diff --git a/backend/src/Controller/FeedbackController.php b/backend/src/Controller/FeedbackController.php
new file mode 100644
index 0000000..fab3199
--- /dev/null
+++ b/backend/src/Controller/FeedbackController.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace App\Controller;
+
+use App\Entity\CoastalPoint;
+use App\Entity\UserFeedback;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Routing\Attribute\Route;
+
+#[Route('/api/feedback', name: 'api_feedback_')]
+class FeedbackController extends AbstractController
+{
+    public function __construct(private EntityManagerInterface $em) {}
+
+    /**
+     * POST /api/feedback
+     *
+     * Corps attendu :
+     * {
+     *   "lat": 14.65,
+     *   "lng": -61.05,
+     *   "hasSeaweed": true,
+     *   "density": "medium",      // optionnel : low|medium|high
+     *   "coastalPointId": "uuid"  // optionnel
+     * }
+     */
+    #[Route('', name: 'create', methods: ['POST'])]
+    public function create(Request $request): JsonResponse
+    {
+        $data = json_decode($request->getContent(), true);
+
+        if (!is_array($data)) {
+            return $this->json(['error' => 'Invalid JSON body'], 400);
+        }
+
+        // Validation minimale
+        if (!isset($data['lat'], $data['lng'], $data['hasSeaweed'])) {
+            return $this->json(['error' => 'Missing required fields: lat, lng, hasSeaweed'], 422);
+        }
+
+        $lat = filter_var($data['lat'], FILTER_VALIDATE_FLOAT);
+        $lng = filter_var($data['lng'], FILTER_VALIDATE_FLOAT);
+
+        if ($lat === false || $lng === false) {
+            return $this->json(['error' => 'lat and lng must be valid floats'], 422);
+        }
+
+        if ($lat < -90 || $lat > 90 || $lng < -180 || $lng > 180) {
+            return $this->json(['error' => 'lat/lng out of valid range'], 422);
+        }
+
+        $feedback = new UserFeedback();
+        $feedback->setLocation(sprintf('SRID=4326;POINT(%f %f)', $lng, $lat));
+        $feedback->setHasSeaweed((bool) $data['hasSeaweed']);
+
+        if (isset($data['density']) && in_array($data['density'], ['low', 'medium', 'high'], true)) {
+            $feedback->setDensity($data['density']);
+        }
+
+        // Fingerprint anonyme : IP hachée (pas de données personnelles)
+        $ip = $request->getClientIp() ?? 'unknown';
+        $feedback->setSource(hash('sha256', $ip . date('Y-m-d')));
+
+        if (!empty($data['coastalPointId'])) {
+            $spot = $this->em->getRepository(CoastalPoint::class)->find($data['coastalPointId']);
+            if ($spot !== null) {
+                $feedback->setCoastalPoint($spot);
+            }
+        }
+
+        $this->em->persist($feedback);
+        $this->em->flush();
+
+        return $this->json(['id' => (string) $feedback->getId()], 201);
+    }
+}
diff --git a/backend/src/Controller/ObservationController.php b/backend/src/Controller/ObservationController.php
new file mode 100644
index 0000000..41c5623
--- /dev/null
+++ b/backend/src/Controller/ObservationController.php
@@ -0,0 +1,126 @@
+<?php
+
+namespace App\Controller;
+
+use Doctrine\DBAL\Connection;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Routing\Attribute\Route;
+
+#[Route('/api/observations', name: 'api_observations_')]
+class ObservationController extends AbstractController
+{
+    public function __construct(private Connection $connection) {}
+
+    /**
+     * GET /api/observations
+     *
+     * Paramètres optionnels :
+     *   ?bbox=minLon,minLat,maxLon,maxLat   filtre spatial PostGIS
+     *   ?date=YYYY-MM-DD                    filtre sur detected_at
+     *   ?source=Sentinel-2                  filtre sur source
+     */
+    #[Route('', name: 'collection', methods: ['GET'])]
+    public function collection(Request $request): JsonResponse
+    {
+        $sql = <<<SQL
+            SELECT
+                id,
+                detected_at       AS "detectedAt",
+                source,
+                tile_id           AS "tileId",
+                cloud_coverage    AS "cloudCoverage",
+                confidence,
+                afai_mean         AS "afaiMean",
+                afai_std          AS "afaiStd",
+                coverage_area     AS "coverageArea",
+                processing_version AS "processingVersion",
+                created_at        AS "createdAt",
+                ST_AsGeoJSON(geometry)::json AS geometry,
+                ST_AsGeoJSON(bbox)::json     AS bbox
+            FROM sargassum_observation
+            WHERE 1=1
+        SQL;
+
+        $params = [];
+        $types  = [];
+
+        // Filtre bbox
+        $bboxParam = $request->query->get('bbox');
+        if ($bboxParam !== null) {
+            $parts = array_map('floatval', explode(',', $bboxParam));
+            if (count($parts) === 4) {
+                [$minLon, $minLat, $maxLon, $maxLat] = $parts;
+                $sql .= ' AND ST_Intersects(geometry, ST_MakeEnvelope(:minLon, :minLat, :maxLon, :maxLat, 4326))';
+                $params['minLon'] = $minLon;
+                $params['minLat'] = $minLat;
+                $params['maxLon'] = $maxLon;
+                $params['maxLat'] = $maxLat;
+            }
+        }
+
+        // Filtre date
+        $dateParam = $request->query->get('date');
+        if ($dateParam !== null) {
+            $sql .= ' AND detected_at::date = :date::date';
+            $params['date'] = $dateParam;
+        }
+
+        // Filtre source
+        $sourceParam = $request->query->get('source');
