DanielCuevas1208 · DanielCuevas1208 · Aug 3, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -4,6 +4,14 @@ on:
   push:
     branches: [main]
   pull_request:
+  workflow_dispatch:
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
 
 jobs:
   verify:

diff --git a/README.md b/README.md
@@ -6,7 +6,7 @@
 [![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, springs, shafts, bearings, stress, sections, and units.
+It gives coding agents verified answers for beams, bolts, springs, shafts, bearings, fatigue, stress, sections, and units.
 Every result shows the formula, the method, and the source.
 
 ## What it provides
@@ -23,6 +23,7 @@ The release covers these domains:
 - Shaft torsion and first critical speed.
 - Bearing rating life to ISO 281.
 - von Mises equivalent stress.
+- Fatigue life and safety factor for cyclic stress.
 - Cross-section properties.
 - Dimension-safe unit conversion.
 - Material property lookup.
@@ -38,7 +39,7 @@ The unit layer knows the dimension of every unit.
 It rejects a conversion between incompatible quantities.
 For example, it rejects a torque-to-energy conversion.
 
-Safety factors appear only when you provide a yield strength.
+Yield-based safety factors appear only when you provide a yield strength.
 The tool never hides an assumption.
 Warnings surface when a method uses an approximation.
 
@@ -53,6 +54,7 @@ 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` | Fatigue safety factor, endurance limit, and predicted life for cyclic loads. |
 | `unit_convert` | Conversion between compatible units. |
 | `material_lookup` | Curated mechanical properties of materials. |
 
