> For the complete documentation index, see [llms.txt](https://corpus-core.gitbook.io/specification-colibri-stateless/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://corpus-core.gitbook.io/specification-colibri-stateless/specifications/op-stack/call-proof.md).

# Call Proof

`eth_call` returns the result of the call. In order to prove that the result is correct, we need to prove every single storage value and account.

This Proof is used for the following RPC-Methods:

* [colibri\_simulateTransaction](https://github.com/corpus-core/colibri-stateless-doc/tree/main/specification/specifications/op-stack/colibri-rpc-methods/colibri_simulatetransaction.md)

## OpCallAccount

A proof for a single account.

The Type is defined in [src/chains/op/ssz/op\_proof\_types.h](https://github.com/corpus-core/colibri-stateless/blob/dev/src/chains/op/ssz/op_proof_types.h#L159).

```python
class OpCallAccount(Container):
    accountProof : List [bytes_1024, 256]      # Patricia Merkle proof
    address      : Address                     # the address of the account
    code         : Union [                     # the code of the contract
        Boolean,                               # flag indicating whether code is provided (false = no code, true = code follows)
        Bytes[4194304]]                        # the contract bytecode (max 4MB)
    storageProof : List [OpStorageProof, 4096] # the storage proofs for requested storage keys
```

**Referenced Types**

* [OpStorageProof](/specification-colibri-stateless/specifications/op-stack/account-proof.md#opstorageproof)

## OpCallProof

Container type for account data in call proofs The main proof data for a call.

The Type is defined in [src/chains/op/ssz/op\_proof\_types.h](https://github.com/corpus-core/colibri-stateless/blob/dev/src/chains/op/ssz/op_proof_types.h#L169).

```python
class OpCallProof(Container):
    accounts    : List [OpCallAccount, 256] # used accounts
    block_proof : Union [                   # proof for the block header
        OpPreconf,                          # preconfirmation proof (sequencer-signed execution payload)
        Bytes32]                            # blockhash hint identifying the cached execution payload
```

**Referenced Types**

* [OpCallAccount](#opcallaccount)
* [OpPreconf](/specification-colibri-stateless/specifications/op-stack.md#oppreconf)