What is OpenShelf AGENTS.md?

Repository instructions for OpenShelf, a project that manages searchable knowledge bases built from document collections. They describe how agents should search those collections and cite retrieved evidence.

Use them when answering questions from PDF collections, choosing among multiple knowledge databases, following citation rules, and handling missing evidence.

They help keep answers grounded in the project’s documents and prevent agents from bypassing the supported knowledge-base tools.

How vecbase-labs/OpenShelf configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to vecbase-labs/OpenShelf. 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/vecbase-labs/OpenShelf/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/vecbase-labs/OpenShelf

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/vecbase-labs/openshelf/agents-md/github.svg)](https://agentmods.dev/instructions/vecbase-labs/openshelf/agents-md)

Your own site

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

Per session 523 This file is loaded in full into every session.

When invoked 523 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	$0.00523	$0.00523
Opus 5.5	$0.00209	$0.00209
Sonnet 5.5	$0.00105	$0.00105
Haiku 4.5	$0.00052	$0.00052

Measured 2mo ago against content hash af090c96d662, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

OpenShelf 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 · 36 lines

How it starts

The opening of the file, as written. The whole thing — 36 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Repository Agent Guidelines

Use the repository's MCP tools and public APIs when working with the knowledge base. Do not bypass the server by reading DuckDB files, generated indexes, or cached artifacts directly unless the task is explicitly to debug storage internals.

Knowledge Base Policy

When a user asks a question that should be grounded in an existing PDF corpus, search the configured knowledge base first. Treat retrieved evidence as the source of truth and cite the returned document, page, chunk, or evidence item in answers.

If direct evidence is not found, say so plainly. Only use independent reasoning when the user allows it or when the selected database profile permits labeled independent reasoning. Keep independent reasoning clearly separated from knowledge-base evidence.

Multiple Knowledge Databases

This project can manage multiple physical DuckDB knowledge bases with a single MCP server. Different corpora are selected by db_name; openshelf is the MCP server name and must not be used as a database name.

General workflow:

If the user has not specified a database and multiple databases exist, call list_db and ask which db_name to use.
If the user specifies a database for the current session, call set_active_db.
Do not search across databases unless the user explicitly asks for cross-database search.
When searching multiple databases, report each database's evidence and answerability status separately.
If a tool returns status: "db_selection_required", stop and ask the user to choose a database.

Answering Rules

Answer from the knowledge base only when answerability.status is supported or the tool explicitly returns direct evidence.
Cite returned evidence locations; do not present weakly related material as direct support.
If the status is related_only, explain that the corpus contains only weakly related material and ask whether to proceed with independent reasoning.
If the status is not_found, explain that no usable evidence was found and ask whether to proceed independently.
When independent reasoning is used, label it as independent reasoning and do not imply it came from the corpus.

Read the full file on GitHub · 36 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 · 36 lines · 523 tokens per session scan A af090c96d662

Subscribe to this mod's changes

OpenShelf AGENTS.md is an instructions file published in the GitHub repository vecbase-labs/OpenShelf (3 stars, last pushed 4mo ago), licensed MIT. It adds 523 tokens to every session, about $0.0021 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 2026-08-31.

OpenShelf AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
OpenShelf AGENTS.mdvecbase-labs/OpenShelf	Instructions file	3	4mo ago	MIT	A	523	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
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
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

OpenShelf: Instructions file for Codex