[match] tachyon support endpoint

apps/match/src/match.app.ts

@@ -61,6 +61,7 @@ import {
 	ExclusiveLoginResponse,
 	form,
 	InProgressRequest,
+	InstanceIdResponse,
 	InviteRequest,
 	InviteResponse,
 	JoinModeRequest,
@@ -612,7 +613,6 @@ function nextLiveMessageId(): number {
 	return Date.now()
 }
 
-
 /**
  * Deliver a game invite from `fromId` to `toId` for a room instance — a `MessageReceived`
  * frame carrying a game-invite `Message` the client renders the join prompt from. `data`
@@ -662,6 +662,13 @@ async function sendGameInvite(
  */
 const ORIENTATION_INSTANCE_ID = -2
 
+/**
+ * What `/tachyon` answers for a player who is not in an instance. A stored
+ * `room_instance` id is never 0 — the table is AUTOINCREMENT from 1 — so the sentinel can't
+ * be mistaken for a real instance, and the body stays a number the way the caller reads it.
+ */
+const NO_INSTANCE = 0
+
 /**
  * Instance-relevant fields pulled from a stored room (scene, name, capacity, …).
  * The `location` is the SubRoom's real `UnitySceneId` — an empty/unknown location
@@ -1389,6 +1396,56 @@ const app = new Hono<App>()
 		}
 	)
 
+	// Which room instance a player is in, as a bare number (`/tachyon?id=123`). The whole
+	// presence blob is what `/player` serves; this answers the one field out of it, for a
+	// caller that only needs to know where someone is.
+	//
+	// UNGATED, unlike the rest of this worker's presence surface: it takes the player id from
+	// the query rather than from a token, so anyone can ask about anyone. What it discloses
+	// is an instance id and nothing else — no room, no name, no status — and `/player` is
+	// already ungated on the same rows.
+	//
+	// 0 for "not in an instance": the body is a number, so absence has to be one too, and a
+	// real instance id is never 0 (the `room_instance` table is AUTOINCREMENT from 1). The
+	// synthetic negatives ARE real answers and pass through — -2 is the Orientation seed.
+	.get(
+		'/tachyon',
+		describeRoute({
+			tags: ['Presence'],
+			summary: 'The room instance a player is in',
+			description: [
+				'The `roomInstanceId` from a player’s live presence (`?id=123`), as a BARE NUMBER —',
+				'the whole body is the id, not an object around it. The single field out of what',
+				'`/player` serves whole.',
+				'',
+				'0 means not in an instance: no live presence, an expired row, or no usable `id`. A',
+				'real instance id is never 0, so the sentinel can’t collide with one. Synthetic ids',
+				'pass through as they stand — -2 is the Orientation presence the `auth` worker seeds',
+				'a brand-new player with.',
+				'',
+				'Ungated: the player is named by the query rather than by a token, so anyone may ask',
+				'about anyone. It discloses an instance id and nothing else.',
+			].join(' '),
+			parameters: [
+				{
+					name: 'id',
+					in: 'query',
+					required: false,
+					description: 'The account to look up. Absent or unparseable answers 0',
+					schema: { type: 'integer' },
+				},
+			],
+			responses: { 200: json(InstanceIdResponse, 'The instance id, or 0') },
+		}),
+		async (c) => {
+			const playerId = Number.parseInt(c.req.query('id') ?? '', 10)
+			if (!Number.isInteger(playerId)) return c.json(NO_INSTANCE)
+
+			const presence = await getPresence<RoomInstance>(c.env.DB, playerId)
+			return c.json(presence?.roomInstance?.roomInstanceId ?? NO_INSTANCE)
+		}
+	)
+
 	.get(
 		'/player',
 		describeRoute({

apps/match/src/openapi.ts

@@ -401,3 +401,15 @@ export const InviteResponse = z.object({
 		.nullable()
 		.describe('The room the invite points at; null when the room instance didn’t resolve'),
 })
+
+/**
+ * `GET /tachyon?id=…` — the room instance a player is in, as a BARE NUMBER: the whole body
+ * is the id, with no object around it.
+ *
+ * 0 means "not in one" — no live presence for that account, an expired row, or no `id`
+ * given. Presence rows carry synthetic ids too, which are passed through as they stand:
+ * -2 is the Orientation seed the `auth` worker writes for a brand-new player.
+ */
+export const InstanceIdResponse = z
+	.int()
+	.describe('The player’s room instance id, or 0 when they are not in one')

apps/match/src/test/integration/api.test.ts

@@ -332,6 +332,71 @@ describe('public endpoints', () => {
 		])
 	})
 
