feat: add MCP server core, stdio and streamable HTTP transports and serve command

Low-level SDK server built from the catalog plus gitea_api_request, with TOOLSETS/READ_ONLY/DISABLED_TOOLS filters, schema validation without value echo, one audit event per call, static bearer verifier, identity resolver hook, /health, DNS-rebinding protection, rate limiting and fail-closed startup checks.

tests/test_auth.py

@@ -0,0 +1,173 @@
+"""Tests for the static bearer verifier, composite verifier and identity resolution."""
+
+from __future__ import annotations
+
+import hmac
+from typing import Any
+
+import pytest
+from mcp.server.auth.provider import AccessToken
+from pytest_httpx import HTTPXMock
+
+from aegis_gitea_mcp import auth as auth_module
+from aegis_gitea_mcp.auth import (
+    STATIC_CLIENT_ID,
+    AdminIdentityResolver,
+    CompositeVerifier,
+    StaticBearerVerifier,
+)
+from aegis_gitea_mcp.errors import ToolError
+from aegis_gitea_mcp.gitea import GiteaExecutor
+from tests.test_server_helpers import API, BEARER_TOKEN, GITEA_TOKEN, server_settings
+
+# Static bearer verifier
+
+
+async def test_correct_token_yields_an_admin_access_token_without_the_secret() -> None:
+    access = await StaticBearerVerifier(BEARER_TOKEN).verify_token(BEARER_TOKEN)
+
+    assert access is not None
+    assert access.client_id == STATIC_CLIENT_ID == "aegis-static-bearer"
+    assert access.scopes == ["gitea"]
+    assert access.subject == "admin"
+    assert access.token == "static"
+    assert BEARER_TOKEN not in repr(access)
+
+
+@pytest.mark.parametrize(
+    "presented",
+    [
+        "",
+        "x",
+        BEARER_TOKEN + "x",
+        BEARER_TOKEN[:-1],
+        BEARER_TOKEN.upper(),
+        "Bearer " + BEARER_TOKEN,
+    ],
+)
+async def test_wrong_tokens_are_rejected(presented: str) -> None:
+    assert await StaticBearerVerifier(BEARER_TOKEN).verify_token(presented) is None
+
+
+async def test_comparison_is_constant_time_even_for_different_lengths(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    calls: list[tuple[bytes, bytes]] = []
+    real = hmac.compare_digest
+
+    def spy(left: Any, right: Any) -> bool:
+        calls.append((left, right))
+        return real(left, right)
+
+    monkeypatch.setattr(auth_module.hmac, "compare_digest", spy)
+    verifier = StaticBearerVerifier(BEARER_TOKEN)
+
+    await verifier.verify_token("short")
+    await verifier.verify_token(BEARER_TOKEN + "-much-longer-than-expected")
+    await verifier.verify_token(BEARER_TOKEN)
+
+    assert len(calls) == 3
+    # Digests of equal length are compared, never the raw secrets.
+    assert all(len(left) == len(right) == 32 for left, right in calls)
+    assert all(BEARER_TOKEN.encode() not in pair for pair in calls)
+
+
+async def test_composite_verifier_returns_first_match() -> None:
+    other = AccessToken(token="t", client_id="oauth-client", scopes=["x"])
+
+    class Accepts:
+        async def verify_token(self, token: str) -> AccessToken | None:
+            return other if token == "oauth-token" else None
+
+    composite = CompositeVerifier(StaticBearerVerifier(BEARER_TOKEN), Accepts())
+
+    static = await composite.verify_token(BEARER_TOKEN)
+    oauth = await composite.verify_token("oauth-token")
+
+    assert static is not None and static.client_id == STATIC_CLIENT_ID
+    assert oauth is other
+    assert await composite.verify_token("nothing") is None
+    assert await CompositeVerifier().verify_token(BEARER_TOKEN) is None
+
+
+# Identity resolver
+
+
+async def test_no_access_token_resolves_to_the_admin_identity(httpx_mock: HTTPXMock) -> None:
+    httpx_mock.add_response(url=f"{API}/user", json={"login": "root"})
+    settings = server_settings()
+    resolver = AdminIdentityResolver(settings, GiteaExecutor(settings))
+
+    identity = await resolver.resolve(None)
+
+    assert (identity.login, identity.mode, identity.token) == ("root", "admin-token", GITEA_TOKEN)
+    assert GITEA_TOKEN not in repr(identity)
+    assert httpx_mock.get_requests()[0].headers["Authorization"] == f"token {GITEA_TOKEN}"
+
+
+async def test_login_is_looked_up_once_and_cached(httpx_mock: HTTPXMock) -> None:
+    httpx_mock.add_response(url=f"{API}/user", json={"login": "root"})
+    settings = server_settings()
+    resolver = AdminIdentityResolver(settings, GiteaExecutor(settings))
+    access = AccessToken(token="static", client_id=STATIC_CLIENT_ID, scopes=["gitea"])
+
+    first = await resolver.resolve(access)
+    second = await resolver.resolve(access)
+
+    assert first.login == second.login == "root"
+    assert len(httpx_mock.get_requests()) == 1
+
+
+@pytest.mark.parametrize(
+    "response",
+    [
+        {"status_code": 401, "json": {"message": "bad token"}},
+        {"status_code": 200, "json": ["not", "an", "object"]},
+        {"status_code": 200, "json": {"login": ""}},
+        {"status_code": 200, "json": {"login": 5}},
+    ],
+)
+async def test_failed_lookup_leaves_the_login_unknown_and_is_throttled(
+    httpx_mock: HTTPXMock, response: dict[str, Any]
+) -> None:
+    httpx_mock.add_response(url=f"{API}/user", **response)
+    settings = server_settings()
+    resolver = AdminIdentityResolver(settings, GiteaExecutor(settings))
+
+    first = await resolver.resolve(None)
+    second = await resolver.resolve(None)
+
+    assert first.login is None and second.login is None
+    assert first.mode == "admin-token" and first.token == GITEA_TOKEN
+    assert len(httpx_mock.get_requests()) == 1  # no retry inside the back-off window
+
+
+async def test_lookup_is_retried_after_the_backoff(
+    httpx_mock: HTTPXMock, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    httpx_mock.add_response(url=f"{API}/user", status_code=500)
+    httpx_mock.add_response(url=f"{API}/user", json={"login": "root"})
+    settings = server_settings()
+    resolver = AdminIdentityResolver(settings, GiteaExecutor(settings))
+    clock = [1000.0]
+    monkeypatch.setattr(auth_module.time, "monotonic", lambda: clock[0])
+
+    assert (await resolver.resolve(None)).login is None
+    clock[0] += auth_module._LOGIN_RETRY_SECONDS + 1
+    assert (await resolver.resolve(None)).login == "root"
+
+
+async def test_other_client_ids_are_refused() -> None:
+    settings = server_settings()
+    resolver = AdminIdentityResolver(settings, GiteaExecutor(settings))
+
+    with pytest.raises(ToolError, match="unknown identity"):
+        await resolver.resolve(AccessToken(token="x", client_id="oauth-client", scopes=[]))
+
+
+async def test_missing_gitea_token_is_refused() -> None:
+    settings = server_settings(gitea_token=None)
+    resolver = AdminIdentityResolver(settings, GiteaExecutor(settings))
+
+    with pytest.raises(ToolError, match="GITEA_TOKEN"):
+        await resolver.resolve(None)

tests/test_cli.py

@@ -8,6 +8,7 @@ import pytest
 
 from aegis_gitea_mcp import __version__
 from aegis_gitea_mcp.cli import build_parser, main
+from tests.test_server_helpers import ANY_HOST
 
 
 def test_version_prints_package_version(capsys: pytest.CaptureFixture[str]) -> None:
@@ -15,12 +16,9 @@ def test_version_prints_package_version(capsys: pytest.CaptureFixture[str]) -> N
     assert capsys.readouterr().out.strip() == __version__
 
