Conditional transactions API (eth_sendRawTransactionConditional) on Robinhood Chain

Last updated: October 25, 2026

Conditional or plain send?

Use the conditional method when a late or stale inclusion is worse than no inclusion:

• a bot or backend that priced an action against a block and must not execute it many blocks later;
• a quote or order that expires at a wall-clock time;
• a transaction built against specific storage values (a pool reserve, a nonce slot, an allowance) that must not run if those values change first;
• account-abstraction bundlers: ERC-7796 names the ERC-4337 use case as one the method makes workable.

Use plain eth_sendRawTransaction when the transaction is valid whenever it lands — a transfer, a deposit. A condition you do not need is only one more way for a good transaction to be refused.

One request

curl https://triport.io/rpc/robinhood -X POST \
  -H 'Content-Type: application/json' -H "x-token: $TRIPORT_API_KEY" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_sendRawTransactionConditional",
       "params":["0x<signed tx>",{
         "blockNumberMax":"0x<parent-chain block>",
         "timestampMax":"0x<unix seconds>",
         "knownAccounts":{"0x<20-byte address>":{"0x<32-byte slot>":"0x<32-byte value>"}}
       }]}'
# -32602 "invalid conditional options: ..."  -> Triport rejected the shape; nothing was sent
# "result":"0x<tx hash>"                     -> routed; confirm with eth_getTransactionReceipt

Five options are accepted. Anything else is rejected, not ignored:

The block-number trap

On the Arbitrum Nitro stack that Robinhood Chain runs on, blockNumberMin and blockNumberMax are checked against the parent-chain block number, not against the Robinhood Chain block number that eth_blockNumber returns. The two are far apart: Robinhood Chain block 56,782,442 carried l1BlockNumber 25,925,047 (Triport's eth_getBlockByNumber example, 7 September 2026).

• A blockNumberMax computed from eth_blockNumber sits tens of millions of blocks above the parent chain, so it never expires: the deadline you think you set does nothing.
• A blockNumberMin computed the same way is never reached, so every submission is refused.

Read the current block with eth_getBlockByNumber("latest", false), take its l1BlockNumber, and add your margin to that. Several Robinhood Chain blocks share one parent-chain number, so this bound is coarse; when the deadline is really about time, use timestampMax.

What comes back, and what to do

Triport validates option names and shapes and never evaluates the conditions. The messages it returns name the field, for example blockNumberMax: must be a non-negative hex or decimal number, paysCoinbase: unknown field or knownAccounts: 0x…: address must be 20-byte hex. In a JSON-RPC batch each conditional element is dispatched on its own, so one malformed element gets its own -32602 and the rest go ahead.

One method name, three rule sets

The method is written up as ERC-7796, “Conditional send transaction RPC”, and the OP Stack sequencer implements it too. Code written against the ERC or another stack's documentation does not carry over unchanged:

Plans

eth_sendRawTransactionConditional and eth_sendRawTransaction share one per-second budget, robinhood_send_tx, from tier-matrix.yaml — the same source as RPC pricing. A batch of N submissions costs N. The key needs the robinhood:rpc scope.

A flat monthly price, no credits or overage. These budgets are configured plan limits, not measured capacity — see Robinhood Chain limits.

What it does not do

• Not private orderflow. The transaction goes to the sequencer like any other.
• Not a queue advantage. Robinhood Chain sequencing is first-come, first-served; a condition does not move a transaction forward.
• Not proof of inclusion. A returned hash means routed. Only a receipt shows the outcome.
• Not evaluated by Triport. Triport checks names and shapes; the chain checks the conditions.
• Not a substitute for on-chain checks. A condition narrows the window for stale execution; keep the checks your contract needs anyway.

Sources

1. Triport, Conditional transaction submission and the step-by-step guide: accepted options, local validation, per-item batches.
2. Arbitrum Nitro source, checked 13 October 2026: arbitrum_types/txoptions.go (block bounds against the parent-chain block number, timestamps against the L2 block, -32003 messages) and execution/gethexec/tx_pre_checker.go (conditions checked when the transaction is pre-checked, and again when it is sequenced).
3. ERC-7796: Conditional send transaction RPC, checked 13 October 2026.
4. OP Stack: SendRawTransactionConditional, checked 13 October 2026.
5. Triport tier-matrix.yaml, category robinhood_send_tx.