diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -20,6 +20,9 @@
     nullid,
     short,
 )
+from .thirdparty.zope import (
+    interface as zi,
+)
 from . import (
     bookmarks,
     branchmap,
@@ -318,6 +321,7 @@
 # set to reflect that the extension knows how to handle that requirements.
 featuresetupfuncs = set()
 
+@zi.implementer(repository.completelocalrepository)
 class localrepository(object):
 
     # obsolete experimental requirements:
diff --git a/mercurial/repository.py b/mercurial/repository.py
--- a/mercurial/repository.py
+++ b/mercurial/repository.py
@@ -10,6 +10,9 @@
 import abc
 
 from .i18n import _
+from .thirdparty.zope import (
+    interface as zi,
+)
 from . import (
     error,
 )
@@ -266,3 +269,360 @@
 
 class legacypeer(peer, _baselegacywirecommands):
     """peer but with support for legacy wire protocol commands."""
+
+class completelocalrepository(zi.Interface):
+    """Monolithic interface for local repositories.
+
+    This currently captures the reality of things - not how things should be.
+    """
+
+    supportedformats = zi.Attribute(
+        """Set of requirements that apply to stream clone.
+
+        This is actually a class attribute and is shared among all instances.
+        """)
+
+    openerreqs = zi.Attribute(
+        """Set of requirements that are passed to the opener.
+
+        This is actually a class attribute and is shared among all instances.
+        """)
+
+    supported = zi.Attribute(
+        """Set of requirements that this repo is capable of opening.""")
+
+    requirements = zi.Attribute(
+        """Set of requirements this repo uses.""")
+
+    filtername = zi.Attribute(
+        """Name of the repoview that is active on this repo.""")
+
+    wvfs = zi.Attribute(
+        """VFS used to access the working directory.""")
+
+    vfs = zi.Attribute(
+        """VFS rooted at the .hg directory.
+
+        Used to access repository data not in the store.
+        """)
+
+    svfs = zi.Attribute(
+        """VFS rooted at the store.
+
+        Used to access repository data in the store. Typically .hg/store.
+        But can point elsewhere if the store is shared.
+        """)
+
+    root = zi.Attribute(
+        """Path to the root of the working directory.""")
+
+    path = zi.Attribute(
+        """Path to the .hg directory.""")
+
+    origroot = zi.Attribute(
+        """The filesystem path that was used to construct the repo.""")
+
+    auditor = zi.Attribute(
+        """A pathauditor for the working directory.
+
+        This checks if a path refers to a nested repository.
+
+        Operates on the filesystem.
+        """)
+
+    nofsauditor = zi.Attribute(
+        """A pathauditor for the working directory.
+
+        This is like ``auditor`` except it doesn't do filesystem checks.
+        """)
+
+    baseui = zi.Attribute(
+        """Original ui instance passed into constructor.""")
+
+    ui = zi.Attribute(
+        """Main ui instance for this instance.""")
+
+    sharedpath = zi.Attribute(
+        """Path to the .hg directory of the repo this repo was shared from.""")
+
+    store = zi.Attribute(
+        """A store instance.""")
+
+    spath = zi.Attribute(
+        """Path to the store.""")
+
+    sjoin = zi.Attribute(
+        """Alias to self.store.join.""")
+
+    cachevfs = zi.Attribute(
+        """A VFS used to access the cache directory.
+
+        Typically .hg/cache.
+        """)
+
+    filteredrevcache = zi.Attribute(
+        """Holds sets of revisions to be filtered.""")
+
+    names = zi.Attribute(
+        """A ``namespaces`` instance.""")
+
+    def close():
+        """Close the handle on this repository."""
+
+    def peer():
+        """Obtain an object conforming to the ``peer`` interface."""
+
+    def unfiltered():
+        """Obtain an unfiltered/raw view of this repo."""
+
+    def filtered(name, visibilityexceptions=None):
+        """Obtain a named view of this repository."""
+
+    obsstore = zi.Attribute(
+        """A store of obsolescence data.""")
+
+    changelog = zi.Attribute(
+        """A handle on the changelog revlog.""")
+
+    manifestlog = zi.Attribute(
+        """A handle on the root manifest revlog.""")
+
+    dirstate = zi.Attribute(
+        """Working directory state.""")
+
+    narrowpats = zi.Attribute(
+        """Matcher patterns for this repository's narrowspec.""")
+
+    def narrowmatch():
+        """Obtain a matcher for the narrowspec."""
+
+    def setnarrowpats(newincludes, newexcludes):
+        """Define the narrowspec for this repository."""
+
+    def __getitem__(changeid):
+        """Try to resolve a changectx."""
+
+    def __contains__(changeid):
+        """Whether a changeset exists."""
+
+    def __nonzero__():
+        """Always returns True."""
+        return True
+
+    __bool__ = __nonzero__
+
+    def __len__():
+        """Returns the number of changesets in the repo."""
+
+    def __iter__():
+        """Iterate over revisions in the changelog."""
+
+    def revs(expr, *args):
+        """Evaluate a revset.
+
+        Emits revisions.
+        """
+
+    def set(expr, *args):
+        """Evaluate a revset.
+
+        Emits changectx instances.
+        """
+
+    def anyrevs(specs, user=False, localalias=None):
+        """Find revisions matching one of the given revsets."""
