Second Life MCP

Offline MCP tools for Second Life LSL and SLua: API reference, caveats, migration guidance and optional local compilation. Includes 1,640 LSL and 1,993 SLua records from pinned official sources.

Install

Requires Python 3.11+. Install the 1.0.0 release in your Python environment:

python -m pip install https://github.com/voidel/second-life-mcp/releases/download/v1.0.0/second_life_mcp-1.0.0-py3-none-any.whl

The release includes a source archive and SHA-256 checksums. The package is not published to PyPI. Normal use requires no network, credentials or Second Life account.

Related MCP server: ACE-MCP

Connect

Add this to your MCP client's configuration, replacing the interpreter path:

{
  "mcpServers": {
    "second-life": {
      "command": "/absolute/path/to/.venv/bin/python",
      "args": ["-m", "second_life_mcp"]
    }
  }
}

On Windows, use the environment's Scripts\python.exe. Client-specific examples: Claude Code and VS Code.

The server uses stdio and waits for MCP requests. Use lsl_mcp or slua_mcp instead of second_life_mcp for a single language. Console commands are second-life-mcp, lsl-mcp and slua-mcp.

Tools

Tool names start with lsl_ or slua_. All are read-only.

Examples:

• slua_lookup_symbol: {"name":"LLTimers:every"}

• lsl_migration_guidance: {"symbol":"llSetTimerEvent"}

• lsl_get_guidance: {"topic":"async-recovery"}

Status is also available through lsl://status and slua://status resources. Lookups include index origins, enum/boolean semantics, permissions and provenance where verified. Unknown symbols are not automatically corrected or declared invalid.

Compiler setup

second-life-toolchains --output-dir .toolchains

This downloads the hash-pinned SLua v0.732.17 compiler and luau-lsp 1.70.1 analyzer for Windows/Linux x86-64. Set SECOND_LIFE_MCP_TOOLCHAINS in your MCP host's environment to the absolute .toolchains/toolchains.json path.

LSL uses SLua's LSL compiler frontend; SLua uses compilation and optional type analysis against the bundled official definitions. Checks are time-limited, verify executable hashes and never execute submitted code. Single-file checks do not resolve imports. No compiler is downloaded during MCP requests.

Limits and sources

check_code is lexical, not compilation. It does not establish types, callback lifecycles or runtime safety; SLua backtick interpolation bodies are not inspected. Compilation also cannot verify simulator timing, memory, throttles or rendering. Empty caveats do not prove safety, and a null delay means unknown. Confirm SLua viewer/region support before deployment.

References use the Second Life Wiki, creation documentation and pinned official definitions. Import dates and manual review dates are recorded separately.

Development

python -m pip install uv==0.13.7
uv sync --locked --extra dev
uv run --no-sync python -m pytest
uv run --no-sync second-life-evaluate
uv run --no-sync python -m build

For compiler and fixed native-runtime tests, fetch the toolchains above and set SECOND_LIFE_MCP_TOOLCHAINS and SECOND_LIFE_MCP_TEST_RUNTIME to the absolute toolchains.json and test-runtime.json paths. CI tests Windows/Linux with Python 3.11–3.13. Evaluations exercise real MCP transport, not in-world behavior.

second-life-source-audit checks upstream fingerprints. To prepare a reviewable reference update without changing bundled data:

second-life-update --output-dir candidate --cache-dir .source-cache

Review candidates before applying them. See contributing and data attribution.

Release 1.0.0

• Canonical index, enum and boolean semantics, permissions and purity metadata.

• Expanded SLua migration guidance and behavior caveats.

• Native semantic regressions and stable wheel/source releases with checksums.