feat: add Tencent Hunyuan cloud video provider via TokenHub API

Introduce a new video generation provider backed by the Tencent TokenHub
API (tokenhub.tencentmaas.com), an OpenAI-compatible gateway for Tencent
Hunyuan video models with simple Bearer-token auth.

- Add hunyuan_cloud_video tool (submit → poll → download) supporting
  both text-to-video (hy-video-1.5) and image-to-video (yt-video-2.0)
- Add env vars: TENCENT_TOKENHUB_API_KEY, TENCENT_TOKENHUB_MODEL
- Add contract tests for the new tool
- Document setup, API flow, model pricing, and schema constraints in
  PROVIDERS.md
- Update provider tables and capability matrix throughout docs

tests/contracts/test_hunyuan_cloud_video.py

@@ -0,0 +1,820 @@
+"""Contract tests for the Tencent Hunyuan cloud video provider tool (TokenHub API).
+
+These tests verify that the tool satisfies the BaseTool contract without
+requiring real Tencent Cloud credentials or making any API calls.
+
+Run: pytest tests/contracts/test_hunyuan_cloud_video.py -v
+"""
+
+from __future__ import annotations
+
+import json
+import sys
+import types
+from pathlib import Path
+
+import pytest
+
+from tools.base_tool import (
+    BaseTool,
+    ExecutionMode,
+    ToolRuntime,
+    ToolStability,
+    ToolStatus,
+    ToolTier,
+)
+from tools.video.hunyuan_cloud_video import HunyuanCloudVideo
+
+
+# ------------------------------------------------------------------
+# Fake HTTP infrastructure (used by execute-path tests)
+# ------------------------------------------------------------------
+
+class FakeResponse:
+    def __init__(self, json_data=None, content=b"", ok=True, status_code=200, headers=None, text=""):
+        self._json = json_data
+        self.content = content
+        self.ok = ok
+        self.status_code = status_code
+        self.headers = headers or {}
+        self.text = text or (json.dumps(json_data) if json_data is not None else "")
+
+    def json(self):
+        return self._json
+
+    def raise_for_status(self):
+        if not self.ok:
+            raise RuntimeError(f"HTTP {self.status_code}")
+
+
+def _install_fake_requests(monkeypatch, post_responses, get_responses):
+    """Inject a fake requests module; returns the recorded calls."""
+    calls = {"post": [], "get": []}
+    fake = types.ModuleType("requests")
+
+    def fake_post(url, headers=None, json=None, data=None, timeout=None, params=None):
+        calls["post"].append({"url": url, "headers": headers, "json": json, "data": data})
+        return post_responses.pop(0)
+
+    def fake_get(url, headers=None, timeout=None, params=None):
+        calls["get"].append({"url": url, "headers": headers, "params": params})
+        return get_responses.pop(0)
+
+    fake.post = fake_post
+    fake.get = fake_get
+    monkeypatch.setitem(sys.modules, "requests", fake)
+    return calls
+
+
+# ------------------------------------------------------------------
+# Fixtures
+# ------------------------------------------------------------------
+
+@pytest.fixture()
+def hunyuan_env(monkeypatch):
+    """Set fake TokenHub API credentials."""
+    monkeypatch.setenv("TENCENT_TOKENHUB_API_KEY", "thub-fake-test-key")
+
+
+@pytest.fixture()
+def no_hunyuan_env(monkeypatch):
+    """Ensure no TokenHub credentials are set."""
