feat: Support foreign accounts #1486

sergerad · 2026-01-05T23:53:13Z

Context

Neither the Validator's TransactionInputsDataStore nor the NTX Builder's NtxDataStore handle foreign accounts for the purposes of the following functions of DataStore trait:

get_foreign_account_inputs()
get_foreign_account_inputs()
get_vault_asset_witnesses()

NOTE: This will remain in draft until miden-base has the TransactionIniputs::read_foreign_account_inputs() functionality merged into next.

Closes #1387 and #1305.

Changes

Update TransactionInputsDataStore to handle foreign accounts through self.tx_inputs.
Update NtxDataStore to handle foreign accounts by accessing AccountProofResponse from the store.

…ransactionInputsDataStore

sergerad · 2026-01-05T23:54:41Z

crates/validator/src/tx_validation/data_store.rs

+            }
+
+            let foreign_inputs =
+                self.tx_inputs.read_foreign_account_inputs(foreign_account_id).unwrap(); // todo unwrap


@bobbinth do we need the impl for TransactionInputsDataStore, rather than just NtxDataStore?

If yes, do you imagine the impl looking like this - in the sense that account inputs are derived from tx inputs. The read_foreign_account_inputs fn is a stub for now in a branch of mine, just trying to flesh out integration first.

I think here we should be able to get all the data from the TransactionInputs - so, it would work differently from NtxDataStore. Basically, the main difference between the validator and NTX builder is:

NTX builder: executes a transaction from scratch and so it doesn't now what execution path will be taken during transaction execution. For example, it doesn't know which foreign accounts would need to be loaded ahead of time, and so, we need to load them dynamically (i.e., by fetching the requested accounts from the store).

Validator: re-executes transaction that was previously executed by the user/NTX builder. All foreign account data should already be loaded into the TransactionInputs. The main challenge here would be to figure out how to extract the relevant data from TransactionInputs as it is not too structured. I believe I left a comment somewhere sketching out how to extract this data (and maybe putting some logic for this in miden-base would simplify things).

sergerad · 2026-01-05T23:55:54Z

crates/ntx-builder/src/actor/execute.rs

+            }
+            // TODO(currentpr): We don't have tx inputs here so what do we do?
+            let foreign_inputs =
+                self.tx_inputs.read_foreign_account_inputs(foreign_account_id).unwrap(); // todo unwrap


@bobbinth assuming we expect to get foreign account inputs from tx inputs, is it possible to do so here? Should we somehow retrieve the tx inputs through the store or something?

I'm not sure we can get foreign account inputs from the original TX inputs - or at least it may not always work.

I think to get foreign account inputs, we'd need to make a request to the store and load the account from there. We may also want to cache the foreign account NtxDataStore so that if there are additional requests, we won't need to go to the store again for the same data.

There is one nuance here though: currently, we are able to fetch the full account from the store, but this functionality will go away after the refactoring @drahnr is working on. So, it may make sense to add a dedicated endpoint to the data store that would return the data sufficient to construct AccountInputs (i.e., the PartialAccount and AccountWitness structs).

Any advice on how to do this? Seems like we would have to get the full account from store state, convert that to partial account + get account witness somehow.

it may make sense to add a dedicated endpoint to the data store that would return the data sufficient to construct AccountInputs (i.e., the PartialAccount and AccountWitness structs).

While we have the ability to get the full account from the store, things should be pretty easy:

The get the partial account, we get the full account and then convert it to partial account (we have impl From<&Account> for PartialAccount implemented).

The witness we'd get from the AccountTree - that should be pretty straight-forward too.

I think both of these we should be able to get from the current GetAccountProof endpoint. But soon, the ability to get full account will go away.

After a series of @drahnr's PRs gets merged, GetAccountProof becomes GetAccount and it no longer would return the full account. But it would still return enough info to build a PartialAccount + account witness. For partial account, all we really need is account_id, vault root, storage header, code, and nonce - and I believe all of this should be available from the GetAccount endpoint.

After a series of @drahnr's PRs gets merged, GetAccountProof becomes GetAccount and it no longer would return the full account. But it would still return enough info to build a PartialAccount + account witness. For partial account, all we really need is account_id, vault root, storage header, code, and nonce - and I believe all of this should be available from the GetAccount endpoint.

