Canvas's behavior and theme live in one JSON file:

~/Library/Application Support/Blink/config.json

Canvas watches this file and applies valid changes to open panels without a restart. The default path is unchanged from Blink.

Current source builds use the first nonempty CANVAS_HOME, then BLINK_HOME, to override the file-backed root. Empty values are ignored. The selected root contains config.json, Notes, and attachments; use the same root for app and CLI. These overrides do not redirect UserDefaults, and either disables mobile sharing. Existing releases recognize BLINK_HOME only.

Examples use the current canvas command. The compatible blink command and published package name @arach/blink remain supported. The rename does not change config keys, blink.* frontmatter, attachment URLs, or settings keys; hotkeys.blink still controls showing and hiding all notes.

Rules:

Every field is optional. Missing fields use the defaults below. {} is a valid config.
Invalid JSON never breaks the app: Canvas keeps the last good config and logs [BLINK] config invalid — keeping last good. An invalid file found at startup stays untouched; the app uses defaults with mobile access off.
Write atomically (write temp + rename, or your editor's normal save) — Canvas watches the directory, so atomic replaces are picked up fine.
The settings window is a view over this file; edits there round-trip through it.

Schema

{
  "appearance": "auto",         // app-wide light/dark: "auto" (follow macOS) | "light" | "dark"
                                // "auto" tracks the system live; menubar → Appearance overrides it
  "behavior": {
    "mobileAccess": false,     // new installs default off; see upgrade policy below
    "restoreSession": true,     // reopen last session's panels at launch
    "defaultMode": "read",      // "read" | "edit" — mode for notes with no remembered mode
    "launchAtLogin": false      // register Canvas as a login item (SMAppService)
  },
  "hotkeys": {
    // Chord strings: modifiers joined by "+", ending in one key.
    // Modifiers: hyper (⌃⌥⇧⌘), cmd, ctrl, alt, shift.
    // Keys: a–z, 0–9, punctuation (. , / ; ' [ ] \ - = `), space, return,
    // tab, escape, delete. An invalid chord is logged and the previous
    // binding kept — a bad edit never leaves the app unreachable.
    "newNote": "hyper+n",       // global — create a note from anywhere
    "blink": "hyper+b",         // global — show all notes / hide all
    "grid": "hyper+c",          // global — grid/constellation overlay ("c" — hyper+g collides with Lattices)
    "reader": "hyper+e",        // global — read the frontmost app's selection in the reader layer
    "toggleMode": "cmd+shift+p",// per-panel — flip read/edit
    "focus": "cmd+.",           // per-panel — quiet everything else
    "toggleChrome": "cmd+shift+t" // per-panel — pin the chrome rail after hover leaves
  },
  "panel": {
    "sheet": "glass",           // sheet template: "glass" | "card" | "dotted" | "bracket" | "marginalia"
                                // per-note override: a `sheet:` frontmatter key in the note file
    "material": "hud",          // glass material: "hud" | "underWindow" | "popover" | "sidebar" | "menu"
    "cornerRadius": 12,
    "tintRead": 0.28,           // 0–1 black tint over the glass in read mode (contrast floor)
    "tintEdit": 0.38,           // 0–1 tint in edit mode (focused writing surface)
    "shadow": true,             // window drop shadow
    "defaultWidth": 420,        // size for panels opening for the first time
    "defaultHeight": 340,
    "background": null,         // optional CSS color; null keeps the glass sheet transparent
    "mark": null,               // optional identity mark from <home>/attachments
    "chrome": "rail"            // where the ✕ and mode toggle live:
                                // "rail"   — a detached strip above the note, off the page.
                                //            Shown on hover (or pinned with hotkeys.toggleChrome);
                                //            the strip stays reachable across the seam. Idle notes
                                //            stay bare. Edit mode does not force it.
                                // "inside" — the original hover-earned chrome floating over
                                //            the note's own top corners.
  },
  "focus": {
    "dim": 0.30                 // 0–1 strength of the focus-mode veil over everything else
  },
  "reader": {                   // the reader layer (hotkeys.reader)
    "width": 760,               // reading column width in points, capped at 80% of the screen
    "fontSize": 17,             // starting size; ⌘+ / ⌘− adjust, ⌘0 resets
    "dim": 0.5                  // 0–1 veil over the screen behind the sheet
  },
  "drape": {                    // a backdrop parked BEHIND every note — a calm stage under the set
    "enabled": false,           // off by default; true parks a full-screen blur+dim behind the notes
    "dim": 0.45,                // 0–1 black tint over the blurred backdrop
    "opacity": 1.0,             // 0–1 overall presence; lower = a lighter veil the desktop shows through
    "material": "hud"           // blur material: "hud" | "underWindow" | "popover" | "sidebar" | "menu"
  },
  "motion": {                   // Arrival: every show/hide is choreographed
    "entrance": "shimmer",      // "shimmer" | "drop" | "draw" | "none" — how a note lands
    "durationMs": 260,          // base duration for one panel's entrance
    "staggerMs": 40,            // per-panel delay in group reveals (session restore, show all notes)
    "enabled": true             // master switch — false = instant show/hide (today's behavior)
  },
  "physics": {                  // panel physics: how a note behaves under the hand
    "flingEnabled": true,       // throw a panel by its top band — it glides on and bounces off screen edges
    "flingFriction": 3.2,       // exponential glide friction (1/s); higher = heavier, stops sooner
                                // (total glide distance ≈ release speed / flingFriction)
    "flingMinVelocity": 900,    // release speed (pt/s) that starts a glide; below it the panel just stays
    "bounceDamping": 0.6,       // 0–1 velocity kept after an edge bounce
    "shakeEnabled": true        // shake side-to-side during a drag to fold the panel into its band (shade);
                                // shake again — or double-click the band — to restore
  },
  "editor": {                   // typography & colors; the reader takes the typography, keeps its own colors
    "fontFamily": null,         // null → system font stack; any CSS font-family string
    "monoFamily": null,         // null → ui-monospace stack
    "titleFamily": null,        // null → body stack; headings/titles only
    "fontSize": 13,             // px
    "lineHeight": 1.75,
    "paddingX": 20,             // px
    "paddingY": 16,
    "textColor": null,          // any CSS color; null → rgba(255,255,255,0.85)
    "textStrongColor": null,    // headings/bold; default rgba(255,255,255,0.96)
    "textMutedColor": null,     // markers/list bullets; default rgba(255,255,255,0.45)
    "dimColor": null,           // Markdown syntax markers
    "borderColor": null,        // rules, quote borders, sheet frame
    "accentColor": null,        // links; default rgba(158,203,255,0.9)
    "accentDimColor": null,      // source-mode link targets
    "codeBackground": null,     // default rgba(255,255,255,0.07)
    "codeTextColor": null,       // inline + block code ink
    "caretColor": null,         // default white
    "selectionColor": null,     // default rgba(255,255,255,0.18)
    "h1Size": null,             // px, reader scale; default 20 (editor derives slightly smaller)
    "h2Size": null,             // default 17
    "h3Size": null              // default 15
  }
}

