agentmods.dev

behold: Instructions file for Codex

AGENTS.md

behold AGENTS.md is an instructions file for Codex, OpenCode from kitlangton/behold. It costs 1,116 tokens per session, scanned A, original, MIT.

Project instructions for Behold, a local-first Markdown viewer for presenting agent work, collecting browser comments, and optionally publishing fixed public snapshots.

In plain words
What is it for?
Use them when modifying Behold's viewer, local server, review storage, MCP connection, or Cloudflare publishing code.
Why use it?
They give an agent the project structure and rules it must preserve when changing Behold.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is kitlangton/behold's own configuration. It tells Codex and OpenCode how to work on behold itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything behold configures →

not rated 14repo 2mo ago A scan 1,116 tokens original MIT
View source ↗ kitlangton/behold behold.kitlangton.dev
Reuse

Borrowing it

Nothing to install: this file belongs to kitlangton/behold. 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/kitlangton/behold/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/kitlangton/behold

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.

agentmods badge for behold AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/kitlangton/behold/agents-md/github.svg)](https://agentmods.dev/instructions/kitlangton/behold/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/kitlangton/behold/agents-md"><img src="https://agentmods.dev/badge/instructions/kitlangton/behold/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.

agentmods 80×15 button for behold AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/kitlangton/behold/agents-md"><img src="https://agentmods.dev/badge/instructions/kitlangton/behold/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 1,116 This file is loaded in full into every session.
When invoked 1,116 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.01116 $0.01116
Opus 5.5 $0.00446 $0.00446
Sonnet 5.5 $0.00223 $0.00223
Haiku 4.5 $0.00112 $0.00112

Measured 2mo ago against content hash 1ff2adac5e18, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

behold 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 · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Behold

Behold is a local-first Markdown viewer for presenting agent work, collecting browser comments, and optionally publishing frozen public snapshots.

Architecture

  • src/App.tsx: Solid viewer and annotation UI
  • src/lib/document-viewer.ts: browser Effect v4 HTTP client
  • shared/document-contracts.ts: shared local API response schemas
  • server/document-reviews.ts: revisions, comments, feedback cursors, and JSON persistence
  • server/document-api.ts: local HTTP and SSE adapter
  • server/local-viewer.ts: packaged asset and API server
  • server/mcp-main.ts: Effect v4 stdio MCP client for the local HTTP API
  • cloudflare/worker.ts: public Cloudflare Worker serving the built viewer, publish/list/get snapshot API, and published page shells from R2

Vite mounts the local API during development. The packaged daemon serves built assets directly. Both use the same DocumentReviews service, and the MCP process never accesses persistence directly.

Invariants

  • Local authoring and public publishing are separate systems.
  • The local viewer process is the sole owner of in-memory state, persistence, SSE clients, and long-poll waiters.
  • Package root locates executable assets; invocation cwd supplies project .env and .env.local configuration.
  • Runtime reuse requires matching package, assets, and configuration roots.
  • Public snapshots and manifests must never expose local filesystem paths.
  • Reposting a filePath updates the same hosted document id.
  • Deleting a local document never deletes an independently published snapshot.
  • Hosted documents retain a local publication receipt; startup reconciliation updates its remote status without treating network failure as deletion.
  • Document updates retain the current revision plus 20 previous revisions.
  • wait_for_feedback currently reads and acknowledges feedback in one MCP call.

Agent Surface

MCP tools:

  • host_document
  • update_document
  • get_document
  • list_documents
  • list_document_versions
  • diff_document_versions
  • wait_for_feedback
  • set_comment_status
  • delete_document
  • get_agent_guide

Read the full file on GitHub · 119 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.

  1. 2mo ago First seen · 119 lines · 1,116 tokens per session scan A 1ff2adac5e18

Subscribe to this mod's changes

behold AGENTS.md is an instructions file published in the GitHub repository kitlangton/behold (14 stars, last pushed 2mo ago), licensed MIT. It adds 1,116 tokens to every session, about $0.0045 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.

cloudflare-workersmarkdownmcpsolidjs
Related

behold AGENTS.md compared with instructions from other repositories

behold AGENTS.md next to 6 instructions from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
behold AGENTS.mdkitlangton/beholdInstructions file142mo agoMITA1,116Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA9,719GitHub Copilot
next.js AGENTS.mdvercel/next.jsInstructions file143kyesterdayMITA7,461Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchainInstructions file149kyesterdayMITA4,680Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA5,516GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA3,093GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harnessInstructions file274k2d agoMITA4,313Codex, OpenCode