diff --git a/src/opencode_github/__init__.py b/src/opencode_github/__init__.py
index 71f9d28..cb5189f 100644
--- a/src/opencode_github/__init__.py
+++ b/src/opencode_github/__init__.py
@@ -1 +1,44 @@
 """OpenCode GitHub integration helpers."""
+
+from opencode_github.comment_parser import (
+    ParsedCommand,
+    extract_commands,
+    is_command_comment,
+    split_arguments,
+)
+from opencode_github.config import Config
+from opencode_github.github_client import (
+    GitHubAPIError,
+    GitHubClient,
+    IssueComment,
+    PullRequest,
+)
+from opencode_github.handler import HandlerResult, WebhookProcessor
+from opencode_github.webhook_handler import (
+    EventType,
+    WebhookEvent,
+    classify_event,
+    parse_payload,
+    parse_raw,
+    verify_signature,
+)
+
+__all__ = [
+    "Config",
+    "EventType",
+    "GitHubAPIError",
+    "GitHubClient",
+    "HandlerResult",
+    "IssueComment",
+    "ParsedCommand",
+    "PullRequest",
+    "WebhookEvent",
+    "WebhookProcessor",
+    "classify_event",
+    "extract_commands",
+    "is_command_comment",
+    "parse_payload",
+    "parse_raw",
+    "split_arguments",
+    "verify_signature",
+]
diff --git a/src/opencode_github/handler.py b/src/opencode_github/handler.py
new file mode 100644
index 0000000..7bdb59a
--- /dev/null
+++ b/src/opencode_github/handler.py
@@ -0,0 +1,104 @@
+"""End-to-end webhook processing that ties all components together."""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass, field
+
+from opencode_github.comment_parser import ParsedCommand, extract_commands
+from opencode_github.config import Config
+from opencode_github.github_client import GitHubClient
+from opencode_github.webhook_handler import WebhookEvent, parse_raw, verify_signature
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass(frozen=True)
+class HandlerResult:
+    """Outcome of processing a single webhook delivery."""
+
+    event: WebhookEvent | None
+    commands: list[ParsedCommand] = field(default_factory=list)
+    acknowledged: bool = False
+    skipped_reason: str = ""
+
+
+class WebhookProcessor:
+    """Orchestrate signature verification, payload parsing, and command extraction.
+
+    Parameters
+    ----------
+    config:
+        Runtime configuration (tokens, allowed commands, etc.).
+    webhook_secret:
+        Optional shared secret for verifying ``X-Hub-Signature-256``.
+        When ``None`` signature verification is skipped.
+    """
+
+    def __init__(self, config: Config, webhook_secret: str | None = None) -> None:
+        self._config = config
+        self._webhook_secret = webhook_secret
+        self._client = GitHubClient(
+            token=config.github_token,
+            base_url=config.github_api_url,
+            timeout=config.request_timeout,
+        )
+
+    async def close(self) -> None:
+        await self._client.close()
+
+    async def __aenter__(self) -> WebhookProcessor:
+        return self
+
+    async def __aexit__(self, *exc: object) -> None:
+        await self.close()
+
+    async def process(
+        self,
+        event_header: str,
+        body: bytes,
+        signature: str | None = None,
+    ) -> HandlerResult:
+        """Process a raw webhook delivery.
+
+        Parameters
+        ----------
+        event_header:
+            Value of the ``X-GitHub-Event`` request header.
+        body:
+            Raw request body bytes.
+        signature:
+            Value of the ``X-Hub-Signature-256`` header, if present.
+
+        Returns
+        -------
+        HandlerResult
+        """
+        if self._webhook_secret:
+            if not signature or not verify_signature(body, signature, self._webhook_secret):
+                logger.warning("Webhook signature verification failed")
+                return HandlerResult(event=None, skipped_reason="invalid_signature")
+
+        event = parse_raw(event_header, body)
+        if event is None:
+            return HandlerResult(event=None, skipped_reason="unsupported_event")
+
+        commands = extract_commands(event.comment_body, self._config.allowed_commands)
+        if not commands:
+            return HandlerResult(event=event, skipped_reason="no_commands")
+
+        await self._acknowledge(event)
+
+        return HandlerResult(event=event, commands=commands, acknowledged=True)
+
+    async def _acknowledge(self, event: WebhookEvent) -> None:
+        """Add a reaction to the triggering comment so the user knows we saw it."""
+        try:
+            await self._client.add_reaction(
+                event.repo_owner,
+                event.repo_name,
+                event.comment_id,
+                reaction="eyes",
+            )
+        except Exception:
+            logger.debug("Failed to add acknowledgement reaction", exc_info=True)
diff --git a/tests/test_handler.py b/tests/test_handler.py
new file mode 100644
index 0000000..854f2e9
--- /dev/null
+++ b/tests/test_handler.py
@@ -0,0 +1,159 @@
+"""Tests for opencode_github.handler."""
