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costheta MCP server

Which servers in the official MCP registry are costheta's own, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-26

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Whose server it is
  • Registry namedev.costheta/costhetaverified in the MCP registry

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

When we asked itchecked 2026-10-26
  • Stateanswerschecked 2026-10-26
  • Tools3
  • Server calls itselfcostheta
  • Server version0.1.0
  • Protocol version2025-06-18

On 2026-10-26 the server answered initialize and tools/list without a sign-in. First answer in 231 ms.

Should an agent connect itNot proven either way yet
  • Its tools do every use case we checked: Commit a choice before a detector event fixes the result; Draw public random bits from a detector pulse.
  • Checked on 1 of the 7 days it takes to judge reliability.

Once connected

  • For "Commit a choice before a detector event fixes the result", the likely first call is costheta_decide.
  • For "Draw public random bits from a detector pulse", the likely first call is costheta_random.
  • Parameters are untyped or undescribed in 1 of 3 tools: check arguments before calling.

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.

Measured dailydaily checks: 1, the first on 2026-10-26
  • INITE MCP scoreafter a weeka score needs 7 daily checks: 1 so far
  • What an agent can do with it2 of 2 use cases
  • Answeredmeasuring1 of the 7 daily checks it takes to print a share
  • Median first answer581 ms
  • Space in an agent's context≈ 412 tokensthe definitions of all its tools (3), which an agent carries on every turn
  • Tool definitionsB · 78 of 100
  • Typed results0 of 3 toolsdeclared outputSchema: results come typed, read once
  • Parameters without a description: in 1 of 3
  • Not saying whether it only reads or can destroy: 3 of 3

What an agent can do with it

  • can do · Commit a choice before a detector event fixes the result
  • not sure · Obtain a signed certificate for a challenged decision
  • can do · Draw public random bits from a detector pulse

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

None of the five warning signs in these definitions.

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 (30%), doing the product's job (25%), definitions (20%), context (10%) and use (15%). 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 →

Tools it offers3 tools · read 2026-10-26
  • costheta_random

    Free public random outcome anchored to the latest signed cosmic-ray coincidence pulse. This is a shared beacon: every caller sees the same latest signed pulse until the next muon arrives. For private commitments and retry-safe paid…

  • costheta_decide

    Paid x402 Base mainnet tool: commit-and-reveal decision with a signed certificate. Requires PAYMENT-SIGNATURE and idempotency_key.

  • costheta_witness

    Paid x402 Base mainnet tool: witness a caller commitment against a signed pulse certificate. Requires PAYMENT-SIGNATURE and idempotency_key.

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "costheta": {
      "type": "http",
      "url": "https://costheta.dev/mcp"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http costheta https://costheta.dev/mcp

Add to CursorAdd to VS Code

claude.ai, ChatGPT and other clients: add https://costheta.dev/mcp as a custom connector in the settings.

OpenAPI spec

21 paths, read 2026-10-26. Open the spec ↗

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.