What is lance-duckdb AGENTS.md?

Repository instructions for a DuckDB extension that lets DuckDB query Lance datasets, including vector and full-text searches. DuckDB is a database for analytics, while Lance is a data format for machine-learning data.

Use them when documenting, implementing, reviewing, testing, or changing compatibility in the lance-duckdb extension.

They explain which upstream DuckDB and Lance rules take priority and how the C++ and Rust parts must work together.

How lance-format/lance-duckdb configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to lance-format/lance-duckdb. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/lance-format/lance-duckdb/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/lance-format/lance-duckdb

Made for: Codex, OpenCode.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/lance-format/lance-duckdb/agents-md/github.svg)](https://agentmods.dev/instructions/lance-format/lance-duckdb/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/lance-format/lance-duckdb/agents-md"><img src="https://agentmods.dev/badge/instructions/lance-format/lance-duckdb/agents-md/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/lance-format/lance-duckdb/agents-md"><img src="https://agentmods.dev/badge/instructions/lance-format/lance-duckdb/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,967 This file is loaded in full into every session.

When invoked 1,967 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.01967	$0.01967
Opus 5.5	$0.00787	$0.00787
Sonnet 5.5	$0.00393	$0.00393
Haiku 4.5	$0.00197	$0.00197

Measured 20d ago against content hash d6b91fab2148, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

lance-duckdb AGENTS.md 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 20d 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.

AGENTS.md · 163 lines

How it starts

The opening of the file, as written. The whole thing — 163 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Project Overview

This repository contains a DuckDB extension for querying Lance format datasets (including scan, vector search, and full-text search). The DuckDB integration is implemented in C++ (under src/) and links a Rust static library (lance_duckdb_ffi) that uses the Lance Rust crate and exports data via the Arrow C Data Interface.

Version and Release Policy

Lance is a DuckDB core extension. lance-duckdb has no independent product version or release cadence; delivery follows DuckDB releases and the target DuckDB commit.
Do not propose or create lance-duckdb version bumps, release tags, or GitHub releases. DuckDB owns official core-extension publication and selects this repository's latest main for the active target.
Identify compatibility by DuckDB release/commit and platform. Identify extension source by its lance-duckdb commit. Record both commits when reporting validation; repository CI success is distinct from official artifact availability.
The duckdb gitlink pins the tested upstream commit. DuckDB-named maintenance branches are compatibility lines, not independent extension versions. Keep gitlinks, branch annotations, and CI targets aligned when changing the DuckDB target.
Cargo package versions are internal metadata; Lance dependency versions and dataset/storage/IR versions are separate concepts. Preserve DuckDB's generated build metadata without treating it as an independent product version.
Follow DuckDB compatibility and release policy for branch and publication details.

Documentation Language

All documentation in this repository (including README.md and files under docs/) must be written in English.

Constraint Hierarchy (Highest Priority)

For any planning, implementation, review, or refactor work in this repository:

The only hard constraints are upstream DuckDB requirements and upstream Lance requirements.
If any repository-local guidance conflicts with DuckDB or Lance behavior/contracts, follow DuckDB/Lance.
Any decision made inside lance-duckdb (APIs/ABIs, FFI boundaries, internal formats, module boundaries, naming, testing conventions, or implementation strategies) is mutable and may be changed when a better design is found.
Treat repository-local rules in this document as default guidance, not immutable policy.

Read the full file on GitHub · 163 lines

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.

20d ago Changed · +9 lines · +231 tokens per session d6b91fab2148
21d ago Changed · +4 lines · +64 tokens per session 46ef21eb0ba0
2mo ago First seen · 150 lines · 1,672 tokens per session scan A e5c687fc3d5b

Subscribe to this mod's changes

lance-duckdb AGENTS.md is an instructions file published in the GitHub repository lance-format/lance-duckdb (136 stars, last pushed 2d ago), licensed Apache-2.0. It adds 1,967 tokens to every session, about $0.0079 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.

lance-duckdb AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
lance-duckdb AGENTS.mdlance-format/lance-duckdb	Instructions file	136	2d ago	Apache-2.0	A	1,967	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
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vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

lance-duckdb: Instructions file for Codex