Euler Lite

Overview

Euler Lite provides all the core functionality of Euler Finance in a customizable package:

• Lending & Borrowing: Users can deposit assets to earn yield or borrow against collateral
• Portfolio Management: Track positions and performance
• Rewards: Participate in Merkl, Incentra, and Fuul reward programs
• Multi-chain Support: Connect to multiple EVM-compatible networks

Prerequisites

• Node.js 24.22.1 (see .nvmrc)
• npm 11.20.0 (pinned in package.json, CI and the Docker build)
• Git
• A Reown Project ID for AppKit wallet connections - get one at reown.com

Quick Start

1. Clone and Install

git clone <repository-url>
cd euler-lite
npm install --global npm@11.20.0
npm ci

2. Environment Configuration

Copy .env.example to .env and fill in your values:

cp .env.example .env

Required Variables

Variable	Description
APPKIT_PROJECT_ID or NUXT_PUBLIC_APP_KIT_PROJECT_ID	Reown (WalletConnect) project ID
NUXT_PUBLIC_APP_URL	Your app's public URL
RPC_URL_<chainId>	RPC endpoint per chain (e.g. RPC_URL_1 for Ethereum)
SUBGRAPH_CATALOG_URL or SUBGRAPH_URL_<chainId>	Subgraph source for each enabled chain: an active entry in the selected catalog, or an explicit URL. NUXT_PUBLIC_SUBGRAPH_URI_<chainId> is also supported. Explicit URLs take priority; all settings stay server-side.

API URLs

Variable	Default	Description
V3_API_URL	https://v3.euler.finance	Euler V3 upstream used by the server /api/internal/v3 proxy
DISABLE_V3	false	Explicitly disables V3 adapters, proxying, image discovery and V3 utility reads. Requires static labels. Alias: EULER_SDK_DISABLE_V3. See Fork setup.
EULER_SDK_V3_API_KEY	—	Optional server-side V3 API key forwarded by /api/internal/v3 as X-API-Key
SWAP_API_URL or NUXT_PUBLIC_SWAP_API_URL	—	Euler swap API
PYTH_API_KEY	—	Server-side API key sent to https://hermes.pyth.network as Bearer authentication by /api/internal/pyth/updates

Doppler compatibility: If your secret manager injects prefixed URL names, the server also accepts EULER_SDK_V3_API_URL and NUXT_PUBLIC_V3_API_URL. API keys use server-side names such as EULER_SDK_V3_API_KEY, PYTH_API_KEY, and TURTLE_EARN_API_KEY.

SDK Data Source Controls

Euler Lite uses the Euler V2 SDK for vault reads, portfolio data, prices, rewards, and transaction plans. These controls select which SDK adapter path is used for cached browsing reads and the server-side vault snapshot:

Variable	Default	Description
SERVER_VAULT_CACHE_SOURCE	fallback	Server snapshot builder adapter chain: fallback, onchain, or v3.
NUXT_PUBLIC_BROWSER_VAULT_SOURCE	fallback	Browser "fast" SDK adapter chain: fallback, onchain, or v3. The plan-time SDK is always on-chain.
DISABLE_SERVER_VAULT_CACHE	false	Set to true to disable /api/internal/vaults snapshots and let the browser fall through to the normal RPC pipeline.
DEPRECATED_CHAINS	—	Optional comma-separated deprecated-chain override. Enabled chains marked deprecated here or in EulerChains.json appear collapsed in the chain selector, skip warm-cache cycles, and use V3 metadata with on-chain labels verification. They must also be in ONCHAIN_SDK_CHAINS.
ONCHAIN_SDK_CHAINS	—	Comma-separated chain IDs pinned to the onchain SDK adapter config for chain-aware browser reads and the server vault snapshot, bypassing V3. Independent of deprecated status; include every enabled chain using metadata-only labels verification.
EVAULT_FETCH_CHUNK_CHAINS	—	Comma-separated chain IDs whose EVault list reads are split into small sequential SDK calls. Use for RPC/lens endpoints that fail under larger concurrent onchain EVault fetches.
EULER_SDK_EULER_INTERFACES_BRANCH	master	Euler interfaces branch used for runtime ABIs and EulerChains.json. Explicit NUXT_PUBLIC_CONFIG_EULER_CHAINS_URL and NUXT_PUBLIC_CONFIG_EULER_ABIS_BASE_URL overrides take precedence over the branch for their respective manifests.

