Regenerate dynamic API docs on every build

OpenAPI spec, Python API reference, and C API reference are derived from
code and regenerated by fern/generate_api_docs.py on every docs build.
RST→MDX conversion is still gone; hand-edited MDX pages are not touched.

- Restore fern/extract_python_api.py and fern/extract_c_api.py
- Add fern/generate_api_docs.py (orchestrates the three dynamic outputs)
- Restore fern/requirements-docs.txt (fastapi, pydantic, pyyaml)
- build.sh docs: run generate_api_docs.py before fern check
- CI: install Python deps, run generate_api_docs.py, then fern check
- Re-add C++/Python source paths to CI triggers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ramakrishnap-nv

.github/workflows/fern-docs.yml

@@ -6,10 +6,18 @@ on:
       - main
     paths:
       - "fern/**"
+      - "cpp/**/*.h"
+      - "cpp/**/*.hpp"
+      - "python/cuopt/cuopt/**"
+      - "python/cuopt_server/**"
       - ".github/workflows/fern-docs.yml"
   pull_request:
     paths:
       - "fern/**"
+      - "cpp/**/*.h"
+      - "cpp/**/*.hpp"
+      - "python/cuopt/cuopt/**"
+      - "python/cuopt_server/**"
   workflow_dispatch:
   # Stage 2: triggered after a PR build completes.
   # Runs in base-branch context so FERN_TOKEN secret is accessible.
@@ -24,6 +32,19 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install Python dependencies
+        run: |
+          pip install -r fern/requirements-docs.txt
+          pip install -e python/cuopt_server --no-deps
+
+      - name: Regenerate dynamic API docs
+        run: python fern/generate_api_docs.py
+
       - name: Install Fern CLI
         run: npm install -g fern-api@$(jq -r .version fern/fern.config.json)
 

build.sh

@@ -457,6 +457,21 @@ if hasArg docs; then
         npm install -g "fern-api@${FERN_VERSION}"
     fi
 
+    # Regenerate dynamic API reference pages (OpenAPI spec, Python API, C API)
+    if command -v python3 &>/dev/null || command -v python &>/dev/null; then
+        PY=${PYTHON:-python3}
+        pip install --quiet -r "${REPODIR}/fern/requirements-docs.txt"
+        if pip install --quiet -e "${REPODIR}/python/cuopt_server" --no-deps 2>/dev/null; then
+            ${PY} "${REPODIR}/fern/generate_api_docs.py"
+        else
+            echo "  [WARN] cuopt_server not installable; skipping OpenAPI spec regeneration."
+            echo "         Python API and C API docs will still be regenerated."
+            ${PY} "${REPODIR}/fern/generate_api_docs.py"
+        fi
+    else
+        echo "  [WARN] Python not found; skipping API doc generation."
+    fi
+
     echo "Running fern check..."
     fern check
 

dependencies.yaml

@@ -788,6 +788,9 @@ dependencies:
         packages:
           - jq
           - nodejs        # provides npm; used to install fern-api CLI
+          - *pyyaml
+          - fastapi
+          - pydantic
 
   notebooks:
     common: