For AI agents: the complete documentation index is available at https://a3s-lab.github.io/Use/en/llms.txt, the full documentation bundle is available at https://a3s-lab.github.io/Use/en/llms-full.txt, and this page is available as Markdown at https://a3s-lab.github.io/Use/en/index.md.
A3S Use
  • English
      • OPEN SOURCE · AI NATIVE PACKAGE MANAGER

      Packages for software.Capabilities for agents.

      A3S Use gives native tools and A3S cognitive plugins one verifiable package lifecycle across Linux, macOS, and Windows.

      Get startedView on GitHub
      v0.2 package foundationAvailableCognitive plugin platformIn development
      Install the verified releaseInstall the complete release through the A3S CLI
      $ a3s install use --source release
      PACKAGE INSPECTIONschema v3
      $ a3s-use capability snapshot --json
      package
      acme/research@2.0.0
      target
      darwin-arm64
      trust
      TUF · SHA-256 verified
      generation
      0042 · 7f3a…e91c
      ToolconvertREADY
      MCPlibraryREADY
      SkillreviewREADY
      UIreviewREADY
      OKFdomain-knowledgeTARGET
      capability projection ready
      TRUST PATHroot → snapshot → target
      TARGETSLINUX · MACOS · WINDOWS
      ONE PACKAGE · TWO PLANES

      One immutable identity for native programs and cognition

      Traditional package managers stop after placing files. The target platform also verifies declared Tool, MCP, Skill, UI, and OKF knowledge surfaces, then projects readiness evidence to hosts.

      NATIVE PLANE

      Platform-native execution

      Target-specific executables, runtime assets, native argv, and standard process status.

      COGNITIVE PLANE

      Agent-discoverable capabilities

      Content-bound instructions, tool dependencies, MCP services, sandboxed UI, and shareable OKF knowledge with no authority derived from text.

      Select a surface to inspect its execution boundary

      ToolTASK / SERVICE

      Keep the native CLI or HTTP contract

      A Tool is a Runtime-managed workload—not a private action protocol and not an MCP tools/list item.

      • provider evidence
      • exact generation
      • bounded I/O
      TRUSTED LIFECYCLE

      Prove readiness before publishing capability

      Search reads signed metadata only. Before mutation, target, permissions, provider, and impact are bound into one immutable plan.

      01

      Discover

      Refresh and search a TUF-signed catalog without package payloads.

      02

      Plan

      Bind package digests, surfaces, permissions, and Runtime evidence.

      03

      Authorize

      Bind ACL policy and user confirmation to the same plan digest.

      04

      Stage

      Verify the archive, ACL manifest, and content in a bounded root.

      05

      Reconcile

      Prepare grants, Runtime bindings, projections, and dependency closure.

      06

      Publish

      Switch capability generation atomically, then drain the old one.

      CLEAR OWNERSHIP

      One Manager, one lifecycle truth

      CLI, Web, and agent management MCP share one Plugin Manager. A3S Use owns packages and evidence; Runtime owns workloads; hosts own policy, credentials, and rendering.

      Read the architecture guide
      LOCALRELEASETUF
      Package sourcesShared Plugin Managercatalog · policy · confirmation · plan/apply · replay
      A3S Use package engineverify · stage · receipt · grant · reconcile
      Native + cognitive surfacesTool · MCP · Skill · UI · OKF
      A3S hostsA3S Code · Web · Knowledge · agents
      SECURE BY EVIDENCE

      Package content cannot authorize itself

      Skill text, UI messages, OKF knowledge, tool output, and remote content are data. Authority comes only from host policy, explicit grants, and generation-bound receipts.

      PROVENANCE

      Verifiable supply chain

      Pin TUF roots, signed metadata, length, and SHA-256 while rejecting rollback and expired state.

      PLAN DIGEST

      Fail closed on drift

      Resolve again before apply. Version, content, permission, or provider changes require a new review.

      NO AMBIENT AUTHORITY

      Exact-generation authority

      Grants, Runtime bindings, route leases, and capability snapshots bind to one package generation.

      CROSS-PLATFORM

      One package model across three desktop families

      macOS and Linux cover complete release archives and package lifecycle. Windows x86_64 is currently Preview while runtime and plugin lifecycle gates are completed.

      LLinuxSUPPORTED
      MmacOSSUPPORTED
      WWindowsPREVIEW
      START WITH THE FOUNDATION

      Inspect local capabilities. Build a cognitive package.

      Install the v0.2 release and run doctor plus capability snapshot. Use the schema-v3 contracts and roadmap for cognitive plugin development.

      Open the quick startRead the roadmap