fallback uses V3 first and on-chain reads second. If no V3 URL is configured, Lite passes disableV3: true to the SDK so fallback reads go straight on-chain.

Optional Server Controls

Variable	Description
CORS_ALLOWED_ORIGINS	Comma-separated allowlist for /api/*; falls back to NUXT_PUBLIC_APP_URL.
FIRST_PARTY_COOKIE_SECRET	Optional server-only secret that keeps the internal API marker cookie stable across replicas and deploys. Defaults to a value derived from NUXT_PUBLIC_APP_URL when configured, otherwise a random value per process.
CSP_EXTRA_CONNECT_SRC	Extra connect-src origins for development or staging endpoints.
DEV_GEO_COUNTRY	Local/preview country fallback when the edge provides no country. Production (DOPPLER_ENVIRONMENT=prd) refuses to boot with it set.
ADDRESS_SCREENING_URI / ADDRESS_SCREENING_API_KEY	Server-side data-v3 compliance endpoint + restricted API key, proxied by /api/internal/screen-address (also serves first-party *.euler.finance SPAs). Both unset ⇒ screening disabled (all addresses pass) — except in production (DOPPLER_ENVIRONMENT=prd), where missing configuration fails closed; only one set ⇒ fails closed everywhere. URI must be https (localhost http allowed for dev).
MERKL_API_KEY	Optional server-side Merkl key. The Merkl API works anonymously (10 req/sec shared across all users via /api/internal/proxy/merkl); set this to send X-API-Key upstream for a higher quota. Server-only — never exposed to the browser.
TENDERLY_ACCESS_KEY, TENDERLY_ACCOUNT_SLUG, TENDERLY_PROJECT_SLUG	Optional Tenderly simulation configuration.
FUUL_API_URL or NUXT_PUBLIC_FUUL_API_URL	Optional Fuul API upstream override.
INCENTRA_API_URL or NUXT_PUBLIC_INCENTRA_API_URL	Optional Incentra/Brevis API upstream override.
LABELS_SOURCE	v3 (default) or static; selects the shared label snapshot producer.
LABELS_VAULT_TAG	Optional exact, case-sensitive tag for discovery and new-target suggestions, e.g. base or governance limited. Blank disables tag filtering.
STATIC_LABELS_BASE_URL	Required directory URL for static authoring files; unused by hosted V3 mode.
LABELS_IMAGE_ORIGINS	Optional comma-separated HTTP(S) origins for hosted label images in the UI and public metadata, in addition to the configured custom V3 origin and Euler's image hosts.
LIQUIDATION_BOT_API_URL	Optional default liquidation bot API with a {chainId} placeholder, e.g. https://{chainId}-liquidations.euler.finance. When set, the server reads each enabled chain's /vault-filter and borrowable vaults the bot does not cover get a "Not covered by default liquidation bot" badge in lists and portfolio rows and a notice on the vault overview. A chain whose bot has not answered since the server started, or whose last answer is more than 30 minutes old, counts as having no bot, so all its borrowable vaults get the badge. Unset disables the feature. HTTPS only (localhost HTTP allowed for dev). Server-only.
TURTLE_EARN_API_KEY	Required when NUXT_PUBLIC_CONFIG_ENABLE_TURTLE is on. Server-only Turtle Earn API key sent as X-API-Key by /api/internal/proxy/turtle and by the server-side SDK's rewards adapters (server/utils/sdk-server.ts), which call Turtle directly for stream discovery. Turtle rejects unauthenticated requests with 401; without this variable the proxy answers 503 and never calls upstream, and the server SDK disables direct Turtle discovery (rewardsEnableTurtle: false) instead of issuing unauthenticated calls, so reward proofs and claims are unavailable. Turtle campaigns sourced from euler-data-v3 may still appear in snapshots and APYs, because the flag only gates the SDK's direct adapter. Configure the secret before rolling out. Never exposed to the browser.

