# io.github.nexus-mcp-infra/similarity-search-api-sdk

> Stateless NMI + cosine fusion with entropy-driven alpha calibration

- name: io.github.nexus-mcp-infra/similarity-search-api-sdk
- version: 1.0.0
- connection class: R0 (autonomous)
- trust: 87/100
- quality: 79/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/io.github.nexus-mcp-infra%2Fsimilarity-search-api-sdk
- tools: https://api.protogrid.dev/v1/servers/io.github.nexus-mcp-infra%2Fsimilarity-search-api-sdk/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "similarity-search-api-sdk": {
      "type": "http",
      "url": "https://similarity-search-api-production.up.railway.app/mcp"
    }
  }
}
```


## Trust

- hygiene: 100
- liveness: 100
- freshness: 65
- provenance: 80
- drivers: +repository +namespace-matches-repo +reachable +uptime-100% ~updated-95d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 79/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 71 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- fail `tools.annotations`: no tool declares readOnlyHint or destructiveHint, so clients cannot tell safe calls from risky ones
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: nexus_similarity_search_api_estimate_corpus_entropy_profile (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); nexus_similarity_search_api_score_pair_nmi_cosine (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); nexus_similarity_search_api_rank_items_by_nmi_cosine_fusion (readOnlyHint, destructiveHint, idempotentHint, openWorldHint)
- pass `tools.token_cost`: about 1,195 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 3, about 1,195 tokens to load them all
- tool set hash: be3b8bba7ac8d0d90794dc2d16366dbe
- badge: [![protogrid quality](https://protogrid.dev/badge/io.github.nexus-mcp-infra/similarity-search-api-sdk.svg)](https://protogrid.dev/servers/io.github.nexus-mcp-infra/similarity-search-api-sdk)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://similarity-search-api-production.up.railway.app/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (3)

- `nexus_similarity_search_api_estimate_corpus_entropy_profile`: Computes the aggregate entropy-calibrated alpha for a corpus without running a full search -- useful to inspect before committing to a large rank_items_by_nmi_cosine_fusion call. Returns a single aggregate corpus_entropy value, NOT a per-dimension breakdown -- the real logic only exposes the mean marginal entropy across dimensions, not H(X_d) per individual dimension. Do NOT use expecting per-dimension granularity. Requires an x402 payment.
- `nexus_similarity_search_api_rank_items_by_nmi_cosine_fusion`: Ranks a corpus of items against a query vector using a calibrated fusion score (alpha * cosine + (1-alpha) * NMI_normalizado), where alpha is auto-derived from the corpus's marginal entropy unless overridden. Results are identified by their 0-indexed position in corpus_vectors (this tool does not accept explicit item IDs). Use this when you need semantically-calibrated similarity over a stateless corpus of up to 500k items without a vector database. Do NOT use for purely geometric nearest-neighbor search where NMI overhead is unnecessary, nor for corpora larger than 500k items per call. Requires an x402 payment.
- `nexus_similarity_search_api_score_pair_nmi_cosine`: Computes the NMI-cosine fusion score for exactly one (query, target) vector pair at a fixed alpha. Use for explainability, debugging, or unit-level validation of fusion scores before running full corpus ranking. Unlike corpus-level ranking, alpha is NOT auto-calibrated for a single pair -- the real logic requires a fixed alpha (default 0.5); pass alpha explicitly for a specific blend. Do NOT use in a loop to score many pairs; batch them into rank_items_by_nmi_cosine_fusion instead. Requires an x402 payment.