feat: dynamic environment filter from observed data

crates/trapfall-core/src/store.rs

@@ -188,6 +188,10 @@ impl Store {
         self.db.count_release_health(project_id, release, env).await
     }
 
+    pub async fn list_environments(&self, project_id: &str) -> Result<Vec<String>> {
+        self.db.list_environments(project_id).await
+    }
+
     // ── Alert Rules ────────────────────────────────────────────────────
 
     pub async fn create_alert_rule(

crates/trapfall-db/src/lib.rs

@@ -258,6 +258,11 @@ pub trait Database: Send + Sync {
     ) -> Result<Vec<crate::common::ReleaseHealthRow>>;
     async fn count_release_health(&self, project_id: &str, release: Option<&str>, env: Option<&str>) -> Result<i64>;
 
+    /// List distinct environment values observed for a project, drawn from
+    /// both `release_health` and `transactions` tables. NULL environments
+    /// are excluded. Ordered alphabetically.
+    async fn list_environments(&self, project_id: &str) -> Result<Vec<String>>;
+
     // ── Alert Rules ────────────────────────────────────────────────────
 
     async fn create_alert_rule(

crates/trapfall-db/src/postgres.rs

@@ -564,6 +564,23 @@ impl Database for PostgresBackend {
         Ok(count)
     }
 
+    async fn list_environments(&self, project_id: &str) -> Result<Vec<String>> {
+        let rows: Vec<(String,)> = sqlx::query_as(
+            "SELECT DISTINCT environment FROM (
+                SELECT environment FROM release_health
+                WHERE project_id = $1 AND environment IS NOT NULL
+                UNION
+                SELECT environment FROM transactions
+                WHERE project_id = $2 AND environment IS NOT NULL
+            ) AS envs ORDER BY environment",
+        )
+        .bind(project_id)
+        .bind(project_id)
+        .fetch_all(&self.pool)
+        .await?;
+        Ok(rows.into_iter().map(|(e,)| e).collect())
+    }
+
     // ── Alert Rules ────────────────────────────────────────────────────
 
     async fn create_alert_rule(

crates/trapfall-db/src/sqlite.rs

@@ -554,6 +554,23 @@ impl Database for SqliteBackend {
         Ok(count)
     }
 
+    async fn list_environments(&self, project_id: &str) -> Result<Vec<String>> {
+        let rows: Vec<(String,)> = sqlx::query_as(
+            "SELECT DISTINCT environment FROM (
+                SELECT environment FROM release_health
+                WHERE project_id = ? AND environment IS NOT NULL
+                UNION
+                SELECT environment FROM transactions
+                WHERE project_id = ? AND environment IS NOT NULL
+            ) AS envs ORDER BY environment",
+        )
+        .bind(project_id)
+        .bind(project_id)
+        .fetch_all(&self.pool)
+        .await?;
+        Ok(rows.into_iter().map(|(e,)| e).collect())
+    }
+
     // ── Alert Rules ────────────────────────────────────────────────────
 
     async fn create_alert_rule(
@@ -1476,6 +1493,55 @@ mod tests {
         assert_eq!(none, 0);
     }
 
+    #[tokio::test]
+    async fn test_list_environments_unions_release_health_and_transactions() {
+        let db = open_backend().await;
+        db.create_project("app", "App").await.unwrap();
+        let project = db.get_project_by_slug("app").await.unwrap().unwrap();
+
+        // release_health contributes `production` + `staging`
+        for env in ["production", "staging"] {
+            let aggregates = trapfall_proto::SessionAggregates {
+                aggregates: vec![trapfall_proto::SessionAggregateItem {
+                    started: "2026-01-01T00:00:00Z".into(),
+                    distinct_id: None,
+                    exited: 1,
+                    errored: 0,
+                    abnormal: 0,
+                    crashed: 0,
+                }],
+                attributes: trapfall_proto::SessionAttributes {
+                    release: "1.0.0".into(),
+                    environment: Some(env.into()),
+                    ip_address: None,
+                    user_agent: None,
+                },
+            };
+            db.insert_release_health(&project.id, &aggregates).await.unwrap();
+        }
+
+        // transactions contribute `development` (verifies UNION across tables)
+        let tx = trapfall_proto::Transaction {
+            event_id: "tx-env-1".into(),
+            level: trapfall_proto::Level::Info,
+            transaction: "GET /".into(),
+            start_timestamp: 1703894474.0,
+            timestamp: 1703894474.5,
+            release: Some("1.0.0".into()),
+            environment: Some("development".into()),
+            spans: vec![],
+            contexts: None,
+            request: None,
+            tags: None,
+            extra: None,
+        };
+        db.insert_transaction(&project.id, &tx).await.unwrap();
+
+        let envs = db.list_environments(&project.id).await.unwrap();
+        // Distinct + sorted alphabetically, NULLs excluded
+        assert_eq!(envs, vec!["development".to_string(), "production".to_string(), "staging".to_string()]);
+    }
+
     #[tokio::test]
     async fn test_crash_rate_calculation() {
         let db = open_backend().await;