 
-@pytest.mark.parametrize("argv", [[], ["serve"], ["serve", "--transport", "http"]])
-def test_unbuilt_commands_exit_2(argv: list[str], capsys: pytest.CaptureFixture[str]) -> None:
-    assert main(argv) == 2
-    captured = capsys.readouterr()
-    assert "not implemented yet" in captured.err
-    assert captured.out == ""
+def test_serve_parses_host_and_port() -> None:
+    args = build_parser().parse_args(["serve", "--host", ANY_HOST, "--port", "9000"])
+    assert (args.host, args.port) == (ANY_HOST, 9000)
 
 
 def test_serve_transport_choices() -> None:

tests/test_server.py

@@ -0,0 +1,665 @@
+"""Tests for the MCP server core: tool list, filters, dispatcher, audit."""
+
+from __future__ import annotations
+
+import base64
+import json
+from typing import Any
+
+import pytest
+from mcp import Client, MCPError
+from mcp.server.auth.provider import AccessToken
+from pytest_httpx import HTTPXMock
+
+from aegis_gitea_mcp.audit import validate_audit_log_integrity
+from aegis_gitea_mcp.catalog import load_catalog
+from aegis_gitea_mcp.errors import ToolError
+from aegis_gitea_mcp.gitea import RAW_TOOL_NAME, UNTRUSTED_NOTICE, GiteaExecutor, ToolOutcome
+from aegis_gitea_mcp.identity import Identity
+from aegis_gitea_mcp.server import (
+    RAW_INPUT_SCHEMA,
+    ServerConfigError,
+    ToolRegistry,
+    build_raw_tool,
+    build_server,
+    max_request_body_size,
+    validate_arguments,
+)
+from tests.test_server_helpers import (
+    API,
+    GITEA_TOKEN,
+    audit_entries,
+    connected,
+    mock_user,
+    server_settings,
+)
+
+CATALOG = load_catalog()
+REPO_ARGS = {"owner": "octo", "repo": "demo"}
+
+
+def payload_of(result: Any) -> dict[str, Any]:
+    """Decode the JSON text content of a tool result."""
+    assert len(result.content) == 1
+    decoded: dict[str, Any] = json.loads(result.content[0].text)
+    return decoded
+
+
+@pytest.fixture(autouse=True)
+def _env(mock_env: None) -> None:
+    """Every test here needs GITEA_URL for the audit logger's settings."""
+
+
+# Tool list
+
+
+async def test_list_tools_has_every_operation_plus_raw_tool() -> None:
+    async with connected() as client:
+        tools = (await client.list_tools()).tools
+
+    names = [tool.name for tool in tools]
+    assert len(tools) == len(CATALOG.operations) + 1 == 538
+    assert len(set(names)) == len(names)
+    assert names == sorted(names)
+    assert RAW_TOOL_NAME in names
+    for tool in tools:
+        assert tool.input_schema["type"] == "object"
+        assert tool.annotations is not None
+        assert tool.annotations.open_world_hint is False
+
+
+async def test_list_tools_annotations_follow_the_catalog() -> None:
+    async with connected() as client:
+        tools = {tool.name: tool for tool in (await client.list_tools()).tools}
+
+    get_repo = tools["gitea_repo_get"].annotations
+    delete_repo = tools["gitea_repo_delete"].annotations
+    create_issue = tools["gitea_issue_create_issue"].annotations
+    assert get_repo is not None and delete_repo is not None and create_issue is not None
+    assert (get_repo.read_only_hint, get_repo.destructive_hint, get_repo.idempotent_hint) == (
+        True,
+        False,
+        True,
+    )
+    assert (delete_repo.read_only_hint, delete_repo.destructive_hint) == (False, True)
+    assert (create_issue.destructive_hint, create_issue.idempotent_hint) == (False, False)
+    assert tools["gitea_repo_get"].title == get_repo.title
+    assert tools["gitea_repo_get"].description
+
+
+async def test_raw_tool_definition() -> None:
+    async with connected() as client:
+        raw = next(t for t in (await client.list_tools()).tools if t.name == RAW_TOOL_NAME)
+
+    assert raw.input_schema == RAW_INPUT_SCHEMA
+    assert raw.input_schema["additionalProperties"] is False
+    assert raw.input_schema["properties"]["method"]["enum"] == [
+        "GET",
+        "POST",
+        "PUT",
+        "PATCH",
+        "DELETE",
+    ]
+    assert raw.input_schema["properties"]["path"]["maxLength"] == 2048
+    assert raw.annotations is not None
+    assert (raw.annotations.read_only_hint, raw.annotations.destructive_hint) == (False, True)
+
+
+async def test_list_tools_ignores_cursor() -> None:
+    async with connected() as client:
+        result = await client.list_tools(cursor="whatever")
+
+    assert len(result.tools) == 538
+    assert result.next_cursor is None
+
+
+# Filters
+
+
+async def test_toolsets_limit_listing_and_calling(httpx_mock: HTTPXMock) -> None:
+    settings = server_settings(toolsets=["issue"])
+    async with connected(settings) as client:
+        tools = (await client.list_tools()).tools
+        assert {CATALOG.get(t.name).domain for t in tools if CATALOG.get(t.name)} == {"issue"}
+        assert RAW_TOOL_NAME not in {t.name for t in tools}
+        with pytest.raises(MCPError):
+            await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert httpx_mock.get_requests() == []
+
+
+async def test_misc_toolset_includes_the_raw_tool() -> None:
+    async with connected(server_settings(toolsets=["misc"])) as client:
+        names = {t.name for t in (await client.list_tools()).tools}
+
+    assert RAW_TOOL_NAME in names
+    assert {CATALOG.get(n).domain for n in names - {RAW_TOOL_NAME}} == {"misc"}  # type: ignore[union-attr]
+
+
+async def test_read_only_lists_only_read_operations_and_keeps_the_raw_tool() -> None:
+    async with connected(server_settings(read_only=True)) as client:
+        tools = {t.name: t for t in (await client.list_tools()).tools}
+
+    assert RAW_TOOL_NAME in tools
+    read_ops = [op for op in CATALOG.operations if op.read_only]
+    assert len(tools) == len(read_ops) + 1
+    assert "gitea_repo_delete" not in tools
+    raw = tools[RAW_TOOL_NAME]
+    assert raw.annotations is not None and raw.annotations.read_only_hint is True
+    assert raw.description is not None and "only GET" in raw.description
+
+
+async def test_read_only_rejects_non_get_raw_requests(httpx_mock: HTTPXMock) -> None:
+    async with connected(server_settings(read_only=True)) as client:
+        blocked = await client.call_tool(
+            RAW_TOOL_NAME, {"method": "DELETE", "path": "/repos/octo/demo"}
+        )
+
+    assert blocked.is_error
+    assert payload_of(blocked)["error"]["kind"] == "read_only"
+    assert httpx_mock.get_requests() == []
+    assert audit_entries()[-1]["outcome"] == "read_only"
+
+
+async def test_read_only_allows_get_raw_requests(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(url=f"{API}/version", json={"version": "1.22"})
+    async with connected(server_settings(read_only=True)) as client:
+        result = await client.call_tool(RAW_TOOL_NAME, {"method": "GET", "path": "/version"})
+
+    assert not result.is_error
+    assert payload_of(result)["data"] == {"version": "1.22"}
+
+
+async def test_disabled_tools_are_hidden_and_unknown_when_called() -> None:
+    settings = server_settings(disabled_tools=["gitea_repo_delete", RAW_TOOL_NAME])
+    async with connected(settings) as client:
+        names = {t.name for t in (await client.list_tools()).tools}
+        assert len(names) == 536
+        assert "gitea_repo_delete" not in names
+        assert RAW_TOOL_NAME not in names
+        with pytest.raises(MCPError) as caught:
+            await client.call_tool("gitea_repo_delete", REPO_ARGS)
+
+    assert caught.value.code == -32602
+
+
+def test_unknown_disabled_tool_names_are_a_startup_error() -> None:
+    settings = server_settings(disabled_tools=["gitea_repo_get", "gitea_nope", "other_nope"])
+
+    with pytest.raises(ServerConfigError) as caught:
+        build_server(settings)
+
+    message = str(caught.value)
+    assert "gitea_nope" in message and "other_nope" in message
+    assert "gitea_repo_get" not in message
+
+
+def test_disabled_tool_hidden_by_read_only_is_still_a_valid_name() -> None:
+    settings = server_settings(read_only=True, disabled_tools=["gitea_repo_delete"])
+
+    registry = ToolRegistry(settings, CATALOG)
+
+    assert registry.get("gitea_repo_delete") is None
+    assert len(registry) == sum(op.read_only for op in CATALOG.operations) + 1
+
+
+def test_registry_caches_validators() -> None:
+    registry = ToolRegistry(server_settings(), CATALOG)
+
+    assert registry.validator("gitea_repo_get") is registry.validator("gitea_repo_get")
+
+
+def test_build_raw_tool_read_only_flag() -> None:
+    assert build_raw_tool().annotations is not None
+    assert build_raw_tool(read_only=True).annotations.read_only_hint is True  # type: ignore[union-attr]
+
+