+        if ($sourceParam !== null) {
+            $sql .= ' AND source = :source';
+            $params['source'] = $sourceParam;
+        }
+
+        $sql .= ' ORDER BY detected_at DESC LIMIT 100';
+
+        $rows = $this->connection->fetchAllAssociative($sql, $params, $types);
+
+        // Décoder les champs JSON imbriqués
+        foreach ($rows as &$row) {
+            $row['geometry'] = $row['geometry'] ? json_decode($row['geometry'], true) : null;
+            $row['bbox']     = $row['bbox']     ? json_decode($row['bbox'], true)     : null;
+        }
+
+        return $this->json(['items' => $rows, 'total' => count($rows)]);
+    }
+
+    /**
+     * GET /api/observations/{id}
+     */
+    #[Route('/{id}', name: 'item', methods: ['GET'])]
+    public function item(string $id): JsonResponse
+    {
+        $sql = <<<SQL
+            SELECT
+                id,
+                detected_at       AS "detectedAt",
+                source,
+                tile_id           AS "tileId",
+                cloud_coverage    AS "cloudCoverage",
+                confidence,
+                afai_mean         AS "afaiMean",
+                afai_std          AS "afaiStd",
+                coverage_area     AS "coverageArea",
+                processing_version AS "processingVersion",
+                created_at        AS "createdAt",
+                ST_AsGeoJSON(geometry)::json AS geometry,
+                ST_AsGeoJSON(bbox)::json     AS bbox
+            FROM sargassum_observation
+            WHERE id = :id
+        SQL;
+
+        $row = $this->connection->fetchAssociative($sql, ['id' => $id]);
+
+        if ($row === false) {
+            return $this->json(['error' => 'Observation not found'], 404);
+        }
+
+        $row['geometry'] = $row['geometry'] ? json_decode($row['geometry'], true) : null;
+        $row['bbox']     = $row['bbox']     ? json_decode($row['bbox'], true)     : null;
+
+        return $this->json($row);
+    }
+}
diff --git a/backend/src/Controller/SpotScoreController.php b/backend/src/Controller/SpotScoreController.php
new file mode 100644
index 0000000..ece6077
--- /dev/null
+++ b/backend/src/Controller/SpotScoreController.php
@@ -0,0 +1,67 @@
+<?php
+
+namespace App\Controller;
+
+use App\Entity\CoastalPoint;
+use App\Entity\ImpactScore;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Routing\Attribute\Route;
+
+#[Route('/api/spots', name: 'api_spots_')]
+class SpotScoreController extends AbstractController
+{
+    public function __construct(private EntityManagerInterface $em) {}
+
+    /**
+     * GET /api/spots/{id}/score
+     *
+     * Retourne le score courant pour un CoastalPoint.
+     * Paramètre optionnel : ?at=YYYY-MM-DDTHH:MM:SSZ (score à un instant donné)
+     */
+    #[Route('/{id}/score', name: 'score', methods: ['GET'])]
+    public function score(string $id, Request $request): JsonResponse
+    {
+        $spot = $this->em->getRepository(CoastalPoint::class)->find($id);
+
+        if ($spot === null) {
+            return $this->json(['error' => 'Spot not found'], 404);
+        }
+
+        $qb = $this->em->getRepository(ImpactScore::class)
+            ->createQueryBuilder('s')
+            ->where('s.coastalPoint = :spot')
+            ->setParameter('spot', $spot)
+            ->orderBy('s.timestamp', 'DESC')
+            ->setMaxResults(1);
+
+        $atParam = $request->query->get('at');
+        if ($atParam !== null) {
+            try {
+                $at = new \DateTimeImmutable($atParam);
+                $qb->andWhere('s.timestamp <= :at')->setParameter('at', $at);
+            } catch (\Exception) {
+                return $this->json(['error' => 'Invalid "at" parameter format'], 400);
+            }
+        }
+
+        $latest = $qb->getQuery()->getOneOrNullResult();
+
+        return $this->json([
+            'spotId'  => (string) $spot->getId(),
+            'name'    => $spot->getName(),
+            'type'    => $spot->getType(),
+            'region'  => $spot->getRegion(),
+            'score'   => $latest ? [
+                'value'       => $latest->getScore(),
+                'level'       => $latest->getLevel(),
+                'distance'    => $latest->getDistanceToNearestSargassum(),
+                'density'     => $latest->getDensityEstimate(),
+                'trend'       => $latest->getTrend(),
+                'computedAt'  => $latest->getTimestamp()?->format(\DateTimeInterface::ATOM),
+            ] : null,
+        ]);
+    }
+}
diff --git a/backend/src/Entity/CoastalPoint.php b/backend/src/Entity/CoastalPoint.php
index d33ebee..b106cdc 100644
--- a/backend/src/Entity/CoastalPoint.php
+++ b/backend/src/Entity/CoastalPoint.php
@@ -6,6 +6,7 @@ use ApiPlatform\Metadata\ApiResource;
 use ApiPlatform\Metadata\Get;
 use ApiPlatform\Metadata\GetCollection;
 use App\Repository\CoastalPointRepository;
+use Symfony\Component\Serializer\Annotation\Groups;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
@@ -16,10 +17,13 @@ use Symfony\Component\Uid\Uuid;
 #[ORM\Index(columns: ['type'], name: 'idx_coastal_type')]
 #[ORM\Index(columns: ['region'], name: 'idx_coastal_region')]
 #[ApiResource(
+    shortName: 'Spot',
     operations: [
         new GetCollection(),
         new Get(),
-    ]
+    ],
+    normalizationContext: ['groups' => ['spot:read']],
+    order: ['name' => 'ASC'],
 )]
 class CoastalPoint
 {
@@ -30,15 +34,19 @@ class CoastalPoint
     private ?Uuid $id = null;
 
