diff --git a/GPS/actions/system/index.js b/GPS/actions/system/index.js
index 4c4e5e4..f968bb8 100644
--- a/GPS/actions/system/index.js
+++ b/GPS/actions/system/index.js
@@ -1,5 +1,4 @@
 import { methods as utilities, construct as utilitiesConstruct } from './utilities.js'
-import { methods as positions } from './positions.js'
 import { dispatchMessage } from './dispatch.js'
 
 export const afterLoginMethods = [
@@ -7,6 +6,5 @@ export const afterLoginMethods = [
 ]
 export const meshActions = {
     ...utilities,
-    ...positions,
 }
 export { dispatchMessage }
diff --git a/GPS/actions/system/positions.js b/GPS/actions/system/positions.js
deleted file mode 100644
index ae6d361..0000000
--- a/GPS/actions/system/positions.js
+++ /dev/null
@@ -1,152 +0,0 @@
-import { publishActionReply, parseSimTime } from '../../actionsHelper.js'
-
-export const methods = {
-
-    /*  Event-Rx:
-        {
-            "action": "GETAGENTPOSITION",
-            "reqid": "6az5e4r6a",
-            "payload": {
-                "agentId": "agent42",
-                "t": 12.5
-            }
-        }
-        Event-Tx:
-        {
-            "action": "GETAGENTPOSITION",
-            "success": true,
-            "reqid": "6az5e4r6a",
-            "payload": {
-                "agent": {
-                    "id": "agent42",
-                    "position": { "x": 1, "y": 2, "z": 3 },
-                    "vector": { "x": 0, "y": 0, "z": 0 },
-                    "since": 0,
-                    "generation": 2,
-                    "t": 12.5
-                }
-            }
-        }
-    */
-    async action_GETAGENTPOSITION(action, payload, reqid, sender, roles) {
-        const replyOpts = {
-            action,
-            reqid,
-            sender,
-            replyChannel: this.config.gps.gpsActionsReply,
-        }
-        if(!this.accessRights.canDo(roles, action)) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Unauthorized action !',
-            } })
-            return
-        }
-
-        if(!this.gpsSrv.isLive()) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Simulation not live',
-            } })
-            return
-        }
-
-        const agentId = payload?.agentId
-        if(!agentId || typeof(agentId) !== 'string') {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Missing or invalid agentId',
-            } })
-            return
-        }
-
-        const at = parseSimTime(payload, () => this.gpsSrv.now())
-        if(at === null) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Invalid simulation time',
-            } })
-            return
-        }
-
-        const agent = this.gpsSrv.getAgentPosition(agentId, at)
-        if(!agent) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: `Unknown agent: ${agentId}`,
-            } })
-            return
-        }
-
-        publishActionReply(this, { ...replyOpts, reply: {
-            success: true,
-            payload: { agent },
-        } })
-    },
-
-    /*  Event-Rx:
-        {
-            "action": "GETAGENTSINPRISM",
-            "reqid": "6az5e4r6a",
-            "payload": {
-                "prism": {
-                    "xMin": -10, "xMax": 10,
-                    "yMin": -10, "yMax": 10,
-                    "zMin": 0, "zMax": 5
-                },
-                "t": 0
-            }
-        }
-    */
-    async action_GETAGENTSINPRISM(action, payload, reqid, sender, roles) {
-        const replyOpts = {
-            action,
-            reqid,
-            sender,
-            replyChannel: this.config.gps.gpsActionsReply,
-        }
-        if(!this.accessRights.canDo(roles, action)) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Unauthorized action !',
-            } })
-            return
-        }
-
-        if(!this.gpsSrv.isLive()) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Simulation not live',
-            } })
-            return
-        }
-
-        const prism = payload?.prism
-        if(!this.gpsSrv.isValidPrism(prism)) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Missing or invalid prism bounds',
-            } })
-            return
-        }
-
-        const at = parseSimTime(payload, () => this.gpsSrv.now())
-        if(at === null) {
-            publishActionReply(this, { ...replyOpts, reply: {
-                success: false,
-                err: 'Invalid simulation time',
-            } })
-            return
-        }
-
-        const agents = this.gpsSrv.getAgentsInPrism(prism, at)
-        publishActionReply(this, { ...replyOpts, reply: {
-            success: true,
-            payload: {
-                agents,
-                t: at,
-            },
-        } })
-    },
-
-}
diff --git a/GPS/agentStore.js b/GPS/agentStore.js
index fa64363..e9e9350 100644
--- a/GPS/agentStore.js
+++ b/GPS/agentStore.js
@@ -1,23 +1,23 @@
 
 export class AgentStore {
 
-    constructor(systemCnx, storage, debug = false) {
+    constructor(systemCnx, gpsStorage, debug = false) {
         this.cnx = systemCnx
-        this.storage = storage
+        this.gpsStorage = gpsStorage
         this.debug = debug
     }
 
     agentHashKey(agentId) {
-        return(this.storage.agentHashKey.replace(/\[UID\]/g, agentId))
+        return(this.gpsStorage.agentHashKey.replace(/\[UID\]/g, agentId))
     }
 