Branding & Feature Flags

These settings use NUXT_PUBLIC_CONFIG_* env vars. Branding and announcement values are read by the server at startup and injected into window.__APP_CONFIG__; links and feature flags use Nuxt's public runtimeConfig. The server proxy handlers resolve the upstream source overrides.

Variable	Default	Description
NUXT_PUBLIC_CONFIG_APP_TITLE	Euler Lite	App title (SEO, meta tags)
NUXT_PUBLIC_CONFIG_APP_DESCRIPTION	Lightweight interface for Euler Finance.	App description
NUXT_PUBLIC_CONFIG_LOGO_URL	—	Custom logo URL (falls back to built-in Euler logo)
NUXT_PUBLIC_CONFIG_SOCIAL_IMAGE_URL	—	Absolute URL to social share image (og:image / twitter:image), 1200×630+
NUXT_PUBLIC_CONFIG_EULER_CHAINS_URL	—	Explicit URL for EulerChains.json; takes precedence over the Euler interfaces branch
NUXT_PUBLIC_CONFIG_EULER_ABIS_BASE_URL	—	Base URL serving {contract}.json for runtime ABIs; takes precedence over the Euler interfaces branch.
NUXT_PUBLIC_CONFIG_DOCS_URL	—	Documentation link
NUXT_PUBLIC_CONFIG_TOOLBOX_URL	—	Toolbox link
NUXT_PUBLIC_CONFIG_RISK_ANALYTICS_URL	—	Risk & Analytics link
NUXT_PUBLIC_CONFIG_STARGATE_URL	—	Stargate link
NUXT_PUBLIC_CONFIG_TOS_URL	—	Terms of Service link
NUXT_PUBLIC_CONFIG_TOS_MD_URL	—	TOS markdown URL (enables TOS signing when set)
NUXT_PUBLIC_CONFIG_PRIVACY_POLICY_URL	https://www.euler.finance/privacy-policy	Privacy policy link
NUXT_PUBLIC_CONFIG_RISK_DISCLOSURES_URL	https://www.euler.finance/risk-disclosures	Risk disclosures link
NUXT_PUBLIC_CONFIG_MICA_WHITEPAPER_URL	https://www.euler.finance/MICA-Whitepaper.pdf	MiCA whitepaper link
NUXT_PUBLIC_CONFIG_X_URL	—	X (Twitter) link
NUXT_PUBLIC_CONFIG_DISCORD_URL	—	Discord link
NUXT_PUBLIC_CONFIG_TELEGRAM_URL	—	Telegram link
NUXT_PUBLIC_CONFIG_GITHUB_URL	—	GitHub link
NUXT_PUBLIC_CONFIG_ENABLE_EARN_PAGE	true	Show Earn page
NUXT_PUBLIC_CONFIG_ENABLE_LEND_PAGE	true	Show Lend page
NUXT_PUBLIC_CONFIG_ENABLE_EXPLORE_PAGE	true	Show Explore page
NUXT_PUBLIC_CONFIG_ENABLE_ENTITY_BRANDING	true	Show entity branding
NUXT_PUBLIC_CONFIG_ENABLE_VAULT_TYPE	true	Show vault type labels
NUXT_PUBLIC_CONFIG_ENABLE_APP_TITLE	true	Show app title in the navbar
NUXT_PUBLIC_CONFIG_ENABLE_POWERED_BY_EULER	true	Show the Powered by Euler branding in the navbar
NUXT_PUBLIC_CONFIG_ENABLE_MERKL	true	Enable Merkl rewards integration
NUXT_PUBLIC_CONFIG_ENABLE_INCENTRA	true	Enable Incentra rewards integration
NUXT_PUBLIC_CONFIG_ENABLE_FUUL	true	Enable Fuul rewards integration
NUXT_PUBLIC_CONFIG_ENABLE_TURTLE	true	Enable Turtle rewards integration
NUXT_PUBLIC_CONFIG_ANNOUNCEMENT_TITLE	—	Optional one-time modal title; any announcement content field enables the modal
NUXT_PUBLIC_CONFIG_ANNOUNCEMENT_BODY	—	Optional one-time modal body text
NUXT_PUBLIC_CONFIG_ANNOUNCEMENT_ITEMS	—	Optional newline-delimited or JSON-array bullet items
NUXT_PUBLIC_CONFIG_ANNOUNCEMENT_URL	—	Optional announcement link (https://, http://, or safe root-relative path)
NUXT_PUBLIC_CONFIG_UNISWAP_TOKEN_LIST_URL	https://tokens.uniswap.org	Uniswap token list for swap selector
NUXT_PUBLIC_CONFIG_DEFILLAMA_TOKEN_LIST_URL	https://d3g10bzo9rdluh.cloudfront.net	DefiLlama token list for swap selector

