# Endpoint-free RPC

> Use shared cached results for documented EVM, Solana, Bitcoin, Litecoin, and TRON reads before the Gateway selects an Endpoint.

Canonical page: https://rpc.aurpay.net/docs/endpoint-free-rpc

Endpoint-free RPC lets the Gateway return shared cached results for supported request shapes before accessing an Endpoint. A matching read can return through the same Access Point without an Endpoint on your Gateway.

## In brief

- Endpoint-free RPC covers the exact methods and parameter forms listed on this page.
- A hit returns the shared result without an upstream call. A miss continues through the configured Route to an Endpoint.
- Authentication, rate limits, and Usage accounting apply to both hits and misses.

> Pair Endpoint-free RPC with an Endpoint-backed Route for stable coverage across additional data, methods, and parameter forms.

## Free to use and Endpoint-free RPC

| Term | Meaning |
|---|---|
| Free to use | Describes the RPC Gateway service. Authentication, rate limits, and Usage accounting still apply. |
| Endpoint-free RPC | Supported request shapes check the shared cache before Endpoint selection. |
| Cache miss | The request continues through the configured Route to an Endpoint. |
| Endpoint-backed Route | Provides stable coverage for writes, additional methods, parameter variants, and cache misses. |

See [Free RPC Gateway](https://rpc.aurpay.net/free-rpc) for the service-level overview.

## Request flow

1. The Gateway validates the App API Key, Host, chain, and network.
2. The Gateway classifies the method and parameters against the Endpoint-free RPC policy.
3. A cache hit returns the result immediately.
4. On a miss, the Gateway continues through its Route to a configured Endpoint.

Authentication, rate limits, and Usage accounting apply to both paths.

[Diagram: Request flow: authentication and rate limiting precede the Endpoint-free RPC policy check; a cache hit returns the shared result, while a miss forwards through the Route to an Endpoint.]

## How concurrent cache misses are handled

Concurrent requests for the same eligible cache key are combined while one cache load is in flight. Within a worker, waiting requests reuse the local flight result once it is published. Across workers, distributed flight contention uses a bounded wait; if no result is published within that interval, a request can continue without a cache result.

## Supported methods and parameters

Use these exact request forms for Endpoint-free RPC. Configure an Endpoint-backed Route for additional reads, writes, and parameter variants.

| Protocol | Method | Supported `params` |
|---|---|---|
| EVM | `eth_blockNumber` | omitted or `[]` |
| EVM | `eth_getBlockByNumber` | `["latest", false]` or `["<explicit hexadecimal block height>", false]` |
| EVM | `debug_traceBlockByNumber` | `["<explicit hexadecimal block height>", {"tracer":"callTracer","tracerConfig":{"withLog":true}}]` |
| Solana | `getSlot` | omitted, `[]`, or `[{"commitment":"finalized"}]` |
| Solana | `getLatestBlockhash` | omitted, `[]`, or `[{"commitment":"finalized"}]` |
| Solana | `getBlock` | `[<slot>, {"encoding":"json","commitment":"finalized","rewards":false,"maxSupportedTransactionVersion":0}]` |
| Bitcoin / Litecoin | `getblockchaininfo` | omitted or `[]` |
| Bitcoin / Litecoin | `getblockhash` | `[<non-negative block height>]` |
| Bitcoin / Litecoin | `getblock` | `["<block_hash>", 3]` |
| TRON JSON-RPC | `eth_blockNumber` | omitted or `[]` |

The EVM scope covers Ethereum, Polygon, BNB Smart Chain, Arbitrum, Optimism, and Base. For `eth_getBlockByNumber`, Endpoint-free RPC accepts only `["latest", false]` or an explicit hexadecimal height with `false`. `["latest", true]`, the `safe` and `finalized` tags, decimal heights, and all other variants require an Endpoint-backed Route. The `latest` form uses a short-lived shared cache. During refresh fallback, it may return a stale cached value, so do not treat it as strongly consistent. `debug_traceBlockByNumber` still requires an explicit hexadecimal height.

For Solana `getBlock`, `encoding` may be `json` or `jsonParsed`; `commitment` must be `finalized`, `rewards` must be `false`, and the supported maximum transaction version is `0`. `transactionDetails` may be omitted or set to `full`.

The [TRON native HTTP API](https://rpc.aurpay.net/docs/chains/tron.md#native-http-api) supports these Endpoint-free RPC request shapes:

| Path | Supported request |
|---|---|
| `POST /wallet/getnodeinfo` | No query parameters and no request body |
| `POST /wallet/getblockbynum` | No query parameters and a JSON body containing only `{"num":<non-negative integer>,"visible":true}` |

## Examples

This Ethereum Mainnet request uses an Endpoint-free RPC request shape. A current cache entry returns the latest cached height:

```bash
curl '<ethereum_access_point>' \
  -H 'Authorization: Bearer <app_api_key>' \
  -H 'Content-Type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'
```

Request the latest block without full transaction objects:

```bash
curl '<ethereum_access_point>' \
  -H 'Authorization: Bearer <app_api_key>' \
  -H 'Content-Type: application/json' \
  --data '{"jsonrpc":"2.0","id":2,"method":"eth_getBlockByNumber","params":["latest",false]}'
```

## Production guidance

- Configure an Endpoint-backed Route for stable coverage across block heights, slots, block hashes, and cache refreshes.
- Use upstream-backed reads and chain-specific confirmation rules for pending state, mempool state, newly submitted transactions, and decisions that require irreversible confirmation.
- Configure an Endpoint for stable coverage, writes, and additional methods.
- Use JSON-RPC requests with an `id` when the application needs a response body and cache-result visibility.
- Endpoint-free RPC covers single JSON-RPC HTTP requests and the two exact TRON native HTTP API request shapes above.
- Use the complete RPC Method Catalog in the dashboard for Route configuration and this page for the Endpoint-free RPC request set.

Use [Errors and recovery](https://rpc.aurpay.net/docs/errors.md) as the reference for Gateway error codes and recovery actions.

## Related

- [TRON native HTTP API](https://rpc.aurpay.net/docs/chains/tron.md#native-http-api)
- [Errors and recovery](https://rpc.aurpay.net/docs/errors.md)
- [JSON-RPC](https://rpc.aurpay.net/docs/json-rpc.md)
- [Routing and reliability](https://rpc.aurpay.net/docs/reliability.md)