from fastapi import FastAPI
from mcp.server.fastmcp import FastMCP
from packaging.version import parse, InvalidVersion
from typing import Any
import requests
import json
import re
import os
mcp = FastMCP("GitHub Releases")
GITHUB_API_BASE = "https://api.github.com"
REPO_MAPPING = {}
# Load repo mapping if available
mapping_file = os.path.join(os.path.dirname(__file__), "repo_mapping.json")
if os.path.exists(mapping_file):
try:
with open(mapping_file, "r") as f:
REPO_MAPPING = json.load(f)
except Exception as e:
print(f"Warning: Failed to load repo_mapping.json: {e}")
def is_stable_version(tag_name: str) -> bool:
"""
Checks if a tag name represents a stable version.
"""
if not tag_name:
return False
tag = tag_name.lower()
# Quick filter for common patterns before expensive parsing
unstable_patterns = [r"rc\d*", r"alpha", r"beta", r"dev", r"nightly", r"preview", r"canary", r"pre", r"enterprise", r"ent"]
for pattern in unstable_patterns:
if re.search(pattern, tag):
return False
# Try strict parsing if possible
try:
v = parse(tag_name)
if v.is_prerelease or v.is_devrelease:
return False
return True
except InvalidVersion:
# Fallback to regex heuristics if packaging can't parse it
return tag[0].isdigit() or tag.startswith('v')
def get_latest_github_release(owner: str, repo: str) -> dict[str, Any]:
url = f"{GITHUB_API_BASE}/repos/{owner}/{repo}/releases"
headers = {
"Accept": "application/vnd.github.v3+json",
"User-Agent": "releases-mcp-server"
}
github_token = os.getenv("GITHUB_TOKEN")
if github_token:
headers["Authorization"] = f"token {github_token}"
response = requests.get(url, headers=headers, allow_redirects=True)
if response.status_code == 404:
raise Exception(f"Repository {owner}/{repo} not found")
response.raise_for_status()
releases = response.json()
candidates: list[tuple[Any, dict[str, Any]]] = []
for release in releases:
tag_name = release.get("tag_name", "")
is_draft = release.get("draft", False)
is_prerelease = release.get("prerelease", False)
if not is_draft and not is_prerelease and is_stable_version(tag_name):
try:
v = parse(tag_name)
candidates.append((v, release))
except InvalidVersion:
# If we can't parse it, we can't reliably sort it against others.
# We could include it with a dummy logic or skip.
# For now, let's treat it as a valid candidate but use published_at for sorting?
# Or skipping for robustness.
continue
if candidates:
# Sort by version strictly
candidates.sort(key=lambda x: x[0], reverse=True)
release = candidates[0][1]
return {
"tag_name": release.get("tag_name"),
"name": release.get("name"),
"published_at": release.get("published_at"),
"html_url": release.get("html_url"),
"body": release.get("body")
}
# If no release found in the list, try the /latest endpoint
# ... fallback logic remains ...
latest_url = f"{GITHUB_API_BASE}/repos/{owner}/{repo}/releases/latest"
response = requests.get(latest_url, headers=headers, allow_redirects=True)
if response.status_code == 200:
release = response.json()
tag_name = release.get("tag_name", "")
if is_stable_version(tag_name):
return {
"tag_name": tag_name,
"name": release.get("name"),
"published_at": release.get("published_at"),
"html_url": release.get("html_url"),
"body": release.get("body")
}
raise Exception(f"No stable release found for {owner}/{repo}")
@mcp.tool()
def get_latest_release(repo: str, owner: str | None = None) -> str:
"""
Get the latest stable release version of a GitHub repository.
Args:
repo: The name of the repository (e.g., 'fastapi') or a known product alias (e.g. 'nomad')
owner: The owner of the repository (e.g., 'fastapi'). Optional if 'repo' is a known alias.
"""
# 1. Resolve alias if owner is missing
target_repo = repo
if not owner:
# A. Check keys
if repo.lower() in REPO_MAPPING:
entry = REPO_MAPPING[repo.lower()]
# Handle dict structure or legacy string
if isinstance(entry, dict):
full_name = entry.get("repo", "")
else:
full_name = entry
if "/" in full_name:
owner, target_repo = full_name.split("/", 1)
# B. Check aliases (case-insensitive)
if not owner:
for key, entry in REPO_MAPPING.items():
if isinstance(entry, dict):
aliases = [a.lower() for a in entry.get("aliases", [])]
if repo.lower() in aliases:
full_name = entry.get("repo", "")
if "/" in full_name:
owner, target_repo = full_name.split("/", 1)
break
repo = target_repo
# 2. Validation
if not owner:
return f"Error: Owner is required for repository '{repo}'. Please specify the owner or add '{repo}' to repo_mapping.json."
try:
release_info = get_latest_github_release(owner, repo)
content = (
f"Latest stable release for {owner}/{repo}:\n"
f"Version: {release_info['tag_name']}\n"
f"Name: {release_info['name']}\n"
f"Published at: {release_info['published_at']}\n"
f"URL: {release_info['html_url']}\n"
)
return content
except Exception as e:
return f"Error: {str(e)}"
app = FastAPI()
app.mount("/", mcp.sse_app())
