diff --git a/AGENTS.md b/AGENTS.md
index a0ab0c2..1e11b77 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -4,10 +4,11 @@ Odin + raylib interactive 3D universe map (DESI data), a Rust + axum API, with G
 
 ## Commands
 The root `Makefile` is a lean delegator: base commands (`run`, `build`, `test`, ...) forward into the per-project Makefiles in `gui/`, `api/`, and `infra/`. Project-specific commands are reached via `make -C <dir> <target>`.
-- Run: `make run`; Build: `make build` (`-> bin/desi_explorer`); Web: `make build-web` (Emscripten/WASM -> `build/web`); Debug: `make build-debug`
+- Run: `make run`; Build: `make build` (`-> bin/desi_explorer`); Web: `make build-web` (Emscripten/WASM -> `build/web`); Debug: `make build-debug`; Run Web: `make run-web` (WASM build + API server)
 - Test: `make test` (runs `odin test` in gui/, `cargo test` in api/, `go test` in infra/); Clean: `make clean`; Format: `make fmt`
 - API: `make api-run`, `make api-test`, `make api-check` (thin passthroughs to `make -C api <target>`)
-- Setup: `make setup` (submodules + `go mod tidy` in infra/)
+- Setup: `make setup` (submodules + gui lib/local + `cargo fetch` + `go mod tidy` in infra/)
+- Add dependency: `make -C gui add-dep DEP=<name>` (searches Codeberg/GitHub/GitLab, adds as submodule to `gui/lib/local/`)
 - Infra: `make infra-preview`, `make infra-up`, `make infra-down`, `make infra-refresh` (passthroughs to `make -C infra <target>`)
 - Renovate: `make renovate-validate` (npx renovate-config-validator)
 - Format Odin with `odinfmt` (config `gui/odinfmt.json`: tabs, width 80); format Rust with `cargo fmt`
diff --git a/Makefile b/Makefile
index efc5735..f4c2f0b 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ GUI          := gui
 API          := api
 INFRA        := infra
 
-.PHONY: help setup run build build-debug build-web test clean fmt \
+.PHONY: help setup run run-web build build-debug build-web test clean fmt \
         renovate-validate
 
 help: ## List available targets
@@ -23,24 +23,37 @@ help: ## List available targets
 
 ## ---- Setup ---------------------------------------------------------------
 
-setup: ## Pull submodules + tidy Go deps
+setup: ## Setup all sub-projects (submodules, gui deps, api deps, infra deps)
 	@git submodule update --init --recursive
+	@$(MAKE) -C $(GUI) setup
+	@$(MAKE) -C $(API) setup
 	@$(MAKE) -C $(INFRA) tidy
 
 ## ---- Renderer (Odin) -----------------------------------------------------
 
 run: ## Run the native app (gui/)
-	@$(MAKE) -C $(GUI) run
+	@$(MAKE) -C $(API) run & api_pid=$$!; \
+	trap 'kill $$api_pid 2>/dev/null' INT TERM EXIT; \
+	$(MAKE) -C $(GUI) run; \
+	kill $$api_pid 2>/dev/null
 
-build: ## Release build -> bin/desi_explorer (gui/)
+build: ## Release build (gui/ + api/)
 	@$(MAKE) -C $(GUI) build
+	@$(MAKE) -C $(API) build
 
-build-debug: ## Debug build -> bin/desi_explorer (gui/)
+build-debug: ## Debug build (gui/ + api/)
 	@$(MAKE) -C $(GUI) build-debug
+	@$(MAKE) -C $(API) build
 
 build-web: ## WebAssembly build -> build/web (gui/, needs emscripten)
 	@$(MAKE) -C $(GUI) build-web
 
+run-web: ## Start WASM build + API server for web dev
+	@$(MAKE) -C $(API) run & api_pid=$$!; \
+	trap 'kill $$api_pid 2>/dev/null' INT TERM EXIT; \
+	$(MAKE) -C $(GUI) build-web; \
+	kill $$api_pid 2>/dev/null
+
 ## ---- Aggregates ----------------------------------------------------------
 
 test: ## Test all projects (odin + cargo + go)
diff --git a/api/Makefile b/api/Makefile
index 87ad652..36d94a7 100644
--- a/api/Makefile
+++ b/api/Makefile
@@ -5,12 +5,15 @@
 
