# Glazecalc [Health: Active]

**Category:** 💻 Developer Tools  
**Repository:** https://github.com/AaronFilson/glazecalc  
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**Directory Page:** https://allmcps.com/mcp/glazecalc

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

## Tools
Capabilities this server exposes over MCP:

- **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.
- **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.
- **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. stull says where the recipe sits on Stull's chart (1912, as the recipe page draws it): silica and alumina in moles, the region (unfused, matte, semi-matte, bright or underfired) and whether it falls in the crazed area; a guide to the surface, not a promise.
- **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. A cone is checked in the band the recipe page gives it (low cone 06-02, mid 1-7, high 8-11); from cone 12 up (band 'top') no published limits reach, so the band's limits are not checked and limitsNote says so. 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, cooler than cone 06 or hotter than cone 10...). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). stull says where the recipe sits on Stull's chart, as analyze_recipe gives it. 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, and between °C and °F. Orton cones run 022 to 42: Glazecalc's figure, from 022 to 15, is Orton's older chart for large cones at 150 °C an hour, and Orton's current figures (self-supporting cones at 15, 60 and 150 °C an hour, large cones at 60 and 150, cone 022 to 14) come beside it; Orton publishes no figure above cone 14, so cones from 16 up have none. SK cones (JIS R 8101, SK 022 to SK 20) by the standard's nominal figures. Give a cone, or a temperature to find the nearest cones.
- **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. report.closeness says how near the new unity formula comes to the old, oxide by oxide, as match_from_materials does. Test any suggestion before using it.
- **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. report.closeness says how near the new unity formula comes to the old, oxide by oxide: close (within 0.02, or 5% of a large amount such as silica's), off, or far (more than three times that), with a verdict (close, fair or poor) and a summary. report.miss and report.best are the solver's own scores, for comparing runs. Raw clay is held to 20% of the batch where that costs the match little (report.capped and allowMore say more). Test any suggestion before using it.
- **solve_target** — Makes a glaze recipe, in percent, from the materials given whose unity formula comes as near a target as they allow (Solve for a target in the Glazecalc app). The target is a unity formula (moles; the fluxes are scaled to add up to 1) or an oxide analysis (percent by weight of the fired glaze), with potash and soda apart. Give the materials by their library names, or onHand for the materials on the person’s shelf (with a token or connected app that may read it). closeness says how near each oxide comes: close (within 0.02, or 5% of a large amount such as silica’s), off, or far (more than three times that), with a verdict (close, fair or poor) and a summary; unreachable names the target’s oxides nothing given supplies. Raw clay is held to 20% of the batch where that costs the match little (capped and allowMore say more). Test any recipe before using it.
- **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, its place on the Stull chart (stull), 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.
- **vary_material** — Shows what one material does to a glaze, by putting more and more of it into a base recipe (an ingredient blend or progression test: whiting 0 to 20, say, in 2 to 11 tiles). With mode "add" (the default) it goes on top of the base, so the recipe grows; with mode "replace" the same amount comes out of another material of the base (`instead`), so the total stays the same. Each tile has its amount of the material, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, its place on Stull's chart (stull: region, crazed), the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict). trend sums up what moves from the first tile to the last, and which Stull regions the tiles cross. 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.
- **compare_recipes** — Compares two glaze recipes side by side: for each, its recipe in percent, key unity formula figures, silica to alumina, calculated expansion, place on Stull's chart (stull), the names of the limit cautions it has and, with a firing, whether its chemistry fits that firing (coneFit verdict); then what changes from A to B oxide by oxide (differences), and which materials are in A only, in B only, or in both, with their percents. It is the same comparison blend_recipes makes with two recipes and two steps, under a name that is easy to find. Give base materials only, no colorants. This is a calculation from published figures, not a test result: fire both, and the tiles decide.
- **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.
- **list_recipes** — Lists the glaze recipes saved in your Glazecalc account, newest first, optionally only those whose title or a material matches a search, or whose stated firing includes a cone or names an atmosphere or process ("which of my glazes fire at cone 10 reduction?"). Each lists its stated firing; a recipe with none has not stated one.
