> ## Documentation Index
> Fetch the complete documentation index at: https://hevninc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> HEVN accounts are non-custodial in both products. Self-serve (the General tab): the person who owns the email holds the only key and signs for themselves. Whitelabel (the Whitelabel and REST API tabs): the integrator's customer creates and owns their account through Sign in with HEVN, a HEVN-hosted popup on the integrator's site; the integrator's backend holds a developer key, operates linked accounts and books their payouts, and the account holder approves every payout in that popup. The developer key signs only for the integrator's own wallet; it never signs a client's money.
> Use HEVN's terms exactly. A rail is a bank route a client can request. A virtual account (bnk_) is an opened rail. Account details are what a payer needs in order to wire money, and arrive in a field named requisites. A client is a customer's own account linked to the integrator through Sign in with HEVN (POST /dapi/v1/connect/sessions, then POST /dapi/v1/clients/link); there is no API call that creates one. The business behind it is the integrator's customer. A contact is a saved destination; a beneficiary is the party at the far end of a fiat payout. Every departure of money is a payout, to a bank account or to a wallet alike.
> Never name a banking partner. Say 'a licensed banking partner'.
> There are no published fee rates, spreads or minimums. Prices come from a quote on a specific payment; direct pricing questions to HEVN rather than inventing numbers.
> The whitelabel API is at /dapi/v1 and takes a developer-key session plus an X-Hevn-Account header. Developer keys have an IP allowlist and no scopes. Remote transfers are at /api/v1/remote_spend_limit and take a remote transfer key (rsl_) in X-Api-Key, bounded by an onchain spend permission the account holder grants. They are different credentials and neither works on the other surface. The HEVN CLI is discontinued.

# Escrow actions

> Every escrow action: the amount it takes, the window it is legal in, the state it leaves behind, and how to confirm it.

Five actions you send, one resource. `POST /dapi/v1/escrow/{escrowId}/actions` prepares one and returns a payload to sign; `POST /dapi/v1/escrow/{escrowId}/actions/{idempotencyKey}/confirm` submits the signature. This page is the matrix.

## The matrix

| Action | `amount` | `feeBps` | Legal when | Leaves the deal | Wallet it signs on |
| - | - | - | - | - | - |
| `authorize` | required | ignored | before `approveBy`, nothing collected yet, `0 < amount ≤ maxAmount` | `authorized` | yours |
| `charge` | required | up to the deal's ceiling | before `approveBy`, nothing collected yet, `0 < amount ≤ maxAmount` | `charged` | yours |
| `capture` | required | up to the deal's ceiling | before `holdUntil`, `0 < amount ≤ capturableAmount`, repeatable | `partiallyCaptured`, then `captured` | yours |
| `void` | refused | ignored | any time while `capturableAmount > 0` | `voided` | yours |
| `refund` | required | ignored | before `refundableUntil`, `0 < amount ≤ refundableAmount`, repeatable | `partiallyRefunded`, then `refunded` | yours |

Two more names can appear in `availableActions` and are not verbs you send. `approve` is prepared by `POST /dapi/v1/escrow` and is the buyer's to sign with their own key. `reclaim` is the buyer's own way to take an uncaptured hold back after `holdUntil`. Sending either as `action` answers `422 validation_failed`. Sending an `amount` with `void` answers `409 amount_not_allowed`; omitting it on the four that need it answers `422 validation_failed`.

`charge` is `authorize` and `capture` in one on-chain action — the money goes straight to the seller with no hold in between. Use it when there is nothing to wait for.

## Preparing an action

```json Request — POST /dapi/v1/escrow/esc_5Qb4e17c9d/actions, Idempotency-Key: order-A-1187-capture theme={null}
{ "action": "capture", "amount": "40.00", "feeBps": 250 }
```

`201` for a new action, `200` with `Idempotency-Replayed: true` when the key replays one. A replay returns the same record — with its approval if that is still open, without it once the action was submitted. The same key with a different body answers `409 idempotency_key_reused`.

```json Response — 201 theme={null}
{
  "deal": { "id": "esc_5Qb4e17c9d", "status": "authorized",
            "capturableAmount": "100.000000", "refundableAmount": "0.000000",
            "availableActions": ["capture", "void"] },
  "action": { "action": "capture", "idempotencyKey": "order-A-1187-capture",
              "status": "awaitingSignature", "amount": "40.000000", "feeBps": 250,
              "approval": { "id": "b1d0…", "payload": "eyJ…",
                            "expiresAt": "2026-09-17T10:31:02Z" } }
}
```

The idempotency key you sent **is** the action's address. Send no key and HEVN derives one, echoes it as `action.idempotencyKey`, and that derived value works in the confirm URL exactly the same way. Either way, a lost prepare response costs you nothing: you already know where to confirm.