+	test('GET /tachyon?id=N answers the bare instance id the player is in', async () => {
+		// Ungated — no bearer token anywhere in this test. The player is named by the query.
+		const tachyon = async (query: string) => {
+			const res = await exports.default.fetch(`${ORIGIN}/tachyon${query}`)
+			expect(res.status).toBe(200)
+			return res.json()
+		}
+
+		// Nobody has presence for 4242, so they are in nothing. 0 rather than null: the body
+		// is a number, and a real instance id is never 0.
+		expect(await tachyon('?id=4242')).toBe(0)
+
+		// Put someone in a room the ordinary way, and the id is the one the matchmake handed
+		// them — the same field `/player` serves inside the whole presence blob.
+		const matchmake = await exports.default.fetch(`${ORIGIN}/matchmake/room/2`, {
+			method: 'POST',
+			headers: { ...(await bearer('4243')), 'Content-Type': 'application/x-www-form-urlencoded' },
+			body: new URLSearchParams({ JoinMode: '2' }).toString(),
+		})
+		const { roomInstance } = (await matchmake.json()) as {
+			roomInstance: { roomInstanceId: number } | null
+		}
+		expect(roomInstance).not.toBeNull()
+		expect(await tachyon('?id=4243')).toBe(roomInstance!.roomInstanceId)
+
+		// A synthetic instance id is a real answer and passes through — -2 is the Orientation
+		// presence `auth` seeds a new player with.
+		await env.DB.prepare('INSERT OR REPLACE INTO presence (data) VALUES (?1)')
+			.bind(
+				JSON.stringify({
+					accountId: 4244,
+					roomInstance: { roomInstanceId: -2 },
+					statusVisibility: 0,
+					deviceClass: 0,
+					vrMovementMode: 1,
+					platform: 0,
+					appVersion: GAME_VERSION,
+					expiresAt: Math.floor(Date.now() / 1000) + 900,
+				})
+			)
+			.run()
+		expect(await tachyon('?id=4244')).toBe(-2)
+
+		// An expired row is not presence, so its player is in nothing.
+		await env.DB.prepare('INSERT OR REPLACE INTO presence (data) VALUES (?1)')
+			.bind(
+				JSON.stringify({
+					accountId: 4245,
+					roomInstance: { roomInstanceId: 987 },
+					statusVisibility: 0,
+					deviceClass: 0,
+					vrMovementMode: 1,
+					platform: 0,
+					appVersion: GAME_VERSION,
+					expiresAt: Math.floor(Date.now() / 1000) - 60,
+				})
+			)
+			.run()
+		expect(await tachyon('?id=4245')).toBe(0)
+
+		// No id, and an unparseable one, answer the same 0 rather than erroring.
+		expect(await tachyon('')).toBe(0)
+		expect(await tachyon('?id=notanumber')).toBe(0)
+	})
+
 	test('GET /player?id=&id= returns one payload per id, in order', async () => {
 		const res = await exports.default.fetch(`${ORIGIN}/player?id=1070&id=1380`)
 		const players = (await res.json()) as Array<{ playerId: number; isOnline: boolean }>
@@ -2654,6 +2719,7 @@ describe('auth-gated endpoints', () => {
 			'GET /room/{roomId}/instances',
 			'GET /rooms/requiring/developer',
 			'GET /rooms/requiring/rrplus',
+			'GET /tachyon',
 			'POST /invite',
 			'POST /matchmake/club/{clubId}',
 			'POST /matchmake/dorm',