Borrowing it
Nothing to install: this file belongs to dsswift/ion. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/dsswift/ion/main/AGENTS.mdgit clone --depth 1 https://github.com/dsswift/ionWrote 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.
[](https://agentmods.dev/instructions/dsswift/ion/agents-md)<a href="https://agentmods.dev/instructions/dsswift/ion/agents-md"><img src="https://agentmods.dev/badge/instructions/dsswift/ion/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.
<a href="https://agentmods.dev/instructions/dsswift/ion/agents-md"><img src="https://agentmods.dev/badge/instructions/dsswift/ion/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.03942 | $0.03942 |
| Opus 5.5 | $0.01577 | $0.01577 |
| Sonnet 5.5 | $0.00788 | $0.00788 |
| Haiku 4.5 | $0.00394 | $0.00394 |
Grade A, and why
ion 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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 209 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ion
Layout
| Component | Path | Language |
|---|---|---|
| Engine | engine/ |
Go |
| TypeScript extension SDK | engine/extensions/sdk/ion-sdk/ |
TypeScript (tests in engine/extensions/sdk/__tests__/) |
| Go extension SDK | sdk/go/ |
Go |
| Conversation pipeline sample | samples/conversation-pipeline/ |
Go |
The engine has its own AGENTS.md. The SDKs, the sample, docs/, and scripts/ are governed by this file. Before touching engine/, read docs/engine-grounding.md.
Ion Studio (the desktop app, the headless Studio server, the iOS app, and the relay) is archived with its history at dsswift/ion-studio. Nothing in this repository builds it or depends on it; a client reaches the engine over the wire protocol only.
SDK edits have a source-of-truth split: edit engine/extensions/sdk/ion-sdk/, never the installed copy at ~/.ion/extensions/sdk/ (overwritten at build). See engine/AGENTS.md § "Extension SDK source location".
File-size caps (CI hard-fails above)
| Language | Cap |
|---|---|
| TypeScript | 600 |
Go (*.go) |
800 |
Go (*_test.go) |
1500 |
Override: // @file-size-exception: <reason> (# for shell/yaml/python) on line 1. Files in .file-size-allowlist.yml must not grow; put new code in a new file. Over the cap, split at a natural seam. Never strip comments or compress code to fit. Reference: docs/architecture/file-organization.md.
Context files
AGENTS.md is the only instruction file; Claude Code reads it natively. Never add a CLAUDE.md (file, symlink, or import). Do not add new per-folder AGENTS.md files.
Codebase questions — query the graph first, always
For any question about how code is structured or connected, the first call is a graph query, not Grep or Read. Do not check whether the graph exists. If graphify is missing, the command fails instantly: fall back to Grep/Glob/Read without comment, and never suggest installing it.
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.
- 6d ago Changed · -63 lines · -1,824 tokens per session 8aff4cae7c51
- 7d ago Changed · +1 lines · +141 tokens per session a7dda61965d3
- 23d ago Changed · +1 lines · +27 tokens per session 0e3a55e70ef8
- 24d ago Changed · +15 tokens per session 37215859af03
- 26d ago Changed · +71 tokens per session d70a2321a12b
- 27d ago Changed · +68 tokens per session c1a3984c504d
- 28d ago Changed · -768 lines · -18,734 tokens per session scan C → A 5c78c5d8f54c
- 1mo ago Changed · +91 lines · +1,054 tokens per session bf3448120aa1
- 1mo ago Changed · +1 lines · +159 tokens per session 81a921890c28
- 1mo ago First seen · 946 lines · 22,965 tokens per session scan C 4e05503206e8
ion AGENTS.md is an instructions file published in the GitHub repository dsswift/ion (4 stars, last pushed today), licensed MIT. It adds 3,942 tokens to every session, about $0.0158 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.