+    monkeypatch.delenv("TENCENT_TOKENHUB_API_KEY", raising=False)
+
+
+# ------------------------------------------------------------------
+# Contract compliance
+# ------------------------------------------------------------------
+
+class TestContract:
+
+    def test_inherits_base_tool(self):
+        assert issubclass(HunyuanCloudVideo, BaseTool)
+
+    def test_has_required_identity(self):
+        tool = HunyuanCloudVideo()
+        assert tool.name == "hunyuan_cloud_video"
+        assert tool.version == "0.1.0"
+        assert tool.provider == "hunyuan_cloud"
+        assert tool.capability == "video_generation"
+        assert tool.tier == ToolTier.GENERATE
+        assert tool.stability == ToolStability.EXPERIMENTAL
+        assert tool.runtime == ToolRuntime.API
+
+    def test_execution_mode_is_async(self):
+        assert HunyuanCloudVideo().execution_mode == ExecutionMode.ASYNC
+
+    def test_has_input_schema(self):
+        schema = HunyuanCloudVideo().input_schema
+        assert schema.get("type") == "object"
+        props = schema.get("properties", {})
+        required = schema.get("required", [])
+        assert required == ["prompt"]
+        for field in required:
+            assert field in props
+
+    def test_has_capabilities(self):
+        tool = HunyuanCloudVideo()
+        assert "text_to_video" in tool.capabilities
+        assert "image_to_video" in tool.capabilities
+
+    def test_has_agent_skills(self):
+        assert "ai-video-gen" in HunyuanCloudVideo().agent_skills
+
+    def test_has_fallbacks(self):
+        tool = HunyuanCloudVideo()
+        assert "jimeng_video" in tool.fallback_tools
+        assert "kling_official_video" in tool.fallback_tools
+        assert "minimax_video" in tool.fallback_tools
+
+    def test_has_install_instructions(self):
+        tool = HunyuanCloudVideo()
+        assert "TENCENT_TOKENHUB_API_KEY" in tool.install_instructions
+
+    def test_get_info_returns_dict(self):
+        info = HunyuanCloudVideo().get_info()
+        assert isinstance(info, dict)
+        assert info["name"] == "hunyuan_cloud_video"
+        assert info["provider"] == "hunyuan_cloud"
+        assert info["runtime"] == "api"
+        assert info["capability"] == "video_generation"
+
+    def test_status_unavailable_without_keys(self, no_hunyuan_env):
+        assert HunyuanCloudVideo().get_status() == ToolStatus.UNAVAILABLE
+
+    def test_status_available_with_keys(self, hunyuan_env):
+        assert HunyuanCloudVideo().get_status() == ToolStatus.AVAILABLE
+
+    def test_has_resource_profile(self):
+        rp = HunyuanCloudVideo().resource_profile
+        assert rp.network_required is True
+        assert rp.vram_mb == 0
+
+    def test_has_retry_policy(self):
+        assert HunyuanCloudVideo().retry_policy.max_retries >= 0
+
+    def test_has_side_effects(self):
+        side = HunyuanCloudVideo().side_effects
+        assert len(side) > 0
+        assert any("API" in s for s in side) or any("TokenHub" in s for s in side)
+
+    def test_has_user_visible_verification(self):
+        assert len(HunyuanCloudVideo().user_visible_verification) > 0
+
+    def test_estimate_cost_returns_float(self):
+        cost = HunyuanCloudVideo().estimate_cost({"prompt": "x"})
+        assert isinstance(cost, float)
+        assert cost > 0.0
+
+    def test_dry_run_returns_dict(self):
+        result = HunyuanCloudVideo().dry_run({"prompt": "test"})
+        assert isinstance(result, dict)
+        assert result["tool"] == "hunyuan_cloud_video"
+
+
+# ------------------------------------------------------------------
+# Supports flags
+# ------------------------------------------------------------------
+
+class TestSupports:
+
+    def test_text_to_video_supported(self):
+        assert HunyuanCloudVideo().supports["text_to_video"] is True
+
+    def test_image_to_video_supported(self):
+        assert HunyuanCloudVideo().supports["image_to_video"] is True
+
+    def test_native_audio_not_supported(self):
+        assert HunyuanCloudVideo().supports["native_audio"] is False
+
+    def test_seed_not_supported(self):
+        assert HunyuanCloudVideo().supports["seed"] is False
