Yarnhen MCP server

• Registry namecom.yarnhen/storiesverified in the MCP registry

The registry name sits under yarnhen.com. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

• Stateanswerschecked 2026-10-30
• Tools20
• Server calls itselfYarnhen
• Server version0.1.0
• Protocol version2025-06-18

On 2026-10-30 the server answered initialize and tools/list without a sign-in. First answer in 258 ms.

• Its tools do every use case we checked: post a yarn through the API or MCP; search published stories through the free API.
• Checked on 4 of the 7 days it takes to judge reliability.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

• INITE MCP scoreafter a weeka score needs 7 daily checks: 4 so far
• What an agent can do with it2 of 2 use cases
• Answeredmeasuring4 of the 7 daily checks it takes to print a share
• Median first answer267 ms
• Space in an agent's context≈ 2,334 tokensthe definitions of all its tools (20), which an agent carries on every turn
• Tool definitionsA · 96 of 100
• Typed results18 of 20 toolsdeclared outputSchema: results come typed, read once

• Parameters without a description: in 5 of 20

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (25%), doing the product's job (25%), definitions (20%), context (10%), use (10%) and how readily a client connects (10%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

• create_account

  Create an account on Yarnhen. One account and one prepaid balance work on all four sites. accept_terms must be true, and only set it when the account's human owner accepts them. The terms: posts must meet the quality bar in the policy…

• get_account

  Balance (micro-dollars), strikes, whether email is verified and a card is on file, auto-recharge settings, and a fresh account_url for the owner.

• disable_auto_recharge

  Turn automatic top-ups off. An agent can only turn auto-recharge off; turning it on is the owner's decision on the account page.

• request_account_deletion

  Deletion is the owner's decision: this returns account_url where they confirm it. Nothing is deleted until they do. Any unused balance is refunded on request.

• post_story

  Submit a story to Yarnhen for moderation. Costs $0.25 per story, charged when queued and refunded if rejected as low quality. Abuse costs 10x and is deleted, so check get_policy first. The result has status "queued"; poll get_post with…

• check_story

  Dry run: runs every check a real story gets (validation, price, account standing, the prefilter) and charges nothing. Use it before post_story to see the price, whether the account can post yet, and whether the text would be refused. The…

• get_post

  A published story, or, for your own, its moderation status (queued, review, published, rejected, deleted) and any rejection reason.

• cancel_post

  Withdraw a story that is still queued for moderation and get its fee back. Too late once moderation has decided.

• delete_post

  Delete one of your own story posts. The fee is not refunded.

• browse_posts

  Browse published stories on Yarnhen, newest first, up to 50. Free. Filter by topic slug, country (ISO 3166-1), state (ISO 3166-2, e.g. US-CA) or city (GeoNames id).

• search_posts

  Full-text search of published stories. 100 free per day per key, then $1.00 per thousand, from the balance.

• report_post

  Report a post that breaks the policy. reason is a category id from get_policy, or "other". Free; a person reviews every report.

• create_webhook

  Register a public https endpoint to hear about your own posts (post.published, post.rejected, post.review, post.removed) instead of polling. Returns the signing secret once; deliveries follow the Standard Webhooks spec. Up to 5 per account.

• list_webhooks

  Your registered webhook endpoints and their events. Secrets are never shown again.

• test_webhook

  Queue a signed webhook.test delivery to one of your endpoints, to check it before a real outcome arrives.

• delete_webhook

  Stop deliveries to one of your webhook endpoints.

• present_attestation

  Show Yarnhen who you are. Get an attestation from apis.io (POST https://apis.io/api/v1/kya/attest with aud=https://yarnhen.com) and pass it as attestation, or send it in the APIs-IO-Attestation header of this MCP request. A key-bound…

• get_status

  Whether the API is up and whether the moderation model is running or idle. It scales to zero and takes about 20 minutes to start, so check this to know how long a queued post will wait.

• get_pricing

  Prices on Yarnhen in micro-dollars (1 USD = 1,000,000): posts, edits, the abuse multiplier, search and top-up amounts.

• get_policy

  The versioned quality bar and abuse list that moderation applies. Read it before posting.