Leave Hacker
app.leavehacker/leave-hackerleavehacker.appstreamable-httpv1.0.0Scanned
Which days of annual leave to book around bank holidays for the most days off, and cheap flights.
6 tools: 2 change things and 4 only read.
- Reads private data · 0
- Reads text others write · 1
- Can send data out · 1
- 1 finding
Anlyon alternative
2 of these tools change something. Run those as governed actions.
Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.
Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.
Import an OpenAPI spec →Tools
Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.
6 tools
Changes things 2Claude Code: ask
leave_request_messageWrite the short, polite message asking a manager for the leave days of a break, in the same words as the Leave Hacker app.Can send data out1 finding
Why it is in this group
- The name "leave_request_message" says "request": a word for a change.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- outboundThe name "leave_request_message" says "request" and "message": it writes something other people read.
Findings
- Warn
The server marks "leave_request_message" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
What this check looks forMatched text
annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "leave_request_message" says "request": a word for a change.
Description, as the server wrote it Write the short, polite message asking a manager for the leave days of a break, in the same words as the Leave Hacker app. Pass the dates to book; the break's first and last day are worked out from the weekends (and bank holidays, if you pass region) either side unless you pass them.
Annotations the server declares
- title: Leave request message
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
plan_leave_yearPlan a whole leave year: the set of breaks that turns the person's annual leave allowance into the most days off, using every bank holiday, with the dates to book for each break an…No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it Plan a whole leave year: the set of breaks that turns the person's annual leave allowance into the most days off, using every bank holiday, with the dates to book for each break and the totals. Handles any leave year start date, part-time working days, three plan styles and school holidays (parents: breaks only in school holidays; school staff: the holidays themselves). Use for "Plan my 28 days of leave for 2027, I have kids at school".
Annotations the server declares
- title: Plan a leave year
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
Only reads 4Show 4 read-only tools
best_days_to_bookFind the days of annual leave to book around each public holiday (or cluster, such as Christmas and New Year) to get the most days off in a row: "book 4 days, get 10 off" options, …No findings
Why it is in this group
- The description's first verb is "find": a word for reading.
Description, as the server wrote it Find the days of annual leave to book around each public holiday (or cluster, such as Christmas and New Year) to get the most days off in a row: "book 4 days, get 10 off" options, cheapest first, with the exact dates. Use for "Which days should I book around Easter 2027 in Scotland?". Filter by holiday name (Easter, Christmas, Early May, Spring, Summer, St Patrick...). Past days are skipped.
Annotations the server declares
- title: Best days to book
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
find_tripsFind the cheapest return flights from a departure airport that fit a break, one per destination, cheapest first, with booking links.Reads text others writeNo findings
Why it is in this group
- The name "find_trips" says "find": a word for reading.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
Description, as the server wrote it Find the cheapest return flights from a departure airport that fit a break, one per destination, cheapest first, with booking links. Prices are cached airline fares in GBP and can change; if the result says sample, they are example prices only. Links go through leavehacker.app/go and are affiliate links: Leave Hacker may earn a commission if you book, at no extra cost to you. Say so when you share them. Use for "Find cheap flights from Manchester that fit the May bank holiday weekend" (work out the break's dates with best_days_to_book first).
Annotations the server declares
- title: Find cheap flights for a break
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: true
get_bank_holidaysList the bank holidays (UK, from gov.uk) or public holidays (other countries, from Nager.Date) for a region in a year or between two dates, with weekdays and substitute days.No findings
Why it is in this group
- The name "get_bank_holidays" says "get": a word for reading.
Description, as the server wrote it List the bank holidays (UK, from gov.uk) or public holidays (other countries, from Nager.Date) for a region in a year or between two dates, with weekdays and substitute days. Use it for questions like "When are the bank holidays in Scotland in 2027?". Ranges can be up to three years.
Annotations the server declares
- title: Bank holidays
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
get_school_holidaysTypical state-school holiday dates for a UK nation in a year (half terms, Easter, summer, Christmas).No findings
Why it is in this group
- The name "get_school_holidays" says "get": a word for reading.
Description, as the server wrote it Typical state-school holiday dates for a UK nation in a year (half terms, Easter, summer, Christmas). These are the usual pattern, NOT official dates: councils and schools set their own, so always tell the person to check their school's term dates.
Annotations the server declares
- title: Typical school holidays
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.
Exfil surface
Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.
No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data.
- Reads private data0
- Reads files, mail, messages, databases, secrets, calendars or repositories.
- Reads text others write1
- Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
- Can send data out1
- Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.
Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.
Findings
Matches of fixed checks, with the text they matched.
The server marks "leave_request_message" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
What this check looks forMatched text
annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "leave_request_message" says "request": a word for a change.
History
Changes to its tool definitions and to its remote endpoint, newest first.
No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.
Install
Pinned to version 1.0.0. Values in angle brackets are yours to fill in.
claude mcp add --transport http leave-hacker https://leavehacker.app/mcpclaude mcp add --transport http leave-hacker https://leavehacker.app/mcpRun in a terminal.
Claude Code permissions
Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.
{
"permissions": {
"allow": [
"mcp__leave-hacker__get_bank_holidays",
"mcp__leave-hacker__best_days_to_book",
"mcp__leave-hacker__get_school_holidays",
"mcp__leave-hacker__find_trips"
],
"ask": [
"mcp__leave-hacker__plan_leave_year",
"mcp__leave-hacker__leave_request_message"
],
"deny": []
}
}Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as leave-hacker. Review it before you use it.
Capability tags behind 2 rules
- mcp__leave-hacker__find_trips untrusted-input
- mcp__leave-hacker__leave_request_message outbound
Pin
Keep the decision: fail CI when the tools change, follow every change, or show a badge.
Pin in CI
Fail a build when the tools you reviewed are not the tools the server serves today.
curl -s "https://anlyon.dev/api/v1/servers/app.leavehacker/leave-hacker/verify?hash=900b8bcdc30d357a27e1b3101e0e7adbdb595eb386e1ed245906131a6d247b8e" | jq -e '.changed == false'Pinned hash 900b8bcdc30d, from Oct 25, 2026, 23:17 UTC.
Watch
Get told when its tools change: a new tool, a new description, a new class.
https://anlyon.dev/servers/app.leavehacker/leave-hacker/changes.xmlAn Atom feed. Works in any feed reader or Slack's RSS app.
Badge
[](https://anlyon.dev/servers/app.leavehacker/leave-hacker)Source: MCP Registry. Synced Oct 25, 2026, 23:17 UTC.