     async clearAll() {
         try {
-            const ids = await this.cnx.redisSmembers(this.storage.agentsIndexKey)
+            const ids = await this.cnx.redisSmembers(this.gpsStorage.agentsIndexKey)
             for(const id of ids) {
                 await this.cnx.redisDel(this.agentHashKey(id))
             }
-            await this.cnx.redisDel(this.storage.agentsIndexKey)
+            await this.cnx.redisDel(this.gpsStorage.agentsIndexKey)
             if(this.debug) console.log(`[GPS] Cleared system agent store (${ids.length} agent(s))`)
         } catch(err) {
             console.error('[GPS] Failed to clear system agent store:', err)
@@ -37,11 +37,11 @@ export class AgentStore {
                 simulationId,
             }
             await this.cnx.redisHset(this.agentHashKey(agent.id), 'segment', record)
-            await this.cnx.redisSadd(this.storage.agentsIndexKey, agent.id)
+            await this.cnx.redisSadd(this.gpsStorage.agentsIndexKey, agent.id)
             await this.cnx.redisXadd(
-                this.storage.positionsStream,
+                this.gpsStorage.positionsStream,
                 record,
-                this.storage.streamMaxLen ?? ''
+                this.gpsStorage.streamMaxLen ?? ''
             )
             if(this.debug) console.log(`[GPS] Exported segment ${agent.id} (${eventType})`)
         } catch(err) {
@@ -57,11 +57,11 @@ export class AgentStore {
                 t: simT,
             }
             await this.cnx.redisDel(this.agentHashKey(agentId))
-            await this.cnx.redisSrem(this.storage.agentsIndexKey, agentId)
+            await this.cnx.redisSrem(this.gpsStorage.agentsIndexKey, agentId)
             await this.cnx.redisXadd(
-                this.storage.positionsStream,
+                this.gpsStorage.positionsStream,
                 record,
-                this.storage.streamMaxLen ?? ''
+                this.gpsStorage.streamMaxLen ?? ''
             )
             if(this.debug) console.log(`[GPS] Exported remove ${agentId}`)
         } catch(err) {
diff --git a/GPS/arenaAgentLoader.js b/GPS/arenaAgentLoader.js
index 8c73f9c..828dd76 100644
--- a/GPS/arenaAgentLoader.js
+++ b/GPS/arenaAgentLoader.js
@@ -1,9 +1,9 @@
 
 export class ArenaAgentLoader {
 
-    constructor(arenaCnx, storage, debug = false) {
+    constructor(arenaCnx, arenaStorage, debug = false) {
         this.cnx = arenaCnx
-        this.storage = storage
+        this.arenaStorage = arenaStorage
         this.debug = debug
     }
 
@@ -45,11 +45,11 @@ export class ArenaAgentLoader {
 
     async #listAgentIds(expectedIds = null) {
         if(Array.isArray(expectedIds) && expectedIds.length) return([...expectedIds])
-        return(await this.cnx.redisSmembers(this.storage.agentsIndexKey))
+        return(await this.cnx.redisSmembers(this.arenaStorage.agentsIndexKey))
     }
 
     async #loadAgentFromHash(agentId) {
-        const key = this.storage.agentHashKey.replace(/\[UID\]/g, agentId)
+        const key = this.arenaStorage.agentHashKey.replace(/\[UID\]/g, agentId)
         const positionRaw = await this.cnx.redisHget(key, 'position')
         const vectorRaw = await this.cnx.redisHget(key, 'vector')
         let position = this.#parseHashField(positionRaw)
diff --git a/GPS/gpsServer.js b/GPS/gpsServer.js
index cbca56e..5a0c831 100644
--- a/GPS/gpsServer.js
+++ b/GPS/gpsServer.js
@@ -89,9 +89,9 @@ export class gpsServer {
     }
 
     initAgentStore() {
-        const storage = this.gpsConfig.gps?.storage
-        if(storage && this.systemCnx) {
-            this.agentStore = new AgentStore(this.systemCnx, storage, this.debug)
+        const gpsStorage = this.gpsConfig.gps?.GPSstorage
+        if(gpsStorage && this.systemCnx) {
+            this.agentStore = new AgentStore(this.systemCnx, gpsStorage, this.debug)
         }
     }
 
diff --git a/GPS/startGps.sh b/GPS/startGps.sh
index c3731d0..20b49df 100755
--- a/GPS/startGps.sh
+++ b/GPS/startGps.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
+set -a
 . /etc/p42/secrets.env
+set +a
 
 daemon=p42Gps
 logfile=gps.log
diff --git a/Observer/actions/arena/arenaHandlers.js b/Observer/actions/arena/arenaHandlers.js
index 7c42d3a..cd415bf 100644
--- a/Observer/actions/arena/arenaHandlers.js
+++ b/Observer/actions/arena/arenaHandlers.js
@@ -4,8 +4,28 @@ export const construct = (redisCnx) => {
 
 export const methods = {
 
+    handleLifecycleEvent(msg) {
+        const srv = this.observerSrv
+        if(!srv) return
+
+        if(msg.eventType === 'onYourMarks') {
+            srv.onYourMarks()
+            return
+        }
+
+        if(msg.eventType === 'bigBang') {
+            srv.onBigBang()
+        }
+    },
+
     dispatchArenaMessage(msg, chan) {
-        if(this.debug) console.log(`[${this.redisId}] Arena message (unhandled):`, msg.eventType, chan)
+        const observer = this.config.observer
+        if(!observer || !this.observerSrv) return(false)
+
+        if(this.matchesChan(chan, observer.lifecycle?.arenaChannel ?? 'arena:lifecycle')) {
+            this.handleLifecycleEvent(msg)
+            return(true)
+        }
         return(false)
     },
 
diff --git a/Observer/actions/system/index.js b/Observer/actions/system/index.js
index 6b282da..3f95450 100644
--- a/Observer/actions/system/index.js
+++ b/Observer/actions/system/index.js
@@ -1,4 +1,5 @@
 import { methods as utilities, construct as utilitiesConstruct } from './utilities.js'
+import { methods as positions } from './positions.js'
 import { dispatchMessage } from './dispatch.js'
 
 export const afterLoginMethods = [
@@ -7,6 +8,7 @@ export const afterLoginMethods = [
 