 CARGO ?= cargo
 
-.PHONY: help run build test check fmt clean
+.PHONY: help setup run build test check fmt clean
 
 help: ## List available targets
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | \
 		awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[36m%-18s\033[0m %s\n", $$1, $$2}'
 
+setup: ## Fetch dependencies
+	$(CARGO) fetch
+
 run: ## Run the API server (dev)
 	$(CARGO) run
 
diff --git a/gui/Makefile b/gui/Makefile
index c90d7de..84951f2 100644
--- a/gui/Makefile
+++ b/gui/Makefile
@@ -14,12 +14,21 @@ BINARY       := $(BIN)/desi_explorer
 ODIN_FLAGS   := -collection:lib=lib/local
 WASM_DEFINE  := RAYLIB_WASM_LIB=env.o
 
-.PHONY: help run build build-debug build-web test clean fmt
+.PHONY: help setup add-dep run build build-debug build-web test clean fmt
 
 help: ## List available targets
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | \
 		awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[36m%-18s\033[0m %s\n", $$1, $$2}'
 
+setup: ## Prepare build environment (lib/local)
+	@mkdir -p lib/local
+
+add-dep: ## Add a dependency from Codeberg/GitHub/GitLab as a submodule (DEP=name)
+ifndef DEP
+	$(error Usage: make add-dep DEP=<dependency-name>)
+endif
+	@scripts/add_dep.sh "$(DEP)"
+
 run: ## Run the native app
 	@mkdir -p lib/local
 	$(ODIN) run src $(ODIN_FLAGS)
diff --git a/gui/scripts/add_dep.sh b/gui/scripts/add_dep.sh
new file mode 100755
index 0000000..799a0eb
--- /dev/null
+++ b/gui/scripts/add_dep.sh
@@ -0,0 +1,151 @@
+#!/usr/bin/env bash
+# Search Codeberg, GitHub, and GitLab for an Odin dependency and add it
+# as a git submodule under gui/lib/local/.  Run via `make -C gui add-dep`.
+#
+# Usage:  add_dep.sh <dependency-name>
+#
+# Requires: curl, jq
+# Optional: fzf (interactive selector; falls back to numbered menu)
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+GUI_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
+ROOT_DIR="$(cd "${GUI_DIR}/.." && pwd)"
+LIB_DIR="${GUI_DIR}/lib/local"
+
+# ---- Args ------------------------------------------------------------------
+
+if [[ $# -lt 1 ]]; then
+  echo "Usage: $0 <dependency-name>" >&2
+  exit 1
+fi
+
+QUERY="$1"
+
+# ---- Helpers ---------------------------------------------------------------
+
+TMPDIR_WORK="$(mktemp -d)"
+trap 'rm -rf "${TMPDIR_WORK}"' EXIT
+
+RESULTS="${TMPDIR_WORK}/results"
+touch "$RESULTS"
+
+search_codeberg() {
+  local url
+  url="https://codeberg.org/api/v1/repos/search?q=$(printf '%s' "$QUERY" | jq -sRr @uri)&limit=10"
+  local data
+  data=$(curl -sf --max-time 10 "$url" 2>/dev/null) || return 0
+  printf '%s' "$data" | jq -r '.data[]? | [.owner.username, .name, "codeberg", (.description // "")] | @tsv' 2>/dev/null \
+    | while IFS=$'\t' read -r owner name _ desc; do
+        printf '%s\t%s\t%s\t%s\n' "$owner" "$name" "codeberg" "$desc"
+      done >> "$RESULTS"
+}
+
+search_github() {
+  local url
+  url="https://api.github.com/search/repositories?q=$(printf '%s' "$QUERY" | jq -sRr @uri)&per_page=10"
+  local data
+  data=$(curl -sf --max-time 10 -H "Accept: application/vnd.github+json" "$url" 2>/dev/null) || return 0
+  printf '%s' "$data" | jq -r '.items[]? | [.owner.login, .name, "github", (.description // "")] | @tsv' 2>/dev/null \
+    | while IFS=$'\t' read -r owner name _ desc; do