+# Calls: success and Gitea errors
+
+
+async def test_call_success_envelope(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock, "admin")
+    httpx_mock.add_response(url=f"{API}/repos/octo/demo", json={"full_name": "octo/demo"})
+    async with connected() as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert result.is_error is False
+    payload = payload_of(result)
+    assert payload["identity"] == {"login": "admin", "mode": "admin-token", "sudo": None}
+    assert payload["untrusted_content"] == UNTRUSTED_NOTICE
+    assert payload["data"] == {"full_name": "octo/demo"}
+    assert result.structured_content == payload
+    request = httpx_mock.get_requests(url=f"{API}/repos/octo/demo")[0]
+    assert request.headers["Authorization"] == f"token {GITEA_TOKEN}"
+
+
+async def test_gitea_404_is_an_error_result_with_kind(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(url=f"{API}/repos/octo/demo", status_code=404, json={"message": "nope"})
+    async with connected() as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert result.is_error is True
+    error = payload_of(result)["error"]
+    assert error["kind"] == "not_found" and error["status"] == 404
+    entry = audit_entries()[-1]
+    assert entry["outcome"] == "not_found" and entry["result_status"] == "error"
+    assert entry["params"]["http_status"] == 404
+
+
+async def test_none_arguments_are_treated_as_empty(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(url=f"{API}/user", json={"login": "admin"})
+    async with connected() as client:
+        result = await client.call_tool("gitea_user_get_current")
+
+    assert not result.is_error
+    assert payload_of(result)["data"] == {"login": "admin"}
+
+
+# Calls: validation
+
+
+@pytest.mark.parametrize(
+    ("tool", "arguments", "path", "needle"),
+    [
+        ("gitea_repo_get", {"owner": "octo"}, "$", "repo"),
+        ("gitea_repo_get", {"owner": 5, "repo": "demo"}, "$.owner", "type"),
+        ("gitea_repo_get", {**REPO_ARGS, "surprise": 1}, "$", "unexpected argument"),
+        ("gitea_repo_get", {"owner": "no spaces!", "repo": "demo"}, "$.owner", "pattern"),
+        ("gitea_repo_get", {"owner": "o" * 300, "repo": "demo"}, "$.owner", "maxLength"),
+        ("gitea_repo_get", {"owner": "", "repo": "demo"}, "$.owner", "minLength"),
+        (RAW_TOOL_NAME, {"method": "TRACE", "path": "/x"}, "$.method", "one of"),
+        (RAW_TOOL_NAME, {"method": "GET", "path": "no-slash"}, "$.path", "pattern"),
+        (RAW_TOOL_NAME, {"method": "GET", "path": "/x", "query": {"a": {"b": 1}}}, "$.query.a", ""),
+    ],
+)
+async def test_validation_errors_do_not_call_gitea(
+    httpx_mock: HTTPXMock, tool: str, arguments: dict[str, Any], path: str, needle: str
+) -> None:
+    async with connected() as client:
+        result = await client.call_tool(tool, arguments)
+
+    assert result.is_error
+    error = payload_of(result)["error"]
+    assert error["kind"] == "invalid_argument"
+    assert error["path"] == path
+    assert needle in error["message"]
+    assert httpx_mock.get_requests() == []
+    assert audit_entries()[-1]["outcome"] == "invalid_argument"
+
+
+async def test_validation_error_never_echoes_the_offending_value() -> None:
+    secret = "sk-live-SUPERSECRET-0123456789"
+    async with connected() as client:
+        results = [
+            await client.call_tool("gitea_repo_get", {"owner": secret, "repo": "demo"}),
+            await client.call_tool("gitea_repo_get", {"owner": 1, "repo": "demo", secret: secret}),
+            await client.call_tool("gitea_repo_get", {"owner": ["a", secret], "repo": "demo"}),
+        ]
+
+    for result in results:
+        assert result.is_error
+        assert secret not in result.content[0].text  # type: ignore[union-attr]
+    assert "unexpected argument" in payload_of(results[1])["error"]["message"]
+
+
+def test_validate_arguments_returns_none_for_valid_input() -> None:
+    registry = ToolRegistry(server_settings(), CATALOG)
+
+    assert validate_arguments(registry.validator("gitea_repo_get"), REPO_ARGS) is None
+
+
+def test_validate_arguments_covers_remaining_keyword_messages() -> None:
+    from jsonschema import Draft202012Validator
+
+    validator = Draft202012Validator(
+        {
+            "type": "object",
+            "properties": {
+                "n": {"type": "integer", "minimum": 3},
+                "t": {"anyOf": [{"type": "string"}, {"type": "integer"}]},
+                "k": {"type": ["string", "null"]},
+            },
+        }
+    )
+
+    low = validate_arguments(validator, {"n": 1})
+    anyof = validate_arguments(validator, {"t": [1]})
+    multi = validate_arguments(validator, {"k": 5})
+    assert low is not None and "minimum 3" in low["message"]
+    assert anyof is not None and "'anyOf'" in anyof["message"] and anyof["path"] == "$.t"
+    assert multi is not None and '["string", "null"]' in multi["message"]
+
+
+def test_validate_arguments_array_index_paths() -> None:
+    from jsonschema import Draft202012Validator
+
+    validator = Draft202012Validator(
+        {"type": "object", "properties": {"ids": {"type": "array", "items": {"type": "integer"}}}}
+    )
+
+    error = validate_arguments(validator, {"ids": [1, "x"]})
+
+    assert error is not None and error["path"] == "$.ids[1]"
+
+
+# Calls: unknown tools
+
+
+async def test_unknown_tool_is_a_protocol_error_and_is_audited() -> None:
+    async with connected() as client:
+        with pytest.raises(MCPError) as caught:
+            await client.call_tool("gitea_does_not_exist", {"a": 1})
+
+    assert caught.value.code == -32602
+    assert "gitea_does_not_exist" in caught.value.message
+    entry = audit_entries()[-1]
+    assert entry["tool_name"] == "gitea_does_not_exist"
+    assert entry["outcome"] == "unknown_tool"
+
+
+# Calls: raw tool
+
+
+async def test_raw_tool_happy_path(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(
+        url=f"{API}/repos/octo/demo/issues?state=open&labels=a&labels=b",
+        method="POST",
+        status_code=201,
+        json={"number": 7},
+    )
+    async with connected() as client:
+        result = await client.call_tool(
+            RAW_TOOL_NAME,
+            {
+                "method": "post",
+                "path": "/repos/octo/demo/issues",
+                "query": {"state": "open", "labels": ["a", "b"]},
+                "body": {"title": "hello"},
+                "sudo": "alice",
+            },
+        )
+    # lower-case verbs are not in the enum
+    assert result.is_error
+    assert payload_of(result)["error"]["kind"] == "invalid_argument"
+
+    async with connected() as client:
+        result = await client.call_tool(
+            RAW_TOOL_NAME,
+            {
+                "method": "POST",
+                "path": "/repos/octo/demo/issues",
+                "query": {"state": "open", "labels": ["a", "b"]},
+                "body": {"title": "hello"},
+                "sudo": "alice",
+            },
+        )
+
+    assert not result.is_error
+    payload = payload_of(result)
+    assert payload["status"] == 201 and payload["data"] == {"number": 7}
+    assert payload["identity"]["sudo"] == "alice"
+    sent = httpx_mock.get_requests(method="POST")[0]
+    assert json.loads(sent.content) == {"title": "hello"}
+    assert sent.headers["Sudo"] == "alice"
+    entry = audit_entries()[-1]
+    assert entry["tool_name"] == RAW_TOOL_NAME
+    assert entry["method"] == "POST" and entry["path"] == "/repos/octo/demo/issues"
+    assert entry["sudo"] == "alice" and entry["domain"] == "misc"
+
+
+async def test_raw_tool_without_body_sends_none(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(url=f"{API}/version", json={"version": "1"})
+    async with connected() as client:
+        result = await client.call_tool(RAW_TOOL_NAME, {"method": "GET", "path": "/version"})
+
+    assert not result.is_error
+    assert httpx_mock.get_requests(url=f"{API}/version")[0].content == b""
+
+
+# Audit
+
+
+async def test_audit_event_per_call_never_contains_argument_values(
+    httpx_mock: HTTPXMock,
+) -> None:
+    mock_user(httpx_mock, "admin")
+    httpx_mock.add_response(
+        url=f"{API}/repos/octo/demo/issues", method="POST", status_code=201, json={"number": 1}
+    )
+    httpx_mock.add_response(url=f"{API}/repos/octo/demo", status_code=404, json={"message": "x"})
+    secret = "BODY-SECRET-VALUE-9f8e7d6c5b4a"
+    async with connected() as client:
+        await client.call_tool(
+            "gitea_issue_create_issue",
