). Pass the previous reply's next_offset. |
| type | string | – | Only this kind of access. |
No output schema declared.
No examples provided.
teamup_list_changed_events List changed events ~129
Events created, changed or deleted since a Unix timestamp (at most 30 days back), for syncing. A recurring event comes back once, as its series, not as occurrences. Deleted events carry delete_dt. Pass the reply's timestamp as since_timestamp next time so nothing is missed. GET /{calendarKey}/events?modifiedSince=.
| Name | Type | Req | Description |
|---|---|---|---|
| mode | string | – | synchronize (default): events created and deleted after the timestamp are left out. monitor: they are returned too. |
| since_timestamp | integer | yes | Unix timestamp in seconds, at most 30 days in the past. |
No output schema declared.
No examples provided.
teamup_list_event_signups List event signups ~58
The people signed up for an event (name, email, id). Signups must be enabled on the event. GET /{calendarKey}/events/{id}/signups.
| Name | Type | Req | Description |
|---|---|---|---|
| event_id | string | yes | Event id. |
No output schema declared.
No examples provided.
teamup_list_events List events ~176
List the events in a date range, optionally only on some sub-calendars. Recurring events are expanded: every occurrence in the range is returned with its own id (series id + -rid- + start). Notes come as markdown. Times use the calendar's timezone unless tz is set. GET /{calendarKey}/events.
| Name | Type | Req | Description |
|---|---|---|---|
| end_date | string | – | Last day, inclusive, yyyy-mm-dd (default: start_date). Needs start_date; at most 366 days after it. |
| start_date | string | – | First day, yyyy-mm-dd (default: today). |
| subcalendar_ids | array | – | Only events on these sub-calendars. |
| tz | string | – | Timezone for the times in the reply, e.g. Europe/Berlin. Default: the calendar's timezone. |
No output schema declared.
No examples provided.
teamup_list_subcalendars List sub-calendars ~136
List the sub-calendars (the colored lanes that events belong to, such as people, rooms or resources). A key with admin permission also sees inactive ones. GET /{calendarKey}/subcalendars.
| Name | Type | Req | Description |
|---|---|---|---|
| include_inactive | boolean | – | Include inactive sub-calendars (default false). |
| limit | integer | – | Results per page, 1-200 (default 50). |
| name_contains | string | – | Only sub-calendars whose name matches this text. |
| offset | integer | – | Number of results to skip (default 0). Pass the previous reply's next_offset. |
No output schema declared.
No examples provided.
teamup_search_events Search events ~219
Search events by keyword (2-100 characters) within a date range (default: today only, so always pass the range you mean). Recurring events are expanded. Paged with limit and offset. GET /{calendarKey}/events?query=.
| Name | Type | Req | Description |
|---|---|---|---|
| end_date | string | – | Last day, inclusive, yyyy-mm-dd (default: start_date). Needs start_date; at most 366 days after it. |
| limit | integer | – | Results per page, 1-200 (default 50). |
| offset | integer | – | Number of results to skip (default 0). Pass the previous reply's next_offset. |
| query | string | yes | Search text (Teamup's search syntax applies). |
| start_date | string | – | First day, yyyy-mm-dd (default: today). |
| subcalendar_ids | array | – | Only events on these sub-calendars. |
| tz | string | – | Timezone for the times in the reply, e.g. Europe/Berlin. Default: the calendar's timezone. |
No output schema declared.
No examples provided.
teamup_undo_event_action Undo event change ~78
WRITE: undo a recent event creation, update or deletion with the undo_id from that call. Works for one hour only and is refused if someone else changed the event since. PUT /{calendarKey}/events/undo/{undo_id}.
| Name | Type | Req | Description |
|---|---|---|---|
| undo_id | string | yes | The undo_id returned by create, update or delete. |
No output schema declared.
No examples provided.
teamup_update_event Update event ~371
WRITE: change fields of an event; fields you leave out keep their value (the event is read first and sent back with its version, so a concurrent edit is refused instead of overwritten; an event without a version is not changed). Needs modify permission. For a recurring event pass redit; use the occurrence id (123-rid-<unix start>) with single or future. Attachments are not touched. The reply holds the event and an undo_id for one hour (teamup_undo_event_action). PUT /{calendarKey}/events/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| all_day | boolean | – | – |
| comments_enabled | boolean | – | – |
| comments_visibility | string | – | – |
| custom | object | – | Custom field values to set, keyed by field id; other custom fields keep their value. |
| end | string | – | New end. |
| event_id | string | yes | Event id (occurrence id for one occurrence of a recurring event). |
| location | string | – | – |
| notes | string | – | New notes, in markdown. Replaces the old notes. |
| redit | string | – | Which occurrences of a recurring event: single (only this one), future (this and all later ones) or all. |
| rrule | string | – | New recurrence rule; with redit all or future only. An empty string removes the recurrence (the series becomes a single event). |
| signup_enabled | boolean | – | – |
| signup_limit | integer | – | – |
| signup_visibility | string | – | – |
| start | string | – | New start (same formats as in teamup_create_event). |
| subcalendar_ids | array | – | Sub-calendar ids the event belongs to (from teamup_list_subcalendars). |
| title | string | – | – |
| who | string | – | – |
No output schema declared.
No examples provided.
teamup_update_subcalendar Update sub-calendar ~106
WRITE: change a sub-calendar's name, color, overlap rule or active state; fields you leave out keep their value. Needs admin permission. Making a sub-calendar inactive hides it from users without admin rights. PATCH /{calendarKey}/subcalendars/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| active | boolean | – | – |
| color | integer | – | – |
| name | string | – | – |
| overlap | boolean | – | – |
| subcalendar_id | integer | yes | Sub-calendar id. |
No output schema declared.
No examples provided.
How do I install the Teamup Calendar MCP by usefulapi server?
Teamup Calendar MCP by usefulapi is a hosted endpoint at https://teamup-calendar.usefulapi.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · teamup-calendar.usefulapi.io
claude mcp add --transport http io-usefulapi-teamup-calendar 'https://teamup-calendar.usefulapi.io/mcp'
What is the Teamup Calendar MCP by usefulapi server?
Teamup Calendar MCP by usefulapi is listed in the public MCP registry as io.usefulapi/teamup-calendar. Read and search Teamup Calendar events and sub-calendars; create, update, delete and undo events. This page covers its hosted endpoint (https://teamup-calendar.usefulapi.io/mcp).
Is the Teamup Calendar MCP by usefulapi server safe to use?
Teamup Calendar MCP by usefulapi scores 63 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the Teamup Calendar MCP by usefulapi server expose?
Teamup Calendar MCP by usefulapi exposes 15 tools: teamup_get_calendar, teamup_list_subcalendars, teamup_get_subcalendar, teamup_list_access_keys, teamup_list_events, and 10 more. Their descriptions and schemas cost roughly 2,331 tokens of context every time the server is loaded.
Does the Teamup Calendar MCP by usefulapi server require authentication?
Yes. Teamup Calendar MCP by usefulapi asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.
Is the Teamup Calendar MCP by usefulapi server still maintained?
Teamup Calendar MCP by usefulapi is still listed as active in the MCP registry. We last reached this channel on 17 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.