## Confirming an action

Sign the decoded `approval.payload` bytes — never the base64 string, never a re-serialized JSON object.

```python Python theme={null}
import base64
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import ec


def sign_bytes(key, message: bytes) -> str:
    """base64(DER ECDSA P-256 / SHA-256) over exactly these bytes."""
    return base64.b64encode(key.sign(message, ec.ECDSA(hashes.SHA256()))).decode()


def sign_payload(key, payload_b64: str) -> str:
    return sign_bytes(key, base64.b64decode(payload_b64))
```

```javascript Node theme={null}
import { sign } from "node:crypto";

export function signBytes(key, message) {
  return sign("sha256", message, { key, dsaEncoding: "der" }).toString("base64");
}

export function signPayload(key, payloadB64) {
  return signBytes(key, Buffer.from(payloadB64, "base64"));
}
```

```go Go theme={null}
func SignBytes(key *ecdsa.PrivateKey, message []byte) (string, error) {
	digest := sha256.Sum256(message)
	der, err := ecdsa.SignASN1(rand.Reader, key, digest[:])
	if err != nil {
		return "", err
	}
	return base64.StdEncoding.EncodeToString(der), nil
}

func SignPayload(key *ecdsa.PrivateKey, payloadB64 string) (string, error) {
	message, err := base64.StdEncoding.DecodeString(payloadB64)
	if err != nil {
		return "", err
	}
	return SignBytes(key, message)
}
```

```json Request — POST /dapi/v1/escrow/esc_5Qb4e17c9d/actions/order-A-1187-capture/confirm theme={null}
{ "signature": "MEUCIQDk3f8Zc0xq2w1Yv7pB9nH4mJ6sR2tL5uD8aE0cQ1oXgAIg…" }
```

`publicKey` is optional and only skips a scan of your registered keys. HEVN verifies the signature locally, against the payload it stored, **before** it consumes the approval — a wrong signature costs nothing but the call.

HEVN re-checks the developer key behind the session immediately before it co-signs: a key deleted between prepare and confirm, or a confirm sent from an IP outside the key's allowlist, answers `403` and signs nothing. The prepared action is untouched, so a confirm from an allowlisted host still works.

| Answer | Meaning | What to do |
| - | - | - |
| `200`, action `confirmed` | Mined. The body carries the projected deal and the `events` it produced. | Done. |
| `200`, action `reverted` | Mined, but the contract rejected it. | Read the deal; nothing moved. Prepare again with a **new** key. |
| `202`, `pollUrl` | With the bundler, no receipt yet. | `pollUrl` is the deal read, `GET /dapi/v1/escrow/{escrowId}`; `POST /dapi/v1/escrow/{escrowId}/sync` is the one that reconciles against the chain. Sync until the action settles. |
| `400 signature_invalid` | The signature does not verify. | The approval is untouched. Sign the decoded payload again. |
| `403 forbidden` | The developer key was deleted, or the confirm left an IP outside its allowlist. | Nothing was signed. Use a key that covers this host. |
| `403 account_not_controlled` | The action would sign on a wallet your key does not control — the buyer's. | Nothing was signed. Only operator actions are yours to confirm. |
| `410 approval_expired` | The 60-second approval closed, or the action has no open approval left. | Prepare the action again with the **same** key; you get a fresh approval on the same record. |
| `409 approval_consumed` | That approval already signed something. | Prepare again with the same key, then read the deal before you sign anything else. |
| `409 action_in_flight` | Another action of yours is still on chain. | Sync this deal, then retry. The refusal carries no `details`; the deal to sync is the one you are acting on. |
| `409 escrow_state_changed` | The deal moved since prepare — nothing capturable, or the payment was already collected. | Re-read the deal and pick from `availableActions`. |
| `503 bundler_rejected`, `503 bundler_unavailable` | Chain infrastructure. | Confirm again with backoff. |

```python Python theme={null}
def confirm_action(hevn, escrow_id, key, payload, signing_key):
    signature = signing_key.sign_payload(payload)
    receipt = hevn.post(f"/escrow/{escrow_id}/actions/{key}/confirm", {"signature": signature})
    if receipt["action"]["status"] in ("confirmed", "reverted"):
        return receipt
    return poll_until(
        lambda: hevn.post(f"/escrow/{escrow_id}/sync"),
        lambda deal: deal["action"]["status"] not in ("signing", "submitted"),
        first=15.0,
    )
```

```javascript Node theme={null}
export async function confirmAction(hevn, escrowId, key, payload, signingKey) {
  const signature = signingKey.signPayload(payload);
  const receipt = await hevn.post(`/escrow/${escrowId}/actions/${key}/confirm`, { signature });
  if (["confirmed", "reverted"].includes(receipt.action.status)) return receipt;
  return pollUntil(
    () => hevn.post(`/escrow/${escrowId}/sync`),
    (deal) => !["signing", "submitted"].includes(deal.action.status),
    { first: 15_000 },
  );
}
```

```go Go theme={null}
var pending = map[string]bool{"signing": true, "submitted": true}

func ConfirmAction(c *hevn.Client, escrowID, idemKey, payload string, key *hevn.Key) (hevn.Payload, error) {
	signature, err := key.SignPayload(payload)
	if err != nil {
		return nil, err
	}
	receipt, err := c.Post("/escrow/"+escrowID+"/actions/"+idemKey+"/confirm",
		hevn.Body{"signature": signature})
	if err != nil || !pending[receipt.Str("action.status")] {
		return receipt, err
	}
	return hevn.PollUntil(
		func() (hevn.Payload, error) { return c.Post("/escrow/"+escrowID+"/sync", nil) },
		func(deal hevn.Payload) bool { return !pending[deal.Str("action.status")] },
		2*time.Minute,
	)
}
```

