Technical specifications.

Requirements, documents, Agency, model routes, proof, privacy, plans, and measurements. All in one place.

Minimum: macOS 26
Files: Plain Markdown
AI domains: 4, separately controlled
App payload: Around 40 MB

Compatibility

Made for Mac.

App: Native Mac app
Minimum system: macOS 26 or later
Macs: Apple silicon and Intel
Delivery: Direct downloadSigned and notarized. Distributed outside the Mac App Store.
App payload: Models download separatelyThe signed installer includes the local runtime. Model storage is managed in Settings.
Local runtime: Included with FlowModels and storage are managed together in Settings ▸ Models.

Documents

Your files stay files.

Flow works on the folders you choose. Other apps can read the same files.

Storage: Ordinary folders and .md filesNo private library format and no import step.
Writing format: MarkdownGFM tables, footnotes, code blocks, images, links, and wiki links.
Workspace: Multiple folders, document tabs and a WorkbenchOne primary document surface with Jobs, Sources, History or Settings in the Workbench beside it. The Workbench remembers its width.
Document views: Editor, Reader, Source, tables, pictures, charts, and diagrams
Tables: A grid over the Markdown in the fileA one-cell edit splices one cell instead of rewriting the table. Header and last-column invariants protect its structure.
Pictures: A gallery over images in the folderSwap or describe an image while the document keeps an ordinary Markdown image reference.
Visuals: 34 chart types and 20 diagram typesDrawn offline from readable text that remains in the file.
Search: Full text and meaning, on deviceThe index stays on the Mac. Opening a result returns to a byte-verified passage in the source file.
Living Documents: 28 Living Documents in four categoriesSearch the chooser or begin with five featured documents. Create an independent copy with its inputs and assets, then inspect its Jobs.
Data bindings: Charts and tables redraw from their source filesFlow notices changes while running, on return, on Refresh Folders, after the Night Shift and at launch.
Night Shift Base: Collect, watch, list and redraw on every planIncludes the Morning Briefing and Keep, Revert or Later in Review Changes. Scheduled work runs when this Mac is plugged in and idle, even with Flow quit; Run Jobs starts the open document’s saved work.
Night Shift Pro: Overnight notes from a model on this MacNumbers are checked against source rows or withheld. Notes are marked, reviewable and receipted.
Settings: General, Documents, Models, Smart Routing, Evidence, Night ShiftSix categories in the Workbench, with search and plan and licence controls inside General.
File safety: Collisions refuse; saved files move to system TrashFlow never silently overwrites or renames. Folders have no Delete command.

Agency

A proposal. Then your decision.

Every AI action uses one approval path. Flow states the scope before it runs, shows the proposed work, and saves only what you approve.

Actions: 7 approval-gated actionsProofread, Summarize, Translate, two table conversions, Expand with Sources, and Visualize.
Before a run: Scope, estimated cost, model, locality, and deciding ruleA local route says No cost. An unavailable action says why instead of inventing a route or price.
Proposal: The proposed document first; exact changes one tab awayFlow saves nothing until the reviewed proposal is approved.
Long documents: Improved in ordered, reviewable partsEach part has its own range, proposal, evidence, receipt, and coverage state. Flow never silently truncates the document.
Lookups: Read the document and search open foldersExpand with Sources runs on a model on this Mac or supported Anthropic models. Each local lookup is receipted.
Run controls: Pause, Stop, 12-lookups maximum, 180-second maximumA run that reaches its bound ends without changing the document.
Approval: Approve saves exactly the reviewed bytesDecline changes nothing. Approval writes one History boundary and appends the run record.

Models and privacy

You choose where AI runs.

Execution domains: This Mac or configured cloud API providersThis Mac comes first. A cloud provider is enabled by its key and bills token use separately.
Fallback: Permission before crossing a boundaryIf a fallback would leave the Mac, Flow stops and asks.
Discovery: Find compatible models on this MacWith discovery enabled, Flow briefly opens local models and shares compatible ones with Flow Runtime.
Smart Routing: Ordered rules; first matching rule appliesThe deciding rule is named. Unmeasured speed and unpublished price are never guessed.
Benchmarks: Measured on this MacFirst word, reading speed, memory headroom, and model fit remain separate facts.
Model work: ProIf a model runs, it is part of the subscription, including local models.

ProviderDomainStateWhat that means

Flow Runtime

Local

Built in

Flow can run compatible local models without another runtime installed.

Ollama

Local

Runnable now

Detected models on this Mac can run directly through Flow Agency. A runtime pointed at another machine is refused.

Anthropic

Cloud postpaid

Runnable now

Bring your own API key. Anthropic also carries source-lookup tool runs.

OpenAI

Cloud postpaid

Runnable now

Bring your own API key.

OpenRouter

Cloud postpaid

Runnable now

Bring your own API key. Reported charges are recorded to the exact decimal.

LM Studio

Local

Runnable now

Flow can run the exact loaded text model directly through Agency without copying or sharing its weights. The receipt records LM Studio, the model, locality, and no charge for a local run.