At server startup, short CONFIG_ANNOUNCEMENT_* names take precedence over the corresponding NUXT_PUBLIC_CONFIG_ANNOUNCEMENT_* names. In Nitro-served deployments, both naming forms are read at server startup, so updates require a server restart without rebuilding client assets. Generated/static deployments must rebuild when NUXT_PUBLIC_CONFIG_ANNOUNCEMENT_* fallback values change. To disable an announcement, clear both naming forms for all four content fields. See Announcement Modal for rollout and dismissal behavior.

Chain Configuration

Chains are configured dynamically at runtime. Set one RPC URL per chain and select a subgraph source. .env.example selects Euler's published catalog, which supplies endpoints for its active chain entries:

SUBGRAPH_CATALOG_URL=https://raw.githubusercontent.com/euler-xyz/euler-subgraph/catalog/v1/catalog.json
SUBGRAPH_CATALOG_DISABLED=false

# Ethereum Mainnet
RPC_URL_1=https://your-rpc-endpoint.com

# Arbitrum
RPC_URL_42161=https://your-arbitrum-rpc.com

The app scans RPC_URL_<chainId> variables at server startup; catalog membership does not enable a chain. Browser SDK subgraph reads use /api/internal/proxy/subgraph/<chainId>. Per-chain disabling takes priority, followed by SUBGRAPH_URL_<chainId>, its compatibility alias NUXT_PUBLIC_SUBGRAPH_URI_<chainId>, then the selected catalog. Leave both URL aliases unset for chains managed by the catalog.

Forks can replace the catalog URL or use only their own direct endpoints. For direct-only operation, clear SUBGRAPH_CATALOG_URL, set SUBGRAPH_CATALOG_DISABLED=true to prevent bundled server SDK fallback, and configure the intended per-chain URLs. Clear or replace any existing Euler URL overrides as well. See Your own subgraphs for copyable examples and disable behaviour.

A chain also needs an entry in euler-interfaces EulerChains.json, and both the pinned @eulerxyz/euler-v2-sdk and @reown/appkit/networks must support it. When they already do, adding a chain needs no code change; otherwise it needs a dependency bump and a release. See Adding a Chain for the full checklist.

The chain's status in EulerChains.json decides whether an enabled chain is shown: production chains are shown, staging chains only where DOPPLER_ENVIRONMENT is not prd, deprecated chains in the chain selector's deprecated section (like DEPRECATED_CHAINS), and unlisted chains not at all.

Base App In-App Browser

Euler Lite remains a normal multichain web app, but it supports opening inside the Base App in-app browser. The wallet flow prefers the injected Base App provider when it is available, then falls back to the standard Reown AppKit modal for all other browsers and wallets.

