diff --git a/stovepipe/core/filter/filter.go b/stovepipe/core/filter/filter.go
new file mode 100644
index 00000000..356f6d56
--- /dev/null
+++ b/stovepipe/core/filter/filter.go
@@ -0,0 +1,41 @@
+// Copyright (c) 2025 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package filter implements a filter for commit events.
+package filter
+
+import (
+	"strings"
+
+	"github.com/uber/submitqueue/stovepipe/entity"
+)
+
+// Config controls which VCS URIs are watched.
+// WatchedURIPrefixes is a list of URI prefixes to match against ChangeInfo.URI.
+// Example: "git://github.com/uber/go-code/refs/heads/main"
+// watches all commits on the main branch of uber/go-code.
+type Config struct {
+	WatchedURIPrefixes []string
+}
+
+// ShouldProcess returns true if the commit event's URI matches
+// any of the configured watched prefixes.
+func ShouldProcess(cfg Config, event entity.ChangeInfo) bool {
+	for _, prefix := range cfg.WatchedURIPrefixes {
+		if strings.HasPrefix(event.URI, prefix) {
+			return true
+		}
+	}
+	return false
+}
diff --git a/stovepipe/entity/entity.go b/stovepipe/entity/entity.go
index 15ac8680..80c625df 100644
--- a/stovepipe/entity/entity.go
+++ b/stovepipe/entity/entity.go
@@ -4,7 +4,7 @@
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
-//     http://www.apache.org/licenses/LICENSE-2.0
+//	http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ -12,5 +12,38 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package entity holds Stovepipe-specific domain types (distinct from shared repo entity/).
+// Package entity holds Stovepipe-specific domain entities.
 package entity
+
+// ChangeInfo represents a new change detected on a VCS remote.
+// It is intentionally VCS-agnostic: the URI scheme carries the
+// provider identity, mirroring the github:// scheme used in
+// SubmitQueue's ChangeInfo.
+//
+// URI format: "git://<host>/<repo>/<ref>/<new-revision>"
+// Example:    "git://github.com/uber/go-code/refs/heads/main/c3a4d5e6f789..."
+//
+// Fields are immutable after construction.
+type ChangeInfo struct {
+	// URI is the canonical VCS identifier for this change.
+	// Scheme is "git://"; path encodes host, repo, ref, and new revision.
+	// This mirrors the ChangeInfo.URI pattern used in SubmitQueue.
+	URI string `json:"uri"`
+
+	// PreviousURI is the URI of the prior revision on the same ref, if known.
+	// Empty string if unavailable.
+	// Example: "git://github.com/uber/go-code/refs/heads/main/aabbccdd..."
+	PreviousURI string `json:"previous_uri,omitempty"`
+
+	// Author is the identity of the person who authored the change.
+	Author Author `json:"author"`
+}
+
+// Author identifies the person who authored a change.
+// Mirrors SubmitQueue's Author to keep the two domains consistent.
+type Author struct {
+	// Name is the display name of the author.
+	Name string `json:"name"`
+	// Email is the email address of the author.
+	Email string `json:"email,omitempty"`
+}
diff --git a/stovepipe/extension/changeingester/logging.go b/stovepipe/extension/changeingester/logging.go
new file mode 100644
index 00000000..e3c50e57
--- /dev/null
+++ b/stovepipe/extension/changeingester/logging.go
@@ -0,0 +1,46 @@
+// Copyright (c) 2025 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package changeingester provides ChangeIngester implementations.
+package changeingester
+
+import (
+	"context"
+
+	"github.com/uber/submitqueue/stovepipe/entity"
+	"github.com/uber/submitqueue/stovepipe/extension"
+	"go.uber.org/zap"
+)
+
+// LoggingHandler is a stub ChangeHandler that logs received changes.
+// Replace with real persistence logic once DB schema is ready.
+type LoggingHandler struct {
+	logger *zap.Logger
+}
+
+// New constructs a new LoggingHandler.
+// The return type enforces interface compliance at compile time.
+func New(logger *zap.Logger) extension.ChangeHandler {
+	return LoggingHandler{logger: logger}
+}
+
+func (h LoggingHandler) IngestChange(ctx context.Context, info entity.ChangeInfo) error {
+	h.logger.Info("ingested change",
+		zap.String("uri", info.URI),
+		zap.String("previous_uri", info.PreviousURI),
+		zap.String("author", info.Author.Name),
+		zap.String("author_email", info.Author.Email),
+	)
+	return nil
+}
diff --git a/stovepipe/extension/extension.go b/stovepipe/extension/extension.go
index 92d4bcea..5a891faf 100644
--- a/stovepipe/extension/extension.go
+++ b/stovepipe/extension/extension.go
@@ -14,3 +14,21 @@
 
 // Package extension holds Stovepipe-specific extension implementations.
 package extension
+
+import (
+	"context"
+
+	"github.com/uber/submitqueue/stovepipe/entity"
+)
+
+// ChangeIngester subscribes to change events from a VCS source
+// and dispatches them for processing. The source and VCS are
+// implementation details left to the injected backend.
+type ChangeIngester interface {
+	Start(ctx context.Context) error
+}
+
+// ChangeHandler processes a single change received from the ingester.
+type ChangeHandler interface {
+	IngestChange(ctx context.Context, info entity.ChangeInfo) error
+}