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Coil Review: A Mac Agent Harness That Shows Which Model Answered

·7 min readBy Hans Kuepper · Founder of PromptQuorum · Discovery engine for open-weight & open-source AI

Coil (version 1.16.0, updated 20 October 2026) is a Mac App Store app for $14.99, with no stated license, that, per the developer, runs open-weights models on your Mac and splits each turn between a small router and a stronger worker model. Every behavior and privacy statement in this review comes from the maker's own pages; PromptQuorum has not installed or tested it.

Key Takeaways

  • Maintenance: the listing shows 15 versions from 1.2.0 on 8 July to 1.16.0 on 20 October 2026, so it is actively updated and no stale-project warning applies.
  • License: not stated, and no public repository was found.
  • Reach: Mac only; there is no Windows, Linux or mobile version.
  • Ratings: the App Store shows too few ratings to display a score.
  • Basis: the maker's site and policy and the store listing, read on 24 October 2026, with no hands-on testing.

📍 In One Sentence

Coil is a Mac-only app that runs open-weights models on-device and shows which model handled each turn.

💬 In Plain Terms

A small model decides whether a question is quick or hard, a stronger model takes the hard ones, and the app asks before it changes files in the folder you picked.

📌Note: PromptQuorum has not installed, tested or benchmarked Coil. Behavior, speed and privacy statements below are the maker's own.

Read in:
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Coil is a Mac App Store app from Silo Systems that, per its own pages, sends each turn either to a fast on-device router model or to a stronger worker model, prints a routing receipt on every reply and asks before it touches files in one chosen folder. This review reflects the maker's site, privacy policy and the App Store listing as checked on 24 October 2026.

Coil Review: A Mac Agent Harness That Shows Which Model Answered

What Is Coil?

Coil, listed on the Mac App Store as "Coil - Local AI Harness", is an agent harness: a wrapper that runs open-weights language models on Apple silicon and decides which model handles each request. The page calls it "a local agent harness that shows its work". It is published under the brand Silo Systems; the App Store seller is Omar Quddusi.

The design has two tiers. A fast router answers or dispatches quick turns, and a stronger worker takes harder ones; the model residency table shows which models are loaded, pinned or evicted against your memory budget. The maker says it is not a cloud chatbot and does not run unrestricted shell commands. The same maker also sells a second Mac app, Matadoor.

Get It

Coil is sold only through the Mac App Store; there is no direct download.

Channel
Link
Mac App Store (macOS 14+)Coil - Local AI Harness
Websiteohmslaw.net/apps/coil
Privacy policyohmslaw.net/apps/coil/privacy
Supportohmslaw.net/apps/coil/support

Version reviewed: 1.16.0, shown on the App Store as updated 3 days before this check; the listing prints no year, so PromptQuorum dates it 20 October 2026, the latest upstream update at the time of checking. The app is 14.6 MB; model weights are a separate download. No source repository, Windows, Linux, Android or iPhone version was found.

What You Need

Coil needs a Mac with Apple silicon, macOS 14.0 or later and at least 16 GB of unified memory; the listing recommends 36 GB for the strong-worker tier.

Item
Per the sources
Chip and memoryApple silicon, 16 GB or more
Operating systemmacOS 14.0 or later
First-run downloadsChat weights from Hugging Face, after consent
Embedding modelDownloads at first launch

The support page gives no disk figures and names no models or download sizes. Models that the maker has not tested are estimated from published size and format, never selected by default and need an extra confirmation.

Pricing

Coil is a one-time purchase of $14.99 with no subscription and no in-app purchases. Family Sharing covers up to six family members.

Storefront
Price
United States$14.99
Germany, France, Spain17,99 €
Japan¥2,500
BrazilR$ 99,90
South Korea₩25,000

Read from each country's App Store page on 24 October 2026; prices are set by the store and can change. No free trial was mentioned. Bring Your Own Key, if you switch it on, adds whatever your chosen provider charges.

Features Confirmed by the Sources

Every item below comes from the maker's page or the App Store description.