- **get_recipe** — One recipe from your account: its materials and amounts, colorants, notes, its stated firing (firedAt: the cone scale, the low and optional high cone of the claimed range, the cones actually tested, the atmospheres and processes, and for a temperature the rate and hold; each cone exactly as the potter gave it), whether it is for a food surface, the firing logs it went through with a result note each and, where known, the cone and atmosphere each was fired at, the potter’s summary of how it came out at each cone and atmosphere (coneResults; one outside the stated firing is kept), the firing band and target specific gravity saved with it, and its unity formula worked out afresh. It is checked against the limit set chosen in your settings: for the firing given here, or else the band chosen on the recipe, or else the bands its stated firing falls in (a range across two bands is checked at each). A firing from cone 12 up is band 'top', where no limit set has figures: its limits are not checked, and limitsNote says so. coneFit says, for the same firing, whether the chemistry looks like that firing's, as the recipe page's limits panel does: by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen, a note (verdict 'cooler' or 'hotter') only when boron and silica or alumina agree on another band, 'closer' when a range across bands looks nearer one end, 'fits' when nothing points away (not a pass), 'skipped' where the published figures do not reach (among them firings cooler than cone 06 or hotter than cone 10). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). A guide, not a test.
- **list_my_materials** — Lists the materials you have saved in your own Glazecalc account (not the shared library), with their oxides.
- **get_shelf** — The materials you marked as on hand in Glazecalc (the shelf that Match with what I have uses).
- **match_with_what_i_have** — Remakes one of your recipes, or a recipe you give, from only the materials on your shelf, keeping its unity formula as near as they allow (Match with what I have). report.closeness says how near the new unity formula comes to the old, oxide by oxide, as match_from_materials does. Test any suggestion before using it.
- **list_firings** — Lists the firing logs saved in your Glazecalc account, newest first.
- **get_firing** — One firing log from your account: its columns (time, temperature, cone...) and rows, and its notes.
- **list_notes** — The notes in your Glazecalc notebook, newest first, optionally only those about one record (a recipe, material or firing log id).
- **get_my_settings** — Your Glazecalc settings that matter when talking about glazes: region, temperature scale, cones, language, weight unit, whether lead may be suggested, the limit set recipes are checked against, the currency your prices are in (never the prices), and whether changes made by assistants wait for your approval on the website (confirmChanges: off, removals or all; it can be changed only there).
- **create_recipe** — Saves a new glaze recipe in your Glazecalc account, from its base materials and amounts (the library's names, or your own materials'), with optional colorants, notes, firing band and food-surface mark. Glazecalc works out its unity formula, as the recipe page does, and answers with it. Save only a recipe the person asked to save. Needs an access token that can read and change your records.
- **update_recipe** — Changes one of your saved recipes (an id from list_recipes): its title, its base materials and amounts (the unity formula is worked out again), its notes, firing band or food-surface mark. Only what is given changes. The recipe as it was is kept as an earlier version, so the person can undo the change on the website. Needs an access token that can read and change your records.
- **add_notebook_entry** — Adds an entry to your Glazecalc notebook (the Notebook page), with an optional title: a test result, an observation, a firing to try. With about, it is a note about one of your recipes, materials or firing logs, which list_notes finds by that record's id. Needs an access token that can read and change your records.
- **add_my_material** — Saves a material of your own in your Glazecalc account (the Materials page) from its oxide analysis in weight percent, as on a data sheet, with its loss on ignition. Recipes can then use it by name. Needs an access token that can read and change your records.
- **update_my_material** — Changes one of your own materials (an id from list_my_materials): its name, oxide analysis in weight percent, loss on ignition or notes. Only what is given changes. Recipes already saved keep their own copy of it. The material as it was is kept as an earlier version, so the person can undo the change on the website. Needs an access token that can read and change your records.
- **add_to_shelf** — Marks materials as on hand (the shelf that Match with what I have uses), by the library's names or your own materials'. The shelf as it was is kept: undo_shelf_change puts it back. Needs an access token that can read and change your records.
- **remove_from_shelf** — Takes materials off the shelf of materials on hand, by name. The materials themselves stay. The shelf as it was is kept: undo_shelf_change puts it back. Needs an access token that can read and change your records.
