MCP HeartbeatTHE MCP OBSERVATORY
Public workspace

Explore

Evidence for your next connection.

Independent measurements of remote MCP servers. Every observation has a timestamp.

Read-only probes

MCP server · Code & DevOps

Nonobench

By mauricekleine Verified namespace

An open-source benchmark of how well LLMs solve nonogram puzzles, from 5x5 to 20x20.

WebsiteSource codeAI models & agents
Connect to Nonobench
Checks passed
15 / 22

0 failed · 7 not measured

Median response
92 ms

Median of successful probes over 7 days

30-day uptime
Not measured

Share of countable probes over 30 days, including daily rollups. Auth challenges are excluded.

Discovered tools
11

Tool definitions returned by this server

Independent monitoring

Health & checks

Status history

Responded

The server completed its last measured handshake. This is an observation, not a guarantee.

Last checked
Check summary by test group
Test areaPassedFailedUnmeasured
ConnectionCan a client connect and discover tools?
500
Reliability & speedDoes it respond consistently and quickly?
103
Access & authenticationWhat is required to use this server?
102
Tool qualityAre the tool definitions usable by an agent?
400
Publisher identityCan the publisher be traced to its source?
402

Unmeasured means there is not enough evidence to decide. How these checks work

Inspect individual checks 22 recorded

Core

  • Pass
    Reachable

    Latest probe returned HTTP 200 in 93 ms.

  • Pass
    Valid handshake

    protocolVersion 2025-11-25, serverInfo.name nonobench.

  • Pass
    Lists tools

    tools/list returned 11 tools.

  • Pass
    Current protocol

    Negotiated 2025-11-25. The bar is 2025-06-18 or newer.

  • Pass
    HTTPS

    The endpoint URL is https.

Performance

  • Not measured
    Fast (p50)

    Median latency 92 ms over 2 samples in 7 days. The bar is 1000 ms. Need at least 5 samples.

  • Not measured
    Consistent (p95)

    95th percentile 93 ms over 2 samples in 7 days. The bar is 3000 ms. Need at least 20 samples.

  • Not measured
    Reliable (uptime)

    2 of 2 attempts returned a tool list in 30 days (100%). The bar is 99%. Need at least 30 samples.

  • Pass
    Stable tool list

    No tool was removed and no required parameter was added in the last 30 days.

Access

  • Pass
    Open access

    tools/list succeeded with no credential, and the record declares none.

  • Not measured
    Standard auth

    Auth is not required, so the OAuth metadata check does not apply.

  • Not measured
    Free tier cited

    No publisher quote has been checked.

Tools

  • Pass
    Tools described

    Every tool description is at least 20 characters.

  • Pass
    Valid input schemas

    Every inputSchema is a JSON Schema object.

  • Pass
    Parameters documented

    29 of 29 parameters have a description (100%). The bar is 80%.

  • Pass
    Safety hints

    Every tool sets readOnlyHint or destructiveHint.

Publisher

  • Pass
    Verified namespace

    Listed in the Official MCP Registry.

  • Not measured
    Website matches publisher

    This namespace is not a reverse domain, so the website comparison does not apply.

  • Pass
    Source repo linked

    A repository URL is on file.

  • Pass
    Repo owner matches

    The GitHub repository owner matches the namespace login.

  • Pass
    Recently updated

    Updated 2026-09-29T22:16:28.233393Z, within 180 days.

  • Not measured
    Open-source licence

    The GitHub licence lookup has not returned an OSI result yet.

Start using Nonobench

Connect to this server

Choose your client, copy the configuration, then enable the server in your client’s MCP settings.

Run this command in your terminal, then restart Claude Code.

Claude Code

claude mcp add --transport http nonobench https://www.nonobench.com/mcp

Capabilities

Tools 11

check_solution

Check a grid against a puzzle's clues, using the same rule as the benchmark grader. Reports which rows and columns do not match.

Discovered
compare_models

Side-by-side core overall and per-size accuracy, cost, latency and token results for model or family names.

Discovered
get_leaderboard

Models ranked by accuracy; defaults to all effort levels for compatibility.

Discovered
get_model_puzzles

Which puzzles one model solved, missed, timed out on, or has not run.

Discovered
get_model_results

Accuracy, cost, latency and token use for one model, broken down by grid size.

Discovered
get_puzzle

One puzzle, including the clue text models were prompted with. The reference solution is only included on request; some puzzles have several valid solutions.

Discovered
get_puzzle_results

Per-model outcomes for one puzzle. Answers are omitted unless requested.

Discovered
list_families

Model families, available efforts and best variants.

Discovered
list_providers

Provider ids, names, families and variant counts.

Discovered
list_puzzles

The benchmark puzzles with their ids and row/column clues.

Discovered
list_runs

Individual benchmark runs (one model on one puzzle), optionally with the raw prompt and model output.

Discovered

Recent measurements

Probe history

View status
Latest stored probes. Raw probe rows are kept for 14 days.
CheckedResultResponseTools
Connected93 ms11
Connected91 ms11

Related servers

All alternatives

Same function and industry, ranked by checks passed then median latency.

Explore alternatives to Nonobench