With the catalog configured above and an active Base entry, add Base mainnet's RPC:

RPC_URL_8453=https://your-base-rpc.com

Use SUBGRAPH_URL_8453 only to pin an explicit compatible endpoint instead of the catalog entry.

3. Customize Your Instance

Theme Colors (assets/styles/variables.scss)

All colors are defined as CSS custom properties in variables.scss. The file has a clearly marked THEME CONFIGURATION section at the top — change these values to restyle the entire app:

// — Brand Accent (buttons, links, focus rings, highlights) —
--accent-500: #1c997c;          // Main accent color
--accent-rgb: 28, 153, 124;    // RGB components (for alpha variants)

// — Status Colors —
--success-500: #62ad4f;
--warning-500: #ecc033;
--error-500: #c02723;

Key design principles:

• RGB companion variables (--accent-rgb, --success-rgb, etc.) — all rgba() values throughout the app derive from these automatically
• Chart colors (--chart-*) — 15 variables controlling Chart.js canvas rendering, with light/dark overrides
• Graph colors (--graph-*) — 5 variables controlling SVG topology visualizations
• Accent shadows (--accent-glow, --accent-shadow-*) — auto-derived from --accent-rgb
• Dark theme — all variables are overridden in the [data-theme="dark"] section at the bottom of the file

The useThemeColors composable bridges CSS variables into JavaScript for Chart.js by reading computed styles from document.body. It uses useTheme() for reactivity so chart re-renders happen after the DOM data-theme attribute updates.

Logo

The app logo is rendered by components/base/LogoBrand.vue. By default it displays the Euler logo as an inline SVG using currentColor, so it automatically follows the theme's accent color.

To use a custom logo, set the LOGO_URL environment variable (or NUXT_PUBLIC_CONFIG_LOGO_URL). If the custom logo fails to load, the app falls back to the default Euler logo.

Intrinsic APY Sources

Intrinsic APY is populated by the Euler V2 SDK through the V3 backend and exposed on fetched vault entities as intrinsicApy. Lite enables this in utils/sdk-fetch-options.ts; provider coverage is configured upstream in V3. See Intrinsic APY for the current data flow.

Favicon

Replace the favicon files in public/favicons/:

• favicon.ico
• favicon.svg

Token Icons

Token icons are resolved from a unified server-side token list that aggregates the Euler SDK token list, DefiLlama, Uniswap, and Merkl. All sources are fetched in parallel with 5-minute caching and stale-fallback resilience. Euler SDK entries take priority for vault assets.

To override an icon for a specific token, add a file to assets/tokens/:

assets/tokens/
  eul.png       # overrides the EUL token icon
  mytoken.png   # overrides MYTOKEN icon

The resolution order in getAssetLogoUrl(address, symbol):

1. Local override in assets/tokens/<symbol>.png
2. logoURI from the unified token list (Euler SDK token list > DefiLlama > Uniswap > Merkl)
3. Empty string (component shows initials fallback)

Public Labels

Vault inventory, products, entities, hosted logos, tags, campaigns, and deprecation metadata come from the versioned Public Labels API at V3_API_URL. Lite resolves version=latest to one immutable publication before fetching a chain bundle and follows every paginated list through meta.total.

Hosted labels, visibility and geo policies come exclusively from V3. Fork deployments can set LABELS_SOURCE=static and provide their own authoring files through STATIC_LABELS_BASE_URL. Start with Fork setup for complete examples using your own V3, static labels, or static labels without V3. See Static labels for the authoring format and failure semantics.

4. Development

npm run dev

The app will be available at http://localhost:3000.

For HTTPS in local development, set HTTPS_KEY and HTTPS_CERT env vars pointing to your certificate files.

Development with the SDK

The committed dependency uses the npm version in package.json and package-lock.json. Keep those files pinned to a published @eulerxyz/euler-v2-sdk version unless the PR is intentionally updating the SDK dependency.