All of this will be available once #1385 is merged as GetAccount

…nputsDataStore

…reign-acc-inputs

crates/ntx-builder/src/actor/execute.rs

bobbinth · 2026-01-08T01:27:03Z

crates/ntx-builder/src/actor/execute.rs

+                let account_proof = store.get_account(account_id, None).await.map_err(|err| {
                    DataStoreError::Other {
-                        error_msg: "failed to open vault asset tree".into(),
+                        error_msg: format!("Failed to get account inputs from store: {err}").into(),
                        source: Some(Box::new(err)),
                    }
-                })
-            }))
+                })?;
+
+                // Construct vault from account details.
+                let account_details =
+                    account_proof.details.ok_or_else(|| DataStoreError::Other {
+                        error_msg: "account proof does not contain account details".into(),
+                        source: None,
+                    })?;
+                let asset_vault =
+                    AssetVault::new(&account_details.vault_details.assets).map_err(|err| {
+                        DataStoreError::Other {
+                            error_msg: format!("failed to create asset vault: {err}").into(),
+                            source: Some(Box::new(err)),
+                        }
+                    })?;
+
+                get_asset_witnesses(vault_keys, &asset_vault)


A couple of comments on this approach:

First, when we make a request to the store, we should use the reference block of this data store (i.e., self.reference_header.block_num().

But also, getting the full account proof is very heavy compared to what we need here. Maybe that's OK for this PR, but we should follow it up with using dedicated endpoints on the store to get asset/storage witnesses. Let's create an issue for this.

crates/validator/src/tx_validation/data_store.rs

bobbinth · 2026-01-08T01:33:55Z

crates/validator/src/tx_validation/data_store.rs

+                let foreign_inputs = self
+                    .tx_inputs
+                    .read_foreign_account_inputs(account_id)
+                    .map_err(|err| DataStoreError::Other {
+                        error_msg: format!("failed to read foreign account inputs: {err}").into(),
+                        source: Some(Box::new(err)),
+                    })?;
+                get_asset_witnesses_from_account(foreign_inputs.account(), vault_keys)


I'm not sure if extracting account inputs first and then trying to get asset witness from the account inputs will work (though, it depends on how read_foreign_account_inputs() works).

An alternative approach would be to read the asset witness directly. It should actually be much simpler than reading the whole account inputs object (we should be able to look up the path based on the vault_root in the Merkle store).

bobbinth · 2026-01-08T01:34:31Z

crates/validator/src/tx_validation/data_store.rs

+                let foreign_inputs = self
+                    .tx_inputs
+                    .read_foreign_account_inputs(account_id)
+                    .map_err(|_| DataStoreError::AccountNotFound(account_id))?;


Similar comment as above, but about reading storage witnesses directly rather than going though account inputs.

sergerad · 2026-01-09T01:49:37Z

Moving the Validator impl to this PR #1493

sergerad · 2026-01-16T00:18:57Z

Closing in favour of #1521

sergerad added 2 commits January 6, 2026 12:50

Update get_vault_asset_witnesses and get_foreign_account_inputs for T…

8638784

…ransactionInputsDataStore

Add todo for ntxdatastore

9df9847

sergerad commented Jan 5, 2026

View reviewed changes

sergerad force-pushed the sergerad-foreign-acc-inputs branch from a7edd4f to 9df9847 Compare January 5, 2026 23:55

sergerad commented Jan 5, 2026

View reviewed changes

sergerad added 6 commits January 7, 2026 09:20

Add get_foreign_account_inputs impl for NtxDataStore

7a13e15

Move impl to use existing get_account_proof

485f543

Add get_vault_asset_witnesses impl for NtxDataStore

014ffb4

Add get_storage_map_witness impl for NtxDataStore

8135b4f

expect instead of unwrap

454043f

Add partial get_storage_map_witness impl for TransactionInputsDataStore

ae1b914

sergerad force-pushed the sergerad-foreign-acc-inputs branch from cd2b667 to ae1b914 Compare January 7, 2026 01:44

sergerad added 5 commits January 7, 2026 15:32

Add foreign account impl for get_storage_map_witness for TransactionI…

d22e32e

…nputsDataStore

Add impl TryFrom<&AccountDetails> for Account

be374a1

Minor fixes and todos

5d92060

Fix expect todos

c025849

Merge branch 'next' of github.com:0xMiden/miden-node into sergerad-fo…

aa59a0e

…reign-acc-inputs

sergerad requested a review from bobbinth January 7, 2026 22:09

bobbinth reviewed Jan 8, 2026

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crates/ntx-builder/src/actor/execute.rs Outdated Show resolved Hide resolved

bobbinth reviewed Jan 8, 2026

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crates/ntx-builder/src/actor/execute.rs Show resolved Hide resolved

bobbinth reviewed Jan 8, 2026

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crates/validator/src/tx_validation/data_store.rs Outdated Show resolved Hide resolved

bobbinth reviewed Jan 8, 2026

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sergerad added 6 commits January 9, 2026 10:11

Replace try from impl to avoid account creation

31a30c5

Comments and factoring

a07d656

Assert ref block

5b0e863

Use ref header block num in ntx builder foreign fns

95faf66

Rm vault root check

243a28e

Replace map err

27f7919

sergerad closed this Jan 16, 2026

feat: Support foreign accounts #1486

feat: Support foreign accounts #1486

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sergerad commented Jan 5, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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sergerad commented Jan 9, 2026

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sergerad commented Jan 5, 2026 •

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