+            {**REPO_ARGS, "body": {"title": secret, "body": secret}, "sudo": "alice"},
+        )
+        await client.call_tool("gitea_repo_get", REPO_ARGS)
+        await client.call_tool("gitea_repo_get", {"owner": secret + "!", "repo": "x"})
+        with pytest.raises(MCPError):
+            await client.call_tool("gitea_unknown", {"value": secret})
+
+    entries = audit_entries()
+    assert [e["outcome"] for e in entries] == [
+        "success",
+        "not_found",
+        "invalid_argument",
+        "unknown_tool",
+    ]
+    first = entries[0]
+    assert first["tool_name"] == "gitea_issue_create_issue"
+    assert first["domain"] == "issue" and first["method"] == "POST"
+    assert first["path"] == "/repos/{owner}/{repo}/issues"
+    assert first["identity_login"] == "admin" and first["identity_mode"] == "admin-token"
+    assert first["sudo"] == "alice" and first["result_status"] == "success"
+    assert first["params"] == {
+        "argument_names": ["body", "owner", "repo", "sudo"],
+        "http_status": 201,
+    }
+    assert first["duration_ms"] >= 0 and first["correlation_id"]
+    assert len({e["correlation_id"] for e in entries}) == 4
+    from aegis_gitea_mcp.audit import get_audit_logger
+
+    log_path = get_audit_logger().log_path
+    assert secret not in log_path.read_text(encoding="utf-8")
+    assert validate_audit_log_integrity(log_path) == (True, [])
+
+
+async def test_audit_failure_does_not_break_the_call(
+    httpx_mock: HTTPXMock, caplog: pytest.LogCaptureFixture
+) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(url=f"{API}/repos/octo/demo", json={})
+
+    class BrokenAudit:
+        def log_tool_invocation(self, *args: Any, **kwargs: Any) -> str:
+            raise OSError("disk full: " + GITEA_TOKEN)
+
+    async with connected(audit=BrokenAudit()) as client:  # type: ignore[arg-type]
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert not result.is_error
+    assert "OSError" in caplog.text
+    assert GITEA_TOKEN not in caplog.text
+
+
+# Internal errors
+
+
+class ExplodingExecutor(GiteaExecutor):
+    """Executor whose calls raise an exception carrying a secret."""
+
+    async def execute(self, *args: Any, **kwargs: Any) -> ToolOutcome:
+        raise RuntimeError(f"boom with {GITEA_TOKEN} and a stack")
+
+
+async def test_internal_error_is_generic_and_audited(
+    httpx_mock: HTTPXMock, caplog: pytest.LogCaptureFixture
+) -> None:
+    mock_user(httpx_mock)
+    settings = server_settings()
+    async with connected(settings, executor=ExplodingExecutor(settings)) as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert result.is_error
+    error = payload_of(result)["error"]
+    assert error["kind"] == "internal_error"
+    assert "boom" not in result.content[0].text  # type: ignore[union-attr]
+    assert "RuntimeError" not in error["message"]
+    assert GITEA_TOKEN not in caplog.text and "Traceback" not in caplog.text
+    assert audit_entries()[-1]["outcome"] == "internal_error"
+
+
+async def test_internal_error_shows_class_name_when_details_are_exposed(
+    httpx_mock: HTTPXMock,
+) -> None:
+    mock_user(httpx_mock)
+    settings = server_settings(expose_error_details=True)
+    async with connected(settings, executor=ExplodingExecutor(settings)) as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    message = payload_of(result)["error"]["message"]
+    assert "RuntimeError" in message and "boom" not in message
+
+
+# Identity
+
+
+class FixedResolver:
+    """Resolver returning a per-user identity (what the OAuth mode will plug in)."""
+
+    def __init__(self) -> None:
+        self.seen: list[AccessToken | None] = []
+
+    async def resolve(self, access: AccessToken | None) -> Identity:
+        self.seen.append(access)
+        return Identity(login="alice", mode="oauth", token="user-token-abcdefgh")
+
+
+async def test_custom_resolver_identity_reaches_gitea_and_audit(httpx_mock: HTTPXMock) -> None:
+    httpx_mock.add_response(url=f"{API}/repos/octo/demo", json={})
+    resolver = FixedResolver()
+    async with connected(resolver=resolver) as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert payload_of(result)["identity"] == {"login": "alice", "mode": "oauth", "sudo": None}
+    assert httpx_mock.get_requests()[0].headers["Authorization"] == "Bearer user-token-abcdefgh"
+    assert resolver.seen == [None]  # in-memory transport has no access token
+    entry = audit_entries()[-1]
+    assert entry["identity_login"] == "alice" and entry["identity_mode"] == "oauth"
+
+
+async def test_identity_resolution_failure_is_an_error_result(httpx_mock: HTTPXMock) -> None:
+    class Refusing:
+        async def resolve(self, access: AccessToken | None) -> Identity:
+            raise ToolError("unknown identity", status_code=401)
+
+    async with connected(resolver=Refusing()) as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert result.is_error
+    assert payload_of(result)["error"] == {"kind": "identity_error", "message": "unknown identity"}
+    assert httpx_mock.get_requests() == []
+    assert audit_entries()[-1]["outcome"] == "identity_error"
+
+
+async def test_missing_gitea_token_is_an_identity_error(httpx_mock: HTTPXMock) -> None:
+    async with connected(server_settings(gitea_token=None)) as client:
+        result = await client.call_tool("gitea_repo_get", REPO_ARGS)
+
+    assert result.is_error
+    assert "GITEA_TOKEN" in payload_of(result)["error"]["message"]
+    assert httpx_mock.get_requests() == []
+
+
+# Uploads
+
+
+def attachment_args(content: bytes) -> dict[str, Any]:
+    return {
+        **REPO_ARGS,
+        "index": 1,
+        "attachment": {
+            "filename": "a.bin",
+            "content_base64": base64.b64encode(content).decode("ascii"),
+        },
+    }
+
+
+@pytest.mark.parametrize("size", [10, 9, 8])
+async def test_upload_within_cap_is_sent(httpx_mock: HTTPXMock, size: int) -> None:
+    mock_user(httpx_mock)
+    httpx_mock.add_response(
+        url=f"{API}/repos/octo/demo/issues/1/assets", method="POST", status_code=201, json={"id": 1}
+    )
+    async with connected(server_settings(max_binary_bytes=10)) as client:
+        result = await client.call_tool(
+            "gitea_issue_create_issue_attachment", attachment_args(b"x" * size)
+        )
+
+    assert not result.is_error
+
+
+@pytest.mark.parametrize("size", [11, 12, 13, 1000])
+async def test_upload_over_cap_is_rejected_before_any_request(
+    httpx_mock: HTTPXMock, size: int
+) -> None:
+    async with connected(server_settings(max_binary_bytes=10)) as client:
+        result = await client.call_tool(
+            "gitea_issue_create_issue_attachment", attachment_args(b"x" * size)
+        )
+
+    assert result.is_error
+    error = payload_of(result)["error"]
+    assert error["kind"] == "invalid_argument"
+    assert error["path"] == "$.attachment.content_base64"
+    assert "MAX_BINARY_BYTES" in error["message"]
+    assert httpx_mock.get_requests() == []
+
+
+def test_max_request_body_size_covers_the_upload_cap() -> None:
+    default = max_request_body_size(server_settings(max_binary_bytes=1))
+    big = max_request_body_size(server_settings(max_binary_bytes=5_242_880))
+
+    assert default == 4 * 1024 * 1024
+    assert big >= 5_242_880 * 4 // 3 + 1024 * 1024
+    assert big > default
+
+
+# Lifecycle
+
+
+async def test_server_lifespan_closes_the_executor() -> None:
+    settings = server_settings()
+    executor = GiteaExecutor(settings)
+    server = build_server(settings, executor=executor)
+
+    async with Client(server) as client:
+        await client.list_tools()
+        assert executor._client.is_closed is False
+
+    assert executor._client.is_closed is True
+
+
+def test_get_tool_input_schema_hook() -> None:
+    server = build_server(server_settings(disabled_tools=["gitea_repo_get"]))
+
+    assert server.get_tool_input_schema is not None
+    assert server.get_tool_input_schema("gitea_repo_delete")["type"] == "object"  # type: ignore[index]
+    assert server.get_tool_input_schema("gitea_repo_get") is None
+    assert server.tool_count == 537
+
+
+def test_upload_cap_ignores_absent_and_malformed_file_arguments() -> None:
+    from aegis_gitea_mcp.server import _upload_cap_error
+
+    operation = CATALOG.get("gitea_issue_create_issue_attachment")
+    assert operation is not None
+
+    assert _upload_cap_error(operation, REPO_ARGS, 10) is None
+    assert _upload_cap_error(operation, {"attachment": {"content_base64": 5}}, 10) is None
+    assert _upload_cap_error(operation, {"attachment": "not-an-object"}, 10) is None