crates/trapfalld/src/openapi.yaml

@@ -239,6 +239,37 @@ paths:
         "404":
           description: Not found
 
+  # ── Environments ───────────────────────────────────────────────
+
+  /api/0/projects/{slug}/environments:
+    get:
+      tags: [Projects]
+      summary: List distinct environments for a project
+      description: >
+        Returns distinct `environment` values observed across the project's
+        release-health sessions and transactions, ordered alphabetically.
+        Powers the dynamic environment filter in the dashboard. NULL
+        environments are excluded.
+      operationId: listEnvironments
+      parameters:
+        - name: slug
+          in: path
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: Distinct environment values
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  type: string
+                example: ["development", "production", "staging"]
+        "404":
+          description: Project not found
+
   # ── Issues ──────────────────────────────────────────────────────
 
   /api/0/projects/{slug}/issues:

crates/trapfalld/src/server.rs

@@ -156,6 +156,7 @@ pub fn router(state: AppState) -> Router {
         .route("/api/0/projects/{slug}/search", get(search_issues))
         .route("/api/0/projects/{slug}/release-health/crash-rate", get(get_crash_rate))
         .route("/api/0/projects/{slug}/release-health", get(list_release_health))
+        .route("/api/0/projects/{slug}/environments", get(list_environments))
         .route("/api/0/projects/{slug}/transactions", get(list_transactions))
         .route("/api/0/projects/{slug}/transactions/slowest", get(get_slowest_transactions))
         .route("/api/0/projects/{slug}/transactions/{txn_id}", get(get_transaction))
@@ -895,6 +896,27 @@ async fn list_release_health(
     Ok(Json(ListResponse { data, total, page, per_page: limit as u32 }))
 }
 
+/// List distinct environments observed for a project (release_health +
+/// transactions). Powers the dynamic environment filter in the dashboard.
+async fn list_environments(
+    State(state): State<AppState>,
+    Path(slug): Path<String>,
+) -> Result<Json<Vec<String>>, StatusCode> {
+    let store = state.store.clone();
+    let project = store
+        .get_project_by_slug(&slug)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    let envs = store.list_environments(&project.id).await.map_err(|e| {
+        tracing::warn!(error = %e, project_slug = %slug, "list_environments failed");
+        StatusCode::INTERNAL_SERVER_ERROR
+    })?;
+
+    Ok(Json(envs))
+}
+
 async fn get_crash_rate(
     State(state): State<AppState>,
     Path(slug): Path<String>,

web/src/lib/api.ts

@@ -310,6 +310,10 @@ class ApiClient {
 		if (env) path += `&env=${encodeURIComponent(env)}`;
 		return this.get<CrashRateResponse>(path);
 	}
+
+	async listEnvironments(projectSlug: string): Promise<string[]> {
+		return this.get<string[]>(`/projects/${projectSlug}/environments`);
+	}
 }
 
 

web/src/routes/(dashboard)/release-health/+page.svelte

@@ -29,13 +29,25 @@
 	let error = $state('');
 	let filterRelease: string = $state('');
 	let filterEnv: string = $state('');
+	let environments: string[] = $state([]);
 	let debounceTimer: ReturnType<typeof setTimeout> | undefined = undefined;
 
-	const envOptions = [
-		{ value: '', label: 'All' },
-		{ value: 'production', label: 'Production' },
-		{ value: 'development', label: 'Development' }
-	];
+	// Dynamic environment filter options. Built from distinct environments
+	// observed in the DB (release-health + transactions), plus "All".
+	// The active filter is always present even if not yet loaded from the API
+	// (e.g. restored from a URL param before the fetch resolves).
+	let envOptions = $derived.by(() => {
+		const opts = [{ value: '', label: 'All' }];
+		const seen = new Set<string>();
+		for (const env of environments) {
+			opts.push({ value: env, label: env });
+			seen.add(env);
+		}
+		if (filterEnv && !seen.has(filterEnv)) {
+			opts.push({ value: filterEnv, label: filterEnv });
+		}
+		return opts;
+	});
 
 	let aggregateExited: number = $derived(sessions.reduce((s, r) => s + r.exited, 0));
 	let aggregateErrored: number = $derived(sessions.reduce((s, r) => s + r.errored, 0));
@@ -56,6 +68,15 @@
 		}
 	}
 
+	async function loadEnvironments() {
+		if (!selectedProject) return;
+		try {
+			environments = await api.listEnvironments(selectedProject);
+		} catch {
+			environments = [];
+		}
+	}
+
 	async function loadSessions() {
 		if (!selectedProject) return;
 		loading = true;
@@ -90,6 +111,7 @@
 	}
 
 	function loadData() {
+		loadEnvironments();
 		loadCrashRate();
 		loadSessions();
 	}