Venue plan

The JSON gatecrash-keys venue writes and gatecrash-keys manifest signs. The compiler refuses anything that does not make sense and says which line is wrong, so an invalid plan fails on your laptop rather than at a door.

The reasoning behind these shapes is in Zones, seats and doors.

Top level

{
  "zones": [],
  "sections": [],
  "checkpoints": [],
  "tiers": [],
  "amenities": [],
  "map": {}
}

Codes are normalised — lower-cased, trimmed — so Block-A, block-a and BLOCK-A are the same section rather than three.

zones

{
  "code": "pit",
  "name": "Front Pit",
  "kind": "pit",
  "parent": "arena",
  "restricted": true,
  "capacity": 200,
  "colour": "#A855F7",
  "shape": [
    { "x": 42, "y": 21 },
    { "x": 78, "y": 21 },
    { "x": 78, "y": 42 },
    { "x": 42, "y": 42 }
  ]
}

Field	Notes
kind	perimeter, concourse, arena, pit, backstage, campsite, vip. Display and default colour only; nothing decides on it.
parent	Nesting. Somebody in the pit is in the arena and in the perimeter, which is how one admission counts at every level.
restricted	The security flag. A tier's grant cascades down the tree, so without this a perimeter grant inherits backstage. Set it and the cascade stops, so nesting fails closed.
capacity	Optional and honest: an open field has no meaningful number, and the dashboard only meters zones that declare one. For a fully seated zone the compiler fills it from the seat count.
shape	A polygon in map units. Optional — a venue with no floor plan still runs an event, it just has no map.

checkpoints

{
  "code": "pit-gate",
  "name": "Pit Wristband",
  "zone": "pit",
  "direction": "in",
  "policy": "once",
  "count_limit": 0,
  "requires": ["arena"],
  "tiers": ["vip"],
  "sections": [],
  "lane": "1",
  "node": "n-pit",
  "position": { "x": 60, "y": 40 },
  "opens_at": "2026-08-21T18:00:00+05:30",
  "closes_at": "2026-08-22T01:00:00+05:30"
}

Field	Notes
direction	in, out, both. An outbound scan removes the zone and everything nested inside it, which is what keeps a capacity meter honest on a room people leave.
policy	once, re-entry, or counted with count_limit.
requires	Zones the holder must already have entered. This is the sequencing, and a failure is PREREQUISITE_MISSING with a redirect.
tiers	Who may pass at all. Empty means anybody whose entitlement covers the zone.
sections	Narrows the door to specific seat blocks — what a stadium vomitory is. A mismatch is WRONG_DOOR, with a redirect.
node	The walk-graph node. position is taken from it when omitted, so the coordinates are not written twice — two copies of one fact is two chances to disagree, and the way it disagrees is a gate drawn in the wrong place.
opens_at / closes_at	Outside them, DOORS_CLOSED.

WARNING

Every arena door being sections-restricted means a standing or VIP ticket with no seat has no way in at all — and that only shows up when somebody is standing at a gate. The starter plan includes a general arena entrance for exactly this reason.

sections

{
  "code": "block-a",
  "name": "Block A",
  "kind": "seated",
  "zone": "arena",
  "entrances": ["portal-a"],
  "node": "n-portal-a",
  "view_note": "Upper tier, behind the mix position",
  "shape": [
    { "x": 28, "y": 50 },
    { "x": 92, "y": 50 },
    { "x": 92, "y": 68 },
    { "x": 28, "y": 68 }
  ],
  "rows": [
    {
      "label": "A",
      "start": { "x": 30, "y": 55 },
      "end": { "x": 90, "y": 55 },
      "curve": 4,
      "aisle": "n-aisle-a",
      "seats": [{ "number": "1", "kind": "standard" }]
    }
  ]
}

kind is seated or standing; a standing section takes a capacity and no rows.

Rows are described as geometry — a start, an end, a curve, a seat list — and the compiler lays the seats along a quadratic bezier. A positive curve bows the row left of the direction of travel, which for a row running left to right in front of a stage is towards the audience. An explicit position on a seat survives untouched, for the one row that does not fit a formula.

Seat kind is standard, accessible, companion or restricted-view, and blocked takes a seat out of sale while leaving it on the map.

tiers

{
  "code": "vip",
  "name": "VIP",
  "zones": ["perimeter", "arena", "pit"],
  "colour": "#A855F7",
  "priority": 20
}

zones is the entitlement, and it cascades into nested zones except where restricted stops it. colour is the band on the verdict screen a guard matches against a wristband, so pick colours that are distinguishable under a floodlight rather than on a monitor.

amenities

{
  "id": "wc-concourse",
  "kind": "washroom",
  "name": "Concourse Toilets",
  "zone": "concourse",
  "position": { "x": 45, "y": 92 },
  "node": "n-concourse",
  "accessible": true
}

kind is one of washroom, food, bar, water, medical, exit, info, lost-found, charging, atm, smoking, merch, cloakroom, accessible. node is inferred from the position when omitted. Marking one accessible is what makes the wallet's step-free search mean anything.

map

{
  "width": 120,
  "height": 110,
  "metres_per_unit": 1.5,
  "outline": [],
  "stage": [],
  "nodes": [],
  "edges": []
}

Units are arbitrary and metres_per_unit converts them, which is what turns a route into "about a 2 minute walk". Node kinds: gate, concourse, portal, aisle, seat-block, amenity, junction. An edge marked stairs is excluded from the step-free route; level on a node is what makes a route say "up one level".

Checking it

gatecrash-keys inspect manifest.json

Prints the compiled plan: zone tree, doors with their prerequisites, sections with seat counts, and anything the compiler filled in for you.