units-static

High-quality unit conversion MCP server with fixed conversion tables (no network I/O). Companion dogfood to meteo-static: this repo is the good MCP baseline — tools are designed so schema-clarity judges should score well (clear names, deep descriptions, strict enums, typed output schemas).

Tools

Tool	Description
`list_units`	List supported unit ids (optionally filter by dimension)
`convert_length`	Convert length between SI / imperial units
`convert_mass`	Convert mass / weight
`convert_temperature`	Convert °C / °F / K (rejects below absolute zero)
`convert_volume`	Convert liquid volume (US + imperial + SI)
`compare_quantities`	Compare two quantities in the same dimension

Design goals (judge-friendly)

Names: lowercase, descriptive, verb-led (convert_*, list_*, compare_*)
Descriptions: when to call the tool, what it does, what not to use it for
Inputs: closed enums / constrained fields with per-parameter descriptions
Outputs: Pydantic models → MCP outputSchema objects (no bare arrays)
Deterministic: static factor tables; safe for CI evals

Running

STDIO (default)

pip install -r requirements.txt
python src/server.py

Streamable HTTP

pip install -r requirements.txt
python src/server.py --transport http --port 8000

Export tools/list (local)

pip install -r requirements.txt
python scripts/export_tools_list.py --output ci/tools-list.json

GitHub Actions

Shared Actions from plugin-federation/actions:

Job	Purpose
`tools-list-validate`	Export `tools/list` + structural validation
`nexus-catalog`	OIDC → catalog, schema verify, selection-surface embeddings, LLM-as-judge (fail-on-judge-fail)
`evals`	Functional evals (`evals/evaluations.xml`, 100% threshold)

Nexus pipeline setup

Variable / secret	Purpose
`NEXUS_URL`	e.g. `https://api.nonprod.plugin-federation.com`
`NEXUS_OIDC_AUDIENCE`	Must match Nexus GitHub audience
`TENANT_ID`	Target tenant UUID
`MCP_SOURCE_ID`	New stable tool source UUID for this server
`XAI_API_KEY`	Judge model + functional evals
`OPENAI_API_KEY`	Embeddings (`text-embedding-3-small`)

Embeddings use name + description + input schema (tool-embedding-report/v1). Embed failures do not fail judges. Similarity reports are derived by Nexus from a registered semantic-analysis profile whose profileVersion and model match text-embedding-3-small (1536 dimensions unless shortened). CI cannot create that profile.

Also register this repository in the tenant OIDC trust policy (same pattern as meteo-static) and create a dedicated tool source for units-static.

Status

Working — stdio + streamable HTTP
Tools — six conversion tools with structured I/O
CI — Plugin Federation Actions with hard fail gates