Mobile access

behavior.mobileAccess controls the encrypted LAN peer host. Explicit true and false are preserved. For a config that predates this key, Canvas retains access only when it can read a valid, nonempty Keychain approval list. Missing or malformed trust data and Keychain read failures leave access off. A custom home never reads the production trust list and never starts the peer host.

This compatibility check does not rewrite an existing config or preferences. A later settings save writes the effective Boolean explicitly. An explicit null or non-Boolean value is invalid; it cannot inherit permission from stored approvals. Pairing approval and per-request authorization still apply.

How it applies

panel.* and focus.* are native (NSVisualEffectView material, tint layers, window shadow, overlay dim) — applied immediately to all open panels.
hotkeys.* hot-apply too: global chords re-register with Carbon on change; panel chords are read live on each keypress.
behavior.launchAtLogin syncs the macOS login item on change.
motion.* choreographs every show/hide (see Motion (Arrival) below); applied live, so the next note you open — or the next Hyper+B — uses the new feel. enabled: false restores the instant behavior exactly.
physics.* is read at each gesture, so edits apply to the very next drag — see Panel physics below. macOS Reduce Motion disables the fling and shake gestures regardless of these values.
editor.* maps to the web bundle's CSS custom properties (--blink-font-size, --blink-text, …) and is pushed over the bridge via window.blink.setTheme. The full variable table lives in web/editor/README.md.

