Extend Engineer MCP

.github/workflows/ci.yml

@@ -38,3 +38,6 @@ jobs:
 
       - name: Verify the demo runs
         run: npm run demo
+
+      - name: Verify the package contents
+        run: npm pack --dry-run

.gitignore

@@ -2,6 +2,7 @@ node_modules/
 dist/
 coverage/
 *.tsbuildinfo
+*.tgz
 
 *.sqlite
 *.sqlite-journal

README.md

@@ -1,11 +1,12 @@
 # Engineer MCP
 
+[![CI](https://github.com/DanielCuevas1208/engineer-mcp/actions/workflows/ci.yml/badge.svg)](https://github.com/DanielCuevas1208/engineer-mcp/actions/workflows/ci.yml)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
 [![TypeScript](https://img.shields.io/badge/TypeScript-5.9-blue.svg)](https://www.typescriptlang.org/)
 [![Node](https://img.shields.io/badge/Node-%3E%3D22.13-brightgreen.svg)](package.json)
 
 Engineer MCP is a Model Context Protocol server for mechanical-engineering calculations.
-It gives coding agents verified answers for beams, bolts, shafts, bearings, stress, sections, and units.
+It gives coding agents verified answers for beams, bolts, shafts, bearings, stress, fatigue, sections, and units.
 Every result shows the formula, the method, and the source.
 
 ## What it provides
@@ -21,6 +22,7 @@ The release covers these domains:
 - Shaft torsion and first critical speed.
 - Bearing rating life to ISO 281.
 - von Mises equivalent stress.
+- Fatigue analysis for cyclic loads.
 - Cross-section properties.
 - Dimension-safe unit conversion.
 - Material property lookup.
@@ -50,6 +52,7 @@ Warnings surface when a method uses an approximation.
 | `shaft_analysis` | Torsion stress, twist, and critical speed. |
 | `bearing_life` | ISO 281 rating life in revolutions and hours. |
 | `von_mises` | Equivalent stress and yield safety factor. |
+| `fatigue_analysis` | Endurance limit, fatigue safety factor, and estimated life. |
 | `unit_convert` | Conversion between compatible units. |
 | `material_lookup` | Curated mechanical properties of materials. |
 
@@ -124,6 +127,22 @@ References:
   - Mechanics of Materials (Euler-Bernoulli beam theory)
 ```
 
+A call to `fatigue_analysis` for a machined S355 part with a 220 MPa amplitude and 60 MPa mean stress:
+
+```text
+Corrected endurance limit               214 MPa
+Fatigue safety factor                0.8692
+Equivalent fully reversed amplitude    250.7 MPa
+Yield safety factor                   1.268
+Estimated life to failure            220564 cycles
+
+Warning: The fatigue safety factor is below 1. Fatigue failure is predicted.
+Method: Stress-life fatigue analysis
+Formula: Se = ka kb kc (0.5 Sut), 1/n = Sa/Se + Sm/Sut
+References:
+  - Shigley's Mechanical Engineering Design (Tenth edition, 2015)
+```
+
 A call to `unit_convert` with a torque-to-energy request fails safely:
 
 ```text
@@ -146,9 +165,9 @@ Use a unit of the same quantity.
 The test suite is deterministic and offline.
 It covers the engines, the unit layer, the database, and the tools.
 
-- 73 tests across 9 files.
+- 100 tests across 10 files.
 - All tests pass on Node 22 and Node 24.
-- The CI workflow runs typecheck, tests, build, and demo.
+- The CI workflow runs typecheck, tests, build, demo, and a package check.
 
 Run `npm test` to reproduce the results.
 
@@ -159,6 +178,7 @@ Run `npm test` to reproduce the results.
 - The bolt tables cover coarse metric threads from M5 to M36.
 - The bearing factors are typical values for deep-groove ball bearings.
 - The critical speed is a first-mode approximation.
+- The fatigue model uses typical Marin factors. Confirm critical designs with test data.
 - The built-in SQLite module of Node.js is still experimental.
 
 Check the cited sources for exact values.
@@ -168,10 +188,18 @@ Check the cited sources for exact values.
 The server grows in independent releases.
 Each release stays useful on its own.
 
-- Add fatigue analysis for cyclic loads.
-- Add press-fit and spring calculators.
-- Add more unit categories.
+### Complete
+
+- Fatigue analysis for cyclic loads.
+  The `fatigue_analysis` tool estimates the endurance limit and the safety factor.
+
+### Remaining
+
+- Add press-fit and interference-fit calculators.
+- Add a spring calculator for helical compression springs.
+- Add more unit categories, including viscosity and thermal conductivity.
 - Add HTTP transport.
+- Add a catalog of ISO and DIN standard sections.
 