+
+from __future__ import annotations
+
+import hashlib
+import hmac
+import json
+
+import httpx
+import respx
+
+from opencode_github.config import Config
+from opencode_github.handler import WebhookProcessor
+
+BASE = "https://api.github.com"
+
+
+def _sign(body: bytes, secret: str) -> str:
+    digest = hmac.new(secret.encode(), body, hashlib.sha256).hexdigest()
+    return f"sha256={digest}"
+
+
+def _make_config() -> Config:
+    return Config(
+        github_token="test-token",
+        anthropic_api_key="test-key",
+        github_api_url=BASE,
+    )
+
+
+def _issue_comment_body(comment_text: str = "/oc fix the bug") -> bytes:
+    return json.dumps(
+        {
+            "action": "created",
+            "issue": {"number": 42},
+            "comment": {
+                "id": 1001,
+                "body": comment_text,
+                "user": {"login": "contributor"},
+                "html_url": "https://github.com/owner/repo/issues/42#issuecomment-1001",
+            },
+            "repository": {
+                "name": "repo",
+                "owner": {"login": "owner"},
+            },
+        }
+    ).encode()
+
+
+class TestProcess:
+    async def test_valid_command_acknowledged(self) -> None:
+        config = _make_config()
+        body = _issue_comment_body()
+
+        with respx.mock(base_url=BASE, assert_all_called=False) as router:
+            router.post("/repos/owner/repo/issues/comments/1001/reactions").mock(
+                return_value=httpx.Response(201, json={"id": 1, "content": "eyes"})
+            )
+            async with WebhookProcessor(config) as processor:
+                result = await processor.process("issue_comment", body)
+
+        assert result.event is not None
+        assert result.acknowledged is True
+        assert len(result.commands) == 1
+        assert result.commands[0].trigger == "/oc"
+        assert result.commands[0].arguments == "fix the bug"
+        assert result.skipped_reason == ""
+
+    async def test_no_commands_skipped(self) -> None:
+        config = _make_config()
+        body = _issue_comment_body("just a regular comment")
+
+        async with WebhookProcessor(config) as processor:
+            result = await processor.process("issue_comment", body)
+
+        assert result.event is not None
+        assert result.acknowledged is False
+        assert result.commands == []
+        assert result.skipped_reason == "no_commands"
+
+    async def test_unsupported_event_skipped(self) -> None:
+        config = _make_config()
+        body = json.dumps({"action": "created"}).encode()
+
+        async with WebhookProcessor(config) as processor:
+            result = await processor.process("push", body)
+
+        assert result.event is None
+        assert result.skipped_reason == "unsupported_event"
+
+    async def test_signature_verification_pass(self) -> None:
+        secret = "webhook-secret"
+        config = _make_config()
+        body = _issue_comment_body()
+        sig = _sign(body, secret)
+
+        with respx.mock(base_url=BASE, assert_all_called=False) as router:
+            router.post("/repos/owner/repo/issues/comments/1001/reactions").mock(
+                return_value=httpx.Response(201, json={"id": 1, "content": "eyes"})
+            )
+            async with WebhookProcessor(config, webhook_secret=secret) as processor:
+                result = await processor.process("issue_comment", body, signature=sig)
+
+        assert result.acknowledged is True
+
+    async def test_signature_verification_fail(self) -> None:
+        secret = "webhook-secret"
+        config = _make_config()
+        body = _issue_comment_body()
+
+        async with WebhookProcessor(config, webhook_secret=secret) as processor:
+            result = await processor.process("issue_comment", body, signature="sha256=bad")
+
+        assert result.event is None
+        assert result.skipped_reason == "invalid_signature"
+
+    async def test_missing_signature_when_secret_set(self) -> None:
+        config = _make_config()
+
+        async with WebhookProcessor(config, webhook_secret="secret") as processor:
+            result = await processor.process("issue_comment", b"{}", signature=None)
+
+        assert result.skipped_reason == "invalid_signature"
+
+    async def test_acknowledge_failure_does_not_raise(self) -> None:
+        config = _make_config()
+        body = _issue_comment_body()
+
+        with respx.mock(base_url=BASE, assert_all_called=False) as router:
+            router.post("/repos/owner/repo/issues/comments/1001/reactions").mock(
+                return_value=httpx.Response(500, text="Internal Server Error")
+            )
+            async with WebhookProcessor(config) as processor:
+                result = await processor.process("issue_comment", body)
+
+        assert result.commands != []
+        assert result.acknowledged is True
+
+    async def test_multiple_commands_extracted(self) -> None:
+        config = _make_config()
+        body = _issue_comment_body("/oc first task\nsome text\n/opencode second task")
+
+        with respx.mock(base_url=BASE, assert_all_called=False) as router:
+            router.post("/repos/owner/repo/issues/comments/1001/reactions").mock(
+                return_value=httpx.Response(201, json={"id": 1, "content": "eyes"})
+            )
+            async with WebhookProcessor(config) as processor:
+                result = await processor.process("issue_comment", body)
+
+        assert len(result.commands) == 2
+        assert result.commands[0].arguments == "first task"
+        assert result.commands[1].arguments == "second task"
+
+
+class TestContextManager:
+    async def test_async_with(self) -> None:
+        config = _make_config()
+        async with WebhookProcessor(config) as processor:
+            assert processor._config is config