Reader layer

hotkeys.reader lifts the text selected in the frontmost app — usually a long answer in a terminal — into a centered reading column over a dimmed screen (reader.dim). Esc, ⌘W, a click outside the column, the hotkey again, or switching to another app closes it; ⌘S keeps the text as a new note (opened in read mode). ⌘+ / ⌘− change the reading size and ⌘0 resets it to reader.fontSize.

Arrival is sequenced: a breathing cue lands beside the cursor the moment the hotkey fires, then the screen dims and the sheet rises while the cue grows at its centre, and the text streams in block by block once both the sheet and editor are ready. Closing is a short fade. Reduced Motion skips the rise and the stream. The sheet uses a fixed paper/ink palette (light or dark with the app's appearance), not the note glass or editor colors.
Canvas becomes the active app while the reader is up, and the column is an ordinary resizable window, so window-manager placement (Lattices tiling shortcuts, Rectangle, and the like) moves and sizes it. The placed frame is remembered and reused while it sits on the screen the reader opens on. Closing returns focus to the app the text came from.
The selection comes from Accessibility (AXSelectedText) when the app exposes it. Terminals mostly don't, so Canvas presses the app's own ⌘C menu item through Accessibility (posting ⌘C once the hotkey's modifiers lift only for apps without one), reads the pasteboard, and restores its previous contents. If Copy leaves the pasteboard untouched — Ghostty with copy-on-select already put the selection there — the current clipboard is used. All of this needs Accessibility permission; until it is granted, Canvas prompts and shows the current clipboard instead.
Terminal text is cleaned before rendering: ANSI escapes, TUI box frames, and Claude Code's ⏺/⎿ markers are stripped, the common indent removed, and lines the program hard-wrapped are rejoined. Box-drawn tables are kept as monospace. Short lines, lists, and headings keep their breaks.
The text is not a note, so it renders under the editor's untrusted policy: raw HTML shows as text, only web and mail links are clickable, and images show their alt text.

Examples

Cozy serif reading, warmer accent, softer glass:

{
  "editor": {
    "fontFamily": "Charter, Georgia, serif",
    "fontSize": 14,
    "lineHeight": 1.8,
    "accentColor": "rgba(255,196,150,0.9)"
  },
  "panel": { "tintRead": 0.12, "cornerRadius": 16 }
}

Maximum-contrast writing mode:

{
  "panel": { "tintEdit": 0.6 },
  "focus": { "dim": 0.45 }
}

Reusable treatment with a restrained identity mark (a neutral house style — substitute your own colors, faces, and mark):

{
  "styles": {
    "terminal": {
      "background": "#070908",
      "text": "#f2f4ef",
      "textStrong": "#f2f4ef",
      "textMuted": "#aab1a7",
      "dim": "#777e75",
      "border": "rgba(239,244,237,.09)",
      "accent": "#a6ef87",
      "accentDim": "rgba(166,239,135,.58)",
      "font": "\"JetBrains Mono\", ui-monospace, Menlo, monospace",
      "mono": "\"JetBrains Mono\", ui-monospace, Menlo, monospace",
      "titleFont": "\"JetBrains Mono\", ui-monospace, Menlo, monospace",
      "codeBackground": "#111411",
      "codeText": "#f2f4ef",
      "caret": "#a6ef87",
      "selection": "rgba(166,239,135,.1)",
      "radius": 6,
      "mark": "marks/terminal.svg"
    }
  }
}

panel.mark, styles.<name>.mark, and a workspace brand's mark are relative paths under <home>/attachments, using the root described above (default: ~/Library/Application Support/Blink/attachments). The mark appears at 20px in a 24pt top-left chrome cell and yields that position to the close control on hover. Marked themes receive a compact content gutter so the identity never overlaps the first heading or editor source. Keeping it in the treatment instead of the markdown body preserves the note as portable, presentation-free Markdown. Absolute paths and paths escaping the attachments directory are ignored — canvas workspace brand … --install-mark copies an asset into bounds for you.

Treatments are partial overlays. In addition to the original sheet/accent/font/fontSize/lineHeight/tint*/radius fields, they accept background, text, textStrong, textMuted, accentDim, mono, titleFont, dim, border, codeBackground, codeText, caret, and selection. These map to the same editor and sheet variables as their global config counterparts, but apply only to notes that reference that named style.