- **undo_shelf_change** — Puts back the shelf as it was before its last change (by the website, an access token or an assistant). One step back only: a second call finds nothing to undo until the shelf changes again. Needs an access token that can read and change your records.
- **move_to_trash** — Moves one of your recipes, materials, notebook entries or firing logs to the Trash, as removing it on the website does. It can be put back from the Trash on the website for 30 days; nothing is deleted for good. A token moves at most 100 an hour, and none while the Trash is full. Remove only what the person asked to remove. Needs an access token that can read and change your records.
- **create_firing_log** — Saves a new firing log in your Glazecalc account (the Firing page): its title, the day, the kiln, the columns kept (time, temperature, cone, atmosphere, comments...) and a row for each reading, as the person dictated them. Add later readings with add_firing_rows. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.
- **add_firing_rows** — Adds rows to the end of one of your firing logs (an id from list_firings), in the log's own columns (get_firing gives them): the readings dictated during a firing. The rows already there stay as they are, and the log as it was is kept as an earlier version. At most 500 rows a log. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.
- **link_firing** — Links one of your recipes to a firing log it went through, as the recipe page does, and sets what came of it there: the result in the person's words (at most 500 characters), and the cone and atmosphere when they differ from the log. Linked already, it changes only what is given. A recipe links to at most 100 logs. Taking a link off is done on the website. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "glazecalc": {
    "command": "npx",
    "args": ["-y","ng"]
  }
}
```

## Documentation

## What Glazecalc does

Glazecalc provides MCP tools for ceramic glaze chemistry and potter-focused record keeping. Its shared library contains glaze materials and colorants with oxide data, aliases, manufacturer information, hazards, and source data. Agents can look up materials, inspect their chemistry, search plain-language guides, and convert between cone and temperature values.

The chemistry tools work from base-material recipes. They calculate a Seger or unity molecular formula, oxide groups, silica-to-alumina ratio, fired analysis, loss on ignition, and estimated thermal expansion. Several tools also report a position on Stull's chart, recommended-limit cautions, and a chemistry-based fit to a stated firing. These outputs are guides derived from published figures; they are not firing results or food-safety certification.

## How it works

The server is exposed at Glazecalc's `/mcp` endpoint and can be connected to MCP-compatible assistants. Public library and calculation operations can be used without managing a personal collection. Access to saved records uses Glazecalc's OAuth connection or an access token; read-only access is available unless permission to change records is granted.

Material names should be resolved with `search_materials` before passing them to recipe tools. Calculation tools accept base materials and amounts, while colorants are excluded from blend, variation, comparison, and solver operations.

Account changes are deliberate operations. Recipes, custom materials, notebook entries, and shelf contents can be created, updated, moved to Trash, or restored in the case of shelf changes. Recipe and custom-material edits retain an earlier version for undoing changes on the website. Trash removal is reversible on the website for 30 days.

## Tools and capabilities

- Search the material library, retrieve material chemistry and hazards, and find potter guides.
- Analyze recipes, check recommended limits, estimate firing fit, and convert cones and temperatures.
- Replace discontinued or scarce materials while keeping the unity formula close to the original.
- Rebuild recipes from an available shelf or solve toward a unity-formula or oxide-analysis target.
- Generate line blends, triaxial blends, and material-variation progressions for test tiles.
- Compare recipes by oxides, materials, calculated expansion, Stull placement, and cautions.
- List and retrieve saved recipes, materials, shelves, firings, notes, and glaze-related settings.
- Create or update recipes and materials, manage shelf contents, add notebook entries, and move records to Trash.

## Limitations and notes

Cone and limit guidance follows the ranges and published figures used by Glazecalc. Cone 12 and above use a `top` band without published limit figures, while some firings and materials fall outside the available comparison rules. Cone 6 versus cone 10 can be distinguished only approximately. A `fits` result means that nothing in the selected checks points away from the firing; it is not a pass or a guarantee.

Suggested substitutions, solved recipes, blends, and variations should be tested as fired tiles. The calculations do not replace kiln testing, material verification, studio safety procedures, or food-surface evaluation. Tools that change account data require an access token with read-and-change permission, and records should only be altered or removed when the user has requested it.

_Full upstream README: https://allmcps.com/mcp/glazecalc/readme_