tests/test_server_helpers.py

@@ -0,0 +1,59 @@
+"""Shared builders for the server, auth and transport tests."""
+
+from __future__ import annotations
+
+import json
+from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
+from typing import Any
+
+from mcp import Client
+from pytest_httpx import HTTPXMock
+
+from aegis_gitea_mcp.audit import get_audit_logger
+from aegis_gitea_mcp.config import Settings
+from aegis_gitea_mcp.server import AegisServer, build_server
+from tests.test_executor_helpers import API, BEARER_TOKEN, GITEA_TOKEN
+
+ANY_HOST = "0.0.0.0"  # noqa: S104 (a wildcard bind address used as test input)
+
+__all__ = [
+    "ANY_HOST",
+    "API",
+    "BEARER_TOKEN",
+    "GITEA_TOKEN",
+    "audit_entries",
+    "connected",
+    "mock_user",
+    "server_settings",
+]
+
+
+def server_settings(**overrides: Any) -> Settings:
+    """Settings for server tests: admin token, no bearer, no OAuth secrets."""
+    values: dict[str, Any] = {
+        "gitea_url": "https://gitea.example.com",
+        "gitea_token": GITEA_TOKEN,
+    }
+    values.update(overrides)
+    return Settings(**values)
+
+
+def mock_user(httpx_mock: HTTPXMock, login: str = "admin") -> None:
+    """Answer the admin login lookup (``GET /user``) for as many calls as needed."""
+    httpx_mock.add_response(url=f"{API}/user", json={"login": login}, is_reusable=True)
+
+
+@asynccontextmanager
+async def connected(settings: Settings | None = None, **kwargs: Any) -> AsyncIterator[Client]:
+    """An in-memory SDK client connected to a freshly built server."""
+    server: AegisServer = build_server(settings or server_settings(), **kwargs)
+    async with Client(server) as client:
+        yield client
+
+
+def audit_entries() -> list[dict[str, Any]]:
+    """Payloads of every tool invocation written to the (test) audit log."""
+    path = get_audit_logger().log_path
+    entries = [json.loads(line) for line in path.read_text(encoding="utf-8").splitlines()]
+    return [entry["payload"] for entry in entries if entry["event_type"] == "tool_invocation"]

