Anansi Haven core tools

Eight free, read-only utilities for AI assistants. No account, no sign-up, no key. Connect any MCP client to:

https://anansi-haven.anansidata.workers.dev/mcp/core

In Claude: Settings, Connectors, Add custom connector, paste the URL above. In Claude Code: claude mcp add anansi-haven --transport http https://anansi-haven.anansidata.workers.dev/mcp/core

Try it

Pick a tool, edit the arguments, and run it against the live server.

Result appears here.

The tools

DraftCheck draftcheck_check

Scores English text from 0 to 100 for common AI-writing tells and points to each one with a fix hint. Up to 5,000 characters; 5 free checks per caller per day.

Example prompt: Check this paragraph for AI-writing tells before I post it.

{"text":"In today's fast-paced world, it's not just about writing. It's about connecting."}

Time zones and dates time_tools

Current time in any zone, converting times between zones, durations, and date math. Handles daylight saving time.

Example prompt: What time is 9am in New York in Tokyo and London?

{"action":"convert","time":"2026-10-12T09:00","from_tz":"America/New_York","to_tz":["Asia/Tokyo","Europe/London"]}

Unit converter unit_convert

Length, mass, volume, area, speed, time, data size, pressure, energy and temperature.

Example prompt: Convert 26.2 miles to kilometers.

{"value":26.2,"from":"mi","to":"km"}

Calculator calculate

Exact arithmetic with percentages and common functions. No code is executed.

Example prompt: What is 18% of 2,450, plus the square root of 144?

{"expression":"18% * 2450 + sqrt(144)"}

Text utilities text_tools

Word counts, slugs, case changes, base64 and URL encoding, HTML stripping, URL extraction, line sorting and diffs.

Example prompt: Turn this title into a URL slug.

{"action":"slugify","text":"Ten Small Fixes for Better Release Notes"}

JSON Schema validator json_validate

Checks data against a JSON Schema and lists every error with its path, or just checks JSON syntax.

Example prompt: Does this object match my schema?

{"schema":{"type":"object","required":["id"],"properties":{"id":{"type":"integer"}}},"data":{"id":"7"}}

UUIDs and hashes uuid_hash

UUID v4s, random bytes, and sha256/sha512/sha3-256/md5 hashes in hex or base64.

Example prompt: Give me the sha256 of the word hello.

{"action":"hash","input":"hello","algorithm":"sha256"}

Web page metadata url_metadata

Title, description, Open Graph tags, canonical URL and icon of a public page. Page text is third-party content.

Example prompt: What is the title and description of example.com?

{"url":"https://example.com"}

Limits: about 120 requests per minute per address; DraftCheck allows 5 free checks per caller per day. See privacy and support.