+
+
+# ------------------------------------------------------------------
+# Idempotency keys
+# ------------------------------------------------------------------
+
+class TestIdempotencyKeys:
+
+    def test_includes_all_output_affecting_fields(self):
+        fields = HunyuanCloudVideo().idempotency_key_fields
+        for field in ("prompt", "operation", "model", "image_url", "resolution"):
+            assert field in fields, f"missing idempotency field: {field}"
+
+    def test_excludes_execution_only_fields(self):
+        fields = HunyuanCloudVideo().idempotency_key_fields
+        for field in ("output_path", "poll_interval_seconds", "timeout_seconds"):
+            assert field not in fields
+
+    def test_differs_on_operation(self):
+        tool = HunyuanCloudVideo()
+        base = {"prompt": "x"}
+        assert tool.idempotency_key(base) != tool.idempotency_key(
+            {**base, "operation": "image_to_video"}
+        )
+
+    def test_differs_on_model(self):
+        tool = HunyuanCloudVideo()
+        base = {"prompt": "x"}
+        assert tool.idempotency_key(base) != tool.idempotency_key(
+            {**base, "model": "yt-video-2.0"}
+        )
+
+    def test_differs_on_image_url(self):
+        tool = HunyuanCloudVideo()
+        base = {"prompt": "x", "operation": "image_to_video"}
+        assert tool.idempotency_key(base) != tool.idempotency_key(
+            {**base, "image_url": "https://example.com/img.png"}
+        )
+
+    def test_ignores_execution_params(self):
+        tool = HunyuanCloudVideo()
+        base = {"prompt": "x"}
+        assert tool.idempotency_key(base) == tool.idempotency_key(
+            {**base, "output_path": "/tmp/out.mp4", "timeout_seconds": 999}
+        )
+
+
+# ------------------------------------------------------------------
+# Tool-specific behavior
+# ------------------------------------------------------------------
+
+class TestToolSpecific:
+
+    def test_default_operation_is_text_to_video(self):
+        tool = HunyuanCloudVideo()
+        assert tool.input_schema["properties"]["operation"]["default"] == "text_to_video"
+
+    def test_default_resolution_is_720p(self):
+        tool = HunyuanCloudVideo()
+        assert tool.input_schema["properties"]["resolution"]["default"] == "720p"
+
+    def test_default_logo_add_is_1(self):
+        tool = HunyuanCloudVideo()
+        assert tool.input_schema["properties"]["logo_add"]["default"] == 1
+
+    def test_default_poll_interval_is_5(self):
+        tool = HunyuanCloudVideo()
+        assert tool.input_schema["properties"]["poll_interval_seconds"]["default"] == 5.0
+
+    def test_default_timeout_is_600(self):
+        tool = HunyuanCloudVideo()
+        assert tool.input_schema["properties"]["timeout_seconds"]["default"] == 600
+
+    # -- _resolve_model --
+
+    def test_resolve_model_defaults_t2v(self):
+        model = HunyuanCloudVideo._resolve_model({"prompt": "test"})
+        assert model == "hy-video-1.5"
+
+    def test_resolve_model_defaults_i2v(self):
+        model = HunyuanCloudVideo._resolve_model({
+            "prompt": "test", "operation": "image_to_video",
+        })
+        assert model == "yt-video-2.0"
+
+    def test_resolve_model_explicit_input(self):
+        model = HunyuanCloudVideo._resolve_model({
+            "prompt": "test", "model": "yt-video-2.0",
+        })
+        assert model == "yt-video-2.0"
+
+    def test_resolve_model_from_env(self, monkeypatch):
+        monkeypatch.setenv("TENCENT_TOKENHUB_MODEL", "hy-video-1.5")
+        model = HunyuanCloudVideo._resolve_model({
+            "prompt": "test", "operation": "image_to_video",
+        })
+        assert model == "hy-video-1.5"
+
+    def test_resolve_model_input_overrides_env(self, monkeypatch):
+        monkeypatch.setenv("TENCENT_TOKENHUB_MODEL", "hy-video-1.5")
+        model = HunyuanCloudVideo._resolve_model({
+            "prompt": "test", "model": "yt-video-2.0",
+        })
+        assert model == "yt-video-2.0"
+
+    # -- _build_payload --
+
+    def test_build_payload_t2v_minimal(self):
+        """Minimal T2V payload — only prompt is required by TokenHub."""