tests/test_transports.py

@@ -0,0 +1,450 @@
+"""Tests for the streamable HTTP app: health, auth, DNS-rebinding, rate limiting, MCP e2e."""
+
+from __future__ import annotations
+
+import json
+import logging
+from collections.abc import AsyncIterator, Iterator
+from contextlib import asynccontextmanager
+from typing import Any
+
+import httpx
+import httpx2
+import pytest
+from mcp import Client
+from mcp.client.streamable_http import streamable_http_client
+from mcp.server.auth.provider import AccessToken
+from pytest_httpx import HTTPXMock
+from starlette.routing import Route
+from starlette.testclient import TestClient
+
+from aegis_gitea_mcp import __version__
+from aegis_gitea_mcp.auth import STATIC_CLIENT_ID
+from aegis_gitea_mcp.config import Settings
+from aegis_gitea_mcp.gitea import RAW_TOOL_NAME
+from aegis_gitea_mcp.identity import Identity
+from aegis_gitea_mcp.transports import (
+    GiteaProbe,
+    build_http_app,
+    transport_security,
+)
+from tests.test_server_helpers import (
+    ANY_HOST,
+    API,
+    BEARER_TOKEN,
+    GITEA_TOKEN,
+    mock_user,
+    server_settings,
+)
+
+BASE = "http://127.0.0.1:8080"
+INITIALIZE = {
+    "jsonrpc": "2.0",
+    "id": 1,
+    "method": "initialize",
+    "params": {
+        "protocolVersion": "2025-06-18",
+        "capabilities": {},
+        "clientInfo": {"name": "test", "version": "0"},
+    },
+}
+MCP_HEADERS = {
+    "Content-Type": "application/json",
+    "Accept": "application/json, text/event-stream",
+}
+
+
+@pytest.fixture(autouse=True)
+def _env(mock_env: None) -> None:
+    """The audit logger and rate limiter read GITEA_URL from the environment."""
+
+
+def http_settings(**overrides: Any) -> Settings:
+    """Settings with a bearer token on port 8080."""
+    values: dict[str, Any] = {"mcp_bearer_token": BEARER_TOKEN, "mcp_port": 8080}
+    values.update(overrides)
+    return server_settings(**values)
+
+
+@pytest.fixture
+def client(request: pytest.FixtureRequest) -> Iterator[TestClient]:
+    settings = http_settings()
+    with TestClient(build_http_app(settings), base_url=BASE) as test_client:
+        yield test_client
+
+
+def auth(token: str = BEARER_TOKEN) -> dict[str, str]:
+    return {"Authorization": f"Bearer {token}"}
+
+
+# Health and index
+
+
+def test_health_ok_uses_the_admin_token_and_is_cached(
+    client: TestClient, httpx_mock: HTTPXMock
+) -> None:
+    httpx_mock.add_response(url=f"{API}/version", json={"version": "1.22"})
+
+    first = client.get("/health")
+    second = client.get("/health")
+
+    assert first.status_code == second.status_code == 200
+    assert first.json() == {
+        "status": "ok",
+        "version": __version__,
+        "tools": 538,
+        "gitea": "reachable",
+    }
+    requests = httpx_mock.get_requests()
+    assert len(requests) == 1  # 10 second cache
+    assert requests[0].headers["Authorization"] == f"token {GITEA_TOKEN}"
+
+
+@pytest.mark.parametrize(
+    "outcome",
+    [
+        httpx.Response(500, text="gitea exploded at https://gitea.example.com " + GITEA_TOKEN),
+        httpx.Response(302, headers={"Location": "https://elsewhere.example/"}),
+        httpx.ConnectError("connection refused to https://gitea.example.com"),
+        httpx.ReadTimeout("slow"),
+    ],
+)
+def test_health_degraded_leaks_nothing(
+    client: TestClient, httpx_mock: HTTPXMock, outcome: httpx.Response | Exception
+) -> None:
+    if isinstance(outcome, Exception):
+        httpx_mock.add_exception(outcome)
+    else:
+        httpx_mock.add_response(
+            status_code=outcome.status_code, headers=outcome.headers, content=outcome.content
+        )
+
+    response = client.get("/health")
+
+    assert response.status_code == 503
+    assert response.json() == {"status": "degraded", "gitea": "unreachable"}
+    assert "gitea.example.com" not in response.text and GITEA_TOKEN not in response.text
+
+
+def test_health_probe_without_a_token_is_anonymous(httpx_mock: HTTPXMock) -> None:
+    httpx_mock.add_response(url=f"{API}/version", json={})
+    settings = http_settings(gitea_token=None)
+
+    with TestClient(build_http_app(settings), base_url=BASE) as test_client:
+        assert test_client.get("/health").status_code == 200
+
+    assert "Authorization" not in httpx_mock.get_requests()[0].headers
+
+
+def test_health_recovers_after_the_cache_expires(
+    client: TestClient, httpx_mock: HTTPXMock, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    from aegis_gitea_mcp import transports
+
+    clock = [100.0]
+    monkeypatch.setattr(transports.time, "monotonic", lambda: clock[0])
+    httpx_mock.add_exception(httpx.ConnectError("down"))
+    httpx_mock.add_response(url=f"{API}/version", json={})
+
+    assert client.get("/health").status_code == 503
+    assert client.get("/health").status_code == 503  # still cached
+    clock[0] += 11
+    assert client.get("/health").status_code == 200
+
+
+def test_health_and_index_need_no_token(client: TestClient, httpx_mock: HTTPXMock) -> None:
+    httpx_mock.add_response(url=f"{API}/version", json={})
+
+    assert client.get("/").json() == {
+        "name": "aegis-gitea-mcp",
+        "version": __version__,
+        "mcp_endpoint": "/mcp",
+    }
+    assert client.get("/health").status_code == 200
+
+
+async def test_probe_closes_only_its_own_client() -> None:
+    settings = http_settings()
+    own = GiteaProbe(settings)
+    await own.aclose()
+    assert own._client.is_closed
+
+    shared = httpx.AsyncClient()
+    borrowed = GiteaProbe(settings, shared)
+    await borrowed.aclose()
+    assert not shared.is_closed
+    await shared.aclose()
+
+
+# Authentication
+
+
+def test_mcp_without_token_is_401_with_resource_metadata(client: TestClient) -> None:
+    response = client.post("/mcp", json=INITIALIZE, headers=MCP_HEADERS)
+
+    assert response.status_code == 401
+    challenge = response.headers["WWW-Authenticate"]
+    assert challenge.startswith("Bearer ")
+    assert (
+        'resource_metadata="http://127.0.0.1:8080/.well-known/oauth-protected-resource/mcp"'
+        in challenge
+    )
+
+
+@pytest.mark.parametrize("token", ["wrong", BEARER_TOKEN + "x", ""])
+def test_mcp_with_wrong_token_is_401(client: TestClient, token: str) -> None:
+    response = client.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth(token)})
+
+    assert response.status_code == 401
+    assert "resource_metadata" in response.headers["WWW-Authenticate"]
+
+
+def test_mcp_initialize_with_the_right_token(client: TestClient) -> None:
+    response = client.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth()})
+
+    assert response.status_code == 200
+    body = response.text
+    assert "aegis-gitea-mcp" in body
+    assert BEARER_TOKEN not in body
+
+
+def test_protected_resource_metadata_names_the_mcp_endpoint(client: TestClient) -> None:
+    response = client.get("/.well-known/oauth-protected-resource/mcp")
+
+    assert response.status_code == 200
+    assert response.json()["resource"] == "http://127.0.0.1:8080/mcp"
+
+
+@asynccontextmanager
+async def sdk_client(app: Any, token: str | None = BEARER_TOKEN) -> AsyncIterator[Client]:
+    """The SDK client talking to ``app`` over an in-process ASGI transport."""
+    headers = {"Authorization": f"Bearer {token}"} if token else {}
+    async with (
+        app.router.lifespan_context(app),
+        httpx2.AsyncClient(
+            transport=httpx2.ASGITransport(app=app), headers=headers, base_url=BASE
+        ) as http_client,
+        Client(streamable_http_client(f"{BASE}/mcp", http_client=http_client)) as c,
+    ):
+        yield c
+
+
+async def test_sdk_client_lists_and_calls_tools_as_the_admin(httpx_mock: HTTPXMock) -> None:
+    mock_user(httpx_mock, "admin")
+    httpx_mock.add_response(url=f"{API}/repos/octo/demo", json={"full_name": "octo/demo"})
+    app = build_http_app(http_settings())
+
+    async with sdk_client(app) as c:
+        assert len((await c.list_tools()).tools) == 538
+        result = await c.call_tool("gitea_repo_get", {"owner": "octo", "repo": "demo"})
+
+    assert not result.is_error
+    payload = json.loads(result.content[0].text)  # type: ignore[union-attr]
