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Head to head · Assistants that remember you · October 2026 research run

Atticus vs Leon

Atticus scores 42.9 (E) on agent readiness against Leon's 41 (E), and leads in 3 of 7 scored categories. Leon leads on schema & documentation and agent ergonomics. Both do assistants that remember you.

Best AI personal assistants that act for one person · All 875 assistants comparisons

AtticusSaarthurR (Saarth Ranka) · Platform E42.9/100#974 of 1094 LeonLouis Grenard (Leon AI) · Agent harness E41/100#995 of 1094

Which one, for what

Atticus E

Best for A person on macOS 26 with a Claude Pro or Max plan who wants voice control of apps, windows, files and the browser.

Ahead on

  • Reliability, 68 against 32
  • Security & auth, 49 against 34
  • Maintenance & community, 51 against 15

Watch for

No API, MCP server or documented command an outside agent can call

Leon E

Best for A developer who wants a self-hosted assistant with memory, computer use and a local model, and who will read the source.

Ahead on

  • Schema & documentation, 33 against 15
  • Agent ergonomics, 57 against 9

Watch for

No tagged release of the core since 1.0.0-beta.8 on 1 May 2023. The 2.0 Developer Preview is installed by cloning the develop branch

Score by category

CategoryWeight this runAtticusLeonEdge
Reliability16%206832Atticus +36
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.21533Leon +18
Agent ergonomics13%16.2957Leon +48
Security & auth14%17.54934Atticus +15
Payments & pricing10%12.56060even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85115Atticus +36
Transparency & trust7%8.85660Leon +4
Negative events≤1500
TotalE 42.9/100E 41/100

Facts side by side

FactAtticusLeon
KindPlatformAgent harness
VendorSaarthurR (Saarth Ranka)Louis Grenard (Leon AI)
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingYour planFree
x402nono
LicenceMITMIT
Read-only variant documentednono
llms.txtnono
Last release2026-10-142023-05-01
Terms last updatedno document linkedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularity163 stars18k stars

Verdicts

Atticus

Atticus runs a person's Mac by voice on their existing Claude or Devin plan, with a sandboxed safe mode and a local log of every command. It has no API, MCP server or documented command for another agent, it is five days old, and it rebuilds itself from the main branch every six hours by default.

Leon

Connected-app credentials are encrypted per profile and the Gmail connection is read-only. The 2.0 Developer Preview has no tagged release, runs tools and a 30-minute proactive pulse with no approval step, listens on every network interface with client authentication off, and sends telemetry by default.

Before you call either

Atticus

  1. Don't plan to call Atticus from another agent. It takes requests only from its own shortcut and typing box
  2. If a user runs Atticus beside you, expect it to move windows and type into apps on the same Mac
  3. Point a user who wants pinned versions to Settings > About & Updates to turn off self-update

Leon

  1. Clone the develop branch for 2.0. npm install --global @leon-ai/cli and docs.getleon.ai install and describe the legacy 1.0 betas
  2. Set client_interface.auth.enabled: true and a LEON_PROFILE_TOKEN before the machine joins a shared network. The server binds 0.0.0.0
  3. Set telemetry_enabled: false and runtime.pulse_enabled: false in the profile config.yml for an unattended or private run
  4. Use availability.tools.allowed to limit tools. Shell, file writes, computer use and browser control are otherwise available to the agent with no approval prompt
  5. Back up LEON_CONNECTIONS_ENCRYPTION_KEY from the profile .env. Without it the stored connections cannot be read

Questions

Which is better for AI agents, Atticus or Leon?

Atticus scores 42.9 (E) on agent readiness against Leon's 41 (E), and leads in 3 of 7 scored categories. Leon leads on schema & documentation and agent ergonomics.

Are Atticus and Leon open source?

Yes. Atticus is open source (MIT). Leon is open source (MIT).

Other comparisons with Atticus or Leon

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