# Glazecalc

> Ceramic glaze chemistry: unity formulas, limit checks, substitutes, cones and potters' guides.

- name: com.glazecalcapp/glazecalc
- version: 1.1.0
- connection class: R0 (autonomous)
- trust: 96/100
- quality: 94/100 (new)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.glazecalcapp%2Fglazecalc
- tools: https://api.protogrid.dev/v1/servers/com.glazecalcapp%2Fglazecalc/tools

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

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "glazecalc": {
      "type": "http",
      "url": "https://glazecalcapp.com/mcp",
      "headers": {
        "Authorization": "Bearer ${GLAZECALC_TOKEN}"
      }
    }
  }
}
```

Placeholders to fill: `${GLAZECALC_TOKEN}`.

## Trust

- hygiene: 100
- liveness: 100
- freshness: 100
- provenance: 85
- drivers: +repository +dns-namespace +website +reachable +uptime-100% +updated-1d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 94/100 (new)

### protocol: 88 (weight 25)

- pass `protocol.modern`: supports 2026-07-28 (server/discover)
- pass `protocol.stateless`: answers without a session
- pass `protocol.transport`: streamable HTTP
- warn `protocol.list_ttl`: tools/list declares ttlMs 0, so clients re-fetch it on every use

### 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: 100 (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
- pass `tools.annotations`: 9 of 9 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 4,314 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

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

- n/a `stability.changes`, `stability.rug_pull`: tool history recorded for 1 of the 7 days needed

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

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

- tools: 9, about 4,314 tokens to load them all
- tool set hash: 28be2dc2235301553773538d6e7b1555
- tools last changed: 2026-10-20T06:40:14.278Z
- badge: [![protogrid quality](https://protogrid.dev/badge/com.glazecalcapp/glazecalc.svg)](https://protogrid.dev/servers/com.glazecalcapp/glazecalc)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

- 2026-10-20 `search_guides` changed (description, inputSchema)
  - before: Searches Glazecalc's plain-language guides for potters (glazing from first principles, making a glaze, safe mixing, safety at home with children and pets, firing a kiln) in the language asked for, or in English where that language has no match. Returns each matching section's title, anchor, a short excerpt, its address on the website and its resource URI, which resources/read returns in full. Use it for glaze defects, safety, firing and terms, and cite the address.
  - after: Searches Glazecalc's plain-language guides for potters (glazing from first principles, making a glaze, safe mixing, safety at home with children and pets, firing a kiln, and a companion to John Britt's free glaze course, in English only) in the language asked for, or in English where that language has no match. Returns each matching section's title, anchor, a short excerpt, its address on the website and its resource URI, which resources/read returns in full. Use it for glaze defects, safety, firing and terms, and cite the address.
- 2026-10-20 `blend_recipes` added
  - Works out the test tiles of a line blend between recipes a and b (2 to 11 steps), or of a triaxial blend when c is given too (2 to 6 rows, up to 21 tiles), as the Blends page of the Glazecalc app does. Each tile is a mix of the corner recipes, each taken as a percent of its base: its shares, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict). With two recipes and steps 2 it compares them oxide by oxide (differences). Give base materials only, no colorants. This is a calculation from published figures, not a test result: the tiles, fired, decide, and the cautions are guides, not a guarantee of food safety.
- 2026-10-20 `check_limits` changed (inputSchema)
- 2026-10-20 `check_limits` changed (description) **meaning changed**
  - before: Checks a glaze recipe for what is past a recommended limit for its firing (too much boron or alkali, too little alumina, too little or too much clay, rising expansion...) and says what the fired glaze will likely do, as the Glazecalc app does. These are cautions from published limits, not a guarantee of food safety.
  - after: Checks a glaze recipe for what is past a recommended limit for its firing (too much boron or alkali, too little alumina, too little or too much clay, rising expansion...) and says what the fired glaze will likely do, as the Glazecalc app does. With a firing, coneFit says whether the chemistry looks like that firing's, by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen: verdict 'cooler' or 'hotter' only when boron and silica or alumina agree on another band; 'fits' (nothing points away, not a pass); 'skipped' where the published figures do not reach (lead, lithium, much soda and potash or zinc, raku, cones 01 to 3...). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). These are cautions and guides from published figures, not a test and not a guarantee of food safety.

Full history: https://api.protogrid.dev/v1/servers/com.glazecalcapp%2Fglazecalc/changes

## Remotes

- https://glazecalcapp.com/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (9)

- `analyze_recipe`: Works out a glaze recipe's unity (Seger) formula, oxide groups, silica to alumina ratio, fired analysis, loss on ignition and calculated thermal expansion, as the Glazecalc app does.
- `blend_recipes`: Works out the test tiles of a line blend between recipes a and b (2 to 11 steps), or of a triaxial blend when c is given too (2 to 6 rows, up to 21 tiles), as the Blends page of the Glazecalc app does. Each tile is a mix of the corner recipes, each taken as a percent of its base: its shares, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict). With two recipes and steps 2 it compares them oxide by oxide (differences). Give base materials only, no colorants. This is a calculation from published figures, not a test result: the tiles, fired, decide, and the cautions are guides, not a guarantee of food safety.
- `check_limits`: Checks a glaze recipe for what is past a recommended limit for its firing (too much boron or alkali, too little alumina, too little or too much clay, rising expansion...) and says what the fired glaze will likely do, as the Glazecalc app does. With a firing, coneFit says whether the chemistry looks like that firing's, by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen: verdict 'cooler' or 'hotter' only when boron and silica or alumina agree on another band; 'fits' (nothing points away, not a pass); 'skipped' where the published figures do not reach (lead, lithium, much soda and potash or zinc, raku, cones 01 to 3...). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). These are cautions and guides from published figures, not a test and not a guarantee of food safety.
- `convert_cone_temperature`: Converts between a pyrometric cone and its temperature (Orton large cones at 60 °C an hour, cones 06 to 6; SK cones, JIS R 8101, 022 to 42), and between °C and °F. Give a cone, or a temperature to find the nearest cones.
- `get_material`: One material from Glazecalc's library: its oxides, loss on ignition, whether it is discontinued and what replaces it, where it is sold, hazards and the data sheet it comes from.
- `match_from_materials`: Remakes a glaze recipe from only the materials listed in "have", keeping its unity formula as near as they allow, as Match with what I have does in the Glazecalc app. Test any suggestion before using it.
- `search_guides`: Searches Glazecalc's plain-language guides for potters (glazing from first principles, making a glaze, safe mixing, safety at home with children and pets, firing a kiln, and a companion to John Britt's free glaze course, in English only) in the language asked for, or in English where that language has no match. Returns each matching section's title, anchor, a short excerpt, its address on the website and its resource URI, which resources/read returns in full. Use it for glaze defects, safety, firing and terms, and cite the address.
- `search_materials`: Finds ceramic raw materials (feldspars, clays, frits, fluxes) and, if asked, colorants in Glazecalc's library by name, alias or maker. Use it to find the exact name the other tools take.
- `suggest_substitutes`: Finds the discontinued or scarce materials in a recipe and the modern ones that replace them, then suggests amounts that keep the unity formula as near as the materials allow, as the Glazecalc app does. Test any suggestion before using it.