Indexing / Data·EVM · Solana · Multi-chain
Sim by Dune
Realtime onchain developer platform from Dune. One API key unlocks pre-enriched balances, token metadata, prices, NFTs, and activity feeds across 60+ EVM chains and Solana with sub-200ms data availability after block propagation.
- 01wallet pages with multi-chain balances
- 02token metadata and price lookups
- 03real-time activity feeds
- 04NFT collectibles for a wallet
- 05transaction history APIs
- pnpm add axios
| Variable | Scope | Description |
|---|---|---|
| SIM_API_KEY | Server | Sim API key from sim.dune.com. Sent as the `X-Sim-Api-Key` header. Server-side only. |
Hit the Sim REST API from a server route with the `X-Sim-Api-Key` header. Base URL: `https://api.sim.dune.com/v1`. Core endpoints: `GET /evm/balances/{address}?chain_ids=1,8453,42161` (multi-chain ERC20 + native), `GET /evm/activity/{address}` (decoded activity feed), `GET /evm/transactions/{address}`, `GET /evm/collectibles/{address}` (NFTs), `GET /evm/token-info/{chain_id}/{contract}` (metadata + price). For Solana swap `/evm/` for `/svm/` (e.g. `GET /svm/balances/{address}`). Responses include cursor-based pagination — pass `next_offset` from the previous response. Cache aggressively per (address, chain_ids) tuple; data refreshes within 200ms of block, but you don't need to refetch every render.
- ⚑Sim is a separate product from Dune Analytics — `SIM_API_KEY` is NOT the same as `DUNE_API_KEY`, and Sim does NOT execute SQL queries (use Dune for that).
- ⚑Free tier has monthly compute-unit caps and per-second rate limits; high-traffic wallet pages need a paid plan or aggressive caching.
- ⚑Chain coverage is 60+ EVM chains and Solana — Bitcoin, Cosmos, Sui, Aptos, NEAR are NOT supported; verify the chain at docs.sim.dune.com/chains before promising a feature.
- ⚑Activity and transaction feeds are decoded best-effort — for very new contracts (< 24h after deploy) decoding may fall back to raw logs until Sim ingests the ABI.
- ⚑Pagination is cursor-based via `next_offset`; do NOT assume offset/limit semantics or you'll skip rows during a reorg or miss new data on subsequent polls.