# PT Chart

> PT chart lookups, superheat/subcooling calculators, and diagnostics for HVAC technicians.

- name: io.github.Tsonnn/pt-chart-mcp
- version: 1.0.0
- connection class: R0 (autonomous)
- trust: 80/100 flags: no-repository
- quality: 79/100 (new)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/io.github.Tsonnn%2Fpt-chart-mcp
- tools: https://api.protogrid.dev/v1/servers/io.github.Tsonnn%2Fpt-chart-mcp/tools

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

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "pt-chart-mcp": {
      "type": "http",
      "url": "https://pt-chart-mcp-production.up.railway.app/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 100
- freshness: 100
- provenance: 45
- drivers: +website +reachable +uptime-100% +updated-2d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 79/100 (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: 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: refrigerant_info (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); superheat (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); subcooling (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); …
- pass `tools.token_cost`: about 1,122 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 2 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: 8, about 1,122 tokens to load them all
- tool set hash: 94b69824684797c44e9c66db138aced5
- badge: [![protogrid quality](https://protogrid.dev/badge/io.github.Tsonnn/pt-chart-mcp.svg)](https://protogrid.dev/servers/io.github.Tsonnn/pt-chart-mcp)
- 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://pt-chart-mcp-production.up.railway.app/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (8)

- `convert_units`: Convert between pressure units (psig, psia, kpa, bar) and temperature
units (F, C). A bare 'psi' is treated as psig. For certified HVAC
technicians (EPA 608; A2L certification where required).

- `coolbooked_info`: About CoolBooked: the AI appointment-booking connector for HVAC shops.
This is NOT a diagnostic tool -- call it when someone asks what
CoolBooked is, how shop owners can try it, or how the free PT tools
connect to paid bookings.

- `diagnose`: Conversational diagnostic copilot: give it field readings and get back
computed superheat/subcooling plus a ranked 'check this first' list.
For certified HVAC technicians (EPA 608; A2L certification where
required). Informational only -- it suggests what to CHECK, never how
to defeat a safety device, vent refrigerant, or work uncertified.

metering: 'txv' (default) or 'fixed' for fixed-orifice/piston systems.

- `pt_lookup`: Saturation pressure (bubble and dew, in psig) for a refrigerant at a
temperature in Fahrenheit. For certified HVAC technicians (EPA 608; A2L
certification where required). Example: pt_lookup("R-454B", 45).

Bubble point: use for subcooling calculations. Dew point: use for
superheat calculations. Pure fluids (R-32, R-410A, R-22, R-134a) have
no glide, so both values match.

- `pt_reverse`: Saturation temperature (bubble and dew, in Fahrenheit) for a
refrigerant at a pressure in psig. For certified HVAC technicians
(EPA 608; A2L certification where required). Example: a 130 psig
suction reading on R-454B -- pt_reverse("R-454B", 130).

Use the DEW temperature for superheat work and the BUBBLE temperature
for subcooling work on blended refrigerants.

- `refrigerant_info`: Reference card for a refrigerant: GWP, ASHRAE safety class,
composition, typical oil, temperature glide, and handling notes.
For certified HVAC technicians (EPA 608; A2L certification where
required). Informational only.

- `subcooling`: Subcooling in Fahrenheit from head pressure (psig) and liquid-line
temperature (F). For certified HVAC technicians (EPA 608; A2L
certification where required). Uses the BUBBLE point as the saturation
basis, which is the correct basis for blended refrigerants.
Typical TXV target: 8-12F.

- `superheat`: Superheat in Fahrenheit from suction pressure (psig) and suction-line
temperature (F). For certified HVAC technicians (EPA 608; A2L
certification where required). Uses the DEW point as the saturation
basis, which is the correct basis for blended refrigerants.
Typical TXV target: 8-12F.