 export const meshActions = {
     ...utilities,
+    ...positions,
 }
 
 export { dispatchMessage }
diff --git a/Observer/actions/system/positions.js b/Observer/actions/system/positions.js
new file mode 100644
index 0000000..223f820
--- /dev/null
+++ b/Observer/actions/system/positions.js
@@ -0,0 +1,280 @@
+import { publishActionReply, parseSimTime } from '../../actionsHelper.js'
+import { Frustum } from '../../frustum.js'
+
+export const methods = {
+
+    /*  Event-Rx:
+        {
+            "action": "GETAGENTPOSITION",
+            "reqid": "6az5e4r6a",
+            "payload": {
+                "agentId": "agent42",
+                "t": 12.5
+            }
+        }
+        Event-Tx:
+        {
+            "action": "GETAGENTPOSITION",
+            "success": true,
+            "reqid": "6az5e4r6a",
+            "payload": {
+                "agent": {
+                    "id": "agent42",
+                    "position": { "x": 1, "y": 2, "z": 3 },
+                    "vector": { "x": 0, "y": 0, "z": 0 },
+                    "since": 0,
+                    "generation": 2,
+                    "t": 12.5
+                }
+            }
+        }
+    */
+    async action_GETAGENTPOSITION(action, payload, reqid, sender, roles) {
+        const replyOpts = {
+            action,
+            reqid,
+            sender,
+            replyChannel: this.config.observer.observerActionsReply,
+        }
+        if(!this.accessRights.canDo(roles, action)) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Unauthorized action !',
+            } })
+            return
+        }
+
+        const reader = this.observerSrv.gpsStorageReader
+        if(!reader) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'GPS storage reader not ready',
+            } })
+            return
+        }
+
+        if(!this.observerSrv.isLive()) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Simulation not live',
+            } })
+            return
+        }
+
+        const agentId = payload?.agentId
+        if(!agentId || typeof(agentId) !== 'string') {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Missing or invalid agentId',
+            } })
+            return
+        }
+
+        const at = parseSimTime(payload, () => this.observerSrv.now())
+        if(at === null) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Invalid simulation time',
+            } })
+            return
+        }
+
+        const agent = await reader.getAgentPosition(agentId, at)
+        if(!agent) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: `Unknown agent: ${agentId}`,
+            } })
+            return
+        }
+
+        publishActionReply(this, { ...replyOpts, reply: {
+            success: true,
+            payload: { agent },
+        } })
+    },
+
+    /*  Event-Rx:
+        {
+            "action": "GETAGENTSINFRUSTUM",
+            "reqid": "6az5e4r6a",
+            "payload": {
+                "planes": [
+                    { "nx": 1, "ny": 0, "nz": 0, "d": -10 },
+                    { "nx": -1, "ny": 0, "nz": 0, "d": 10 },
+                    { "nx": 0, "ny": 1, "nz": 0, "d": -10 },
+                    { "nx": 0, "ny": -1, "nz": 0, "d": 10 },
+                    { "nx": 0, "ny": 0, "nz": 1, "d": 0 },
+                    { "nx": 0, "ny": 0, "nz": -1, "d": 5 }
+                ],
+                "t": 0
+            }
+        }
+    */
+    async action_GETAGENTSINFRUSTUM(action, payload, reqid, sender, roles) {
+        const replyOpts = {
+            action,
+            reqid,
+            sender,
+            replyChannel: this.config.observer.observerActionsReply,
+        }
+        if(!this.accessRights.canDo(roles, action)) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Unauthorized action !',
+            } })
+            return
+        }
+
+        const registry = this.observerSrv.requestorRegistry
+        if(!registry) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Requestor registry not ready',
+            } })
+            return
+        }
+
+        if(!this.observerSrv.isLive()) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Simulation not live',
+            } })
+            return
+        }
+
+        const frustum = Frustum.fromPlanes(payload?.planes)
+        if(!frustum) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Missing or invalid frustum planes (expected 6)',
+            } })
+            return
+        }
+
+        const at = parseSimTime(payload, () => this.observerSrv.now())
+        if(at === null) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Invalid simulation time',
+            } })
+            return
+        }
+
+        const result = await registry.evaluateOnce({ frustum, t: at })
+        if(!result.ok) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: result.err,
+            } })
+            return
+        }
+
+        publishActionReply(this, { ...replyOpts, reply: {
+            success: true,
+            payload: {
+                agents: result.agents,
+                t: result.t,
+            },
+        } })
+    },
+
+    /*  Event-Rx:
+        {
+            "action": "SUBSCRIBEFRUSTUM",
+            "reqid": "6az5e4r6a",
+            "sender": "client-uuid",
+            "payload": {
+                "planes": [
+                    { "nx": 1, "ny": 0, "nz": 0, "d": -10 },
+                    { "nx": -1, "ny": 0, "nz": 0, "d": 10 },
+                    { "nx": 0, "ny": 1, "nz": 0, "d": -10 },
+                    { "nx": 0, "ny": -1, "nz": 0, "d": 10 },
+                    { "nx": 0, "ny": 0, "nz": 1, "d": 0 },
+                    { "nx": 0, "ny": 0, "nz": -1, "d": 5 }
+                ],
+                "frequency": 800
+            }
+        }
+        Event-Tx:
+        {
+            "action": "SUBSCRIBEFRUSTUM",
+            "success": true,
+            "reqid": "6az5e4r6a",
+            "payload": {
+                "frequency": 900,
+                "agents": [ ... ],
+                "t": 12.5
+            }
+        }
+        Periodic push (no reqid):
+        {
+            "action": "GETAGENTSINFRUSTUM",
+            "success": true,
+            "sender": "observer",
+            "payload": { "agents": [ ... ], "t": 12.5 }
+        }
+    */
+    async action_SUBSCRIBEFRUSTUM(action, payload, reqid, sender, roles) {
+        const replyOpts = {
+            action,
+            reqid,
+            sender,