+
+    def url():
+        """Returns a string representing the location of this repo."""
+
+    def hook(name, throw=False, **args):
+        """Call a hook."""
+
+    def tags():
+        """Return a mapping of tag to node."""
+
+    def tagtype(tagname):
+        """Return the type of a given tag."""
+
+    def tagslist():
+        """Return a list of tags ordered by revision."""
+
+    def nodetags(node):
+        """Return the tags associated with a node."""
+
+    def nodebookmarks(node):
+        """Return the list of bookmarks pointing to the specified node."""
+
+    def branchmap():
+        """Return a mapping of branch to heads in that branch."""
+
+    def revbranchcache():
+        pass
+
+    def branchtip(branchtip, ignoremissing=False):
+        """Return the tip node for a given branch."""
+
+    def lookup(key):
+        """Resolve the node for a revision."""
+
+    def lookupbranch(key, remote=None):
+        """Look up the branch name of the given revision or branch name."""
+
+    def known(nodes):
+        """Determine whether a series of nodes is known.
+
+        Returns a list of bools.
+        """
+
+    def local():
+        """Whether the repository is local."""
+        return True
+
+    def publishing():
+        """Whether the repository is a publishing repository."""
+
+    def cancopy():
+        pass
+
+    def shared():
+        """The type of shared repository or None."""
+
+    def wjoin(f, *insidef):
+        """Calls self.vfs.reljoin(self.root, f, *insidef)"""
+
+    def file(f):
+        """Obtain a filelog for a tracked path."""
+
+    def changectx(changeid):
+        """Obtains a changectx for a revision.
+
+        Identical to __getitem__.
+        """
+
+    def setparents(p1, p2):
+        """Set the parent nodes of the working directory."""
+
+    def filectx(path, changeid=None, fileid=None):
+        """Obtain a filectx for the given file revision."""
+
+    def getcwd():
+        """Obtain the current working directory from the dirstate."""
+
+    def pathto(f, cwd=None):
+        """Obtain the relative path to a file."""
+
+    def adddatafilter(name, fltr):
+        pass
+
+    def wread(filename):
+        """Read a file from wvfs, using data filters."""
+
+    def wwrite(filename, data, flags, backgroundclose=False, **kwargs):
+        """Write data to a file in the wvfs, using data filters."""
+
+    def wwritedata(filename, data):
+        """Resolve data for writing to the wvfs, using data filters."""
+
+    def currenttransaction():
+        """Obtain the current transaction instance or None."""
+
+    def transaction(desc, report=None):
+        """Open a new transaction to write to the repository."""
+
+    def undofiles():
+        """Returns a list of (vfs, path) for files to undo transactions."""
+
+    def recover():
+        """Roll back an interrupted transaction."""
+
+    def rollback(dryrun=False, force=False):
+        """Undo the last transaction.
+
+        DANGEROUS.
+        """
+
+    def updatecaches(tr=None, full=False):
+        """Warm repo caches."""
+
+    def invalidatecaches():
+        """Invalidate cached data due to the repository mutating."""
+
+    def invalidatevolatilesets():
+        pass
+
+    def invalidatedirstate():
+        """Invalidate the dirstate."""
+
+    def invalidate(clearfilecache=False):
+        pass
+
+    def invalidateall():
+        pass
+
+    def lock(wait=True):
+        """Lock the repository store and return a lock instance."""
+
+    def wlock(wait=True):
+        """Lock the non-store parts of the repository."""
+
+    def currentwlock():
+        """Return the wlock if it's held or None."""
+
+    def checkcommitpatterns(wctx, vdirs, match, status, fail):
+        pass
+
+    def commit(text='', user=None, date=None, match=None, force=False,
+               editor=False, extra=None):
+        """Add a new revision to the repository."""
+
+    def commitctx(ctx, error=False):
+        """Commit a commitctx instance to the repository."""
+
+    def destroying():
+        """Inform the repository that nodes are about to be destroyed."""
+
+    def destroyed():
+        """Inform the repository that nodes have been destroyed."""
+
+    def status(node1='.', node2=None, match=None, ignored=False,
+               clean=False, unknown=False, listsubrepos=False):
+        """Convenience method to call repo[x].status()."""
+
+    def addpostdsstatus(ps):
+        pass
+
+    def postdsstatus():
+        pass
+
+    def clearpostdsstatus():
+        pass
+
+    def heads(start=None):
+        """Obtain list of nodes that are DAG heads."""
+
+    def branchheads(branch=None, start=None, closed=False):
+        pass
+
+    def branches(nodes):
+        pass
+
+    def between(pairs):
+        pass
+
+    def checkpush(pushop):
+        pass
+
+    prepushoutgoinghooks = zi.Attribute(
+        """util.hooks instance.""")
+
+    def pushkey(namespace, key, old, new):
+        pass
+
+    def listkeys(namespace):
+        pass
+
+    def debugwireargs(one, two, three=None, four=None, five=None):
+        pass
+
+    def savecommitmessage(text):
+        pass
diff --git a/tests/test-check-interfaces.py b/tests/test-check-interfaces.py
--- a/tests/test-check-interfaces.py
+++ b/tests/test-check-interfaces.py
@@ -2,16 +2,27 @@
 
