strom

move usdc and sol from solana to near in one signature. no gas token needed.

strom by seedless · live at strom.seedlesslabs.xyz · installable as an app (pwa)

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the problem

moving money from solana to near today takes three apps and four steps: swap on a dex, find a bridge, pay gas on both sides, then wait and hope it lands. you also need sol in your wallet for gas before you can move anything at all.

strom turns that into one screen and one approval:

• one signature. the swap, the fee and the bridge transfer ride in a single solana transaction.
• no gas token. a relayer pays the solana network fee. you pay it back out of what you send: in usdc if you send usdc, in sol if you send sol.
• non-custodial. strom never holds your money and never signs for you. your wallet approves every move, and funds go from your wallet straight to your near account.
• plain words. a small ai layer turns "swap 10 usdc to near" into a filled-in swap. it reads only. you still approve in your wallet.
• both ways. near back to sol on solana goes through near intents and 1click, also with one approval.

proven on mainnet

run	what happened
usdc → near	swap, usdc fee and bridge transfer in one tx. finalised on near in 81s, 0.2703 near on the user's intents account at 84s. user sol spent: 0
sol → near	0.001 sol in. fee 0.00012 sol paid in sol, no usdc held. tx 44EH2Y…qKq6, 1151 bytes. +0.0202 near on intents 87s later
near → sol	0.2703 near → 0.0116 sol back in the solana wallet in 114s, one signed intent. tx 5qmy…7GyG

how a swap works

solana → near (one solana transaction)

sequenceDiagram
  participant U as your wallet
  participant S as strom (browser)
  participant K as /api/kora (relayer proxy)
  participant J as jupiter
  participant O as omni bridge
  participant N as near intents
  S->>J: quote usdc/sol → bridged near (3ZLek)
  S->>S: build one v0 tx: fee + jupiter swap + omni init_transfer
  S->>K: estimate fee (simulated real cost)
  S->>U: approve one transaction
  U-->>S: signed
  S->>K: signAndSend
  K->>K: checks: programs, fee, payer not touched
  K->>O: relayer co-signs as fee payer, sends
  O->>N: bridge finalises, near credited to your account

Loading

1. quote. jupiter quotes your usdc or sol into near as it lives on solana (mint 3ZLek…9wBG, bridged by the omni bridge).
2. build. src/lib/buildSwap.ts puts three things in one transaction:
   • the relayer fee (a usdc transfer, or a sol transfer when sol goes in)
   • the jupiter swap instructions
   • omni init_transfer to near, with the bridge fee taken out of the bridged near, so you need no native token on either side
3. fit. solana caps a transaction at 1232 bytes. strom compresses accounts with jupiter's lookup tables plus its own (6wsh…21iZi). if a route is still too big, it asks jupiter for a smaller one, down to a single pool.
4. sign. your wallet signs once, through the wallet standard. any solana wallet that supports it works.
5. send. the relayer co-signs as fee payer and sends. the omni relayer picks up the transfer and finalises it on near. #/track follows it to the end.

near → solana (one near intent)

src/lib/near.ts: 1click quotes near → sol, your solana wallet signs one transfer intent for your near implicit account, strom simulates it against intents.near, publishes it to the solver relay, and 1click delivers sol to your solana address.

the root cause we fixed on the way

the omni relayer reads solana transactions as v0 or legacy only, and resolves the token, sender and emitter of init_transfer from the static account keys. a v1 transaction, or a v0 one with those accounts in a lookup table, is never indexed and the transfer sits unfinalised. strom builds v0 and masks those three accounts out of every lookup table so they stay static (keepStatic in buildSwap.ts). reported upstream: Near-One/bridge-sdk-rs#331. v1 support is kept behind txVersion: 1 for when the relayer reads it.

fees

	who pays	amount
solana network fee	the relayer, paid back by you	simulated real cost × 1.2, never under $0.01
fee currency	you choose by what you send	usdc in → usdc fee · sol in → sol fee
bridge fee	taken from the bridged near	quoted live by the omni api
swap	jupiter routing, 0.5% slippage cap	market

below the bridge fee, strom says "amount too small" before you sign. above your balance, it says how much you can send. a small reserve (0.005 sol or 0.01 usdc) stays back for the fee.

