# when-free (pypi · when-free)

Which days and times am I free? Reads your calendar feeds and answers with the slots you can offer.

- Trust score: 68/100 (medium)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-23

## Components

- pypi · `when-free`: 68/100 (this document), [markdown](https://verifymcp.io/servers/yauhenbichel-when-free/when-free.md), [page](https://verifymcp.io/servers/yauhenbichel-when-free/when-free)

## Channel facts

- Registry: `pypi`
- Package: `when-free`
- Version: `0.4.1`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-23.

- **Supply Chain Security**: 50/100
  - Malware scan not yet available for this package.
  - No known CVEs affecting this package version or its production dependencies.
  - Runs hatchling.build at install time, a recognised build step with no custom scripting around it.
  - No production dependencies, so there is no dependency health to assess.
- **Provenance & Transparency**: 100/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to YauhenBichel/when-free).
  - Clear OSI-approved license (Apache-2.0).
  - Actively maintained (last published 13 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 68/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 740 tokens (~246/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 30/100
  - Stability observed for 9 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### How do I install the when-free MCP server?

when-free runs locally as a PyPI package, launched with uvx when-free. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add yauhenbichel-when-free -- uvx when-free
```

### Cursor

```json
{
  "mcpServers": {
    "yauhenbichel-when-free": {
      "command": "uvx",
      "args": [
        "when-free"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "yauhenbichel-when-free": {
      "command": "uvx",
      "args": [
        "when-free"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add yauhenbichel-when-free -- uvx when-free
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "yauhenbichel-when-free": {
      "type": "local",
      "command": [
        "uvx",
        "when-free"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add yauhenbichel-when-free --command uvx --arg when-free
```

### Hermes

```yaml
mcp_servers:
  yauhenbichel-when-free:
    command: "uvx"
    args: ["when-free"]
```

### Netclaw

```json
{
  "McpServers": {
    "yauhenbichel-when-free": {
      "Transport": "stdio",
      "Command": "uvx",
      "Arguments": [
        "when-free"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add yauhenbichel-when-free -t stdio -c uvx -a when-free
```

### Other

```json
{
  "mcpServers": {
    "yauhenbichel-when-free": {
      "command": "uvx",
      "args": [
        "when-free"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-23 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-22 (score 67, −12)

- [security regression] Malware scan: pass → unverified
- [functional improvement] Stability: unverified → 0.27

### 2026-10-20 (score 79, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-10-19 (score 64, −15)

- [security regression] Malware scan: pass → unverified

### 2026-10-17 (score 79, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-10-16 (score 64, −15)

- [security regression] Malware scan: pass → unverified

### 2026-10-14 (score 79, +29)

- [security improvement] Injection markers: unverified → pass
- [security] First check of Judged manipulation: pass
- [security] Stability: Stability not yet verified: not enough scan history yet (needs a 30-day window).
- [functional regression] MCP protocol: unverified → fail
- [functional improvement] Tool coverage: unverified → 100
- [functional] First check of Schema quality: fail
- [functional] First check of Schema quality: excellent
- [functional] First check of Destructive annotations: pass
- [functional] First check of Schema quality: fail
- [functional] First check of Tool coverage: 100

### 2026-10-12 (score 50)

First indexed and scored.

## MCP tools (3)

### `free_slots` (~521 tokens)

Find when the user is free. Reads the user's own calendars and returns, for each day asked about, the time ranges with no events, in the user's time zone. Use it when the user needs to offer, choose or confirm times for a meeting, call or interview. Say which days in one of three ways: `days` (explicit dates), `from` and `to` (a range), or `message` (text such as a recruiter's email, from which the days and a daily window are read). With none of them, the next working days are returned. It never guesses: if a calendar cannot be read it returns an error instead of slots, and days already past are listed under `past`. It only reads. It cannot create or change events.

Input parameters:

- `all_day_busy` (boolean): Treat whole-day events as busy. Default false.
- `buffer_minutes` (integer): Time kept free before and after every event. Default: the user's setting, usually 15.
- `days` (string): Specific days, comma-separated. ISO dates are safest: "2026-10-05, 2026-10-06". Also understood: "Thu 1 Oct, Fri 2 Oct", "tomorrow", "next week".
- `from` (string): First day of a range, YYYY-MM-DD. Default: today.
- `hours` (string): The part of the day to offer, HH:MM-HH:MM, for example "10:00-16:00", or "morning", "afternoon", "evening". Default: the user's configured hours.
- `include_busy` (boolean): Also return what blocks each day, with event titles. Titles are private: ask only if the user wants to see them. Default false.
- `message` (string): Text to read the proposed days and hours from, for example the email asking for availability. Explicit dates are read, and when there are none, phrases relative to today: "tomorrow", "Thursday", "nex…
- `min_minutes` (integer): Shortest slot to return, in minutes. Set it to the meeting length. Default: the user's setting, usually 60.
- `timezone` (string): Time zone for the answer, like "Europe/London". Default: the user's zone.
- `to` (string): Last day of a range, YYYY-MM-DD.
- `weekends` (boolean): Include Saturday and Sunday in a range. Default false.

### `status` (~100 tokens)

Whether the user is free right now, until when, and their next free slot. Use it for "am I free now?", "when is my next gap?" or before interrupting the user. Returns no event titles.

Input parameters:

- `min_minutes` (integer): Shortest gap that counts as the next free slot. Default: the user's setting.
- `timezone` (string): Time zone for the answer, like "Europe/London". Default: the user's zone.

### `check_calendars` (~63 tokens)

Check that the user's calendars can be read. Returns each calendar's name, how many events it holds and how many block time in the next 14 days. Use it when free_slots fails or to confirm the setup. Returns no event details and no calendar addresses.

## Diagnostics

Captured diagnostic sections: Provenance, Install scripts, Dependencies. The full working is on the page: https://verifymcp.io/servers/yauhenbichel-when-free/when-free#diagnostics

## Score history

- 2026-10-23: 68
- 2026-10-22: 67
- 2026-10-21: 79
- 2026-10-20: 79
- 2026-10-19: 64
- 2026-10-18: 79
- 2026-10-17: 79
- 2026-10-16: 64
- 2026-10-15: 79
- 2026-10-14: 79
- 2026-10-13: 50
- 2026-10-12: 50

## Common questions

### What is the when-free MCP server?

when-free is an MCP server listed in the public MCP registry as io.github.YauhenBichel/when-free. Which days and times am I free? Reads your calendar feeds and answers with the slots you can offer. This page covers its PyPI package (when-free).

### Is the when-free MCP server safe to use?

when-free scores 68 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 23 October 2026. Its build provenance is signed and verified. 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 when-free MCP server expose?

when-free exposes 3 tools: free_slots, status, check_calendars. Their descriptions and schemas cost roughly 684 tokens of context every time the server is loaded.

### Is the when-free MCP server still maintained?

when-free is still listed as active in the MCP registry. We last reached this channel on 23 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the when-free MCP server under?

when-free declares the Apache-2.0 licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- PyPI project: https://pypi.org/project/when-free/
- Socket report: https://socket.dev/pypi/package/when-free
- Repository: https://github.com/YauhenBichel/when-free
- Changelog RSS feed: https://verifymcp.io/servers/yauhenbichel-when-free/when-free.xml
- Changelog JSON feed: https://verifymcp.io/servers/yauhenbichel-when-free/when-free.json
- HTML version of this page: https://verifymcp.io/servers/yauhenbichel-when-free/when-free