Metaxy

What it does

When your agent uses it

• Asks to define a feature
• Create a BaseFeature class
• Track feature versions
• Set up metadata store

Example prompts

• “define a feature”
• “create a BaseFeature class”
• “track feature versions”
• “/metaxy”

Requirements

• Python 3

What it can do on your machine

Read from SKILL.md and the folder at commit 8337842. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are python and bash).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • docs.metaxy.io

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Metaxy loads about 1.5k tokens when it runs. Until then it costs about 144 tokens; SKILL.md has 410 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~144

When it runs · the whole SKILL.md, loaded when a task matches

~1.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from anam-org/metaxy at commit 8337842, republished under its Apache-2.0 licence (© anam-org). 410 words, ~1,534 tokens.

name

metaxy

description

This skill should be used when the user asks to "define a feature", "create a BaseFeature class", "track feature versions", "set up metadata store", "field-level lineage", "FieldSpec", "FeatureDep", "run metaxy CLI", "metaxy migrations", "metaxy lock", "lock features", "external features", "multi-environment", "monorepo features", "enable Map datatype", "enable_map_datatype", or needs guidance on metaxy feature definitions, versioning, metadata stores, CLI commands, testing patterns, feature locking, Map datatype configuration, or multi-environment configuration.

import metaxy as mx


class Video(
    mx.BaseFeature,
    spec=mx.FeatureSpec(
        key="media/video",
        id_columns=["video_id"],
        fields=["audio", "frames"],  # Logical fields: describe data contents for versioning
    ),
):
    # Metadata columns: stored in the metadata store, tracked by metaxy
    video_id: str
    path: str
    duration: float
    height: int
    width: int

fields = [
    mx.FieldSpec(key="embedding", code_version="2"),  # Bump to invalidate downstream
]

config = mx.MetaxyConfig(
    stores={"dev": mx.StoreConfig(
        type="metaxy.ext.polars.handlers.delta.DeltaMetadataStore",
        config={"root_path": "/tmp/metaxy"},
    )}
)
with config.use() as cfg:
    store = cfg.get_store("dev")

mx graph render            # Terminal visualization
mx push --store dev        # Push graph to store

mx list features --verbose     # List features with dependencies
mx graph render                # Visualize feature graph
mx metadata status --all-features  # Check metadata freshness (expensive!)
mx mcp                         # Start MCP server for AI assistants

import pytest
import metaxy as mx


@pytest.fixture
def metaxy_env(tmp_path):
    with mx.FeatureGraph().use():
        with mx.MetaxyConfig(
            stores={"test": mx.StoreConfig(
                type="metaxy.ext.polars.handlers.delta.DeltaMetadataStore",
                config={"root_path": str(tmp_path / "delta_test")},
            )}
        ).use() as config:
            yield config

© anam-org, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 5 other files in .claude-plugin/skills/metaxy of anam-org/metaxy.

• SKILL.md
• examples/cli.md
• examples/configuration.md
• examples/feature-definitions.md
• examples/metadata-stores.md
• examples/testing.md

Open the folder on GitHubat commit 8337842