State is part of the specification. Detection alone never grants permission or proves a runnable Agency path. Launch-priority routes remain labelled until their full path is accepted.

Proof and history

The work leaves a record.

A receipt says what happened. Evidence says what was assessed. History preserves the exact revision you can inspect or restore.

Receipts: One durable run cardNames the model, provider, locality, checks, evidence, lookups, and observed cost. A local run records no charge.
History: Exact revisions, diff, review, and restoreA saved change is bound to before-and-after content digests.
Evidence: Scored dimensions with coverage and uncertaintyA comparison delta appears only when Flow verifies the exact baseline revision byte for byte.
Checks: Six explicit statesAn override records the decision. It never relabels Failed as Passed.
Sources: What a run consulted, kept distinct from evidenceRetrieval records what was read. Evidence records what was assessed. One never stands in for the other.
Product telemetry: Anonymized counts, switchableFlow shares how features were used and how long work took, never your document text and nothing that identifies your copy. Two switches in Settings ▸ Observations turn it off.

Base, Pro and add-ons

Your Markdown stays free. Pro and its add-ons extend what you can do.

AI work needs Flow Pro. Import and Publish are separate add-ons that need Pro. Reading old receipts stays free. Producing new AI work is Pro.

Base

Free forever

Write, organize, search, visualize, and save Markdown. Read every past receipt, timeline, evidence score, and guardrail result without an account or expiry.

17 Base capabilities

Markdown editorFull editing, GFM, tables, footnotes, code blocks, images
ReaderRendered view of any document
Vault searchFull text across every folder you have opened
Search by meaningFinds related notes, not just matching words
Open, edit and save MarkdownYour files stay in your own folders
Wiki links and navigationLinks, backlinks, folder tree
Tables, grid view, chartsIncluding the chart gallery
Multiple foldersAdd as many as you like
Tabs, panes, split viewThe whole workspace
Flow GuideThe bundled 58 document guide, plus 24 assets, including seven Living Document folders and its updates
DictationVoice input into a document
Themes and settingsEverything in Settings
App updatesNever gated by a licence, even after you cancel
Read every receiptWhat ran, where it ran, and what it cost
Read the timelineThe history of changes to a document
Read evidence scoresHow a past AI run was judged
GuardrailsThe shipped rules check your text with no model involved

Pro

$10/month

Everything in Base, plus every feature that runs a model: seven actions, agentic tools, routing, approvals, new receipts, and new evidence.

10 Pro capabilities

Everything in BasePro adds to Base, it does not replace it
All AI featuresEverything that sends text to a model
Proofread, rewrite, summariseAnd the other agency actions
Agentic runsTool use, approvals and receipts
Hosted providersAnthropic, OpenAI, and the rest, on your own key
Local model routingOllama, MLX, llama.cpp. Also part of Pro
Flow RuntimeFlow's own model runtime, built in
Smart RoutingYour rules pick the model, and the screen names the rule that decided
Produce new receiptsApproving an AI change is what writes one
Generate new evidenceRunning a fresh evaluation is an AI run

Add-ons to Flow Pro

Flow Import: Import Word, Excel, PowerPoint and PDF into Markdown.

Flow Publish: Publish PDF, GitHub Pages, EPUB, Word, Excel and PowerPoint.

Each add-on is $10/month or $96/year per seat and needs Flow Pro. Add or remove it in Flow’s Billing settings. Cancelling Pro also ends its add-ons.

Try every paid feature, including Import and Publish, free for 10 Pro Days. Subscribe when you're ready.

If Pro ends

No document locks and no read only mode
Markdown editing and saving stay free; Import and Publish need their add-ons
Your files stay plain Markdown in your own folders
App updates keep arriving, including security fixes

Billed every month, or every year on the annual plan, until you cancel. Cancel anytime in Flow, Settings ▸ Billing ▸ Manage Plan. Your plan stays on until the paid period ends. No refunds, except where the law requires.

Measured, not promised

The number and its boundary.

22.3 ms
Search, 95th percentile: Measured on a 10,000-note library, Apple silicon; 620,000
Characters planned part by part: Long documents are split in about 0.5 seconds, and the time grows evenly with length; $0.00425
A real billed run, to the digit: 105 input and 149 output tokens. Exact decimal arithmetic; +19.2 MiB
A complete local AI runtime: Two engines, measured August 14, 2026 on an M3 Max. Historical payload increment, not the current installer size; 7 actions
The Agency catalog: Proofread, Summarize, Translate, two table conversions, Expand with Sources, and Visualize; 2 locations
Where AI may run: This Mac or configured cloud API providers. Cloud keys enable those providers and token billing; 54 pictures
34 chart plus 20 diagram types: Drawn in place from plain text in your file, offline, in one house style; 1.1 s
First index of 10,000 notes: Measured on a 10,000-note library, Apple silicon. Results stream in as it goes

Availability

Flow for Mac.

Public download

Available now

Monthly

$10

Annual

$96

First use

10 Pro Days included

For Mac OS. Base is free forever. 10 Pro days included. No credit card to use. One licence covers one person on their own Macs. Patent pending.

Explore Flow See plans