+        tool = HunyuanCloudVideo()
+        payload = tool._build_payload({"prompt": "一只猫"})
+        assert payload["prompt"] == "一只猫"
+        # resolution and logo_add are optional in TokenHub; only included when
+        # explicitly passed in inputs
+        assert "resolution" not in payload
+        assert "logo_add" not in payload
+
+    def test_build_payload_t2v_with_resolution_and_logo(self):
+        tool = HunyuanCloudVideo()
+        payload = tool._build_payload({
+            "prompt": "test", "resolution": "720p", "logo_add": 0,
+        })
+        assert payload["prompt"] == "test"
+        assert payload["resolution"] == "720p"
+        assert payload["logo_add"] == 0
+
+    def test_build_payload_t2v_custom_logo_add(self):
+        tool = HunyuanCloudVideo()
+        payload = tool._build_payload({"prompt": "test", "logo_add": 0})
+        assert payload["logo_add"] == 0
+
+    def test_build_payload_i2v_includes_image_url(self):
+        tool = HunyuanCloudVideo()
+        payload = tool._build_payload({
+            "prompt": "motion",
+            "operation": "image_to_video",
+            "image_url": "https://example.com/frame.png",
+        })
+        assert payload["image_url"] == "https://example.com/frame.png"
+
+    def test_build_payload_t2v_omits_image(self):
+        tool = HunyuanCloudVideo()
+        payload = tool._build_payload({"prompt": "a cat", "operation": "text_to_video"})
+        assert "image_url" not in payload
+        assert "image" not in payload
+
+    def test_build_payload_i2v_base64_from_path(self, tmp_path):
+        """image_path should be base64-encoded into the image field."""
+        img = tmp_path / "frame.jpg"
+        img.write_bytes(b"\xff\xd8\xff\xe0test-jpeg-data")
+        tool = HunyuanCloudVideo()
+        payload = tool._build_payload({
+            "prompt": "test",
+            "operation": "image_to_video",
+            "image_path": str(img),
+        })
+        assert payload["image"].startswith("/9j/")
+
+    def test_encode_image_returns_base64(self, tmp_path):
+        img = tmp_path / "ref.jpg"
+        img.write_bytes(b"\xff\xd8\xff\xe0\x00\x10JFIF")
+        encoded = HunyuanCloudVideo._encode_image(str(img))
+        assert isinstance(encoded, str)
+        assert encoded.startswith("/9j/")
+
+    def test_encode_image_raises_on_missing(self):
+        with pytest.raises(FileNotFoundError):
+            HunyuanCloudVideo._encode_image("/nonexistent/file.jpg")
+
+    # -- Error paths --
+
+    def test_no_keys_returns_error(self, no_hunyuan_env):
+        result = HunyuanCloudVideo().execute({"prompt": "test"})
+        assert result.success is False
+        assert "TENCENT_TOKENHUB_API_KEY" in result.error
+
+    def test_i2v_without_image_fails(self, hunyuan_env):
+        result = HunyuanCloudVideo().execute(
+            {"prompt": "test", "operation": "image_to_video"}
+        )
+        assert result.success is False
+        assert "image_url" in result.error or "image_path" in result.error
+
+    def test_i2v_both_url_and_path_fails(self, hunyuan_env, tmp_path):
+        img = tmp_path / "ref.jpg"
+        img.write_bytes(b"fake-jpeg")
+        result = HunyuanCloudVideo().execute({
+            "prompt": "test",
+            "operation": "image_to_video",