Workspaces

A workspace is a named group of notes plus the brand they render under. The definition lives here; membership lives in each note's blink.workspace frontmatter key, so note markdown never carries a color, face, or asset path.

{
  "workspaces": {
    "acme-docs": {
      "title": "Acme Documentation",
      "style": "terminal",
      "brand": {
        "accent": "#7aa2f7",
        "background": "#0b0d0c",
        "radius": 6,
        "mark": "marks/acme-docs.svg"
      }
    }
  }
}

style names an entry in styles to use as a base; brand is a treatment overlaid on top of it, so several workspaces can share one house style and tint it differently. Both are optional — a workspace with neither is unbranded, and its notes render with Canvas's defaults.

A note's look resolves least-specific first, so later wins:

config defaults ← workspaces[blink.workspace].brand ← styles[blink.style] ← loose blink: keys

Unknown workspace and style names contribute nothing rather than failing, so a note whose workspace was forgotten still opens — just unbranded. Agents should drive this through canvas workspace (see docs/workspaces.md) rather than hand-editing, because the CLI writes only the workspaces key and leaves every other config key byte-for-byte intact.

Motion (Arrival)

Notes don't appear — they land. Every show/hide is choreographed, with the character set by motion.* so a theme ships a matching feel. All of it no-ops cleanly when motion.enabled is false, and macOS Reduce Motion (System Settings → Accessibility → Display) is always honored as "none".

Entrances (motion.entrance):

shimmer — content fades up from nothing while a soft highlight sweep crosses the sheet left→right.
drop — the panel drifts down ~8pt into place with a slight overshoot settle as the content fades in.
draw — on flat sheets (dotted/bracket/marginalia) the frame draws itself on, then the text fades in behind it. On glass/card (no frame to draw) it falls back to shimmer.
none — instant (today's behavior).

Where the choreography shows up:

Opening a note (new note, popover, focusing) plays one entrance.
Session restore staggers the reopened panels staggerMs apart, left-to-right by on-screen position, so the desk assembles.
Show or hide all notes (Hyper+B): the reveal staggers panels in from their screen-edge direction; the hide is one synchronized exhale (all panels fade + drift outward together, then vanish). The state flips instantly regardless — the motion is garnish, and rapid toggles never leave a panel half-faded. Pending saves and the open-notes list are untouched.
Focus mode recedes the non-key panels a hair (a subtle depth cue), so the note you're writing stands proud. Transform-only — window positions never move.

Panel physics

Notes aren't just placed — they can be thrown. physics.* governs the two gestures on a panel's top band (the invisible 24pt drag strip along its top edge):

Fling. Drag a panel and release it with speed: it glides on with momentum, decays exponentially (flingFriction), and bounces off the edges of the screen it's mostly on, keeping bounceDamping of its speed per hit. Below flingMinVelocity a release is just a drop. Any new grab, close, or programmatic placement kills a glide mid-flight.
Shake-to-shade. Shake the panel side-to-side mid-drag (~3 reversals in 0.6s, ≥40pt each, little vertical travel) and it folds up into its top band, windowshade-style. Shake again — or double-click the band — and it unfolds back to its full frame. Resizing is pinned while shaded so nothing fights the fold.

Geometry is persisted only when a panel is at rest — never mid-glide — and always as the UNSHADED frame, so a note that was shaded when Canvas quit still relaunches full-size. The shaded state itself is session-only.

What does NOT live here

Notes themselves: ~/Library/Application Support/Blink/Notes/*.md (frontmattered markdown). Agents may write their own frontmatter keys into a note — Canvas preserves unknown keys verbatim through every save, and merges on-disk metadata (tags, pinned, foreign keys) before each content save, so editing a note's frontmatter while it's open in a panel is safe.
Per-machine workspace state (open panels, per-note modes, window frames): UserDefaults today, with a planned migration to .blink/workspace.json.

behavior.alwaysShowMenuBarIcon defaults to false: Canvas hides its menu icon while Lattices is running and restores it when Lattices exits. Set it to true to keep a separate Canvas icon. This setting hot-applies and is also available in Settings. Reopening Canvas from Finder or Lattices Apps opens Settings even when the icon is hidden. It does not change notes or launch-at-login behavior.

Find docs fast

Canvas configuration