> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adipredictstreet.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Deposits overview
> How USDC moves from your associated EOA into your on-chain vault, and how long the platform takes to credit available balance.
A **deposit** moves USDC from your associated EOA into your on-chain
vault, where it becomes spendable as `available` balance and is
required collateral for placing BUY orders. It is always a
**user-initiated on-chain transaction** — neither the platform nor a
partner API key can pull funds out of an EOA without the owner's
authorisation.
## Prerequisites
| Requirement | How to satisfy |
| --------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
| Vault deployed for your EOA | Auto-deployed by the platform — see [Backend auto-deploy](/concepts/vaults/auto-deploy). Verify with `GET /api/me/vault` (`deployed: true`). |
| USDC in the EOA | Buy / bridge on-chain per your partner runbook. |
| ERC-20 allowance | Your EOA must have called `USDC.approve(vault, X)` for at least `X = depositAmount`. `MaxUint256` is the standard one-time pattern. |
| Within deposit limits | The platform pre-initialises per-EOA daily / weekly / monthly caps — see [Deposit limits](/concepts/deposits/limits). |
## End-to-end flow
```mermaid theme={null}
sequenceDiagram
participant E as EOA
participant V as Vault contract
participant USDC as USDC ERC-20
participant CORE as core-api
E->>USDC: approve(vault, MaxUint256) (one-time)
Note over E: skip if already approved
E->>V: depositERC20(USDC, amount)
V->>USDC: transferFrom(eoa → vault, amount)
V-->>V: ledger += amount; cap-check passes
V-->>CORE: DepositedERC20 event indexed
Note over CORE: ~1 block lag
CORE-->>E: GET /api/me/balances → available += amount
```
## Step 1 — `approve` (once per vault)
```typescript theme={null}
import { Contract, MaxUint256 } from 'ethers';
const usdc = new Contract(
'0x9cb8142aEBBcdc60AF7c97Af897A67A8f3CA71C2',
['function approve(address,uint256) returns (bool)'],
eoa,
);
await (await usdc.approve(vault, MaxUint256, { gasLimit: 100_000n })).wait();
```
`MaxUint256` saves gas on every future deposit. Tighten to a per-deposit
allowance if your security model requires it — the trade-off is one
extra `approve` per deposit.
## Step 2 — `depositERC20`
```typescript theme={null}
import { Contract, parseUnits } from 'ethers';
const v = new Contract(
vault,
['function depositERC20(address token, uint256 amount)'],
eoa,
);
await (await v.depositERC20(
'0x9cb8142aEBBcdc60AF7c97Af897A67A8f3CA71C2',
parseUnits('500', 6), // 500 USDC (6 decimals)
{ gasLimit: 600_000n },
)).wait();
```
Inside the tx the vault calls `transferFrom(eoa → vault)`, increments
its internal collateral ledger by `amount`, and checks the deposit-cap
windows in `DepositLimitRegistry` before settling. If the cap would be
exceeded, the tx reverts with `DepositCapExceeded()` — see
[Deposit limits](/concepts/deposits/limits).
## Step 3 — wait for the platform to credit
After the deposit tx mines, the platform indexes the on-chain event
and credits `exchange.balances.available` for your associated EOA.
End-to-end latency from mined tx to credited balance is typically
**well under 1 second** in production (chain-watcher streams events
sub-second) and **a few seconds** on mainnet (indexer batches
confirmations into the ledger). Plan UI for the mainnet ceiling — the
production path is faster than partners typically expect, so build for
the slower target and treat the production behaviour as the optimistic
case.
Two ways to observe it:
```typescript Polling theme={null}
async function waitForDeposit(amountUsdc: string, timeoutMs = 30_000) {
const start = Date.now();
while (Date.now() - start < timeoutMs) {
const r = await fetch(`${BASE}/api/me/balances`, {
headers: { 'X-Api-Key': process.env.PS_API_KEY! },
});
const balances = await r.json();
const usdc = balances.find((b: any) => b.token === 'USDC');
if (usdc && Number(usdc.available) >= Number(amountUsdc)) return usdc;
await new Promise(r => setTimeout(r, 1000));
}
throw new Error('deposit not credited within timeout');
}
```
```text Polling fallback theme={null}
// Deposit confirmation isn't currently surfaced on the typed WS
// channels — poll GET /api/me/balances until `available` reflects
// the deposited amount, or watch `vault_positions` for the inflow
// `vault_position_balance_changed` event keyed to your vault.
```
## Idempotency and replays
Deposits are uniquely keyed by their on-chain `(txHash, logIndex)`.
If you receive the same `vault.deposit_confirmed` event twice (network
retry, WS reconnect with replay), the platform credits the deposit
exactly once — replays are cheap no-ops. Safe to handle naively.
## Withdrawing later
Funds in the vault stay liquid — withdraw any time via the dual-signed
flow documented in [Withdrawals overview](/concepts/withdrawals/overview).
The vault also exposes a 7-day-timelocked emergency withdraw for
recovery if the platform is unavailable; see [Vault contract
reference](/concepts/contracts/vaults).
## Common failures
| Symptom | Cause | Fix |
| ---------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------ |
| `ERC20InsufficientAllowance` | Step 1 skipped or insufficient cap | Run `usdc.approve(vault, MaxUint256)` first |
| Revert with selector `0x87138d5c` | `NotInitialized()` — DepositLimitRegistry init lags vault deploy (separate platform job; observed lag 30 s – 4 min). Gating on `GET /api/me/vault.deployed` alone is insufficient. | Poll `GET /api/me/deposit-limits` until `initialized: true` *before* calling `depositERC20`. |
| Revert with `DepositCapExceeded` | The deposit would exceed your daily / weekly / monthly cap | See [Deposit limits](/concepts/deposits/limits) — wait for the rolling window or request a higher tier |
| Tx mined but `available` still 0 in `/api/me/balances` after >1 minute | Indexer lag or transient incident | Check [status page](https://status.predictstreet.com); if persistent, contact support with `txHash` |
## Next
Daily / weekly / monthly caps and how rolling windows are applied.
Dual-signature flow, AML review, state machine.
Sign + POST a vault-backed order against any open market.
Full ABI for the vault, including the deposit entry point.