Record the block context behind a route
Preserve quote and simulation block context so differences can be investigated without pretending routes are immutable.
The reference
All swap guides
Browse 484 guides to DEX aggregation, BNB Chain, swap execution and integration.
Recover from wallet disconnection without losing swap history
Separate wallet connectivity from public transaction observation so disconnecting cannot erase or mislabel pending swaps.
Render token names and logos as untrusted content
Render token labels, logos and links as untrusted external data, even when they arrive from a legitimate quote API.
Review a swap integration before enabling transactions
Collect evidence that a swap integration preserves user intent, handles uncertain outcomes and can stop new execution safely.
Review SDK upgrades as execution changes
Review swap SDK dependency updates for transaction and signing changes, using locked builds and semantic payload comparisons.
RFQ expiry needs a different retry decision from HTTP failure
Refresh an expired RFQ quote instead of retrying its old transaction payload, and distinguish expiry from transport uncertainty.
RFQ quotes may be bound to a particular taker
Include the actual taker in RFQ request identity and invalidate firm quotes when the execution account changes.
Roll out a new swap adapter behind reversible controls
Separate discovery, execution and history controls so a paused or retired provider cannot strand pending attempts.
Rotate a swap API key without losing in-flight swaps
Rotate provider credentials while preserving quote attempt IDs, pending transactions and the separation from wallet authority.
RPC failover must account for different chain heads
Check head freshness and block identity when switching RPC endpoints so older state cannot undo a confirmed approval.
Separate HTTP errors, wallet errors and on-chain reverts
Map errors to actionable application states using separate HTTP, provider, wallet and receipt evidence.
Set a quote deadline across multiple providers
Use a shared deadline for parallel quote requests and present partial coverage without implying every provider responded.
Show quote expiry without promising execution
Expire quote review state predictably and separate a local countdown from the provider and settlement deadlines.
Sign authenticated swap API requests from exact bytes
Build authenticated HTTP requests from one immutable serialized path and body so HMAC inputs match transmitted bytes.
Simulate the exact swap transaction before submission
Construct a meaningful preflight call from the actual sender, destination, calldata and native value of the proposed swap.
Smart contract wallets need signature compatibility checks
Check EIP-1271 and provider execution support before offering signature-based swaps to contract accounts.
State overrides can hide a real approval failure
Use state overrides for diagnosis while preserving the distinction between hypothetical and current-wallet simulation.
Stop stale quote requests from overwriting new input
Combine input debounce, request cancellation and response identity checks to prevent old quotes replacing new trades.
Token identity: chain and address before symbol
Use chain-and-address keys for tokens, with a separate native-asset type and explicit metadata fallback rules.
Track permit expiry and nonce independently
Track permit nonce consumption, signature deadline and allowance expiration separately when diagnosing invalid signatures.
Track replacement and cancellation of a pending swap
Follow the account and nonce when a pending swap is replaced, accelerated or cancelled under a new transaction hash.
Treat encoded swap calldata as a versioned artifact
Preserve encoded swap calldata while validating its envelope and use only version-matched decoders for inspection.
Treat proprietary AMM liquidity as a source capability
Represent proprietary AMM sources by documented routing and execution capabilities instead of assuming constant-product behavior.
Treat transfer-tax tokens as a separate integration capability
Require explicit route support for transfer-tax tokens and reconcile received amounts instead of applying a guessed tax correction.
Treat wallet error 4001 as a user decision
Handle EIP-1193 rejection as a cancelled wallet action and keep earlier confirmed steps intact.
Use a circuit breaker for a failing quote service
Temporarily pause new requests to a failing quote service while keeping pending trade reconciliation available.
Use a content security policy around wallet-facing code
Roll out a browser content security policy around swap scripts, network connections and embedded frames without treating it as transaction validation.
Use fork tests to reproduce a swap integration failure
Pin chain state and preserve the original transaction context when reproducing a swap failure on a fork.
Validate swap API responses at runtime
Add runtime validation at the provider boundary so malformed or newly changed response shapes cannot reach wallet execution.
Validate swap deep links before pre-filling a form
Parse swap deep links as untrusted form suggestions and validate chain, tokens, amount and recipient before use.