+        printf '%s\t%s\t%s\t%s\n' "$owner" "$name" "github" "$desc"
+      done >> "$RESULTS"
+}
+
+search_gitlab() {
+  local url
+  url="https://gitlab.com/api/v4/projects?search=$(printf '%s' "$QUERY" | jq -sRr @uri)&per_page=10"
+  local data
+  data=$(curl -sf --max-time 10 "$url" 2>/dev/null) || return 0
+  printf '%s' "$data" | jq -r '.[]? | [.namespace.full_path, .name, "gitlab", (.description // "")] | @tsv' 2>/dev/null \
+    | while IFS=$'\t' read -r owner name _ desc; do
+        printf '%s\t%s\t%s\t%s\n' "$owner" "$name" "gitlab" "$desc"
+      done >> "$RESULTS"
+}
+
+# ---- Search (Codeberg → GitHub → GitLab) -----------------------------------
+
+echo "Searching for '${QUERY}'..." >&2
+
+search_codeberg
+search_github
+search_gitlab
+
+TOTAL=$(wc -l < "$RESULTS" | tr -d ' ')
+
+if [[ "$TOTAL" -eq 0 ]]; then
+  echo "No results found for '${QUERY}' on Codeberg, GitHub, or GitLab." >&2
+  exit 1
+fi
+
+# ---- Select ----------------------------------------------------------------
+
+SELECTED=""
+
+if command -v fzf >/dev/null 2>&1; then
+  SELECTED=$(while IFS=$'\t' read -r owner name forge desc; do
+    printf '%-20s %-30s [%s]  %s\n' "$owner" "$name" "$forge" "$desc"
+  done < "$RESULTS" \
+    | fzf --prompt="Select dependency > " \
+          --header="${TOTAL} result(s) for '${QUERY}'" \
+          --height=40% \
+          --reverse)
+else
+  echo "" >&2
+  echo "Results for '${QUERY}':" >&2
+  echo "---" >&2
+  IDX=0
+  while IFS=$'\t' read -r owner name forge desc; do
+    IDX=$((IDX + 1))
+    printf '  %2d) %-20s %-30s [%s]  %s\n' "$IDX" "$owner" "$name" "$forge" "$desc" >&2
+  done < "$RESULTS"
+  echo "---" >&2
+  printf 'Select [1-%d]: ' "$TOTAL" >&2
+  read -r CHOICE
+
+  if ! [[ "$CHOICE" =~ ^[0-9]+$ ]] || [[ "$CHOICE" -lt 1 ]] || [[ "$CHOICE" -gt "$TOTAL" ]]; then
+    echo "Invalid selection." >&2
+    exit 1
+  fi
+  SELECTED=$(sed -n "${CHOICE}p" "$RESULTS")
+fi
+
+if [[ -z "$SELECTED" ]]; then
+  echo "No selection made." >&2
+  exit 1
+fi
+
+# ---- Parse & Add -----------------------------------------------------------
+
+ENTRYowner=$(printf '%s' "$SELECTED" | cut -f1)
+ENTRYname=$(printf '%s' "$SELECTED" | cut -f2)
+ENTRYforge=$(printf '%s' "$SELECTED" | cut -f3)
+
+case "$ENTRYforge" in
+  codeberg) URL="https://codeberg.org/${ENTRYowner}/${ENTRYname}.git" ;;
+  github)   URL="https://github.com/${ENTRYowner}/${ENTRYname}.git" ;;
+  gitlab)   URL="https://gitlab.com/${ENTRYowner}/${ENTRYname}.git" ;;
+esac
+
+MODULE_PATH="lib/local/${ENTRYname}"
+
+# Check for name collisions (same dir, different repo).
+if [[ -d "${GUI_DIR}/${MODULE_PATH}" ]]; then
+  EXISTING=$(git -C "${ROOT_DIR}" config --get "submodule.${MODULE_PATH}.url" 2>/dev/null || true)
+  if [[ -n "$EXISTING" ]]; then
+    echo "Dependency '${ENTRYname}' is already installed from ${EXISTING}." >&2
+    exit 1
+  fi
+  echo "Error: '${MODULE_PATH}' already exists but is not a submodule." >&2
+  exit 1
+fi
+
+echo "Adding ${ENTRYowner}/${ENTRYname} (${ENTRYforge}) as submodule..." >&2
+
+mkdir -p "${LIB_DIR}"
+git -C "${ROOT_DIR}" submodule add "$URL" "$MODULE_PATH"
+
+echo "" >&2
+echo "Done — added ${ENTRYowner}/${ENTRYname} from ${ENTRYforge}" >&2
+echo "  path: ${MODULE_PATH}" >&2
+echo "  The Makefile's -collection:lib=lib/local will pick it up automatically." >&2