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

# Compatibility positioning

> How the Qustody Token Management API maps to familiar institutional-custody concepts.

Qustody is designed to expose a familiar institutional-custody API shape. Where it makes sense, concepts in the Qustody API map to widely-used custody-platform workflows. Qustody adds:

* **Quantum Chain-specific post-quantum signing** for every authorized transaction.
* **QRC token support** rather than ERC-style standards.
* A non-custodial model where keys live in an external signer, not in Qustody.

## Compatibility matrix

| Capability                   | Qustody API                                                                                | Familiar custody-platform shape                  |
| ---------------------------- | ------------------------------------------------------------------------------------------ | ------------------------------------------------ |
| Vault account model          | `/v1/vault/accounts`, `/v1/vault/accounts/{id}/wallets`                                    | Hierarchical custody account + sub-account model |
| Vault account asset balances | `/v1/vault/accounts/{id}/assets`                                                           | Per-account asset balance lookup                 |
| Token transfer (fungible)    | `POST /v1/transactions` with `TRANSFER` + `QRC-20`, or `/v1/tokens/{id}/transfers`         | Tokenization / contract-call transfer            |
| Token mint                   | `POST /v1/tokens/{id}/mint`                                                                | Tokenization mint operation                      |
| Token burn                   | `POST /v1/tokens/{id}/burn`                                                                | Tokenization burn operation                      |
| Token contract deployment    | `POST /v1/tokens/{id}/deploy` (Path A) or `CONTRACT_CALL`/`RAW` (Path B)                   | Tokenization deploy + custody-controlled signing |
| Roles management             | `/v1/tokens/{id}/roles[/grant\|/revoke]`                                                   | Role-based contract administration               |
| Pause / freeze               | `/v1/tokens/{id}/{pause\|unpause\|freeze\|unfreeze}`                                       | Emergency-control workflows                      |
| Allowlist / compliance       | `/v1/tokens/{id}/allowlist`, `/v1/tokens/{id}/compliance`                                  | Permissioned-asset administration                |
| Approval workflow            | Existing approval-policy engine (`MAX_AMOUNT`, `WHITELIST_ADDRESS`, `REQUIRE_APPROVAL`, …) | Policy-based multi-approver workflow             |
| Webhook event delivery       | `/v1/webhooks` with HMAC-SHA256 deliveries                                                 | Event-driven custody integration                 |
| Audit log                    | `/v1/audit` and `/v1/audit/verify`                                                         | Tamper-evident audit trail                       |
| Idempotency                  | `Idempotency-Key` header, 24h window                                                       | Idempotent custody requests                      |

## What Qustody intentionally does not promise

* **Drop-in compatibility.** Qustody is not a re-implementation of any specific custody platform. URLs, schemas, and event names are similar in shape but are not byte-for-byte identical.
* **ERC-named token standards.** Qustody publishes **QRC** standards. If you migrate from a platform that uses ERC names, expect a translation layer at the integration boundary.
* **ECDSA signing.** Quantum Chain transactions are authorized with post-quantum signatures. ECDSA-only signers cannot produce valid Quantum Chain transactions.

## How to migrate from a familiar custody platform

<Steps>
  <Step title="Map the resource model">
    `tenant → vault account → wallet → asset balance` aligns 1:1 with most institutional custody platforms.
  </Step>

  <Step title="Translate Ethereum standard references to QRC">
    Any reference to the Ethereum equivalent of `QRC-20` in your existing configuration becomes `QRC-20`. The on-chain operations are the same shape; the standard name is different. The same mapping applies to every other QRC standard listed in [token standards](/reference/token-standards).
  </Step>

  <Step title="Replace ECDSA signers with a post-quantum signer">
    Swap the signing component for a Qustody-compatible external signer (callback, gRPC, or remote). See [external signing](/guides/external-signing).
  </Step>

  <Step title="Re-bind webhooks">
    Subscribe to `transaction.*` events for transaction lifecycle and `token.*` events for typed token operations.
  </Step>

  <Step title="Re-evaluate approval policies">
    The approval-policy engine maps onto most multi-approver workflows. Re-encode your existing rules using the Qustody rule types.
  </Step>
</Steps>

## Related

* [Token standards](/reference/token-standards)
* [Token management overview](/qustody/token-management/overview)
* [API overview](/qustody/api-overview)
* [Quantum safety](/concepts/quantum-safety)