For local Lite + SDK development, link the sibling SDK package without editing Lite package files:

cd ../euler-sdks/packages/euler-v2-sdk
pnpm run build
npm link

cd ../../../euler-lite
npm link @eulerxyz/euler-v2-sdk
npm ls @eulerxyz/euler-v2-sdk --depth=0
npm run dev

Rebuild the SDK after SDK source changes:

cd ../euler-sdks/packages/euler-v2-sdk
pnpm run build

Return Lite to the committed npm package before final validation:

cd ../../../euler-lite
npm ci
npm ls @eulerxyz/euler-v2-sdk --depth=0

5. Build for Production

npm run build
npm run preview   # preview locally

Docker Deployment

The project includes a Dockerfile that uses Doppler for runtime secret injection:

docker build --build-arg APP_PORT=3000 -t euler-lite .

docker run -p 3000:3000 \
  -e DOPPLER_TOKEN=your-doppler-token \
  -e DOPPLER_PROJECT=euler-lite \
  -e DOPPLER_CONFIG=production \
  euler-lite

Doppler injects all environment variables at runtime. The server plugins scan the injected env vars and pass config to the client via window.__APP_CONFIG__ and window.__CHAIN_CONFIG__.

The Docker build uses the npm SDK version from package-lock.json by default. For a Lite PR that needs an unreleased SDK branch, pass the SDK branch as a build argument:

docker build \
  --build-arg EULER_SDK_BRANCH=feat/sdk-branch \
  --build-arg APP_PORT=3000 \
  -t euler-lite .

When EULER_SDK_BRANCH is set, the builder clones euler-xyz/euler-sdks, builds packages/euler-v2-sdk, packs it, and installs that tarball with --no-save before running the Lite build. The committed Lite package files still point at the installed npm version.

The SDK preview build installs pnpm@10 by default. Set EULER_SDK_PNPM_VERSION if the SDK branch requires another pnpm version.

To run without Doppler, override the CMD and pass env vars directly:

docker run -p 3000:3000 \
  -e V3_API_URL=https://v3.euler.finance \
  -e EULER_SDK_V3_API_KEY=your-v3-api-key \
  -e SWAP_API_URL=https://swap.euler.finance \
  -e APPKIT_PROJECT_ID=your-project-id \
  -e RPC_URL_1=https://your-rpc.com \
  -e SUBGRAPH_CATALOG_URL=https://raw.githubusercontent.com/euler-xyz/euler-subgraph/catalog/v1/catalog.json \
  euler-lite node .output/server/index.mjs

Project Structure

assets/
  styles/variables.scss    # Theme config + CSS variables (edit top section to restyle)
  tokens/                  # Token icon overrides
components/
  base/LogoBrand.vue       # App logo (inline SVG default, env var override, error fallback)
  ...                      # Vue components organized by feature
composables/
  useEnvConfig.ts          # Runtime env config (API URLs, Pyth, Reown, logo)
  useDeployConfig.ts       # Branding, social links, feature flags
  useThemeColors.ts        # Bridges CSS color variables into Chart.js
  useChainConfig.ts        # Dynamic chain derivation from env vars
  useEulerConfig.ts        # Aggregated config for Euler services
  useTokenList.ts          # Unified token list and icon resolution
  useEulerTx.ts            # SDK TransactionPlan builders, simulation, and execution
entities/
  account.ts               # Account and position helpers
  chainRegistry.ts         # Supported-chain lookup helpers
  constants.ts             # Shared protocol/API constants
utils/
  vault/                   # Vault classification, APY, LTV, and verification helpers
pages/                     # Nuxt pages/routes
plugins/
  00.wagmi.ts              # Wagmi/Reown wallet configuration
public/
  favicons/                # Favicon files
  logo.svg                 # Default logo (uses currentColor for theme-awareness)
server/
  plugins/app-config.ts    # Injects env config into HTML (incl. logo URL)
  plugins/chain-config.ts  # Injects chain config into HTML

