datachain-core

datachain-core is a skill for Claude Code, Codex from datachain-ai/datachain. It costs 54 tokens per session (391 once invoked), scanned A, original, Apache-2.0.

A reference for using the DataChain Python software library, including its APIs, method signatures, settings, data transformations, and saving or exporting results. It applies to general SDK questions when no particular dataset or storage location is involved.

In plain words
What is it for?
Use it to write or review DataChain code, understand function usage and user-defined functions, handle data changes, materialise results, and save or export data.
Why use it?
It prevents confusion between library mechanics and decisions about how a dataset should be designed. It also keeps dataset-planning rules in the separate knowledge skill that owns them.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to write or review DataChain code, understand function usage and user-defined functions, handle data changes, materialise results, and save or export data.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/datachain-ai/datachain/core
About the project

DataChain is a Python library and data-processing system that turns files from cloud storage or local filesystems into typed, versioned datasets that can be queried and processed. Teams use it to build repeatable pipelines for unstructured data, with optional knowledge-base and agent features that help coding agents understand and work with those datasets. The catalogue entries connect agents to DataChain's data workflows.

datachain-ai/datachain · 2,827 stars · on GitHub · docs.datachain.ai

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add datachain-ai/datachain --skill core
Clone the repo
git clone --depth 1 https://github.com/datachain-ai/datachain

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for datachain-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/datachain-ai/datachain/core/github.svg)](https://agentmods.dev/skills/datachain-ai/datachain/core)
Your own site
<a href="https://agentmods.dev/skills/datachain-ai/datachain/core"><img src="https://agentmods.dev/badge/skills/datachain-ai/datachain/core/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for datachain-core

Your own site · 80×15
<a href="https://agentmods.dev/skills/datachain-ai/datachain/core"><img src="https://agentmods.dev/badge/skills/datachain-ai/datachain/core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 391 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00054 $0.00391
Opus 5.5 $0.00022 $0.00156
Sonnet 5.5 $0.00011 $0.00078
Haiku 4.5 $0.00005 $0.00039

Measured 25d ago against content hash 6ef35001a4c2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

datachain-core scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 25d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

src/datachain/skill/core/SKILL.md · 21 lines

What it actually says

Read {skill_dir}/SDK.md in full before answering DataChain SDK questions or generating DataChain Python code. It holds the SDK rules: API usage, UDF signatures, settings, delta semantics, materialization patterns, saving, exporting. The last section below holds the steps that need a local checkout and the dc-knowledge/ knowledge base.

Scope of this skill

SDK.md owns how DataChain code is written — API usage, UDF signatures, the shape of a saved dataset, saving and exporting. It is self-sufficient on its own.

The datachain-knowledge skill owns the knowledge base at dc-knowledge/: what datasets already exist, what each one holds, how long a run will take, and keeping that record current. When it is loaded, it drives the session and calls the rules here to write the code.

Before writing any pipeline code

  1. If dc-knowledge/index.md exists, read it first.
  2. When the user's task overlaps with an existing dataset, read its .md under dc-knowledge/datasets/ for schema, code patterns, and lineage.
  3. Bucket access: anonymous or authenticated? Check dc-knowledge/buckets/ for a .md file with anon: true/false in frontmatter. If none, run datachain bucket status <uri> to detect. If denied or not found, stop and ask the user.

Never create or modify files under dc-knowledge/ — that directory is owned by the knowledge skill.

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 25d ago Changed · -2 lines 6ef35001a4c2
  2. 1mo ago Changed · -795 lines 7d621ff3d614
  3. 1mo ago Changed · +42 lines 100c2c04cee2
  4. 1mo ago First seen · 776 lines · 54 tokens per session scan A 6efd3b97c239

Subscribe to this mod's changes

datachain-core is a skill published in the GitHub repository datachain-ai/datachain (2,827 stars, last pushed today), licensed Apache-2.0. It adds 54 tokens to every session and 391 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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