  • Router and worker. One small model handles quick turns and a stronger one handles hard work.
  • Routing receipts. Each reply shows model, tier, role, confidence and speed; trace receipts can be exported and keep hashes and outcomes, not file text.
  • Route preview. Set to Always, Ambiguous or Never, it shows destination, model residency, reason, context counts and tool scope before a request runs.
  • Reviewed workspace tools. Read, Write, Edit and a read-only bounded shell, limited to one folder, with policy modes inspect-only, review-changes and ask-every-tool.
  • Workspace map and wiki. Swift types, protocols and functions are drawn as a graph; wiki pages are drafted but written only after approval.
  • Local memory. Conversations are distilled into a store you can search, pin and delete; version 1.16.0 added using saved memory in replies.
  • Signed model catalog. Version 1.13.0 added a signed catalog with per-file model verification.

Privacy and Network Use

The privacy policy (version 1.2, effective 23 September 2026) says Coil collects nothing about you, has no account, no analytics and no telemetry, and that none of your content reaches Silo Systems. The App Store label says "Data Not Collected", which Apple notes is the developer's own statement.

The policy names four network paths: model downloads from Hugging Face, App Store update traffic, an optional model-catalog check that is off by default and downloads only a signed file from ohmslaw.net, and Bring Your Own Key. With that last option on, your message plus built context such as memories and excerpts goes directly to the provider you configure (OpenAI, Anthropic, Gemini or OpenRouter, per the App Store notes) with the key kept in the macOS Keychain; Ollama on your own machine keeps requests on your network. Removing the app does not delete your data from its container.

📌Note: These are the maker's statements. PromptQuorum has not audited the app or its network traffic.

Who Should Use It

  • Mac owners with 16 GB or more who want an on-device agent that reports which model answered.
  • People who want approval before file changes, limited to one folder.
  • Buyers who prefer a one-time price to a subscription.

What We Could Not Verify

  • Hands-on quality and speed. PromptQuorum did not run Coil, and the sources give no benchmark figures or model names.
  • License and code. None is stated and no repository was found, so the code cannot be inspected.
  • Track record. The App Store shows too few ratings for a score, and the version history shown starts on 8 July 2026.
  • Privacy claims. The no-telemetry and offline statements were not checked against network traffic.

Competitors and Alternatives

Goose

Platforms:
macOS, Windows, Linux
Price / license:
Free / Apache-2.0
Key difference:
Open-source agent for coding and automation; works with local or cloud models

Agent Zero

Platforms:
macOS, Windows, Linux
Price / license:
Free / MIT
Key difference:
Minimal open-source autonomous agent with coding ability
Articles about Agent Zero (2)

Also mentioned in:

OpenClaw

Platforms:
macOS, Windows, Linux
Price / license:
Free / MIT
Key difference:
Open-source orchestration framework for agent workflows
Articles about OpenClaw (6)

Also mentioned in:

+2 more not shown

Competitor details change often; confirm each app's current price, license and platforms on its own listing.

Compare in directory

Frequently Asked Questions

Does Coil work offline?

Per the privacy policy, yes once the chat weights and the embedding model are downloaded; the cloud mode is the only path that needs internet for replies.

Can Coil run commands on my Mac?

The maker says it does not run unrestricted shell commands. Its shell is read-only and bounded, and Write and Edit show a preview or diff first.

Can I use my own API key?

Yes, as an optional mode that is off by default; version 1.12.0 added it for OpenAI, Anthropic, Gemini and OpenRouter.

Is there an iPhone or Windows version?

None was found; the page lists only Mac, macOS 14 or later, on Apple silicon.

Verdict

Coil is a one-time-purchase Mac app that, per its maker, keeps open-weights models and your data on the machine, splits work between a router and a stronger worker and shows a receipt for every reply, with file tools limited to one approved folder. It was updated three days before this check and has a clear privacy policy. Against that, it states no license, is Mac-only, needs 16 GB or more, has too few ratings for a score and every behavior and privacy claim comes from the maker. It suits Mac owners who value transparent routing and approval prompts; readers who want open code or other systems can compare Goose or Agent Zero.

Sources

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