Tool Reference: Load Criteria
MCP tools to read and manage project load criteria and apply loads.
Load Criteria is a project's curated set of design loads in psf — dead and live assemblies, allowances, code live loads, and so on. The MCP tools let Claude read and edit that set, and turn a psf into an applied line or point load for a beam. See Load Criteria and Area and Point Loads for the underlying concepts.
Reading and managing the criteria set#
| Tool | What it does | Key arguments |
|---|---|---|
get_load_criteria | Reads a project's load criteria (seeds defaults on first access) | project_id |
add_load_criteria_load | Adds a new design load to the set | project_id, category, name, psf; optional applies, source, note, kind |
update_load_criteria_load | Updates fields of an existing load (partial patch) | project_id, load_id plus any fields to change |
remove_load_criteria_load | Removes a load by id | project_id, load_id |
Each criteria load carries a stable id (used to link or derive from it), a category (dead, live, wind, or snow), a name, an applies note, its psf, a source citation (e.g. "ASCE 7-22 Table 4.3-1"), and an optional kind (assembly, allow, or custom) and note.
add_, update_, and remove_load_criteria_load all preserve the rest of the set — adding appends, updating patches one load, removing drops one. Each returns the full updated criteria set. The id is immutable.
Deriving applied loads#
These tools do the psf-to-load arithmetic for you and return a ready-to-use load object you can drop into a beam design (design_beam / save_beam_design_calc).
| Tool | What it does | Key arguments |
|---|---|---|
define_area_load | Converts a psf over a tributary width into a uniform line load | area_load_psf, tributary_width_ft, load_category; optional name, source_label, source_kind |
define_point_load | Converts a psf over a tributary area into a point load P | load_psf, x_ft, load_category; tributary area via area_sqft or dimensions+terms |
define_area_load_from_criteria | Same as define_area_load, pulling the psf from a criteria load | project_id, criteria_load_id, tributary_width_ft; optional load_category, name |
define_point_load_from_criteria | Same as define_point_load, pulling the psf from a criteria load | project_id, criteria_load_id, x_ft, tributary area args; optional load_category, name |
Criteria-free vs. linked#
define_area_load and define_point_load are the criteria-free builders — bring a psf from anywhere (a code table, a cut sheet, a hand calc) and optionally cite it with source_label. You're never required to use the project's Load Criteria.
The _from_criteria variants instead pull a psf from a criteria load (identified by criteria_load_id, which you get from get_load_criteria). They record a live link back to the criteria, so the app shows the load as linked and flags it stale if the criteria psf later changes. The category comes from the criteria load (e.g. dead→Dead); pass load_category to override it (e.g. tag a roof live load as Lr) while keeping the link.
Tributary area for point loads#
For point loads, give the tributary area either as a single number (area_sqft) or as a named build-up — dimensions (e.g. {"a": 10, "b": 12}) plus terms (e.g. [["a", "b"]] meaning a·b). The build-up wins when present, so the load's provenance is recorded without you doing the arithmetic.
The derivation block travels with the load. On save, the load's w or P is recomputed authoritatively from the block, and the provenance shows in the report.
Related#
- Load Criteria — the design-loads concept.
- Area and Point Loads — tributary-area math in the web app.
- Runners — feed these loads into
design_beam.