+            replyChannel: this.config.observer.observerActionsReply,
+        }
+        if(!this.accessRights.canDo(roles, action)) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Unauthorized action !',
+            } })
+            return
+        }
+
+        if(!sender || typeof(sender) !== 'string') {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Missing or invalid sender',
+            } })
+            return
+        }
+
+        const registry = this.observerSrv.requestorRegistry
+        if(!registry) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Requestor registry not ready',
+            } })
+            return
+        }
+
+        if(!this.observerSrv.isLive()) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: 'Simulation not live',
+            } })
+            return
+        }
+
+        const result = await registry.subscribeFrustum(sender, {
+            planes: payload?.planes,
+            frequency: payload?.frequency,
+        })
+        if(!result.ok) {
+            publishActionReply(this, { ...replyOpts, reply: {
+                success: false,
+                err: result.err,
+            } })
+            return
+        }
+
+        publishActionReply(this, { ...replyOpts, reply: {
+            success: true,
+            payload: {
+                frequency: result.frequency,
+                agents: result.agents,
+                t: result.t,
+            },
+        } })
+    },
+
+}
diff --git a/Observer/actionsHelper.js b/Observer/actionsHelper.js
index 10274e2..7573130 100644
--- a/Observer/actionsHelper.js
+++ b/Observer/actionsHelper.js
@@ -14,3 +14,9 @@ export function publishActionReply(redisCnx, options) {
     const chan = replyChannel.replace(/\[UID\]/g, sender)
     redisCnx.redisPublish(chan, reply)
 }
+
+export function parseSimTime(payload, fallbackFn) {
+    if(payload?.t != null && typeof(payload.t) === 'number' && !Number.isNaN(payload.t)) return(payload.t)
+    if(payload?.at != null && typeof(payload.at) === 'number' && !Number.isNaN(payload.at)) return(payload.at)
+    return(fallbackFn())
+}
diff --git a/Observer/frustum.js b/Observer/frustum.js
new file mode 100644
index 0000000..ed4a2d9
--- /dev/null
+++ b/Observer/frustum.js
@@ -0,0 +1,33 @@
+export class Frustum {
+
+    constructor(planes) {
+        if(!Frustum.#validatePlanes(planes)) throw(new Error('Invalid frustum planes'))
+        this.planes = planes.map(p => ({ ...p }))
+    }
+
+    static #validatePlanes(planes) {
+        if(!Array.isArray(planes) || planes.length !== 6) return(false)
+        for(const p of planes) {
+            if(!p || typeof(p) !== 'object') return(false)
+            if(typeof(p.nx) !== 'number' || Number.isNaN(p.nx)) return(false)
+            if(typeof(p.ny) !== 'number' || Number.isNaN(p.ny)) return(false)
+            if(typeof(p.nz) !== 'number' || Number.isNaN(p.nz)) return(false)
+            if(typeof(p.d) !== 'number' || Number.isNaN(p.d)) return(false)
+        }
+        return(true)
+    }
+
+    static fromPlanes(planes) {
+        if(!Frustum.#validatePlanes(planes)) return(null)
+        return(new Frustum(planes))
+    }
+
+    containsPoint(position) {
+        for(const p of this.planes) {
+            const dist = p.nx * position.x + p.ny * position.y + p.nz * position.z + p.d
+            if(dist < 0) return(false)
+        }
+        return(true)
+    }
+
+}
diff --git a/Observer/gpsStorageReader.js b/Observer/gpsStorageReader.js
new file mode 100644
index 0000000..422a805
--- /dev/null
+++ b/Observer/gpsStorageReader.js
@@ -0,0 +1,82 @@
+import { positionAt } from '../GPS/actions/arena/worldline.js'
+
+export class GpsStorageReader {
+
+    constructor(systemCnx, gpsStorage, debug = false) {
+        this.cnx = systemCnx
+        this.gpsStorage = gpsStorage
+        this.debug = debug
+    }
+
+    agentHashKey(agentId) {
+        return(this.gpsStorage.agentHashKey.replace(/\[UID\]/g, agentId))
+    }
+
+    #parseHashField(raw) {
+        if(raw == null) return(null)
+        if(typeof(raw) === 'object') return(raw)
+        try { return(JSON.parse(raw)) }
+        catch { return(null) }
+    }
+
+    #segmentToAgent(segment) {
+        if(!segment?.id) return(null)
+        if(!this.#isVector(segment.position) || !this.#isVector(segment.vector)) return(null)
+        return({
+            id: segment.id,
+            position: { ...segment.position },
+            vector: { ...segment.vector },
+            since: segment.since ?? 0,
+            generation: segment.generation ?? 0,
+        })
+    }
+
+    #isVector(v) {
+        return(
+            v &&
+            typeof(v) === 'object' &&
+            typeof(v.x) === 'number' &&
+            typeof(v.y) === 'number' &&
+            typeof(v.z) === 'number'
+        )
+    }
+
+    buildAgentSnapshot(agent, at) {
+        return({
+            id: agent.id,
+            position: positionAt(agent, at),
+            vector: { ...agent.vector },
+            since: agent.since,
+            generation: agent.generation ?? 0,
+            t: at,
+        })
+    }
+
+    async loadSegment(agentId) {
+        const raw = await this.cnx.redisHget(this.agentHashKey(agentId), 'segment')
+        return(this.#parseHashField(raw))
+    }
+
+    async listAgentIds() {
+        return(await this.cnx.redisSmembers(this.gpsStorage.agentsIndexKey))
+    }
+
+    async loadAllAgents() {
+        const ids = await this.listAgentIds()
+        const agents = new Map()
+        for(const id of ids) {
+            const segment = await this.loadSegment(id)
+            const agent = this.#segmentToAgent(segment)
+            if(agent) agents.set(id, agent)
+        }
+        return(agents)
+    }
+
+    async getAgentPosition(agentId, at) {
+        const segment = await this.loadSegment(agentId)
+        const agent = this.#segmentToAgent(segment)
+        if(!agent) return(null)
+        return(this.buildAgentSnapshot(agent, at))
+    }
+
+}
diff --git a/Observer/observerServer.js b/Observer/observerServer.js
index fc1f480..bb5f4fa 100644
--- a/Observer/observerServer.js
+++ b/Observer/observerServer.js
@@ -1,4 +1,8 @@
 import { AccesRights } from '../accesRights.js'
+import { GpsStorageReader } from './gpsStorageReader.js'
+import { RequestorRegistry } from './requestorRegistry.js'
+import { publishActionReply } from './actionsHelper.js'
+import { SimState } from '../GPS/simulationState.js'
 