+            "image_url": "https://example.com/img.jpg",
+            "image_path": str(img),
+        })
+        assert result.success is False
+        assert "not both" in result.error.lower()
+
+    def test_safe_error_redacts_keys(self, monkeypatch):
+        monkeypatch.setenv("TENCENT_TOKENHUB_API_KEY", "thub-secret-key")
+        redacted = HunyuanCloudVideo._safe_error(
+            Exception("failed with thub-secret-key in message")
+        )
+        assert "thub-secret-key" not in redacted
+        assert "[redacted]" in redacted
+
+    def test_safe_error_no_empty_string_bug(self, no_hunyuan_env):
+        msg = HunyuanCloudVideo._safe_error(Exception("abc"))
+        assert msg == "abc"
+
+
+# ------------------------------------------------------------------
+# TokenHub auth headers
+# ------------------------------------------------------------------
+
+class TestAuthHeaders:
+
+    def test_auth_headers_includes_bearer(self):
+        headers = HunyuanCloudVideo._auth_headers("test-api-key")
+        assert headers["Authorization"] == "Bearer test-api-key"
+        assert headers["Content-Type"] == "application/json"
+
+
+# ------------------------------------------------------------------
+# Error handling helpers
+# ------------------------------------------------------------------
+
+class TestErrorHelpers:
+
+    def test_json_or_raise_returns_dict(self):
+        class FakeResp:
+            status_code = 200
+            def json(self):
+                return {"id": "task-123", "status": "queued"}
+        result = HunyuanCloudVideo._json_or_raise(FakeResp())
+        assert result == {"id": "task-123", "status": "queued"}
+
+    def test_json_or_raise_raises_on_non_json(self):
+        class FakeResp:
+            status_code = 500
+            def json(self):
+                raise ValueError("not JSON")
+        with pytest.raises(RuntimeError, match="Non-JSON"):
+            HunyuanCloudVideo._json_or_raise(FakeResp())
+
+    def test_check_response_passes_on_success(self):
+        HunyuanCloudVideo._check_response(
+            {"id": "task-123", "status": "completed"}
+        )
+
+    def test_check_response_passes_without_error_field(self):
+        HunyuanCloudVideo._check_response(
+            {"id": "task-456", "status": "running", "progress": 50}
+        )
+
+    def test_check_response_raises_on_api_error(self):
+        with pytest.raises(RuntimeError, match="Prompt too long"):
+            HunyuanCloudVideo._check_response({
+                "error": {"code": "invalid_parameter", "message": "Prompt too long"},
+            })
+
+    def test_check_response_raises_on_auth_failure(self):
+        with pytest.raises(RuntimeError, match="Invalid API key"):
+            HunyuanCloudVideo._check_response({
+                "error": {
+                    "type": "authentication_error",
+                    "message": "Invalid API key",
+                },
+            })
+
+
+# ------------------------------------------------------------------
+# Execute with mocked HTTP
+# ------------------------------------------------------------------
+
+class TestExecuteWithMocks:
+
+    def test_text_to_video_success(self, hunyuan_env, tmp_path, monkeypatch):
+        """Full T2V flow: submit -> poll -> download -> write output."""
+        task_id = "143-test-task-12345"
+        calls = _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                # Submit response
+                FakeResponse({
+                    "id": task_id,
+                    "request_id": "req-sub-001",
+                    "object": "video",
+                    "created_at": 1700000000,
+                    "status": "queued",
+                }),
+                # Poll response (completed)
+                FakeResponse({
+                    "request_id": "req-poll-001",
+                    "object": "video",
+                    "created_at": 1700000000,
+                    "completed_at": 1700000120,
+                    "status": "completed",
+                    "progress": 100,
+                    "data": {"url": "https://example.com/output.mp4"},
+                }),
+            ],
+            get_responses=[
+                # Download response
+                FakeResponse(content=b"fake-hunyuan-mp4-data"),
+            ],
+        )
+
+        output_path = tmp_path / "hunyuan_out.mp4"
+        result = HunyuanCloudVideo().execute({
+            "prompt": "一只猫在草原上奔跑",
+            "output_path": str(output_path),
+        })
+
+        assert result.success, result.error
+        assert output_path.read_bytes() == b"fake-hunyuan-mp4-data"
+        assert result.data["provider"] == "hunyuan_cloud"
+        assert result.data["route"] == "tokenhub"
+        assert result.data["model"] == "hy-video-1.5"
+        assert result.data["task_id"] == task_id
+        assert result.data["operation"] == "text_to_video"
+        assert result.cost_usd == pytest.approx(0.25)
+        assert len(result.artifacts) == 1
+        assert result.artifacts[0] == str(output_path)
+
+        # Verify submit was called to the correct TokenHub endpoint
+        submit_call = calls["post"][0]
+        assert "tokenhub.tencentmaas.com" in submit_call["url"]
+        assert submit_call["url"].endswith("/v1/api/video/submit")
+        assert submit_call["headers"]["Authorization"] == "Bearer thub-fake-test-key"
+        assert submit_call["json"]["model"] == "hy-video-1.5"
+        assert submit_call["json"]["prompt"] == "一只猫在草原上奔跑"
+
+        # Verify poll was called
+        poll_call = calls["post"][1]
+        assert poll_call["url"].endswith("/v1/api/video/query")
+        assert poll_call["json"]["model"] == "hy-video-1.5"
+        assert poll_call["json"]["id"] == task_id
+
+        # Verify download was called
+        assert len(calls["get"]) == 1
+        assert calls["get"][0]["url"] == "https://example.com/output.mp4"
+
+    def test_image_to_video_with_url_success(self, hunyuan_env, tmp_path, monkeypatch):
+        """Full I2V flow with an image URL."""
+        task_id = "i2v-task-999"
+        _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                FakeResponse({
+                    "id": task_id, "request_id": "req-sub", "object": "video",
+                    "created_at": 1700000000, "status": "queued",
+                }),
+                FakeResponse({
+                    "request_id": "req-poll", "object": "video",
+                    "created_at": 1700000000, "completed_at": 1700000120,
+                    "status": "completed", "progress": 100,
+                    "data": {"url": "https://example.com/i2v_out.mp4"},
+                }),
+            ],
+            get_responses=[
+                FakeResponse(content=b"fake-i2v-video"),
+            ],
+        )
+
+        output_path = tmp_path / "i2v_out.mp4"
+        result = HunyuanCloudVideo().execute({
+            "prompt": "让画面动起来",
+            "operation": "image_to_video",
+            "image_url": "https://example.com/frame.jpg",
+            "output_path": str(output_path),
+        })
+
+        assert result.success, result.error
+        assert output_path.read_bytes() == b"fake-i2v-video"
+        assert result.data["operation"] == "image_to_video"
+        assert result.data["model"] == "yt-video-2.0"
+        assert result.data["task_id"] == task_id
+
+    def test_i2v_with_local_image_path(self, hunyuan_env, tmp_path, monkeypatch):
+        """Full I2V flow with a local image path -> base64 encoding."""
+        img = tmp_path / "frame.jpg"
+        img.write_bytes(b"\xff\xd8\xff\xe0test-jpeg-image-data")
+
+        task_id = "i2v-local-task"
+        _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                FakeResponse({
+                    "id": task_id, "request_id": "req-sub", "object": "video",
+                    "created_at": 1700000000, "status": "queued",
+                }),
+                FakeResponse({
+                    "request_id": "req-poll", "object": "video",
+                    "created_at": 1700000000, "completed_at": 1700000120,
+                    "status": "completed", "progress": 100,
+                    "data": {"url": "https://example.com/i2v_local.mp4"},
+                }),
+            ],
+            get_responses=[
+                FakeResponse(content=b"fake-i2v-local-video"),
+            ],
+        )
+
+        output_path = tmp_path / "i2v_local.mp4"
+        result = HunyuanCloudVideo().execute({
+            "prompt": "animate this frame",
+            "operation": "image_to_video",
+            "image_path": str(img),
+            "output_path": str(output_path),
+        })
+
+        assert result.success, result.error
+        assert output_path.read_bytes() == b"fake-i2v-local-video"
+
+    def test_explicit_model_takes_priority(self, hunyuan_env, tmp_path, monkeypatch):
+        """When model is explicitly set, it should be used for both T2V and I2V."""
+        task_id = "model-override-1"
+        calls = _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                FakeResponse({
+                    "id": task_id, "request_id": "req-sub", "object": "video",
+                    "created_at": 1700000000, "status": "queued",
+                }),
+                FakeResponse({
+                    "request_id": "req-poll", "object": "video",
+                    "status": "completed", "progress": 100,
+                    "data": {"url": "https://example.com/out.mp4"},
+                }),
+            ],
+            get_responses=[FakeResponse(content=b"data")],
+        )
+
+        result = HunyuanCloudVideo().execute({
+            "prompt": "test",
+            "operation": "image_to_video",
+            "model": "hy-video-1.5",
+            "image_url": "https://example.com/frame.jpg",
+            "poll_interval_seconds": 0.1,
+            "output_path": str(tmp_path / "out.mp4"),
+        })
+
+        assert result.success, result.error
+        assert result.data["model"] == "hy-video-1.5"
+        assert calls["post"][0]["json"]["model"] == "hy-video-1.5"
+
+    def test_polling_retries_until_success(self, hunyuan_env, tmp_path, monkeypatch):
+        """Polling should retry when status is queued/running, then succeed."""
+        task_id = "poll-retry-task"
+        _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                FakeResponse({
+                    "id": task_id, "request_id": "req-sub", "object": "video",
+                    "created_at": 1700000000, "status": "queued",
+                }),
+                FakeResponse({
+                    "request_id": "r1", "object": "video",
+                    "status": "queued", "progress": 0,
+                }),
+                FakeResponse({
+                    "request_id": "r2", "object": "video",
+                    "status": "running", "progress": 45,
+                }),
+                FakeResponse({
+                    "request_id": "r3", "object": "video",
+                    "status": "completed", "progress": 100,
+                    "data": {"url": "https://example.com/final.mp4"},
+                }),
+            ],
+            get_responses=[
+                FakeResponse(content=b"final-video-data"),
+            ],
+        )
+
+        result = HunyuanCloudVideo().execute({
+            "prompt": "test polling",
+            "poll_interval_seconds": 0.1,
+            "output_path": str(tmp_path / "polled.mp4"),
+        })
+
+        assert result.success, result.error
+        assert result.data["task_id"] == task_id
+
+    def test_polling_fails_on_task_failed(self, hunyuan_env, tmp_path, monkeypatch):
+        """When the API returns status=failed, execute should return error."""
+        task_id = "failed-task"
+        _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                FakeResponse({
+                    "id": task_id, "request_id": "req-sub", "object": "video",
+                    "created_at": 1700000000, "status": "queued",
+                }),
+                FakeResponse({
+                    "request_id": "req-fail", "object": "video",
+                    "status": "failed",
+                    "error": {"code": "internal_error", "message": "Service unavailable"},
+                }),
+            ],
+            get_responses=[],
+        )
+
+        result = HunyuanCloudVideo().execute({
+            "prompt": "this will fail",
+            "poll_interval_seconds": 0.1,
+            "output_path": str(tmp_path / "failed.mp4"),
+        })
+
+        assert result.success is False
+        assert "failed" in result.error.lower()
+        assert "Service unavailable" in result.error
+
+    def test_submit_error_returns_failure(self, hunyuan_env, tmp_path, monkeypatch):
+        """API-level error on submit should be returned as ToolResult error."""
