Why didn't my transaction decode?

DecodedOperation.diagnostics is the chain of decisions for one decode. It is always an array, including on a hit. erc7730 preview --explain prints the same chain as stage code outcome message.

InvalidInputError still throws. A broken calldata or address is not a diagnostic. An include or registry fetch that throws is recorded as INCLUDE_FETCH_FAILED, and decoding continues into the fallback so the wallet still has a screen.

Codes

Code	Stage	What happened	What to do
`REGISTRY_HIT`	registry-lookup	A descriptor came back for this chain and address	Read the next rows
`REGISTRY_NO_DESCRIPTOR`	registry-lookup	`findCalldata` / `findEip712` returned null	The contract is not in the pinned index. Fallback is unverified
`REGISTRY_SKIPPED`	registry-lookup	No registry was passed, or the call has no selector	Pass a registry, or treat an empty call as a value transfer
`INCLUDE_FETCH_FAILED`	include-resolve	Loading a descriptor or include threw	Check the registry pin, cache, and network. The decode still falls back
`CONTEXT_MATCHED`	context-match	Deployments, proxy, factory, or EIP-712 domain matched	Read the format row
`CHAIN_ID_MISMATCH`	context-match	A descriptor exists and none of its deployments use this `chainId`	Confirm the chain, or extend a descriptor that lists it
`CONTEXT_MISMATCH`	context-match	The descriptor did not bind to this address or domain	Do not show it as verified
`FORMAT_MATCHED`	format-match	The selector or EIP-712 type is in `display.formats`	The intent comes from that format
`SELECTOR_NOT_IN_FORMATS`	format-match	Context matched and the selector is not listed	The file is incomplete for this function. Fallback stays unverified
`TRUST_ACCEPTED`	trust	The active policy accepted the source	`screens.verification` can be `verified` for official or attested sources
`POLICY_REJECTED`	trust	`trust.accepted` is false	Show `rejected` when the source was a curated descriptor
`BUILTIN_FALLBACK`	fallback	ERC-20, ERC-721, or WETH builtin rendered the call	Unverified under `officialOnlyPolicy()`
`TRUSTED_TOKEN_FALLBACK`	fallback	A trusted-token template rendered the call	Unverified unless your policy accepts that source
`SOURCIFY_FALLBACK`	fallback	Sourcify ABI rendered the call	Unverified. Sourcify is opt-in
`INFERRED_FALLBACK`	fallback	A known 4-byte signature was inferred	Unverified
`BASIC_FALLBACK`	fallback	No descriptor and no known signature	Unverified. Primary rows are `to` and the raw selector

Happy-path order for a pinned WETH deposit() is REGISTRY_HIT, CONTEXT_MATCHED, FORMAT_MATCHED, TRUST_ACCEPTED.

Preview

erc7730 preview --data 0xd0e30db0 --to 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 --chain-id 1 --value 1000000000000000000 --explain

A hit prints registry-lookup REGISTRY_HIT hit. An address with no file prints registry-lookup REGISTRY_NO_DESCRIPTOR miss.