 export class observerServer {
 
@@ -11,12 +15,17 @@ export class observerServer {
         this.arenaCnx = null
         this.arenaCnxs = []
         this.systemCnx = null
+        this.gpsStorageReader = null
+        this.requestorRegistry = null
+        this.state = SimState.IDLE
+        this.bigBangEpoch = null
     }
 
     getObserverSettings() {
         const observer = this.observerConfig.observer ?? {}
         return({
             senderId: observer.senderId ?? 'observer',
+            scanIntervalMs: observer.scanIntervalMs ?? 300,
             lifecycle: {
                 arenaChannel: observer.lifecycle?.arenaChannel ?? 'arena:lifecycle',
                 godsReadyChannel: observer.lifecycle?.godsReadyChannel ?? 'arena:gods:ready',
@@ -24,6 +33,70 @@ export class observerServer {
         })
     }
 
+    getGpsStorageSettings() {
+        const gps = this.observerConfig.gps ?? {}
+        return(gps.GPSstorage ?? null)
+    }
+
+    initGpsStorageReader() {
+        const gpsStorage = this.getGpsStorageSettings()
+        if(gpsStorage && this.systemCnx) {
+            this.gpsStorageReader = new GpsStorageReader(this.systemCnx, gpsStorage, this.debug)
+            this.initRequestorRegistry()
+        }
+    }
+
+    initRequestorRegistry() {
+        if(!this.gpsStorageReader || this.requestorRegistry) return
+        const { scanIntervalMs } = this.getObserverSettings()
+        this.requestorRegistry = new RequestorRegistry(
+            this.gpsStorageReader,
+            () => this.now(),
+            scanIntervalMs,
+            (sender, payload) => this.publishFrustumUpdate(sender, payload),
+            this.debug
+        )
+    }
+
+    publishFrustumUpdate(sender, payload) {
+        if(!this.systemCnx || !sender) return
+        const observer = this.observerConfig.observer ?? {}
+        publishActionReply(this.systemCnx, {
+            action: 'GETAGENTSINFRUSTUM',
+            sender,
+            replyChannel: observer.observerActionsReply ?? 'system:replies:[UID]',
+            reply: {
+                success: true,
+                payload,
+            },
+        })
+    }
+
+    isLive() {
+        return(this.state === SimState.LIVE)
+    }
+
+    simNow() {
+        if(this.bigBangEpoch === null) return(null)
+        return((performance.now() - this.bigBangEpoch) / 1000)
+    }
+
+    now() {
+        if(this.isLive()) return(this.simNow())
+        return(null)
+    }
+
+    onYourMarks() {
+        this.state = SimState.PREPARE
+        this.bigBangEpoch = null
+        this.requestorRegistry?.clear()
+    }
+
+    onBigBang() {
+        this.bigBangEpoch = performance.now()
+        this.state = SimState.LIVE
+    }
+
     wireSystemConnexion(cnx) {
         cnx.observerSrv = this
         cnx.accessRights = this.accessRights
@@ -31,6 +104,7 @@ export class observerServer {
         cnx.getAccessRights = () => this.getAccessRights()
         if(!this.systemCnx || cnx.redisConfig.role === 'primary') {
             this.systemCnx = cnx
+            this.initGpsStorageReader()
         }
     }
 
diff --git a/Observer/requestorRegistry.js b/Observer/requestorRegistry.js
new file mode 100644
index 0000000..46d897a
--- /dev/null
+++ b/Observer/requestorRegistry.js
@@ -0,0 +1,187 @@
+import { positionAt } from '../GPS/actions/arena/worldline.js'
+import { Frustum } from './frustum.js'
+
+export class RequestorRegistry {
+
+    constructor(reader, getNow, scanIntervalMs, onPush, debug = false) {
+        this.reader = reader
+        this.getNow = getNow
+        this.scanIntervalMs = scanIntervalMs
+        this.onPush = onPush
+        this.debug = debug
+        this.requestors = new Map()
+    }
+
+    #tickTimer = null
+    #scanInFlight = false
+
+    #adjustFrequency(requestedMs) {
+        if(typeof(requestedMs) !== 'number' || Number.isNaN(requestedMs)) return(null)
+        if(requestedMs < 300 || requestedMs > 10000) return(null)
+        const tickMs = this.scanIntervalMs
+        const ticks = Math.round(requestedMs / tickMs)
+        const minTicks = Math.ceil(300 / tickMs)
+        const maxTicks = Math.floor(10000 / tickMs)
+        const clampedTicks = Math.max(minTicks, Math.min(maxTicks, ticks))
+        return(clampedTicks * tickMs)
+    }
+
+    async subscribeFrustum(id, { planes, frequency }) {
+        if(!id || typeof(id) !== 'string') return({ ok: false, err: 'Invalid requestor id' })
+        const frustum = Frustum.fromPlanes(planes)
+        if(!frustum) return({ ok: false, err: 'Invalid frustum planes' })
+
+        const frequencyMs = this.#adjustFrequency(frequency)
+        if(frequencyMs === null) {
+            return({ ok: false, err: 'Invalid frequency (expected 300–10000 ms)' })
+        }
+
+        const t = this.getNow()
+        if(t === null) return({ ok: false, err: 'Simulation not live' })
+
+        const agents = await this.reader.loadAllAgents()
+        const matching = this.#matchAgents(agents, frustum, t)
+        const pushEveryNTicks = frequencyMs / this.scanIntervalMs
+
+        this.requestors.set(id, {
+            id,
+            frustum,
+            tMode: 'live',
+            subscription: true,
+            frequencyMs,
+            pushEveryNTicks,
+            tickCounter: 0,
+            agents: matching,
+            t,
+            updatedAt: Date.now(),
+        })
+        this.#ensureTick()
+
+        return({
+            ok: true,
+            frequency: frequencyMs,
+            agents: matching,
+            t,
+        })
+    }
+
+    updateRequestor(id, spec) {
+        const requestor = this.requestors.get(id)
+        if(!requestor) return({ ok: false, err: 'Unknown requestor' })
+        if(Array.isArray(spec?.planes)) {
+            const frustum = Frustum.fromPlanes(spec.planes)
+            if(!frustum) return({ ok: false, err: 'Invalid frustum planes' })
+            requestor.frustum = frustum
+        }
+        if(typeof(spec?.frequency) === 'number') {
+            const frequencyMs = this.#adjustFrequency(spec.frequency)
+            if(frequencyMs === null) return({ ok: false, err: 'Invalid frequency (expected 300–10000 ms)' })
+            requestor.frequencyMs = frequencyMs
+            requestor.pushEveryNTicks = frequencyMs / this.scanIntervalMs
+            requestor.tickCounter = 0
+        }
+        return({ ok: true, frequency: requestor.frequencyMs })
+    }
+
+    unregisterRequestor(id) {
+        this.requestors.delete(id)
+        if(this.requestors.size === 0) this.#stopTick()
+        return({ ok: true })
+    }
+
+    getRequestorAgents(id) {
+        const requestor = this.requestors.get(id)
+        if(!requestor) return(null)
+        return({
+            agents: [...requestor.agents],
+            t: requestor.t,
+            frequency: requestor.frequencyMs ?? null,
+            updatedAt: requestor.updatedAt,
+        })
+    }
+
+    clear() {
+        this.requestors.clear()
+        this.#stopTick()
+    }
+
+    async evaluateOnce({ frustum, t }) {
+        if(!frustum || !(frustum instanceof Frustum)) {
+            return({ ok: false, err: 'Invalid frustum', agents: [] })
+        }
+        if(typeof(t) !== 'number' || Number.isNaN(t)) return({ ok: false, err: 'Invalid simulation time', agents: [] })
+        const agents = await this.reader.loadAllAgents()
+        const matching = this.#matchAgents(agents, frustum, t)
+        return({ ok: true, agents: matching, t })
+    }
+
+    #resolveT(requestor) {
+        if(requestor.tMode === 'fixed') return(requestor.fixedT)
+        return(this.getNow())
+    }
+
+    #matchAgents(agents, frustum, t) {
+        const matching = []
+        for(const agent of agents.values()) {
+            const position = positionAt(agent, t)
+            if(!frustum.containsPoint(position)) continue
+            matching.push(this.reader.buildAgentSnapshot(agent, t))
+        }
+        return(matching)
+    }
+
+    #pushUpdate(requestor) {
+        if(typeof(this.onPush) !== 'function') return
+        this.onPush(requestor.id, {
+            agents: [...requestor.agents],
+            t: requestor.t,
+        })
+    }
+
+    async #scanAll() {
+        if(this.#scanInFlight || this.requestors.size === 0) return
+        this.#scanInFlight = true
+        try {
+            const agents = await this.reader.loadAllAgents()
+            for(const requestor of this.requestors.values()) {
+                const t = this.#resolveT(requestor)
+                if(t === null) {
+                    requestor.agents = []
+                    requestor.t = null
+                    requestor.updatedAt = Date.now()
+                    continue
+                }
+                requestor.agents = this.#matchAgents(agents, requestor.frustum, t)
+                requestor.t = t
+                requestor.updatedAt = Date.now()
+
+                if(!requestor.subscription) continue
+
+                requestor.tickCounter++
+                if(requestor.tickCounter >= requestor.pushEveryNTicks) {
+                    requestor.tickCounter = 0
+                    this.#pushUpdate(requestor)
+                }
+            }
+            if(this.debug) console.log(`[Observer] Scanned ${agents.size} agent(s) for ${this.requestors.size} requestor(s)`)
+        } catch(err) {
+            console.error('[Observer] Requestor scan failed:', err)
+        } finally {
+            this.#scanInFlight = false
+        }
+    }
+
+    #ensureTick() {
+        if(this.#tickTimer) return
+        this.#tickTimer = setInterval(() => {
+            this.#scanAll()
+        }, this.scanIntervalMs)
+    }
+
+    #stopTick() {
+        if(!this.#tickTimer) return
+        clearInterval(this.#tickTimer)
+        this.#tickTimer = null
+    }
+
+}
diff --git a/Observer/startObserver.sh b/Observer/startObserver.sh
index 2573af3..cc026a2 100755
--- a/Observer/startObserver.sh
+++ b/Observer/startObserver.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
+set -a
 . /etc/p42/secrets.env
+set +a
 
