sandbox-agent is an HTTP and server-sent-events service that runs coding agents inside isolated sandboxes and lets another application control them remotely. Developers use it to run agents such as Claude Code, Codex, OpenCode, Cursor, Amp, or Pi while streaming events, managing sessions, and storing transcripts. The catalogue entries provide agents, skills, commands, instructions, and MCP integration for working with the service.
Borrowing it
Nothing to install: this file belongs to rivet-dev/sandbox-agent. 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/sandbox-agent/main/CLAUDE.mdgit clone --depth 1 https://github.com/rivet-dev/sandbox-agentWrote 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/sandbox-agent/claude-md)<a href="https://agentmods.dev/instructions/rivet-dev/sandbox-agent/claude-md"><img src="https://agentmods.dev/badge/instructions/rivet-dev/sandbox-agent/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/sandbox-agent/claude-md"><img src="https://agentmods.dev/badge/instructions/rivet-dev/sandbox-agent/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 | $0.01291 | $0.01291 |
| Opus 5.5 | $0.00516 | $0.00516 |
| Sonnet 5.5 | $0.00258 | $0.00258 |
| Haiku 4.5 | $0.00129 | $0.00129 |
Grade A, and why
sandbox-agent 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 1mo 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.
- Sandbox Agent install/version references use a pinned minor channel `0.N.x` (for curl URLs and `sandbox-agent` / `@sandbox-agent/cli` npm/bun installs). How it starts
The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Instructions
Naming and Ownership
- This repository/product is Sandbox Agent.
- Gigacode is a separate user-facing UI/client, not the server product name.
- Gigacode integrates with Sandbox Agent via the OpenCode-compatible surface (
/opencode/*) when that compatibility layer is enabled. - Canonical extension namespace/domain string is
sandboxagent.dev(no hyphen). - Canonical custom ACP extension method prefix is
_sandboxagent/...(no hyphen).
Docs Terminology
- Never mention "ACP" in user-facing docs (
docs/**/*.mdx) except in docs that are specifically about ACP itself (e.g.docs/acp-http-client.mdx). - Never expose underlying protocol method names (e.g.
session/request_permission,session/create,_sandboxagent/session/detach) in non-ACP docs. Describe the behavior in user-facing terms instead. - Do not describe the underlying protocol implementation in docs. Only document the SDK surface (methods, types, options). ACP protocol details belong exclusively in ACP-specific pages.
- Do not use em dashes (
—) in docs. Use commas, periods, or parentheses instead.
Docs Source Of Truth (HTTP/CLI)
- For HTTP/CLI docs/examples, source of truth is:
server/packages/sandbox-agent/src/router.rsserver/packages/sandbox-agent/src/cli.rs
- Keep docs aligned to implemented endpoints/commands only (for example ACP under
/v1/acp, not legacy session REST APIs).
Docs Styling
- Docs styling is owned by the shared
@rivet-dev/docs-themerepo (github.com/rivet-dev/docs-theme), consumed viagithub:rivet-dev/docs-theme#<tag>infrontend/packages/website. To change any docs styling (palette, header, sidebar, code blocks, fonts), edit that repo and follow its CLAUDE.md release workflow — never restyle docs here. This site owns only docs content +frontend/packages/website/docs.config.mjs(sidebar icons via each item'sattrs['data-icon']).
Change Tracking
- If the user asks to "push" changes, treat that as permission to commit and push all current workspace changes, not a hand-picked subset, unless the user explicitly scopes the push.
- Keep CLI subcommands and HTTP endpoints in sync.
- Update
docs/cli.mdxwhen CLI behavior changes. - Regenerate
docs/openapi.jsonwhen HTTP contracts change. - Keep
docs/inspector.mdxanddocs/sdks/typescript.mdxaligned with implementation. - Append blockers/decisions to
research/acp/friction.mdduring ACP work. docs/agent-capabilities.mdxlists models/modes/thought levels per agent. Update it when adding a new agent or changingfallback_config_options. If its "Last updated" date is >2 weeks old, re-runcd scripts/agent-configs && npx tsx dump.tsand update the doc to match. Source data:scripts/agent-configs/resources/*.jsonand hardcoded entries inserver/packages/sandbox-agent/src/router/support.rs(fallback_config_options).- Some agent models are gated by subscription (e.g. Claude
opus). The live report only shows models available to the current credentials. The static doc and JSON resource files should list all known models regardless of subscription tier.
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.
- 1mo ago First seen · 85 lines · 1,291 tokens per session scan A a5fe3a309024
sandbox-agent CLAUDE.md is an instructions file published in the GitHub repository rivet-dev/sandbox-agent (1,609 stars, last pushed 14d ago), licensed Apache-2.0. It adds 1,291 tokens to every session, about $0.0052 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.
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Model-specific prompt authoring and registry guidelines.