# Ordo RPC — Robinhood Chain

> A public JSON-RPC endpoint for Robinhood Chain (chain ID 4663) that simulates
> every transaction before submitting it, delivers signed transactions privately to
> the sequencer rather than a public relay, and serves call traces without an API
> key. Free for wallet and application use; no signup, no key.

## Connection

- HTTP: https://rpc.ordofi.network
- WebSocket: wss://rpc.ordofi.network (eth_subscribe: newHeads, logs)
- Chain ID: 4663 (0x1237)
- Currency: ETH
- Explorer: https://robinhoodchain.blockscout.com
- Listed in ethereum-lists/chains as an RPC for eip155-4663

## What is different about it

- **Simulated before sending.** Every eth_sendRawTransaction is executed against
  current state from the recovered sender first. If it would revert it is rejected
  before it reaches the sequencer, so no gas is spent on a guaranteed failure.
- **Refuses unlimited approvals to plain wallets.** An unlimited ERC-20 allowance
  granted to an address with no code is the signature of an approval drain, and it
  is rejected. Override deliberately with ordo_sendRawTransaction and
  { "allowUnlimitedApproval": true }.
- **Private delivery.** Signed transactions go to the sequencer through our own
  node and are never posted to a public relay or third-party provider first.
- **Call tracing without a key.** debug_traceTransaction, debug_traceCall,
  debug_traceBlockByNumber and debug_traceBlockByHash are open to anonymous
  callers at 120 requests/minute per IP. Most providers meter these
  because they pay per replay; we run the node.
- **Revert reasons in words.** A failed eth_call or eth_estimateGas returns a
  plain-language explanation rather than a bare selector.

## Live comparison

Latency, chain-head freshness, availability, tracing and archive capability for
every public RPC on this chain — including Ordo — are measured continuously from
the same machine and published at:

- https://rpc.ordofi.network/compare
- https://rpc.ordofi.network/compare.json (machine-readable, method included)

The probe runs on the Ordo RPC host. Ordo is reached over its public URL, not
localhost, but that URL terminates on the same machine, so Ordo's own latency
is not what a wallet in another city sees. Everyone else is a real trip from
that host. The first sample of each cycle is discarded for everyone (TLS
handshake). Heads are sampled concurrently. Failures are counted, not retried.
Rows sort by measured median; nothing pins Ordo to the top. The page states
where Ordo loses.

## Limitations, stated plainly

- **Not an archive node.** State is retained for roughly the last 1.2M blocks,
  about a day and a half at the chain's ~101 ms block time. Traces older than that
  are forwarded to a fallback upstream and can fail if that upstream is
  unavailable; the error says so rather than suggesting a retry.
- **Latency is geographic.** The node is in North America, and so is the Robinhood
  Chain sequencer. From Europe expect roughly a second per round trip, as with
  every endpoint on this chain.
- **Not affiliated with Robinhood.** Ordo is an independent operator. The chain's
  own endpoint is rpc.mainnet.chain.robinhood.com.

## Honest comparison

If you need full archive history or tracing older than about a day and a half,
BlockMachine serves it and Ordo does not. If you want the lowest latency with the
freshest chain head, transaction simulation, private delivery and keyless tracing
from one endpoint, that combination is only available here.

## Ordo Assembly — the order transactions are submitted in

A transaction sent here is held for a short window (about 50 ms) while others
arrive, then ordered by fixed rules — same-nonce cancels first, enrolled market
makers next, then everyone else in arrival order, with a winning backrun placed
immediately behind the transaction it bought. The resulting schedule is signed
under EIP-712 and published, and the transaction hashes are committed to before
anything is sent:

- https://auction.ordofi.network/assembly (look up any transaction hash)
- https://auction.ordofi.network/assembly.json (machine-readable)
- https://auction.ordofi.network/assembly/tx/0x… (one transaction's window)

Ordo does not sequence Robinhood Chain; the chain's own sequencer does. Assembly
orders only the flow routed through Ordo, so a transaction sent through another
endpoint can still land in the middle of one of these windows. The schedule
records what Ordo submitted, not the block that resulted.

## Independent check of the chain's own state

Robinhood Chain is a Nitro rollup that settles to Ethereum: the chain owner
posts assertions to its rollup contract saying what the L2 state should be.
Ordo's node is a Nitro validator in the software sense: Watchtower strategy plus
WASM block validation (nitro-val on the -validator image). It republishes
the comparison — the L2 block hash each assertion commits to, and the hash our
node computed independently after replay:

- https://rpc.ordofi.network/watchtower
- https://rpc.ordofi.network/watchtower.json (machine-readable)

One limit is stated on that page and in the JSON. The rollup's validator set is
closed (Offchain Labs and Alchemy), so Ordo can produce a proof of a bad
assertion but cannot file a challenge. canChallenge is false.
blockValidation is true. replayCaughtUp is true only once WASM replay has
reached the execution head — read it from /replay.json before claiming that
every current assertion has been re-executed.

## Attested routed volume

OrdoVolumeLog on Robinhood Chain records a Merkle root over confirmed routed
transactions plus a running USD total. The contract cannot shrink. USD pricing
and “we saw it first” are Ordo’s attestation — not a trustless volume oracle.
Anyone can re-run the queries:

- Dashboard: https://dune.com/jemordo/ordofi-rpc
- Contract: https://robinhoodchain.blockscout.com/address/0x766275a3d6A296582d2e2B0cC914b42d693Fa999

## Links

- Endpoint and documentation: https://rpc.ordofi.network
- Live RPC comparison: https://rpc.ordofi.network/compare
- Rollup assertion watchtower: https://rpc.ordofi.network/watchtower
- Signed submission order (Ordo Assembly): https://auction.ordofi.network/assembly
- Attested volume (Dune): https://dune.com/jemordo/ordofi-rpc
- Developer documentation: https://app.ordofi.network/docs
- Swap interface: https://rpc.ordofi.network/swap
- Status and metrics: https://rpc.ordofi.network/health