Borrowing it
Nothing to install: this file belongs to Sealjay/mcp-ical-swift. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Sealjay/mcp-ical-swift/main/CLAUDE.mdgit clone --depth 1 https://github.com/Sealjay/mcp-ical-swiftWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/sealjay/mcp-ical-swift/claude-md)<a href="https://agentmods.dev/instructions/sealjay/mcp-ical-swift/claude-md"><img src="https://agentmods.dev/badge/instructions/sealjay/mcp-ical-swift/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/sealjay/mcp-ical-swift/claude-md"><img src="https://agentmods.dev/badge/instructions/sealjay/mcp-ical-swift/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00361 | $0.00361 |
| Opus 5.5 | $0.00144 | $0.00144 |
| Sonnet 5.5 | $0.00072 | $0.00072 |
| Haiku 4.5 | $0.00036 | $0.00036 |
Grade A, and why
mcp-ical-swift CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 20d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
CLAUDE.md
Architecture
- MCP server (
src/index.ts): Bun,@modelcontextprotocol/serverv2, Zod 4.createServer()registers the tools andserveStdio(createServer)picks the protocol era per connection (2026-07-28 or 2025-erainitialize). Calls the Swift binary viaexecFileSyncwith array args. - Swift binary (
src/calendar-reader.swift, built tobin/calendar-reader, gitignored): EventKit access, JSON on stdout.
Commands
| Command | Purpose |
|---|---|
bun run build |
Compile the Swift binary, then scripts/grant.sh for the one-off Calendar grant |
bun run start / bun run dev |
Run the server (dev = watch mode) |
bun test |
Unit tests: validation, write gate, schema bounds |
Manual check on a Mac: bin/calendar-reader list-calendars, bin/calendar-reader list-events $(date +%Y-%m-%d).
Design decisions
- Writes (
create/update/delete) are off unlessICAL_ALLOW_WRITE=true. execFileSyncwith array args andJSONSerializationoutput: no shell or JSON injection.calendars: nilqueries every calendar unless filtered; documented as a privacy trade-off.- Recurring edits use
.thisEvent, never the series. - stdio only: no HTTP, no network, no API keys.
Conventions
Bun, conventional commits, British English in prose and American English in code. Tool description rules: .claude/rules/mcp-tool-descriptions.md.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 20d ago Changed · -36 lines · -151 tokens per session 3881baf1ec7f
- 2mo ago First seen · 65 lines · 512 tokens per session scan A 5cd5e5c980e1
mcp-ical-swift CLAUDE.md is an instructions file published in the GitHub repository Sealjay/mcp-ical-swift (0 stars, last pushed 4d ago), licensed MIT. It adds 361 tokens to every session, about $0.0014 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
mcp-ical-swift CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mcp-ical-swift CLAUDE.mdSealjay/mcp-ical-swift | Instructions file | 0 | 4d ago | MIT | A | 361 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | yesterday | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |