luaskills-sdk 0.5.1

Python SDK for integrating the LuaSkills runtime through the public JSON FFI surface.

luaskills-sdk

English documentation is the default package documentation. For Chinese, see README_cn.md.

Main LuaSkills repository: LuaSkills/luaskills

Python SDK for integrating the LuaSkills runtime through the public JSON FFI surface.

The SDK wraps native library loading, JSON FFI buffers, engine lifecycle, formal skill roots, authority-aware management calls, skill config, provider callbacks, host-tool callbacks, and runtime asset installation. Hosts should not need to hand-write low-level FFI buffers or JSON envelopes for normal integration.

Installation

pip install luaskills-sdk

The Python wheel does not embed native runtime binaries or LuaRocks modules. Prepare a runtime_root with install-runtime, then pass that root to LuaSkillsClient.

luaskills install-runtime --database none --runtime-root D:\runtime\luaskills
luaskills version --runtime-root D:\runtime\luaskills

After installation, the SDK automatically resolves luaskills.dll / libluaskills.so / libluaskills.dylib from runtime_root/libs. You usually do not need LUASKILLS_LIB.

Use library_path or LUASKILLS_LIB only when your host intentionally manages native libraries outside the SDK runtime root.

Runtime Assets

The source distribution includes a unified script that does not require the Python CLI and directly fetches LuaSkills FFI, Lua runtime packages, and VLDB:

powershell -NoProfile -ExecutionPolicy Bypass -File scripts/deps/sync_runtime_assets.ps1 -Target all -Database vldb-controller -RuntimeRoot D:\runtime\luaskills

RUNTIME_ROOT=/opt/luaskills scripts/deps/sync_runtime_assets.sh all vldb-controller

Supported targets are all, luaskills, lua, and vldb. VLDB presets are none, vldb-controller, vldb-direct, and host-callback. The scripts pin LuaSkills to v0.5.1 by default and accept explicit release-version overrides.

install-runtime downloads GitHub Release assets, verifies .sha256 sidecars, extracts native files and Lua runtime packages, and writes:

runtime_root/resources/luaskills-sdk-runtime-manifest.json

Supported database modes:

• none: installs the Lua runtime archive and the LuaSkills FFI SDK archive, without database providers.
• vldb-direct: installs vldb-sqlite-lib and vldb-lancedb-lib dynamic libraries and uses dynamic_library provider mode.
• vldb-controller: installs vldb-controller and uses managed space_controller provider mode.
• host-callback: installs no VLDB binaries and generates host_callback + json host options.

Default LuaSkills assets:

• lua-runtime-packages-{platform}.tar.gz from LuaSkills/luaskills-packages: installed by default; provides lua_packages, package-side runtime libs, resources, and third-party runtime licenses.
• luaskills-ffi-sdk-{platform}.tar.gz: installed by default; provides the public FFI dynamic library, headers, and FFI licenses.
• lua-deps-{platform}.tar.gz: not installed by the SDK; it is a build-time bundle for CI, source builds, or advanced native module rebuilds.

Managed Python and Node.js child runtimes are optional. Use --managed-runtimes all when Lua skills need vulcan.runtime.python.* or vulcan.runtime.node.*; the installer places Python, uv, Node.js, and pnpm under runtime_root/dependencies/runtimes/....

Managed child runtimes support Windows x64, Linux x64/ARM64, and macOS x64/ARM64. Windows ARM is explicitly rejected before any download or target-directory creation. Source distributions also include the standalone scripts/deps/fetch_managed_runtimes.ps1, scripts/deps/fetch_managed_runtimes.sh, and scripts/debug-tools/managed_runtime_layout_check.py tools used to prepare and validate debug runtime roots.

The current exact managed dependency versions are Python 3.14.6, uv 0.11.28, Node.js 24.18.0, and pnpm 11.11.0. Package dependencies.yaml files must declare the same exact runtime and package-manager versions unless the host deliberately installs another supported version.

Host-selected managed runtime roots

LuaSkills 0.5.1 separates the LuaSkills data root, the read-only interpreter distribution root, and the writable managed-environment root. Both explicit managed roots must be absolute; when omitted, LuaSkills keeps the compatible runtime_root/dependencies/runtimes and runtime_root/dependencies/envs layout.

from luaskills import LuaSkillsClient

distribution_root = "D:/VulcanCode/dependencies/runtimes"
environment_root = "D:/VulcanCodeData/managed-runtime-envs"

client = LuaSkillsClient(
    runtime_root="D:/VulcanCodeData/luaskills",
    host_options={
        "managed_runtime_distribution_root": distribution_root,
        "managed_runtime_environment_root": environment_root,
        "managed_runtime_config": {
            "worker_pool_max_size_per_environment": 8,
            "worker_idle_ttl_secs": 120,
            "persistent_session_limit_per_engine": 128,
            "persistent_session_default_buffer_limit_bytes_per_stream": 2 * 1024 * 1024,
            "invoke_default_timeout_ms": 30_000,
        },
    },
)

python_install = LuaSkillsClient.resolve_managed_runtime_install(
    distribution_root,
    "python",
    "3.14.6",
    "windows-x64",
    runtime_root="D:/VulcanCodeData/luaskills",
)

default_managed_runtime_config() returns the stable engine defaults: 4 Workers per exact environment/package-owner pool, 60 idle seconds, 256 persistent sessions, 1 MiB per session output stream, and no default invoke timeout. Start from that complete object when changing individual values. Every configured number must be positive; per-call invoke.timeout_ms and per-session session.open.buffer_limit_bytes override only their matching engine defaults.

The standalone fetch and debug tools accept the same split layout:

powershell -NoProfile -ExecutionPolicy Bypass -File scripts/deps/fetch_managed_runtimes.ps1 -RuntimeRoot D:\VulcanCodeData\luaskills -DistributionRoot D:\VulcanCode\dependencies\runtimes -Target all
python scripts/debug-tools/managed_runtime_layout_check.py D:\VulcanCodeData\luaskills --distribution-root D:\VulcanCode\dependencies\runtimes --environment-root D:\VulcanCodeData\managed-runtime-envs

The SDK keeps LuaSkills core aligned with the SDK release and resolves runtime packages from the compatible 0.1 series by selecting the newest published patch automatically.

Version Alignment

• Keep the SDK and LuaSkills core on the same current release line whenever possible.
• The current SDK defaults to LuaSkills core tag v0.5.1.
• Runtime packages and native dependencies still come from the split LuaSkills/luaskills-packages and related release assets.
• SDK default host options pass runtime_root, null managed-root override slots, and the complete stable managed_runtime_config; LuaSkills derives the fixed data layout until the host explicitly overrides roots or policy.
• Host tools live directly under runtime_root/bin, not runtime_root/bin/tools.

luaskills install-runtime --database none --runtime-root D:\runtime\luaskills
luaskills install-runtime --database vldb-direct --runtime-root D:\runtime\luaskills
luaskills install-runtime --database vldb-controller --runtime-root D:\runtime\luaskills
luaskills install-runtime --database host-callback --runtime-root D:\runtime\luaskills
luaskills install-runtime --database none --managed-runtimes all --runtime-root D:\runtime\luaskills

Use --dry-run to inspect exact release URLs before downloading:

luaskills install-runtime --database vldb-direct --runtime-root D:\runtime\luaskills --dry-run

Advanced hosts that already manage Lua packages can skip the Lua runtime archive:

luaskills install-runtime --database none --runtime-root D:\runtime\luaskills --skip-lua-runtime

Basic Usage

Prepare runtime_root, then create the client without an explicit library_path:

from luaskills import Authority, LuaSkillsClient, RuntimeRoots

runtime_root = "D:/runtime/luaskills"
roots = RuntimeRoots.standard(runtime_root)

with LuaSkillsClient(runtime_root=runtime_root) as client:
    client.load_from_roots(roots)
    entries = client.list_entries(Authority.DELEGATED_TOOL)
    result = client.call_skill("demo-standard-ffi-skill-ping", {"note": "python-sdk"})

    print(entries)
    print(result["content"])

Use library_path only when bypassing the runtime manifest:

from luaskills import LuaSkillsClient

with LuaSkillsClient(
    library_path="D:/path/to/luaskills.dll",
    runtime_root="D:/runtime/luaskills",
) as client:
    print(client.version())

CLI Flow

End-to-end CLI flow with a prepared runtime root:

luaskills install-runtime --database none --runtime-root D:\runtime\luaskills
luaskills version --runtime-root D:\runtime\luaskills
luaskills list --runtime-root D:\runtime\luaskills
luaskills call demo-standard-ffi-skill-ping '{"note":"python"}' --runtime-root D:\runtime\luaskills

If you need VLDB direct libraries:

luaskills install-runtime --database vldb-direct --runtime-root D:\runtime\luaskills

If you prefer the shared controller mode:

luaskills install-runtime --database vldb-controller --runtime-root D:\runtime\luaskills

Provider Callback

SQLite / LanceDB host_callback + json mode can be registered through the SDK before engine creation:

from luaskills import LuaSkillsClient, LuaSkillsJsonFfi

runtime_root = "D:/runtime/luaskills"
ffi = LuaSkillsJsonFfi(runtime_root=runtime_root)


def sqlite_provider(request):
    return {"ok": True, "request": request}


ffi.set_sqlite_provider_json_callback(sqlite_provider)

try:
    client = LuaSkillsClient(
        runtime_root=runtime_root,
        host_options={
            "sqlite_provider_mode": "host_callback",
            "sqlite_callback_mode": "json",
        },
    )
    client.close()
finally:
    ffi.clear_sqlite_provider_json_callback()

Callbacks must be registered before engine_new. Changing callbacks later does not retroactively affect already-created engines.

Host Tool Callback

vulcan.host.* uses the fixed host-tool callback registered through luaskills_ffi_set_host_tool_json_callback. Register it before running skills that may call host-owned tools:

from luaskills import HostToolJsonRequest, LuaSkillsJsonFfi

# Runtime root used by the host integration.
# 宿主集成使用的运行时根目录。
runtime_root = "D:/runtime/luaskills"
# Low-level FFI bridge that owns callback registration.
# 持有 callback 注册的底层 FFI 桥。
ffi = LuaSkillsJsonFfi(runtime_root=runtime_root)


def host_tool_callback(request: HostToolJsonRequest):
    """
    Handle list, has, and call actions from vulcan.host.*.
    处理来自 vulcan.host.* 的 list、has 和 call 动作。
    """

    if request["action"] == "list":
        return [{"name": "model.embed", "description": "embedding model bridge"}]
    if request["action"] == "has":
        return request["tool_name"] == "model.embed"
    if request["action"] == "call":
        return {"ok": True, "value": {"request": request["args"]}}
    return {"ok": False, "error": {"code": "unsupported_action", "message": request["action"]}}


ffi.set_host_tool_json_callback(host_tool_callback)

The callback receives { action, tool_name, args }. list should return host-visible tool metadata, has should return a boolean or an object with exists / has / available, and call should return one complete table-shaped result. Call ffi.clear_host_tool_json_callback() during shutdown. Streaming is intentionally outside this bridge.

Model Callback

vulcan.models.* uses fixed model callbacks registered through luaskills_ffi_set_model_embed_json_callback and luaskills_ffi_set_model_llm_json_callback. Lua skills can only call vulcan.models.embed(text) and vulcan.models.llm(system, user); provider selection, model names, keys, temperature, thinking, limits, and stream policy stay fully host-owned.

Register model callbacks before creating or using an engine that may run model-aware skills. Keep the LuaSkillsJsonFfi instance alive for as long as the callback should stay registered, and clear callbacks during shutdown or test teardown.

The SDK callback is the host boundary:

• It receives a fixed request shape from LuaSkills.
• It should call the host-selected provider using host-managed configuration.
• It should return a bare success payload for successful provider calls.
• It should return an error envelope for provider failures that need provider_message, provider_code, or provider_status.
• It should not expose API keys, Authorization headers, signatures, or raw request headers in provider error fields.

from luaskills import LuaSkillsJsonFfi, RuntimeModelEmbedRequest, RuntimeModelLlmRequest

runtime_root = "D:/runtime/luaskills"
ffi = LuaSkillsJsonFfi(runtime_root=runtime_root)


def embed_callback(request: RuntimeModelEmbedRequest):
    return {
        "vector": [0.1, 0.2, 0.3],
        "dimensions": 3,
        "usage": {"input_tokens": len(request["text"])},
    }


def llm_callback(request: RuntimeModelLlmRequest):
    if "missing-model" in request["user"]:
        return {
            "ok": False,
            "error": {
                "code": "provider_error",
                "message": "model provider rejected the request",
                "provider_message": "raw provider message after host-side redaction",
                "provider_code": "model_not_found",
                "provider_status": 404,
            },
        }
    return {
        "assistant": f"handled {request['system']}: {request['user']}",
        "usage": {"input_tokens": 12, "output_tokens": 8},
    }


ffi.set_model_embed_json_callback(embed_callback)
ffi.set_model_llm_json_callback(llm_callback)

The callback request includes { text, caller } for embeddings and { system, user, caller } for LLM calls. Return bare success payloads, or { ok: false, error: { code, message, provider_message?, provider_code?, provider_status? } } for provider failures. Call ffi.clear_model_embed_json_callback() and ffi.clear_model_llm_json_callback() during shutdown.

Minimal runtime check after registration:

status = client.run_lua("return vulcan.models.status()")
embed_result = client.run_lua('return vulcan.models.embed("hello")')
llm_result = client.run_lua('return vulcan.models.llm("system", "user")')

Common integration mistakes:

• model_unavailable: the matching callback was not registered or was cleared before the skill call.
• Missing provider details: return a structured error envelope instead of raising provider errors from the callback.
• Missing FFI symbol: install a LuaSkills runtime that exports luaskills_ffi_set_model_embed_json_callback and luaskills_ffi_set_model_llm_json_callback.
• Empty caller fields: call through a loaded runtime skill or a runtime run_lua context, not a detached provider unit test.

Examples

The wheel includes runnable examples:

python -m luaskills.examples.basic
python -m luaskills.examples.host_tool_callback
python -m luaskills.examples.provider_callback
python -m luaskills.examples.runtime_lease

Source-tree examples include query, lifecycle, and persistent runtime-lease flows with a bundled USER-layer fixture skill:

luaskills install-runtime --database none --runtime-root .\examples\fixture_runtime
python .\examples\basic.py
python .\examples\call.py
python .\examples\host_tool_callback.py
python .\examples\query.py
python .\examples\lifecycle.py
python .\examples\runtime_lease.py
python .\examples\provider_callback.py

The fixture skill lives at examples/fixture_runtime/user_skills/demo-standard-ffi-skill, so delegated-query examples can see it without System authority.

See examples/README.md for the full example index and runtime notes. The Chinese example guide is examples/README_cn.md.

Persistent Runtime Leases

Use client.runtime_leases() for the public lease endpoints, or client.system(authority).runtime_leases() when the host wants fixed authority injection through the dedicated system runtime-lease exports provided by the latest native library.

from luaskills import Authority, LuaSkillsClient

client = LuaSkillsClient(runtime_root="D:/runtime/luaskills")

try:
    leases = client.system(Authority.SYSTEM).runtime_leases()
    session = leases.create_handle(
        "demo-session",
        ttl_sec=600,
        replace=True,
        cwd="D:/runtime/luaskills/system_lua_lib",
        mounts={"channel": "demo"},
        system_package={"id": "debug-plugin", "root": "D:/runtime/luaskills/system_lua_lib/debug-plugin", "dependencies_file": "dependencies.json"},
    )
    result = session.eval("counter = (counter or 0) + 1; return { counter = counter }")
    print(result["result"])
    print(session.status())
    print(session.close())
finally:
    client.close()

Migration Notes

• Existing client.system(authority) lifecycle calls keep working; the returned wrapper now also exposes query helpers and runtime_leases().
• RuntimeLeaseHandle persists lease_id + sid + generation and automatically reattaches identity guards on eval, status, and close.
• client.system(authority).runtime_leases() requires the dedicated luaskills_ffi_system_runtime_lease_* exports from the latest native library and fails fast when they are missing.
• When the host explicitly enables request_context.client_capabilities.host_result, call_skill() returns one independent host_result field for IDE-native structured results.
• When host_result["kind"] == "change_set", hosts should treat payload as RuntimeChangeSetPayload.
• Canonical change_set payloads now use file lifecycle records plus hunk-level before + delete[] + insert[] + after blocks for modify changes.
• create and delete file records carry full-file content, while rename records carry old_path and new_path.
• Public leases accept cwd, workspace_root, lua_roots, c_roots, and mounts. System leases require system_package, reject lua_roots/c_roots, and derive roots from the trusted package manifest.
• poll_managed_session_events(), wait_managed_session_events(), and set_managed_session_wake_callback() expose the 0.5.1 event surface.

Authority And Management

Query APIs default to DelegatedTool, so ROOT skills are hidden from delegated tools.

System only means the host may manage ROOT. It does not bypass ROOT ownership or same-skill_id conflict rules.

Ordinary management should target USER or PROJECT:

luaskills install LuaSkills/luaskills-demo-skill --target-root USER
luaskills update LuaSkills/luaskills-demo-skill --target-root USER
luaskills uninstall luaskills-demo-skill --target-root USER

System management should be exposed only through trusted host/admin surfaces:

luaskills system-install LuaSkills/luaskills-demo-skill --target-root ROOT --authority system

If a system command is wrapped for ordinary tools, bind --authority delegated_tool in the host wrapper instead of letting the caller choose it.

Skill Config

Skill config is a plain skill_id + key storage surface. Configuration only affects behavior when the Lua skill reads it. It is not a hard runtime policy layer.

Troubleshooting

fetch failed while installing runtime assets

install-runtime uses Python urllib to download GitHub Release assets. In proxy environments, configure the standard proxy variables before running it.

$env:HTTP_PROXY = "http://127.0.0.1:10808"
$env:HTTPS_PROXY = "http://127.0.0.1:10808"
luaskills install-runtime --database none --runtime-root D:\runtime\luaskills

LuaSkills library path is required

This means the SDK could not find a native LuaSkills library. Run install-runtime, pass --runtime-root, or set LUASKILLS_LIB.

luaskills install-runtime --database none --runtime-root D:\runtime\luaskills
luaskills version --runtime-root D:\runtime\luaskills

Lua modules are missing at runtime

If a skill fails with Lua module loading errors, make sure install-runtime was run without --skip-lua-runtime and that runtime_root/lua_packages exists. The default installer uses LuaSkills/luaskills-packages runtime packages specifically to satisfy these Lua-side dependencies.

luaskills install-runtime --database none --runtime-root D:\runtime\luaskills
Test-Path D:\runtime\luaskills\lua_packages

Verification

For source-tree validation:

python -m compileall src/luaskills
PYTHONPATH=src python -m luaskills.cli version --runtime-root D:/runtime/luaskills

Publishing

The release version is stored in VERSION. Keep VERSION and pyproject.toml aligned before publishing.

For one unified ecosystem release, publish LuaSkills/luaskills-packages first, then publish LuaSkills/luaskills, so the default runtime installer assets for this SDK already exist.

Before publishing:

python -m build
twine check dist/*

Use a new patch version for every PyPI publish. Published versions cannot be overwritten.

Recommended unified publish order: luaskills-packages -> luaskills core release -> TypeScript SDK -> Python SDK -> Go SDK -> SDK examples releases.

After PyPI publishes successfully, run the GitHub Actions workflow Examples Release manually. It reads VERSION, installs luaskills-sdk=={VERSION} from PyPI, installs LuaSkills runtime assets, runs the examples, then creates or updates the examples-v{VERSION} GitHub Release with:

• luaskills-sdk-python-examples-{VERSION}.zip
• luaskills-sdk-python-examples-{VERSION}.zip.sha256

The examples release tag intentionally uses the examples-v prefix because it is an examples asset release, not an SDK package version.