the relayer is guarded

the relayer pays real sol, so api/kora.ts only signs a transaction that looks exactly like strom's own:

• only three methods: getPayerSigner, estimateTransactionFee, signAndSendTransaction
• every top-level program is on an allow list (compute budget, token, token-2022, ata, system, memo, jupiter v6, omni), and the omni bridge must be in it
• the fee payer is used for fees and nothing else: no instruction may move its funds, except to receive the wsol rent back or the sol fee
• every send must carry a fee to the payer that covers what the transaction really costs it, found by simulation
• strom runs its own fee payer, used by nothing else. it holds a small balance, so the most it could ever lose is small
• it signs last, only after every check above passes and your wallet has signed
• spend caps: at most 0.005 sol of real cost per swap, a floor it never goes below, a daily ceiling
• per-ip limit (20/min), a vercel firewall rate rule on top, a body cap
• the payer key lives in server env only, never in the browser bundle

the solana rpc goes through api/rpc.ts, also rate limited, so the rpc key stays server-side too.

the ai layer ("tell strom")

#/agent takes plain words: "swap 10 usdc to near", "how much near for 1 sol", "where is my money".

• api/agent.ts asks a model through vercel ai gateway for a structured intent (kind, dir, tok, amt)
• src/lib/agent.ts runs every answer through a guard (clean) and falls back to a local parser if the server is slow or down
• the result is only ever a link into strom's own swap or track page. it never signs, never sends, and refuses tokens strom does not move

pages

route	what it is
#/	home: what strom does in one screen
#/swap	the swap, both directions, with your balance and a max button
#/track	follows a transfer step by step until it lands
#/agent	tell strom in plain words
#/how	how it works, in plain english
#/builders	addresses, programs and apis, for developers
#/about	who builds it

light and dark themes, works on a phone, installs as an app.

code map

api/
  kora.ts        relayer proxy: checks, fee pricing, rate limits
  rpc.ts         solana rpc proxy, rate limited
  agent.ts       plain words → intent, via vercel ai gateway
src/lib/
  buildSwap.ts   one-tx builder: fee + jupiter + omni, v0 + lookup tables, route fallback
  omni.ts        omni init_transfer instruction, matched byte for byte to the official sdk
  jupiter.ts     quote + swap instructions
  kora.ts        relayer client, fee instructions
  near.ts        near implicit account, intents, 1click, solver relay
  flow.ts        both money flows as plain steps, balances
  agent.ts       guard + local parser
  config.ts      mints, programs, apis, limits
src/pages/       the seven pages
src/ui/          shell, lockup, prose
scripts/         checks and runs (below)

run it

npm install
cp .env.example .env.local   # fill in the server-only keys if you run the api locally
npm run dev

npm run build type-checks and builds. deploys go out with vercel --prod.

env	where	what
VITE_SOLANA_RPC	browser	rpc for reads (defaults to the /api/rpc proxy)
VITE_KORA_URL	browser	relayer url, unset = /api/kora
VITE_NEAR_RECIPIENT	browser	default near recipient, intents.near
STROM_PAYER_KEY	server	strom's own fee payer keypair (64-byte json array). never VITE_
KORA_DAILY_LAMPORTS	server	daily spend cap per instance, optional (default 0.1 sol)
SOLANA_RPC	server	rpc the proxies use
AI_GATEWAY_API_KEY	server	local dev only; on vercel the deployment oidc token is used
STROM_GATEWAY_MODEL	server	model id, optional

checks

command	proves	cost
npm run check:omni	strom's init_transfer matches the official omni sdk byte for byte	no network
npm run check:fork	the full to-near tx on a local mainnet fork: build, co-sign, send	$0, throwaway keys
npm run check:near	near → sol libs against mainnet: implicit account, live quote, signed intent accepted, tampered signature rejected	read-only, nothing moves
scripts/live-run.ts	both directions with real funds, end to end	~$1, keys kept outside the repo

built with

jupiter · omni bridge · near intents + 1click · a kora-style relayer · @solana/kit · wallet standard · vercel ai gateway · react + vite

who

built by seedless, the team behind the seedless money app on solana. github: seedless-labs.

mit license, © Seedless Labs, Inc. see LICENSE.