+    assert payload["identity"] == {"login": "admin", "mode": "admin-token", "sudo": None}
+    assert payload["data"] == {"full_name": "octo/demo"}
+
+
+async def test_access_token_reaches_the_identity_resolver() -> None:
+    seen: list[AccessToken | None] = []
+
+    class Spy:
+        async def resolve(self, access: AccessToken | None) -> Identity:
+            seen.append(access)
+            return Identity(login="spy", mode="admin-token", token=GITEA_TOKEN)
+
+    from aegis_gitea_mcp.server import build_server
+
+    settings = http_settings()
+    app = build_http_app(settings, server=build_server(settings, resolver=Spy()))
+
+    async with sdk_client(app) as c:
+        await c.call_tool("gitea_repo_get", {"owner": "bad owner", "repo": "x"})  # invalid
+        await c.call_tool(RAW_TOOL_NAME, {"method": "GET", "path": "/version"})
+
+    assert len(seen) == 1 and seen[0] is not None
+    assert seen[0].client_id == STATIC_CLIENT_ID
+    assert BEARER_TOKEN not in repr(seen[0])
+
+
+# DNS rebinding and origin
+
+
+def test_bad_host_header_is_rejected(httpx_mock: HTTPXMock) -> None:
+    with TestClient(build_http_app(http_settings()), base_url="http://evil.example:8080") as c:
+        response = c.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth()})
+
+    assert response.status_code == 421
+
+
+def test_bad_origin_is_rejected(client: TestClient) -> None:
+    response = client.post(
+        "/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth(), "Origin": "https://evil.example"}
+    )
+
+    assert response.status_code == 403
+
+
+def test_public_host_is_allowed_when_configured() -> None:
+    settings = http_settings(public_base_url="https://mcp.example.com")
+    with TestClient(build_http_app(settings), base_url="https://mcp.example.com") as c:
+        ok = c.post(
+            "/mcp",
+            json=INITIALIZE,
+            headers={**MCP_HEADERS, **auth(), "Origin": "https://mcp.example.com"},
+        )
+        metadata = c.get("/.well-known/oauth-protected-resource/mcp")
+        challenge = c.post("/mcp", json=INITIALIZE, headers=MCP_HEADERS)
+
+    assert ok.status_code == 200
+    assert metadata.json()["resource"] == "https://mcp.example.com/mcp"
+    assert (
+        "https://mcp.example.com/.well-known/oauth-protected-resource/mcp"
+        in (challenge.headers["WWW-Authenticate"])
+    )
+
+
+def test_transport_security_hosts_and_origins() -> None:
+    settings = http_settings(
+        mcp_host="192.168.1.5",
+        public_base_url="https://mcp.example.com:8443/",
+        allowed_hosts=["proxy.internal:9000"],
+    )
+
+    security = transport_security(settings)
+
+    assert security.enable_dns_rebinding_protection is True
+    assert security.allowed_hosts == [
+        "127.0.0.1:8080",
+        "localhost:8080",
+        "[::1]:8080",
+        "192.168.1.5:8080",
+        "mcp.example.com:8443",
+        "mcp.example.com",
+        "proxy.internal:9000",
+    ]
+    assert "https://mcp.example.com:8443" in security.allowed_origins
+    assert "https://proxy.internal:9000" in security.allowed_origins
+    assert "http://127.0.0.1:8080" in security.allowed_origins
+
+
+def test_transport_security_wildcard_bind_adds_no_bind_host() -> None:
+    security = transport_security(http_settings(mcp_host=ANY_HOST))
+
+    assert security.allowed_hosts == ["127.0.0.1:8080", "localhost:8080", "[::1]:8080"]
+
+
+# Rate limiting
+
+
+def test_rate_limit_returns_429_on_the_mcp_path_only(
+    httpx_mock: HTTPXMock, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    # The limiter reads the process-wide settings.
+    monkeypatch.setenv("RATE_LIMIT_PER_MINUTE", "2")
+    httpx_mock.add_response(url=f"{API}/version", json={}, is_reusable=True)
+    settings = http_settings(rate_limit_per_minute=2)
+    with TestClient(build_http_app(settings), base_url=BASE) as c:
+        statuses = [
+            c.post("/mcp", json=INITIALIZE, headers=MCP_HEADERS).status_code for _ in range(3)
+        ]
+        limited = c.post("/mcp", json=INITIALIZE, headers=MCP_HEADERS)
+        health = c.get("/health")
+
+    assert statuses == [401, 401, 429]
+    assert limited.status_code == 429
+    assert limited.json()["error"]["kind"] == "rate_limited"
+    assert limited.headers["Retry-After"] == "60"
+    assert health.status_code == 200
+
+
+def test_rate_limit_is_keyed_per_token(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("RATE_LIMIT_PER_MINUTE", "1")
+    settings = http_settings(rate_limit_per_minute=1)
+    with TestClient(build_http_app(settings), base_url=BASE) as c:
+        first = c.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth()})
+
+    assert first.status_code == 200
+    from aegis_gitea_mcp.rate_limit import get_rate_limiter
+
+    limiter = get_rate_limiter()
+    assert limiter._token_limiter.max_requests == 1
+    # The raw header is never used as a key, only its hash.
+    keys = list(limiter._token_limiter._events)
+    assert keys and all(BEARER_TOKEN not in key for key in keys)
+
+
+# Auth wiring
+
+
+def test_no_auth_on_loopback_works_and_warns(caplog: pytest.LogCaptureFixture) -> None:
+    settings = http_settings(mcp_bearer_token=None)
+    with caplog.at_level(logging.WARNING):
+        app = build_http_app(settings)
+    with TestClient(app, base_url=BASE) as c:
+        response = c.post("/mcp", json=INITIALIZE, headers=MCP_HEADERS)
+        metadata = c.get("/.well-known/oauth-protected-resource/mcp")
+
+    assert response.status_code == 200
+    assert metadata.status_code == 404
+    assert "WITHOUT authentication" in caplog.text
+
+
+def test_extra_verifier_is_combined_with_the_static_bearer() -> None:
+    class Other:
+        async def verify_token(self, token: str) -> AccessToken | None:
+            if token == "oauth-token":
+                return AccessToken(token="t", client_id="oauth-client", scopes=[])
+            return None
+
+    app = build_http_app(http_settings(), token_verifier=Other())
+    with TestClient(app, base_url=BASE) as c:
+        static = c.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth()})
+        oauth = c.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth("oauth-token")})
+        denied = c.post("/mcp", json=INITIALIZE, headers={**MCP_HEADERS, **auth("nope")})
+
+    assert (static.status_code, oauth.status_code, denied.status_code) == (200, 200, 401)
+
+
+def test_only_an_extra_verifier_protects_the_endpoint() -> None:
+    class Other:
+        async def verify_token(self, token: str) -> AccessToken | None:
+            return None
+
+    app = build_http_app(http_settings(mcp_bearer_token=None), token_verifier=Other())
+    with TestClient(app, base_url=BASE) as c:
+        assert c.post("/mcp", json=INITIALIZE, headers=MCP_HEADERS).status_code == 401
+
+
+def test_auth_provider_without_a_verifier_is_refused() -> None:
+    with pytest.raises(ValueError, match="token verifier"):
+        build_http_app(
+            http_settings(mcp_bearer_token=None),
+            auth_server_provider=object(),  # type: ignore[arg-type]
+        )
+
+
+def test_extra_routes_are_served_without_mcp_auth() -> None:
+    from starlette.responses import PlainTextResponse
+
+    async def callback(request: Any) -> PlainTextResponse:
+        return PlainTextResponse("ok")
+
+    app = build_http_app(http_settings(), extra_routes=[Route("/oauth/callback", callback)])
+    with TestClient(app, base_url=BASE) as c:
+        assert c.get("/oauth/callback").text == "ok"
+
+
+def test_request_body_cap_admits_a_full_size_upload() -> None:
+    settings = http_settings(max_binary_bytes=5_242_880)
+    app = build_http_app(settings)
+    with TestClient(app, base_url=BASE) as c:
+        padding = "x" * (6 * 1024 * 1024)
+        body = {**INITIALIZE, "params": {**INITIALIZE["params"], "padding": padding}}
+        response = c.post("/mcp", json=body, headers={**MCP_HEADERS, **auth()})
+
+    assert response.status_code != 413
+
+    small = build_http_app(http_settings(max_binary_bytes=1))
+    with TestClient(small, base_url=BASE) as c:
+        rejected = c.post("/mcp", json=body, headers={**MCP_HEADERS, **auth()})
+    assert rejected.status_code == 413

