agentOS is a library that lets software agents run inside an existing application backend, using WebAssembly and V8 isolates with controlled access to host resources. It is for developers building agent-powered backends who need embedded execution and permissions, while the catalogue entries provide skills and instructions for operating the framework.
Borrowing it
Nothing to install: this file belongs to rivet-dev/agentos. 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/rivet-dev/agentos/main/CLAUDE.mdgit clone --depth 1 https://github.com/rivet-dev/agentosWrote 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/rivet-dev/agentos/claude-md)<a href="https://agentmods.dev/instructions/rivet-dev/agentos/claude-md"><img src="https://agentmods.dev/badge/instructions/rivet-dev/agentos/claude-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/rivet-dev/agentos/claude-md"><img src="https://agentmods.dev/badge/instructions/rivet-dev/agentos/claude-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 | $0.04197 | $0.04197 |
| Opus 5.5 | $0.01679 | $0.01679 |
| Sonnet 5.5 | $0.00839 | $0.00839 |
| Haiku 4.5 | $0.00420 | $0.00420 |
Grade A, and why
agentos CLAUDE.md scanned grade A with 1 finding 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 24d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
gawk, real curl/sqlite/duckdb/vim, …) compiled to `wasm32-wasip1` against a How it starts
The opening of the file, as written. The whole thing — 312 lines — stays where its author put it; the contents beside it link to each section on GitHub.
agentOS
Always spell the product name agentOS, never AgentOS; do not alter type
identifiers such as AgentOSActorConfig.
agentOS owns the runtime, kernel, VFS, language execution, registry packages, agentOS client APIs, docs, and publish machinery. agentOS Exec is the JavaScript, TypeScript, and Python execution surface of agentOS.
Boundaries
- Keep agentOS product versions pinned at
0.0.1in committed files. Release workflows apply real versions transiently withscripts/publish; never commit release-version rewrites. - agentOS-owned npm packages must use the
@rivet-dev/agentos-*namespace. Registry software packages must use@agentos-software/*. Never introduce packages under@agentos/*. - Call guest environments VMs, not sandboxes, except when referring to a package or public API that already uses the word.
- The protocol has no backward compatibility guarantee. Client, sidecar, and protocol crates ship in same-version lockstep; update both sides together.
- Generic runtime and language-execution work belongs here. Do not add a compatibility mirror or a second package namespace for AgentOS language execution.
- Keep root
package.jsonscripts limited to Turbo orchestration; repo-specific commands belong injustfilerecipes or scoped package scripts. - agentOS targets native Linux/container execution. Browser support is not needed or supported here: browser sources may remain as dormant reference code, but their entrypoints must stay disabled and they must not enter default builds, CI, publication, or behavioral-parity requirements without a separately approved design.
Security Model
Trust model:
- Client: trusted, except for code/payloads it submits for execution.
- Sidecar/runtime: trusted enforcement point. It owns the kernel, VFS, mounts/plugins, socket table, permissions, and resource policy.
- Executor: untrusted V8 isolate or WASM guest. Assume guest JS/Python/WASM and third-party packages are hostile.
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.
- 24d ago Changed · +8 lines · +131 tokens per session 80e878c33fc1
- 1mo ago Changed · -30 lines · -452 tokens per session 6e62dc593af6
- 1mo ago Changed · +15 lines · +200 tokens per session 3c4ba8f21a9e
- 1mo ago Changed · +3 lines · +54 tokens per session 45d9765ace55
- 1mo ago Changed · +11 lines · +207 tokens per session 8e230fe3a586
- 2mo ago Changed · +3 lines · +49 tokens per session dfde56cb3c6d
- 2mo ago First seen · 302 lines · 4,008 tokens per session scan A 7ec9778fa81e
agentos CLAUDE.md is an instructions file published in the GitHub repository rivet-dev/agentos (4,851 stars, last pushed yesterday), licensed Apache-2.0. It adds 4,197 tokens to every session, about $0.0168 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
agentos CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| agentos CLAUDE.mdrivet-dev/agentos | Instructions file | 4.9k | yesterday | Apache-2.0 | A | 4,197 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | 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 |