Pelican plugin for webmentions. This will not work out of the box for you; it's too kryogenix.org-specific. But it may help.

pelican-webmentions.py

from pelican import signals
import json, urllib, urlparse, datetime, html5lib, os, codecs

LIVESITEURL = ""
WM_CACHE_PATH = None
WM_CACHE = {
    "domains": {},
    "pinged": {}
}

def startup(p):
    global LIVESITEURL, WM_CACHE, WM_CACHE_PATH
    LIVESITEURL = p.settings.get("LIVESITEURL")
    if not LIVESITEURL:
        print "Webmentions error: no LIVESITEURL defined in settings"
    WM_CACHE_PATH = os.path.join(p.settings["PLUGIN_PATH"], "..", "webmentions.json")
    if os.path.exists(WM_CACHE_PATH):
        fp = codecs.open(WM_CACHE_PATH, encoding="utf8", mode="r")
        WM_CACHE = json.load(fp)
        fp.close()

def shutdown(p):
    global WM_CACHE, WM_CACHE_PATH
    fp = codecs.open(WM_CACHE_PATH, encoding="utf8", mode="w")
    fp.write(json.dumps(WM_CACHE))
    fp.close()

def fetch_webmentions(generator):
    global LIVESITEURL
    if not LIVESITEURL: return
    site = urlparse.urlparse(LIVESITEURL).netloc
    print "Fetching webmentions for", site
    try:
        fp = urllib.urlopen(
            "https://webmention.herokuapp.com/api/mentions?%s" % 
            urllib.urlencode({"site": site}))
        j = json.load(fp)
    except:
        raise
    by_target = {}
    for x in j:
        wm = {
            "name": x.get("name", ""),
            "published": datetime.datetime.utcfromtimestamp(x.get("published", 954790000000) / 1000),
            "summary": x.get("summary", ""),
            "author_name": x.get("author", {"name": "An unnamed person"}).get("name", "An unnamed person"),
            "author_photo": x.get("author", {"photo": "http://www.gravatar.com/avatar/no?d=mm"}).get("photo", "http://www.gravatar.com/avatar/no?d=mm"),
            "author_url": x.get("author", {"url": ""}).get("url", ""),
            "url": x.get("url", ""),
        }
        if wm["author_photo"] is None:
            wm["author_photo"] = "http://www.gravatar.com/avatar/no?d=mm"
        if wm["url"]:
            wm["parsed_url"] = urlparse.urlparse(wm["url"])
        else:
            wm["parsed_url"] = None
        for t in x["targets"]:
            if t not in by_target:
                by_target[t] = []
            by_target[t].append(wm)
    for article in list(generator.articles):
        article.webmentions = []
        for target, wms in by_target.items():
            if target.endswith(article.url):
                article.webmentions = wms
        if article.webmentions:
            print "Found %s webmentions for %s" % (len(article.webmentions), article.url)

def send_webmentions(generator):
    global LIVESITEURL
    if not LIVESITEURL: return
    counts = {"pinged in past": 0, "no webmentions endpoint": 0, "webmentions endpoint error": 0, "pinged": 0}
    for article in list(generator.articles):
        myurl = "/".join([LIVESITEURL, article.url])
        parser = html5lib.HTMLParser(tree=html5lib.getTreeBuilder("dom"))
        dom = parser.parse(article._content)
        for a in dom.getElementsByTagName("a"):
            href = a.getAttribute("href")
            if not href.startswith("http:") and not href.startswith("https:"): continue
            #print "WM:", article.url[:17]+"...", "->", href[:25]+ "...",
            cache_key = myurl + " + " + href
            if cache_key in WM_CACHE["pinged"]:
                #print "done in past."
                counts["pinged in past"] += 1
                continue
            domain = urlparse.urlparse(href).netloc
            # get webmentions endpoint, if there is one
            endpoint = WM_CACHE["domains"].get(domain, None)
            if endpoint is None:
                # fetch one and cache it
                try:
                    fp = urllib.urlopen(href)
                    link = None
                    linkheader = fp.info().getheader("Link")
                    if linkheader:
                        parts = linkheader.split(";")
                        if len(parts) == 2 and parts[1].strip() == 'rel="webmention"':
                            link = parts[0].strip().replace("<", "").replace(">", "")
                    if not link:
                        parser2 = html5lib.HTMLParser(tree=html5lib.getTreeBuilder("dom"))
                        dom2 = parser.parse(fp.read())
                        for linkel in dom2.getElementsByTagName("link"):
                            if linkel.getAttribute("rel") == "webmention" or \
                               linkel.getAttribute("rel") == "http://webmention.org/ webmention" or \
                               linkel.getAttribute("rel") == "webmention http://webmention.org/":
                               link = linkel.getAttribute("href")
                        if not link:
                            for ael in dom2.getElementsByTagName("a"):
                                if ael.getAttribute("rel") == "webmention" or \
                                   ael.getAttribute("rel") == "http://webmention.org/ webmention" or \
                                   ael.getAttribute("rel") == "webmention http://webmention.org/":
                                   link = ael.getAttribute("href")
                    if link:
                        endpoint = link
                    else:
                        endpoint = False
                        #print "no endpoint."
                except:
                    #print "endpoint error."
                    endpoint = False
                WM_CACHE["domains"][domain] = endpoint
            
            if endpoint == False:
                # we have checked already and there is definitely no endpoint
                #print "no endpoint (cached)."
                counts["no webmentions endpoint"] += 1
                continue

            # now actually ping the endpoint
            try:
                fp2 = urllib.urlopen(endpoint, data=urllib.urlencode({"source": myurl, "target": href}))
                if fp2.getcode() == 200 or fp2.getcode() == 202:
                    #print "ok."
                    counts["pinged"] += 1
                else:
                    #print "failed (code %s)" % fp2.getcode()
                    counts["webmentions endpoint error"] += 1
            except:
                #print "bad endpoint (%s)" % (endpoint,)
                counts["webmentions endpoint error"] += 1
                WM_CACHE["domains"][domain] = False
            WM_CACHE["pinged"][cache_key] = datetime.datetime.now().isoformat()
    print "Sent webmentions: ", ", ".join(["%s: %s" % x for x in counts.items()])

def register():
    signals.article_generator_finalized.connect(fetch_webmentions)
    signals.article_generator_finalized.connect(send_webmentions)
    signals.initialized.connect(startup)
    signals.finalized.connect(shutdown)