Available Scripts

Command	Description
npm run dev	Start development server
npm run build	Build for production
npm run preview	Preview production build locally
npm run generate	Generate static site
npm run lint	Run ESLint
npm run lint:fix	Run ESLint with auto-fix
npm run test	Run unit tests (watch mode)
npm run test:run	Run unit tests (single pass)
npm run typecheck	Type-check the project
npm run postinstall	Prepare Nuxt (runs automatically)

Configuration Checklist

Before deploying:

• Copied .env.example to .env and filled in values
• Set APPKIT_PROJECT_ID and NUXT_PUBLIC_APP_URL
• Set V3_API_URL, optional EULER_SDK_V3_API_KEY, and SWAP_API_URL
• Set TURTLE_EARN_API_KEY if Turtle rewards stay enabled (NUXT_PUBLIC_CONFIG_ENABLE_TURTLE), otherwise Turtle reward proofs return 503 and the server SDK skips Turtle stream discovery
• Added at least one RPC_URL_<chainId> and verified an active catalog entry with SUBGRAPH_CATALOG_URL set, or configured an explicit SUBGRAPH_URL_<chainId> / NUXT_PUBLIC_SUBGRAPH_URI_<chainId>
• Configured branding via NUXT_PUBLIC_CONFIG_* env vars (title, description, logo, social links, social share image)
• Customized theme colors in assets/styles/variables.scss (THEME CONFIGURATION section)
• Replaced favicon files in public/favicons/
• Added token icon overrides in assets/tokens/ (if needed)

Troubleshooting

Token logos not loading

• Verify V3_API_URL is set correctly. If the V3 deployment requires authentication, verify EULER_SDK_V3_API_KEY is set. If using Doppler, ensure the URL env var name matches (V3_API_URL, EULER_SDK_V3_API_URL, or NUXT_PUBLIC_V3_API_URL).
• Token data is fetched server-side via /api/internal/token-list which aggregates Euler V3, DefiLlama, Uniswap, and Merkl sources with fallback. Check server logs for upstream failures.

Turtle rewards missing or claims failing

• The Turtle Earn API requires an API key. Confirm TURTLE_EARN_API_KEY is set on the server; the /api/internal/proxy/turtle route logs reason: missing-api-key and answers 503 when it is not.
• A 502 with upstream failed and status: 401 in the logs means Turtle rejected the configured key (revoked or wrong environment).
• Without the key the server SDK is built with rewardsEnableTurtle: false, which disables the SDK's direct Turtle discovery only. The server SDK runs in fallback mode (euler-data-v3 primary), so Turtle campaigns sourced from V3 can remain visible in vault snapshots (/api/internal/vaults) and APYs while proof requests through the proxy fail with 503. Visible campaigns therefore do not prove the key is set; check the proxy logs.
• Turtle campaigns missing from snapshots is not by itself a missing-key symptom. It also happens when euler-data-v3 is failing or has no active Turtle streams. If the key was the cause, fix the env and restart; each chain's SDK is cached on first use (normally during startup warm-up).

Build Errors

• Ensure Node.js version is 24.22.1 (see .nvmrc)
• Clear and reinstall: rm -rf node_modules && npm ci

Wallet Connection Issues

• Verify APPKIT_PROJECT_ID is correct (or NUXT_PUBLIC_APP_KIT_PROJECT_ID for Doppler)
• Ensure NUXT_PUBLIC_APP_URL matches your domain
• Check browser console for errors

No Chains Available

• Ensure at least one RPC_URL_<chainId> env var is set
• For subgraph discovery, verify an active entry in the catalog selected by SUBGRAPH_CATALOG_URL, or an explicit SUBGRAPH_URL_<chainId> / NUXT_PUBLIC_SUBGRAPH_URI_<chainId>. Subgraph configuration does not enable chains.
• Check the chain's status in EulerChains.json: unlisted chains are always hidden, and staging chains are hidden when DOPPLER_ENVIRONMENT=prd

Additional Resources

• Nuxt.js Documentation
• Reown (WalletConnect) Documentation
• Euler Finance Documentation

License

MIT — see the LICENSE file.