runtime-platform-permissions

A runtime compatibility and permissions contract for running software agents on macOS, Linux, and Windows.

In plain words
What is it for?
Normalizing filesystem behavior, managing runtime homes and temporary files, recording recoverable permission changes, and reporting failures that need operator action.
Why use it?
It prevents platform-specific filesystem or permission assumptions from breaking an agent, and keeps provider state separate from the operator’s normal credentials.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/undertone0809/rudder/runtime-platform-permissions
Clone the repo
git clone --depth 1 https://github.com/Undertone0809/rudder
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 9,064 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. Scan, not verified.
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 $0.00000 $0.09064
Opus 5 $0.00000 $0.04532
Sonnet 5 $0.00000 $0.01813
Haiku 4.5 $0.00000 $0.00906

Measured 2d ago against content hash 5de935664558, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

runtime-platform-permissions scanned grade C 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 2d 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.

Reaches for credential fileshighPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

such as `.git-credentials`, `.npmrc`, `.npm`, `.ssh`, `.config/gh`,
doc/product/domains/agents/runtime-platform-permissions.md · 682 lines

How it starts

The opening of the file, as written. The whole thing — 682 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Runtime Platform Permissions

AGENT.RUNTIME.PERMISSIONS.001

Contract Summary

Local runtime adapters must treat operating-system permissions and filesystem capabilities as part of the agent runtime contract. A supported runtime should not fail because Rudder assumed a Unix-only filesystem behavior on Windows, or because an adapter silently mixed the managed runtime home with the operator's credential home.

Rudder must normalize platform differences before invoking the provider, record recoverable permission substitutions, and surface non-recoverable permission failures as operator-actionable errors.

Intent / User Job

Operators expect a Rudder agent configured on macOS, Linux, or Windows to run with the same product semantics: the child process uses the operator's normal local home by default, while Rudder keeps provider-specific runtime state, selected skills, sessions, and temporary files under adapter-owned managed state. They should not need to know whether a provider adapter uses symlinks, junctions, copied directories, provider home variables, temporary homes, or prompt injection unless a repair action is required.

Why / Design Reasoning

Rudder local runtimes cross two boundaries at the same time:

  • the product boundary between the agent's managed workspace and the human operator's host machine
  • the platform boundary between POSIX filesystems and Windows filesystem permissions

The current design favors operator-home process execution for local trusted runtimes, with provider-owned state split into explicit adapter variables such as CODEX_HOME, CLAUDE_CONFIG_DIR, GEMINI_CLI_HOME, or PI_CODING_AGENT_*. That lets local commands see the same package managers, editor state, shell config, and authenticated host CLIs the operator normally uses, without copying broad credential and tooling directories into a Rudder managed home. The tradeoff is that skills, provider config, sessions, and temporary runtime material must be materialized separately and platform-aware.

Read the full file on GitHub · 682 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. 2d ago First seen · 682 lines · 0 tokens per session scan C 5de935664558

Subscribe to this mod's changes

runtime-platform-permissions is an agent published in the GitHub repository Undertone0809/rudder (287 stars, last pushed 2d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 9,064 tokens. A static security scan graded it C with 1 finding (reaches for credential files). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.