 daemon=p42Observer
 logfile=observer.log
diff --git a/SimMaestro/arenaGroom.js b/SimMaestro/arenaGroom.js
index 0cd889f..4a69b35 100644
--- a/SimMaestro/arenaGroom.js
+++ b/SimMaestro/arenaGroom.js
@@ -1,22 +1,22 @@
 
 export class ArenaGroom {
 
-    constructor(arenaCnx, storage, debug = false) {
+    constructor(arenaCnx, arenaStorage, debug = false) {
         this.cnx = arenaCnx
-        this.storage = storage
+        this.arenaStorage = arenaStorage
         this.debug = debug
     }
 
     agentHashKey(agentId) {
-        return(this.storage.agentHashKey.replace(/\[UID\]/g, agentId))
+        return(this.arenaStorage.agentHashKey.replace(/\[UID\]/g, agentId))
     }
 
     async clearArena() {
-        const ids = await this.cnx.redisSmembers(this.storage.agentsIndexKey)
+        const ids = await this.cnx.redisSmembers(this.arenaStorage.agentsIndexKey)
         for(const id of ids) {
             await this.cnx.redisDel(this.agentHashKey(id))
         }
-        await this.cnx.redisDel(this.storage.agentsIndexKey)
+        await this.cnx.redisDel(this.arenaStorage.agentsIndexKey)
         if(this.debug) console.log(`[Maestro] Cleared arena store (${ids.length} agent(s))`)
     }
 