tests/test_transports_startup.py

@@ -0,0 +1,335 @@
+"""Tests for the transport runners: fail-closed startup, uvicorn wiring, stdio, serve CLI."""
+
+from __future__ import annotations
+
+import json
+import sys
+from pathlib import Path
+from typing import Any
+
+import pytest
+from mcp import Client
+from mcp.client.stdio import StdioServerParameters, stdio_client
+
+from aegis_gitea_mcp import cli, transports
+from aegis_gitea_mcp.cli import main
+from aegis_gitea_mcp.config import Settings
+from aegis_gitea_mcp.transports import (
+    HttpAuthExtras,
+    http_startup_errors,
+    load_oauth_components,
+    run_http,
+    run_stdio,
+)
+from tests.test_server_helpers import ANY_HOST, BEARER_TOKEN, GITEA_TOKEN, server_settings
+
+
+@pytest.fixture(autouse=True)
+def _env(mock_env: None) -> None:
+    """Settings objects here are built explicitly; the audit logger still needs GITEA_URL."""
+
+
+class UvicornSpy:
+    """Replaces ``uvicorn.run`` and records its arguments."""
+
+    def __init__(self) -> None:
+        self.calls: list[tuple[Any, dict[str, Any]]] = []
+
+    def __call__(self, app: Any, **kwargs: Any) -> None:
+        self.calls.append((app, kwargs))
+
+
+@pytest.fixture
+def uvicorn_spy(monkeypatch: pytest.MonkeyPatch) -> UvicornSpy:
+    spy = UvicornSpy()
+    monkeypatch.setattr(transports.uvicorn, "run", spy)
+    return spy
+
+
+def oauth_settings(**overrides: Any) -> Settings:
+    values: dict[str, Any] = {
+        "oauth_enabled": True,
+        "gitea_oauth_client_id": "client",
+        "gitea_oauth_client_secret": "s" * 32,
+        "token_encryption_key": "k" * 32,
+        "public_base_url": "https://mcp.example.com",
+    }
+    values.update(overrides)
+    return server_settings(**values)
+
+
+# HTTP startup checks
+
+
+def test_non_loopback_bind_without_auth_is_refused(
+    uvicorn_spy: UvicornSpy, capsys: pytest.CaptureFixture[str]
+) -> None:
+    assert run_http(server_settings(mcp_host=ANY_HOST)) == 2
+
+    captured = capsys.readouterr()
+    assert uvicorn_spy.calls == []
+    assert "without HTTP authentication" in captured.err
+    assert "MCP_BEARER_TOKEN" in captured.err
+    assert captured.out == ""
+
+
+def test_non_loopback_bind_with_bearer_is_allowed(uvicorn_spy: UvicornSpy) -> None:
+    settings = server_settings(mcp_host=ANY_HOST, mcp_port=9000, mcp_bearer_token=BEARER_TOKEN)
+
+    assert run_http(settings) == 0
+
+    ((app, kwargs),) = uvicorn_spy.calls
+    assert callable(app)
+    assert kwargs["host"] == ANY_HOST
+    assert kwargs["port"] == 9000
+    assert kwargs["proxy_headers"] is True
+    assert kwargs["forwarded_allow_ips"] == "127.0.0.1"
+    assert kwargs["log_level"] == "info"
+    assert kwargs["server_header"] is False
+
+
+def test_loopback_without_auth_runs(uvicorn_spy: UvicornSpy) -> None:
+    assert run_http(server_settings(log_level="DEBUG")) == 0
+
+    assert uvicorn_spy.calls[0][1]["host"] == "127.0.0.1"
+    assert uvicorn_spy.calls[0][1]["log_level"] == "debug"
+
+
+def test_forwarded_allow_ips_setting_is_honoured_when_present(
+    uvicorn_spy: UvicornSpy, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    monkeypatch.setattr(Settings, "forwarded_allow_ips", "10.0.0.0/8", raising=False)
+
+    assert run_http(server_settings()) == 0
+
+    assert uvicorn_spy.calls[0][1]["forwarded_allow_ips"] == "10.0.0.0/8"
+
+
+def test_oauth_misconfiguration_lists_every_missing_setting(
+    uvicorn_spy: UvicornSpy, capsys: pytest.CaptureFixture[str]
+) -> None:
+    settings = server_settings(oauth_enabled=True, mcp_bearer_token=BEARER_TOKEN)
+
+    assert run_http(settings) == 2
+
+    err = capsys.readouterr().err
+    for name in (
+        "GITEA_OAUTH_CLIENT_ID",
+        "GITEA_OAUTH_CLIENT_SECRET",
+        "TOKEN_ENCRYPTION_KEY",
+        "PUBLIC_BASE_URL",
+    ):
+        assert name in err
+    assert uvicorn_spy.calls == []
+
+
+def test_oauth_enabled_but_unavailable_does_not_start_without_a_bearer(
+    uvicorn_spy: UvicornSpy, capsys: pytest.CaptureFixture[str]
+) -> None:
+    assert run_http(oauth_settings()) == 2
+
+    assert "not available in this build" in capsys.readouterr().err
+    assert uvicorn_spy.calls == []
+
+
+def test_oauth_enabled_with_a_bearer_falls_back_to_the_bearer(uvicorn_spy: UvicornSpy) -> None:
+    assert run_http(oauth_settings(mcp_bearer_token=BEARER_TOKEN)) == 0
+    assert len(uvicorn_spy.calls) == 1
+
+
+def test_oauth_components_are_used_when_available(
+    uvicorn_spy: UvicornSpy, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    class Verifier:
+        async def verify_token(self, token: str) -> None:
+            return None
+
+    extras = HttpAuthExtras(token_verifier=Verifier())
+    monkeypatch.setattr(transports, "load_oauth_components", lambda settings: extras)
+    settings = oauth_settings(mcp_host=ANY_HOST, gitea_token=None)
+
+    assert run_http(settings) == 0
+    assert len(uvicorn_spy.calls) == 1
+
+
+def test_default_oauth_components_hook_returns_none() -> None:
+    assert load_oauth_components(oauth_settings()) is None
+
+
+def test_bearer_without_gitea_token_is_refused(
+    uvicorn_spy: UvicornSpy, capsys: pytest.CaptureFixture[str]
+) -> None:
+    assert run_http(server_settings(mcp_bearer_token=BEARER_TOKEN, gitea_token=None)) == 2
+
+    assert "GITEA_TOKEN" in capsys.readouterr().err
+
+
+def test_http_startup_errors_is_empty_for_a_valid_setup() -> None:
+    assert http_startup_errors(server_settings(mcp_bearer_token=BEARER_TOKEN), None) == []
+
+
+def test_bad_disabled_tools_stop_http_startup(
+    uvicorn_spy: UvicornSpy, capsys: pytest.CaptureFixture[str]
+) -> None:
+    assert run_http(server_settings(disabled_tools=["gitea_nope"])) == 2
+
+    assert "gitea_nope" in capsys.readouterr().err
+    assert uvicorn_spy.calls == []
+
+
+# stdio
+
+
+def test_stdio_without_a_token_exits_2(capsys: pytest.CaptureFixture[str]) -> None:
+    assert run_stdio(server_settings(gitea_token=None)) == 2
+
+    captured = capsys.readouterr()
+    assert "GITEA_TOKEN" in captured.err
+    assert captured.out == ""
+
+
+def test_stdio_with_bad_disabled_tools_exits_2(capsys: pytest.CaptureFixture[str]) -> None:
+    assert run_stdio(server_settings(disabled_tools=["nope"])) == 2
+
+    assert "nope" in capsys.readouterr().err
+
+
+def test_stdio_serves_the_built_server(monkeypatch: pytest.MonkeyPatch) -> None:
+    served: list[Any] = []
+
+    def fake_run(function: Any, server: Any) -> None:
+        served.append((function, server))
+
+    monkeypatch.setattr(transports.anyio, "run", fake_run)
+
+    assert run_stdio(server_settings()) == 0
+
+    function, server = served[0]
+    assert function is transports._serve_stdio
+    assert server.tool_count == 538
+
+
+async def test_real_stdio_subprocess_serves_the_catalog(tmp_path: Path) -> None:
+    env = {
+        "GITEA_URL": "http://127.0.0.1:9",
+        "GITEA_TOKEN": GITEA_TOKEN,
+        "DATA_DIR": str(tmp_path / "state"),
+        "AUDIT_LOG_PATH": str(tmp_path / "state" / "audit.log"),
+        "REQUEST_TIMEOUT_SECONDS": "2",
+    }
+    params = StdioServerParameters(
+        command=sys.executable,
+        args=["-m", "aegis_gitea_mcp.cli", "serve", "--transport", "stdio"],
+        env=env,
+        cwd=str(tmp_path),
+    )
+    async with Client(stdio_client(params)) as client:
+        tools = (await client.list_tools()).tools
+        result = await client.call_tool("gitea_repo_get", {"owner": "o", "repo": "r"})
+
+    assert len(tools) == 538
+    # Gitea is unreachable: the call fails as an error result, stdout stayed valid JSON-RPC.
+    assert result.is_error
+    payload = json.loads(result.content[0].text)  # type: ignore[union-attr]
+    assert "error" in payload and GITEA_TOKEN not in json.dumps(payload)
+    audit = (tmp_path / "state" / "audit.log").read_text(encoding="utf-8").splitlines()
+    assert len(audit) == 1
+    assert GITEA_TOKEN not in audit[0]
+
+
+# serve command
+
+
+def test_serve_command_applies_flags_and_runs_http(monkeypatch: pytest.MonkeyPatch) -> None:
+    # Set first so monkeypatch restores whatever ``serve`` writes into the environment.
+    monkeypatch.setenv("MCP_TRANSPORT", "stdio")
+    monkeypatch.setenv("MCP_HOST", "127.0.0.1")
+    monkeypatch.setenv("MCP_PORT", "8080")
+    seen: list[Settings] = []
+    monkeypatch.setattr(transports, "run_http", lambda settings: seen.append(settings) or 0)
+    monkeypatch.setattr(transports, "run_stdio", lambda settings: pytest.fail("wrong transport"))
+
+    code = main(["serve", "--transport", "http", "--host", "127.0.0.2", "--port", "9123"])
+
+    assert code == 0
+    assert (seen[0].mcp_transport, seen[0].mcp_host, seen[0].mcp_port) == (
+        "http",
+        "127.0.0.2",
+        9123,
+    )
+
+
+def test_serve_defaults_to_the_configured_transport(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("MCP_TRANSPORT", "http")
+    seen: list[str] = []
+    monkeypatch.setattr(transports, "run_http", lambda settings: seen.append("http") or 0)
+    monkeypatch.setattr(transports, "run_stdio", lambda settings: seen.append("stdio") or 0)
+
+    assert main([]) == 0
+    assert seen == ["http"]
+
+
+def test_serve_defaults_to_stdio(monkeypatch: pytest.MonkeyPatch) -> None:
+    seen: list[str] = []
+    monkeypatch.setattr(transports, "run_stdio", lambda settings: seen.append("stdio") or 0)
+
+    assert main(["serve"]) == 0
+    assert seen == ["stdio"]
+
+
+def test_serve_with_invalid_configuration_never_echoes_values(
+    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+) -> None:
+    monkeypatch.setenv("MCP_BEARER_TOKEN", "too-short-secret-VALUE")
+    monkeypatch.setattr(transports, "run_stdio", lambda settings: pytest.fail("must not run"))
+
+    assert main(["serve"]) == 2
+
+    captured = capsys.readouterr()
+    assert "MCP_BEARER_TOKEN" in captured.err
+    assert "too-short-secret-VALUE" not in captured.err + captured.out
+
+
+def test_serve_without_gitea_url_exits_2(
+    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+) -> None:
+    monkeypatch.delenv("GITEA_URL")
+
+    assert main(["serve"]) == 2
+
+    assert "GITEA_URL" in capsys.readouterr().err
+
+
+def test_serve_rejects_an_out_of_range_port() -> None:
+    with pytest.raises(SystemExit):
+        cli.build_parser().parse_args(["serve", "--port", "70000"])
+
+
+async def test_serve_stdio_runs_the_server_over_the_stdio_streams(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """``_serve_stdio`` hands the stdio streams to the server (streams replaced by memory)."""
+    from contextlib import asynccontextmanager
+
+    import anyio
+    from mcp.client.session import ClientSession
+    from mcp.shared.memory import create_client_server_memory_streams
+
+    from aegis_gitea_mcp.server import build_server
+
+    async with create_client_server_memory_streams() as (client_streams, server_streams):
+
+        @asynccontextmanager
+        async def fake_stdio() -> Any:
+            yield server_streams
+
+        monkeypatch.setattr(transports, "stdio_server", fake_stdio)
+        server = build_server(server_settings())
+        async with anyio.create_task_group() as group:
+            group.start_soon(transports._serve_stdio, server)
+            async with ClientSession(*client_streams) as session:
+                await session.initialize()
+                tools = await session.list_tools()
+            group.cancel_scope.cancel()
+
+    assert len(tools.tools) == 538