 from __future__ import absolute_import, print_function
 
+import os
+
+from mercurial.thirdparty.zope import (
+    interface as zi,
+)
+from mercurial.thirdparty.zope.interface import (
+    verify as ziverify,
+)
 from mercurial import (
     bundlerepo,
     httppeer,
     localrepo,
+    repository,
     sshpeer,
     statichttprepo,
     ui as uimod,
     unionrepo,
 )
 
+rootdir = os.path.normpath(os.path.join(os.path.dirname(__file__), '..'))
+
 def checkobject(o):
     """Verify a constructed object conforms to interface rules.
 
@@ -41,6 +52,30 @@
         print('public attributes not in abstract interface: %s.%s' % (
             name, attr))
 
+def checkzobject(o):
+    """Verify an object with a zope interface."""
+    ifaces = zi.providedBy(o)
+    if not ifaces:
+        print('%r does not provide any zope interfaces' % o)
+        return
+
+    # Run zope.interface's built-in verification routine. This verifies that
+    # everything that is supposed to be present is present.
+    for iface in ifaces:
+        ziverify.verifyObject(iface, o)
+
+    # Now verify that the object provides no extra public attributes that
+    # aren't declared as part of interfaces.
+    allowed = set()
+    for iface in ifaces:
+        allowed |= set(iface.names(all=True))
+
+    public = {a for a in dir(o) if not a.startswith('_')}
+
+    for attr in sorted(public - allowed):
+        print('public attribute not declared in interfaces: %s.%s' % (
+            o.__class__.__name__, attr))
+
 # Facilitates testing localpeer.
 class dummyrepo(object):
     def __init__(self):
@@ -68,6 +103,8 @@
 
 def main():
     ui = uimod.ui()
+    # Needed so we can open a local repo with obsstore without a warning.
+    ui.setconfig('experimental', 'evolution.createmarkers', True)
 
     checkobject(badpeer())
     checkobject(httppeer.httppeer(None, None, None, dummyopener()))
@@ -80,4 +117,9 @@
     checkobject(statichttprepo.statichttppeer(dummyrepo()))
     checkobject(unionrepo.unionpeer(dummyrepo()))
 
+    ziverify.verifyClass(repository.completelocalrepository,
+                         localrepo.localrepository)
+    repo = localrepo.localrepository(ui, rootdir)
+    checkzobject(repo)
+
 main()