@@ -154,6 +156,24 @@ Error: Category mismatch: N·m is torque, J is energy.
 Use a unit of the same quantity.
 ```
 
+A call to `fatigue_analysis` for an S355 steel part with 180 MPa alternating stress and 40 MPa mean stress:
+
+```text
+Base endurance limit                     245 MPa
+Endurance correction factor             0.765
+Corrected endurance limit              187.4 MPa
+Fatigue strength at 10^3 cycles         441 MPa
+Equivalent fully reversed amplitude       196 MPa
+Predicted fatigue life                696874 cycles
+Fatigue safety factor                  0.9597
+
+Method: Fatigue analysis for fluctuating stress
+Formula: Se' = 0.5 Sut, Se = ka kb kc kd ke kf Se', Goodman: n = 1/(sa/Se + sm/Sut)
+References:
+  - Shigley's Mechanical Engineering Design (Tenth edition, 2015)
+  - Machinery's Handbook (Thirty-first edition)
+```
+
 ## Development
 
 | Command | Purpose |
@@ -169,7 +189,7 @@ 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.
 
-- 98 tests across 10 files.
+- 130 tests across 11 files.
 - All tests pass on Node 22 and Node 24.
 - The CI workflow runs typecheck, tests, build, demo, and a package check.
 
@@ -183,7 +203,10 @@ Run `npm test` to reproduce the results.
 - The bearing factors are typical values for deep-groove ball bearings.
 - The critical speed is a first-mode approximation.
 - The spring design covers static round-wire springs only.
-  It does not estimate fatigue life for cyclic loads.
+  Use `fatigue_analysis` for cyclic loads.
+- The fatigue analysis uses the stress-life method.
+  It assumes a fully reversed load corrected for the mean stress.
+  It estimates the endurance limit for steel unless you supply a tested value.
 - The built-in SQLite module of Node.js is still experimental.
 
 Check the cited sources for exact values.
@@ -195,12 +218,19 @@ Each release stays useful on its own.
 
 ### Complete
 
+- Beam bending stress, deflection, and safety factor.
+- Cross-section properties for five common shapes.
+- ISO 898 bolt tensile design.
 - Helical compression spring design.
-  The `spring_design` tool reports the spring rate, the shear stress, and the safety factor.
+- Shaft torsion and first lateral critical speed.
+- ISO 281 bearing rating life.
+- von Mises equivalent stress.
+- Fatigue analysis for cyclic loads.
+  The `fatigue_analysis` tool reports the corrected endurance limit, the safety factor by four criteria, and the predicted life.
+- Dimension-safe unit conversion and material lookup.
 
 ### Remaining
 
-- Add fatigue analysis for cyclic loads.
 - Add press-fit and interference-fit calculators.
 - Add more unit categories, including viscosity and thermal conductivity.
 - Add HTTP transport.

diff --git a/data/references.json b/data/references.json
@@ -3,7 +3,7 @@
     "title": "Shigley's Mechanical Engineering Design",
     "source": "McGraw-Hill Education",
     "edition": "Tenth edition, 2015",
-    "section": "Chapters 3, 5, 8, 11, and 12",
+    "section": "Chapters 3, 5, 6, 8, 11, and 12",
     "note": "Standard reference for strength, fatigue, fasteners, and bearings."
   },
   "roark-2011": {

diff --git a/docs/integration.md b/docs/integration.md
@@ -40,11 +40,18 @@ Engineer MCP grows in independent releases. Each release stays useful on its own
 
 ### Complete
 
+- Beam bending stress, deflection, and safety factor. The `beam_bending` tool covers point and uniform loads on two supports.
+- Cross-section properties. The `section_properties` tool covers five common shapes.
+- ISO 898 bolt tensile design. The `bolt_strength` tool reports stress area, preload, and capacity.
 - Helical compression spring design. The `spring_design` tool computes the spring rate, the shear stress, and the safety factor.
+- Shaft torsion and critical speed. The `shaft_analysis` tool covers solid and hollow shafts.
+- ISO 281 bearing rating life. The `bearing_life` tool reports life in revolutions and hours.
+- von Mises equivalent stress. The `von_mises` tool covers principal and cartesian stress states.
+- Fatigue analysis for cyclic loads. The `fatigue_analysis` tool reports the corrected endurance limit, the safety factor by four criteria, and the predicted life.
+- Dimension-safe unit conversion and material lookup.
 
 ### Remaining
 
-- Add fatigue analysis for cyclic loads.
 - Add press-fit and interference-fit calculators.
 - Add more unit categories, including viscosity and thermal conductivity.
 - Add HTTP transport in addition to stdio.

diff --git a/docs/mcp-tools.md b/docs/mcp-tools.md
@@ -146,6 +146,27 @@ 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 predicted life of a fluctuating stress state.
+
+The tool defaults to the modified Goodman criterion. It also supports Gerber, Soderberg, and ASME-elliptic criteria.
+
+The endurance limit defaults to 0.5 x ultimate strength for steel. Supply a tested value when you have one.
+
+Inputs:
+
+- `material`: material name from the database. Provides the ultimate and yield strength.
+- `ultimateStrength`: ultimate tensile strength in pascals. Required when no material is set.
+- `yieldStrength`: tensile yield strength in pascals. Required for Soderberg and ASME-elliptic.
+- `enduranceLimit`: tested endurance limit in pascals. Defaults to the steel estimate.
+- `stressAmplitude`: alternating stress in pascals.
+- `meanStress`: mean stress in pascals. The default is zero.
+- `surfaceFactor`, `sizeFactor`, `loadFactor`, `temperatureFactor`, `reliabilityFactor`, `miscellaneousFactor`: Marin correction factors. Each defaults to 1.
+- `criterion`: `goodman`, `gerber`, `soderberg`, or `asme_elliptic`. The default is `goodman`.
+
+The tool warns when it estimates the endurance limit. It warns when the predicted life falls below 10^3 cycles.
+
 ## unit_convert
 
 Convert a value between two units.

diff --git a/examples/demo.ts b/examples/demo.ts
@@ -74,6 +74,7 @@ type ToolHandlers = {
   shaft_analysis: Handler;
   bearing_life: Handler;
   von_mises: Handler;
+  fatigue_analysis: Handler;
   unit_convert: Handler;
   material_lookup: Handler;
 };
@@ -88,6 +89,7 @@ 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],
@@ -145,6 +147,15 @@ const inputs: Array<Record<string, unknown>> = [
     yieldStrength: 355e6,
     outputUnits: { vonMisesStress: "MPa", maxShearStress: "MPa" },
   },
+  {
+    material: "Structural steel S355",
+    stressAmplitude: 180e6,
+    meanStress: 40e6,
+    surfaceFactor: 0.85,
+    sizeFactor: 0.9,
+    criterion: "goodman",
+    outputUnits: { correctedEnduranceLimit: "MPa", equivalentAmplitude: "MPa" },
+  },
   {
     value: 1000,
     from: "psi",

diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@engineerkit/engineer-mcp",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "MCP server for verified mechanical-engineering calculations, references, and material data.",
   "type": "module",
   "license": "MIT",