### One action in flight

A signing wallet runs one on-chain action at a time — across every deal it signs for, not just this one. While one of yours is `signing` or `submitted`, the next prepare or confirm answers `409 action_in_flight`. The refusal names no deal, so a worker that drives many deals has to know which one it left in flight: serialise your actions per signing wallet and keep the in-flight deal id on your side, then `POST /dapi/v1/escrow/{escrowId}/sync` it before retrying.

## Statuses

The deal's status is a label for the last thing that landed. Decide with `availableActions`, `capturableAmount` and `refundableAmount`.

| Deal status | Meaning |
| - | - |
| `draft` | Created. Nothing held. The buyer's approval does not change this. |
| `authorized` | The on-chain hold is in the contract. `capturableAmount` is positive. |
| `charged` | Held and paid out in one action. Only a refund moves it back. |
| `partiallyCaptured` | Part of the hold reached the seller, the rest is still capturable. |
| `captured` | Nothing is capturable any more. |
| `voided` | The hold went back to the buyer. |
| `reclaimed` | The buyer took the hold back after `holdUntil`. |
| `partiallyRefunded` / `refunded` | You sent money back out of your own wallet. |

| Action status | Meaning | What to do |
| - | - | - |
| `awaitingSignature` | Prepared, approval open | Sign and confirm within 60 seconds |
| `signing` | Confirm in progress | Wait. Do not prepare again |
| `submitted` | With the bundler, no receipt | Sync, no more than every 15 seconds |
| `confirmed` | Mined and projected | Done |
| `reverted` | Mined, the call reverted | Read the deal, prepare again with a new key |
| `failed` | Never reached the bundler | Prepare again with the **same** key |
| `dropped` | No receipt within the timeout | Keep syncing: it can still confirm for up to 24 hours |
| `superseded` | A later prepare replaced it | Ignore |

## Reads

`GET /dapi/v1/escrow/{escrowId}` returns one deal with its last action. `GET /dapi/v1/escrow` lists the deals you operate, newest first, cursor-paged:

```bash cURL theme={null}
curl "$HEVN_API/escrow?status=authorized&status=partiallyCaptured&limit=50" \
  -H "Authorization: Bearer $HEVN_ACCESS_TOKEN"
```

```python Python theme={null}
open_deals = hevn.get("/escrow?status=authorized&status=partiallyCaptured&limit=50")["items"]
```

```javascript Node theme={null}
const { items: openDeals } =
  await hevn.get("/escrow?status=authorized&status=partiallyCaptured&limit=50");
```

```go Go theme={null}
page, err := api.Get("/escrow?status=authorized&status=partiallyCaptured&limit=50")
openDeals := page.List("items")
```

`status` repeats, so it goes in the path rather than the client's parameter map, which holds one
value per name. Filters are `status`, `senderClientId` and `receiverClientId`. The envelope is `{ "items": [...], "nextCursor": "…" }`; pass `nextCursor` back as `cursor` until it is absent. A cursor from another query answers `400 invalid_cursor`.

`POST /dapi/v1/escrow/{escrowId}/sync` reconciles the deal against the chain and returns the same shape plus `consistent`. It reads the chain at most once every 15 seconds per deal; calls in between answer the stored projection, which is why polling it in a tight loop buys nothing.

There is no separate action list: the deal read carries the last action, and every action is addressable by the key you chose.

## Refusals

`action_in_flight`, `escrow_state_changed` and `escrow_action_not_found` are the three that change your control flow, and all three are handled above. The full registry, with every status code, is in [Errors](https://hevninc.mintlify.site/whitelabel/reference/errors.md#escrow).

One shape worth knowing: a closed window or an over-large amount arrives today as a bare `400 invalid_request` — the contract-level reason (`preApprovalExpiry has been reached`, `amount exceeds available amount`) is logged on our side but not published, so `message` is the generic one and `details` is absent. Treat it exactly like `window_closed` and `amount_out_of_range`: re-read the deal and pick from `availableActions`, which is computed from the same windows and amounts.

> [card] [Next: Sandbox](https://hevninc.mintlify.site/whitelabel/sandbox.md)
>
> The same operations against an emulated partner on Base Sepolia.


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