@@ -25,7 +25,7 @@ export class ArenaGroom {
             const key = this.agentHashKey(agent.id)
             await this.cnx.redisHset(key, 'position', agent.position)
             await this.cnx.redisHset(key, 'vector', agent.vector)
-            await this.cnx.redisSadd(this.storage.agentsIndexKey, agent.id)
+            await this.cnx.redisSadd(this.arenaStorage.agentsIndexKey, agent.id)
         }
         if(this.debug) console.log(`[Maestro] Groomed ${agents.length} agent(s) into arena store`)
     }
diff --git a/SimMaestro/startMaestro.sh b/SimMaestro/startMaestro.sh
index 559f4cd..b35032c 100755
--- a/SimMaestro/startMaestro.sh
+++ b/SimMaestro/startMaestro.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
+set -a
 . /etc/p42/secrets.env
+set +a
 
 daemon=p42SimMaestro
 logfile=maestro.log
diff --git a/config.json b/config.json
index 8d9e675..084978c 100644
--- a/config.json
+++ b/config.json
@@ -12,7 +12,8 @@
         {
             "canDo": [
                 "GETAGENTPOSITION",
-                "GETAGENTSINPRISM"
+                "GETAGENTSINFRUSTUM",
+                "SUBSCRIBEFRUSTUM"
             ],
             "roles": "*"
         },
@@ -27,7 +28,7 @@
     "gps": {
         "gpsActionsChannel": "system:requests:gps",
         "gpsActionsReply": "system:replies:[UID]",
-        "storage": {
+        "GPSstorage": {
             "agentHashKey": "system:gps:agent:[UID]",
             "agentsIndexKey": "system:gps:agents",
             "positionsStream": "system:gps:positions",
@@ -68,6 +69,7 @@
         "observerActionsChannel": "system:requests:observer",
         "observerActionsReply": "system:replies:[UID]",
         "senderId": "observer",
+        "scanIntervalMs": 300,
         "lifecycle": {
             "arenaChannel": "arena:lifecycle",
             "godsReadyChannel": "arena:gods:ready"
diff --git a/configSchema.json b/configSchema.json
index 4c02853..63a5c42 100644
--- a/configSchema.json
+++ b/configSchema.json
@@ -62,7 +62,7 @@
             "properties": {
                 "gpsActionsChannel": { "type": "string" },
                 "gpsActionsReply": { "type": "string" },
-                "storage": {
+                "GPSstorage": {
                     "type": "object",
                     "properties": {
                         "agentHashKey": { "type": "string" },
@@ -109,7 +109,7 @@
             "required": [
                 "gpsActionsChannel",
                 "gpsActionsReply",
-                "storage",
+                "GPSstorage",
                 "agentVectorChangeChannel",
                 "collisionsChannel"
             ]
@@ -159,6 +159,7 @@
                 "observerActionsChannel": { "type": "string" },
                 "observerActionsReply": { "type": "string" },
                 "senderId": { "type": "string" },
+                "scanIntervalMs": { "type": "integer", "minimum": 50 },
                 "lifecycle": {
                     "type": "object",
                     "properties": {
diff --git a/mysqlClient.js b/mysqlClient.js
index bab229d..6211740 100644
--- a/mysqlClient.js
+++ b/mysqlClient.js
@@ -1,10 +1,12 @@
 import mysql from 'mysql2/promise'
+import { loadP42Secrets } from './secretsLoader.js'
 
 export function resolveMysqlCredentials(config = {}) {
-    const user = process.env.user
+    loadP42Secrets()
+    const user = process.env.mysql_user
     const password = process.env.mysql_pass
     if(!user || !password) {
-        throw new Error('Missing MySQL credentials: set user and mysql_pass in environment')
+        throw new Error('Missing MySQL credentials: set mysql_user and mysql_pass in environment')
     }
     return({
         socketPath: config.socketPath,
diff --git a/secretsLoader.js b/secretsLoader.js
new file mode 100644
index 0000000..8ec7b11
--- /dev/null
+++ b/secretsLoader.js
@@ -0,0 +1,34 @@
+import fs from 'fs'
+
+const DEFAULT_SECRETS_PATH = '/etc/p42/secrets.env'
+
+function stripQuotes(value) {
+    if(
+        (value.startsWith('"') && value.endsWith('"')) ||
+        (value.startsWith("'") && value.endsWith("'"))
+    ) {
+        return(value.slice(1, -1))
+    }
+    return(value)
+}
+
+export function loadP42Secrets(filePath = DEFAULT_SECRETS_PATH) {
+    if(process.env.mysql_user && process.env.mysql_pass) return(true)
+
+    if(!fs.existsSync(filePath)) return(false)
+
+    const text = fs.readFileSync(filePath, 'utf8')
+    for(const rawLine of text.split('\n')) {
+        const line = rawLine.trim()
+        if(!line || line.startsWith('#')) continue
+        const eq = line.indexOf('=')
+        if(eq < 1) continue
+        const key = line.slice(0, eq).trim()
+        const value = stripQuotes(line.slice(eq + 1).trim())
+        if(key === 'mysql_user' || key === 'mysql_pass') {
+            process.env[key] = value
+        }
+    }
+
+    return(Boolean(process.env.mysql_user && process.env.mysql_pass))
+}