 See [docs/integration.md](docs/integration.md) for the EngineerKit plan.
 

docs/integration.md

@@ -38,7 +38,12 @@ This server follows semantic versioning. Breaking a tool signature or the result
 
 Engineer MCP grows in independent releases. Each release stays useful on its own.
 
-- Add fatigue analysis for cyclic loads.
+### Complete
+
+- Fatigue analysis for cyclic loads. The `fatigue_analysis` tool estimates the endurance limit and the fatigue safety factor.
+
+### Remaining
+
 - Add press-fit and interference-fit calculators.
 - Add a spring calculator for helical compression springs.
 - Add more unit categories, including viscosity and thermal conductivity.

docs/mcp-tools.md

@@ -112,6 +112,40 @@ Inputs:
 - Cartesian mode uses `sigmaX`, `sigmaY`, `sigmaZ`, `tauXY`, `tauXZ`, `tauYZ`.
 - `yieldStrength`: enables the safety factor.
 
+## fatigue_analysis
+
+Compute the fatigue safety factor, corrected endurance limit, and estimated life of a cyclic stress.
+
+The tool follows the stress-life method of Shigley. It applies the Marin factors to estimate the endurance limit. It uses a mean stress failure line for the safety factor.
+
+Inputs:
+
+- `ultimateStrength`: ultimate tensile strength Sut in pascals.
+- `yieldStrength`: tensile yield strength in pascals. Enables the yield check and the Soderberg criterion.
+- `stressAmplitude`: stress amplitude of the cycle in pascals.
+- `meanStress`: mean stress of the cycle in pascals. The default is zero for a fully reversed cycle.
+- `enduranceLimit`: corrected endurance limit Se in pascals. When omitted, the tool estimates it from the Marin factors.
+- `surfaceFinish`: `ground`, `machined`, `hot_rolled`, or `as_forged`. Sets the surface factor ka. The default is `machined`.
+- `loading`: `bending`, `axial`, or `torsion`. Sets the load factor kc. The default is `bending`.
+- `sizeFactor`: size factor kb. The default is 1.
+- `criterion`: `goodman`, `soderberg`, or `gerber`. Sets the mean stress failure line. The default is `goodman`.
+- `targetSafetyFactor`: design safety factor. When set, the tool returns the allowable stress amplitude.
+
+Example:
+
+```json
+{
+  "ultimateStrength": 490000000,
+  "yieldStrength": 355000000,
+  "stressAmplitude": 220000000,
+  "meanStress": 60000000,
+  "surfaceFinish": "machined",
+  "loading": "bending"
+}
+```
+
+The tool reports a warning when the peak stress exceeds yield strength. It reports a warning when the fatigue safety factor falls below 1.
+
 ## unit_convert
 
 Convert a value between two units.

examples/demo.ts

@@ -73,6 +73,7 @@ type ToolHandlers = {
   shaft_analysis: Handler;
   bearing_life: Handler;
   von_mises: Handler;
+  fatigue_analysis: Handler;
   unit_convert: Handler;
   material_lookup: Handler;
 };
@@ -86,6 +87,7 @@ const tools: NamedHandler[] = [
   ["shaft_analysis", toolHandlers.shaft_analysis],
   ["bearing_life", toolHandlers.bearing_life],
   ["von_mises", toolHandlers.von_mises],
+  ["fatigue_analysis", toolHandlers.fatigue_analysis],
   ["unit_convert", toolHandlers.unit_convert],
   ["unit_convert (torque to energy)", toolHandlers.unit_convert],
   ["material_lookup", toolHandlers.material_lookup],
@@ -132,6 +134,15 @@ const inputs: Array<Record<string, unknown>> = [
     yieldStrength: 355e6,
     outputUnits: { vonMisesStress: "MPa", maxShearStress: "MPa" },
   },
+  {
+    ultimateStrength: 490e6,
+    yieldStrength: 355e6,
+    stressAmplitude: 220e6,
+    meanStress: 60e6,
+    surfaceFinish: "machined",
+    loading: "bending",
+    outputUnits: { enduranceLimit: "MPa", equivalentStressAmplitude: "MPa" },
+  },
   {
     value: 1000,
     from: "psi",

package.json

@@ -1,10 +1,18 @@
 {
   "name": "@engineerkit/engineer-mcp",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "MCP server for verified mechanical-engineering calculations, references, and material data.",
   "type": "module",
   "license": "MIT",
   "author": "EngineerKit",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/DanielCuevas1208/engineer-mcp.git"
+  },
+  "bugs": {
+    "url": "https://github.com/DanielCuevas1208/engineer-mcp/issues"
+  },
+  "homepage": "https://github.com/DanielCuevas1208/engineer-mcp#readme",
   "engines": {
     "node": ">=22.13.0"
   },