     #[ORM\Column(length: 150)]
+    #[Groups(['spot:read'])]
     private ?string $name = null;
 
     #[ORM\Column(type: 'geometry', options: ['geometry_type' => 'POINT', 'srid' => 4326])]
+    #[Groups(['spot:read'])]
     private mixed $geometry = null;
 
     #[ORM\Column(length: 30)]
+    #[Groups(['spot:read'])]
     private ?string $type = null;
 
     #[ORM\Column(length: 100)]
+    #[Groups(['spot:read'])]
     private ?string $region = null;
 
     #[ORM\OneToMany(targetEntity: ImpactScore::class, mappedBy: 'coastalPoint')]
diff --git a/backend/src/Entity/SargassumForecast.php b/backend/src/Entity/SargassumForecast.php
index 52b844d..97f5058 100644
--- a/backend/src/Entity/SargassumForecast.php
+++ b/backend/src/Entity/SargassumForecast.php
@@ -14,6 +14,7 @@ use Symfony\Component\Uid\Uuid;
 #[ORM\Index(columns: ['valid_at'], name: 'idx_forecast_valid_at')]
 #[ORM\Index(columns: ['time_horizon'], name: 'idx_forecast_horizon')]
 #[ApiResource(
+    shortName: 'Forecast',
     operations: [
         new GetCollection(),
         new Get(),
diff --git a/backend/src/Entity/SargassumObservation.php b/backend/src/Entity/SargassumObservation.php
index 7e95a28..18b0214 100644
--- a/backend/src/Entity/SargassumObservation.php
+++ b/backend/src/Entity/SargassumObservation.php
@@ -2,9 +2,6 @@
 
 namespace App\Entity;
 
-use ApiPlatform\Metadata\ApiResource;
-use ApiPlatform\Metadata\Get;
-use ApiPlatform\Metadata\GetCollection;
 use App\Repository\SargassumObservationRepository;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
@@ -16,12 +13,6 @@ use Symfony\Component\Uid\Uuid;
 #[ORM\Entity(repositoryClass: SargassumObservationRepository::class)]
 #[ORM\Index(columns: ['detected_at'], name: 'idx_observation_detected_at')]
 #[ORM\Index(columns: ['source'], name: 'idx_observation_source')]
-#[ApiResource(
-    operations: [
-        new GetCollection(),
-        new Get(),
-    ]
-)]
 class SargassumObservation
 {
     #[ORM\Id]
diff --git a/docs/roadmap.md b/docs/roadmap.md
index 63fccbb..f6e5d7f 100644
--- a/docs/roadmap.md
+++ b/docs/roadmap.md
@@ -56,9 +56,13 @@
 
 ### API Backend
 
-- [ ] `GET /api/spots` — liste CoastalPoints
-- [ ] `GET /api/spots/{id}` — détail
-- [ ] `GET /api/observations?bbox=&date=` — observations par zone
+- [x] `GET /api/spots` — liste CoastalPoints (API Platform)
+- [x] `GET /api/spots/{id}` — détail (API Platform)
+- [x] `GET /api/spots/{id}/score` — score + niveau + trend
+- [x] `GET /api/observations?bbox=&date=&source=` — PostGIS ST_Intersects
+- [x] `GET /api/observations/{id}` — détail avec geometry GeoJSON
+- [x] `GET /api/forecasts` — API Platform
+- [x] `POST /api/feedback` — feedback anonyme (IP hachée)
 
 ### Frontend React