+        _install_fake_requests(
+            monkeypatch,
+            post_responses=[
+                FakeResponse({
+                    "error": {"code": "invalid_parameter", "message": "Prompt exceeds limit"},
+                }),
+            ],
+            get_responses=[],
+        )
+
+        result = HunyuanCloudVideo().execute({
+            "prompt": "test",
+            "output_path": str(tmp_path / "err.mp4"),
+        })
+
+        assert result.success is False
+        assert "Prompt exceeds limit" in result.error
+
+
+# ------------------------------------------------------------------
+# Registry discovery
+# ------------------------------------------------------------------
+
+class TestRegistryDiscovery:
+
+    def test_discoverable(self, isolated_tool_registry):
+        isolated_tool_registry.discover()
+        tool = isolated_tool_registry.get("hunyuan_cloud_video")
+        assert tool is not None
+        assert tool.provider == "hunyuan_cloud"
+        assert tool.capability == "video_generation"
+
+    def test_distinct_from_local_hunyuan_tool(self, isolated_tool_registry):
+        isolated_tool_registry.discover()
+        cloud = isolated_tool_registry.get("hunyuan_cloud_video")
+        local = isolated_tool_registry.get("hunyuan_video")
+        assert cloud is not None
+        assert local is not None
+        assert cloud.provider == "hunyuan_cloud"
+        assert local.provider == "hunyuan"
+        assert cloud.runtime == ToolRuntime.API
+        assert local.runtime == ToolRuntime.LOCAL_GPU
+
+
+# ------------------------------------------------------------------
+# Schema validation
+# ------------------------------------------------------------------
+
+class TestSchemaValidation:
+
+    def test_prompt_max_length_200(self):
+        schema = HunyuanCloudVideo().input_schema
+        assert schema["properties"]["prompt"]["maxLength"] == 200
+
+    def test_prompt_rejects_over_200_chars(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        instance = {"prompt": "x" * 201}
+        with pytest.raises(jsonschema.ValidationError):
+            jsonschema.validate(instance, schema)
+
+    def test_prompt_accepts_200_chars(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        instance = {"prompt": "x" * 200}
+        jsonschema.validate(instance, schema)
+
+    def test_operation_accepts_valid_values(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        for op in ["text_to_video", "image_to_video"]:
+            jsonschema.validate({"prompt": "test", "operation": op}, schema)
+
+    def test_operation_rejects_invalid_values(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        for invalid in ["video_to_video", "", "TEXT_TO_VIDEO"]:
+            with pytest.raises(jsonschema.ValidationError):
+                jsonschema.validate({"prompt": "test", "operation": invalid}, schema)
+
+    def test_model_accepts_valid_values(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        for m in ["hy-video-1.5", "yt-video-2.0"]:
+            jsonschema.validate({"prompt": "test", "model": m}, schema)
+
+    def test_model_rejects_invalid_values(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        with pytest.raises(jsonschema.ValidationError):
+            jsonschema.validate({"prompt": "test", "model": "invalid-model"}, schema)
+
+    def test_logo_add_accepts_0_and_1(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        for val in [0, 1]:
+            jsonschema.validate({"prompt": "test", "logo_add": val}, schema)
+
+    def test_logo_add_rejects_other_values(self):
+        import jsonschema
+        schema = HunyuanCloudVideo().input_schema
+        for invalid in [2, -1, 99]:
+            with pytest.raises(jsonschema.ValidationError):
+                jsonschema.validate({"prompt": "test", "logo_add": invalid}, schema)
+
+    def test_poll_interval_minimum_2(self):
+        schema = HunyuanCloudVideo().input_schema
+        assert schema["properties"]["poll_interval_seconds"]["minimum"] == 2
+
+    def test_timeout_minimum_60(self):
+        schema = HunyuanCloudVideo().input_schema
+        assert schema["properties"]["timeout_seconds"]["minimum"] == 60
+
+    def test_resolution_only_720p(self):
+        schema = HunyuanCloudVideo().input_schema
+        assert schema["properties"]["resolution"]["enum"] == ["720p", "1080p"]