What is duckrun AGENTS.md?

Instructions for working with duckrun, a dbt adapter that uses DuckDB to run SQL models and Delta Lake tables to store results. dbt is a tool that builds and schedules data transformations, while a monorepo-style project may contain several related packages in one repository.

Use it when developing or assisting with duckrun projects, especially models that write Delta tables or run in CI, on a laptop, or in Microsoft Fabric.

It explains duckrun's less obvious defaults, such as in-memory DuckDB, incremental writes, concurrent models, and Fabric authentication, which can otherwise cause silent mistakes.

How djouallah/duckrun configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to djouallah/duckrun. 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/djouallah/duckrun/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/djouallah/duckrun

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/djouallah/duckrun/agents-md/github.svg)](https://agentmods.dev/instructions/djouallah/duckrun/agents-md)

Your own site

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

Per session 631 This file is loaded in full into every session.

When invoked 631 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	$0.00631	$0.00631
Opus 5.5	$0.00252	$0.00252
Sonnet 5.5	$0.00126	$0.00126
Haiku 4.5	$0.00063	$0.00063

Measured 2mo ago against content hash e2ea7fb0753c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

duckrun 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 2mo 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 · 48 lines

How it starts

The opening of the file, as written. The whole thing — 48 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Guidance for AI agents working in this repo or helping someone use duckrun.

duckrun is a dbt adapter: DuckDB executes the model SQL, delta-rs writes the result as a Delta Lake table, and dbt orchestrates the DAG. It runs the same on a laptop, in CI, or in a Fabric notebook.

Before helping with a duckrun project, read the skill — it is the authoritative guide:

plugins/duckrun-projects/skills/duckrun-projects/SKILL.md

A few defaults differ from other dbt adapters and cause silent mistakes if you assume the usual behavior:

threads: is honored (dbt's default is 1), but every model writes a real table: concurrent writers share one DuckDB memory_limit and a microbatch model's batches always run in order. More threads help many network-bound models; they don't help one big merge.
DuckDB is in-memory; there is no database file. The Delta tables are the only state.
Incremental strategy defaults depend on unique_key (merge with it, append without). For large tables, merge vs a dedup-in-SQL append (auto-fenced when the model reads {{ this }}) matters a lot.
OneLake/Fabric auth is just a bearer token; paths use lakehouse GUIDs, not names.

Consult the SKILL.md before writing profiles.yml or any incremental model.

Working on duckrun itself

Read CONTRIBUTING.md first — it has the full flow and the rules. The short version:

Every change lands via a pull request, including the owner's own. Branch off main (fix/, feat/, docs/, ci/, test/), push the branch, open a PR. This repo overrides any general "you own this repo, so commit straight to main" rule you may be carrying — there is no direct-push path here.
Never push to main, and never touch the legacy branch. Two things stay on main and are not to be "fixed": CI's own [skip ci] scorecard commits, and the release vX.Y.Z tag push.
Never modify a test to make a PR pass. No skip, no xfail, no weakened assertion. A red test means fix the adapter.
Don't add new public API without discussing it first. Agents are the ones most likely to invent surface nobody asked for. A question is not a work order.
It's fine to run tests locally for this project.
Keep duckrun boring: prefer the dull, idiomatic solution. The only intentional bet is the Arrow + delta-rs core, because there's no alternative way to write Delta.

Read the full file on GitHub · 48 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.

2mo ago First seen · 48 lines · 631 tokens per session scan A e2ea7fb0753c

Subscribe to this mod's changes

duckrun AGENTS.md is an instructions file published in the GitHub repository djouallah/duckrun (55 stars, last pushed 17d ago), licensed MIT. It adds 631 tokens to every session, about $0.0025 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.

duckrun AGENTS.md next to 6 instructions from other repositories
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duckrun AGENTS.mddjouallah/duckrun	Instructions file	55	17d ago	MIT	A	631	Codex, OpenCode
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duckrun: Instructions file for Codex