Solver Signing

A winning RFQ response carries the solver’s EIP-712 signature over the onchain Quote — and, depending on how the bond is funded, a Permit2 payload authorising the bond pull. The solver helpers are standalone functions taking a viem WalletClient directly: a solver bot signs quotes and manages allowances but never builds taker transactions, so it does not need the client.iris extension.

Bond funding modes

Iris.take pulls the bond from the solver directly, funded in one of two modes:

Mode	One-time setup	Per quote
Standing allowance (default)	An ERC-20 approval to the Iris core, consumed take after take	Nothing — only the quote signature
Permit2 (`usePermit2: true`)	An ERC-20 approval to the Permit2 contract	A signed `solverPermit2` payload, submitted in-bundle by the taker

Permit2 nonces for (solver, debtToken, Iris) are sequential, so concurrent outstanding quotes race — only the first take can consume its permit. Solvers quoting at volume should prefer the standing-allowance mode and skip the payload entirely.

One-time setup

getSolverRequirements resolves the approvals the chosen funding mode needs — returned as ready-to-send transactions, skipped when already in place:

import { getSolverRequirements } from "@iris-credit/iris-sdk";

const requirements = await getSolverRequirements(client, {
  chainId: 1,
  solver,
  debtToken,
  bond: maxQuoteSize,
  usePermit2: true,
});

for (const tx of requirements) await client.sendTransaction(tx);

Requirements cover allowances only: gate quoting on the solver’s debt-token balance separately, and re-check as takes consume it.

The per-quote hot path

signResponse signs the quote and — in the Permit2 mode — the bond funding payload in one call: everything an RFQ webhook response carries.

import { QUOTE_TTL, randomNonce } from "@iris-credit/core-sdk";
import { Time } from "@iris-credit/iris-ts";
import { signResponse } from "@iris-credit/iris-sdk";

const quote = { ...terms, deadline: Time.timestamp() + QUOTE_TTL, nonce: randomNonce() };

const { quoteSignature, solverPermit2 } = await signResponse(client, {
  chainId: 1,
  quote,
  usePermit2: true,
});

// Respond to the RFQ webhook with { ...quote fields, signature: quoteSignature, solverPermit2 }.

signResponse derives the Permit2 payload from the quote itself (solver, debtToken, bond), so it can never mismatch the quote it accompanies — and scopes the payload’s signature deadline to quote.deadline, so an unfilled quote’s permit becomes unsubmittable once the quote dies.

Granular control

signQuote signs a quote verbatim as the solver; signSolverPermit2 signs just the per-quote Permit2 payload. To hand-roll the payloads instead, build the typed data with getQuoteTypedData and getPermit2PermitTypedData from @iris-credit/core-sdk — the RFQ guide documents the exact field mapping either way.

Running a Solver

Validation

Every check your signed quote must pass, in order.

Solver Economics & Lifecycle

Integration & Development

Smart Contracts Reference

Bond funding modes

One-time setup

The per-quote hot path

Granular control

Next

Running a Solver

Validation

​Bond funding modes

​One-time setup

​The per-quote hot path

​Granular control

​Next

Running a Solver

Validation

Bond funding modes

One-time setup

The per-quote hot path

Granular control

Next