Add tx-trace-snapshot producer

CHANGELOG.md

@@ -21,6 +21,7 @@
 - Added `BlockNumber::saturating_sub()` ([#2660](https://github.com/0xMiden/protocol/issues/2660)).
 - [BREAKING] Added cycle counts to notes returned by `NoteConsumptionInfo` and removed public fields from related types ([#2772](https://github.com/0xMiden/miden-base/issues/2772)).
 - Automatically enable `concurrent` feature in `miden-tx` for `std` context ([#2791](https://github.com/0xMiden/protocol/pull/2791)).
+- Added transaction trace snapshot generation for miden-vm synthetic benchmarks ([#2794](https://github.com/0xMiden/protocol/pull/2794)).
 
 ### Fixes
 

bin/bench-transaction/Cargo.toml

@@ -17,6 +17,8 @@ path    = "src/time_counting_benchmarks/prove.rs"
 
 [dependencies]
 # Workspace dependencies
+miden-core      = { workspace = true }
+miden-processor = { features = ["concurrent"], workspace = true }
 miden-protocol  = { features = ["testing"], workspace = true }
 miden-standards = { workspace = true }
 miden-testing   = { workspace = true }

bin/bench-transaction/README.md

@@ -62,6 +62,44 @@ cargo run --bin bench-transaction --features concurrent
 cargo bench --bin bench-transaction --bench time_counting_benchmarks --features concurrent
 ```
 
+## Generating trace snapshots for miden-vm's synthetic benchmark
+
+A separate bin target, `tx-trace-snapshot`, executes the same representative transaction contexts through the VM in order to build a real `ExecutionTrace`, then it reads per-component trace lengths from `TraceLenSummary`, and writes JSON snapshots consumed by miden-vm's `miden-synthetic-tx-kernel` bench.
+
+```bash
+cargo run --release -p bench-transaction --bin tx-trace-snapshot
+```
+
+Output: one JSON per scenario under `bin/bench-transaction/snapshots/`:
+
+- `consume-single-p2id.json`
+- `consume-two-p2id.json`
+
+These files are captured against whichever miden-processor version this workspace currently pins. To feed them into `miden-vm`, copy over the same-named files in the consumer's snapshot directory:
+
+```bash
+cp bin/bench-transaction/snapshots/*.json \
+   ../miden-vm/benches/synthetic-tx-kernel/snapshots/
+```
+
+then:
+
+```bash
+cargo bench -p miden-synthetic-tx-kernel
+```
+
+The snapshot contract is documented in
+`miden-vm/benches/synthetic-tx-kernel/README.md` and
+`miden-vm/benches/synthetic-tx-kernel/src/snapshot.rs` (two tiers: `trace.*` hard-target totals, `shape.*` advisory per-chiplet breakdown).
+
+The consumer's hard match is based on padded trace brackets, not exact raw row equality:
+`padded_core_side = max(64, next_pow2(max(core_rows, range_rows)))` and
+`padded_chiplets = max(64, next_pow2(chiplets_rows))`. The raw per-chiplet `shape.*` values help
+the synthetic workload stay representative, but they are advisory profiling metadata rather than
+the primary proof-cost contract.
+
+The schema is maintained manually; there is no shared schema crate. The `schema_version` field is cross-checked at load time, and the consumer's loader rejects unknown versions. When changing the schema, bump both sides together.
+
 ## License
 
-This project is [MIT licensed](../../LICENSE).
+This project is [MIT licensed](../../LICENSE).

bin/bench-transaction/snapshots/consume-single-p2id.json

@@ -0,0 +1,18 @@
+{
+  "schema_version": "0",
+  "source": "protocol/bench-transaction:consume-single-p2id",
+  "timestamp": "unix-1776687994",
+  "miden_vm_version": "0.22",
+  "trace": {
+    "core_rows": 77699,
+    "chiplets_rows": 123129,
+    "range_rows": 20203
+  },
+  "shape": {
+    "hasher_rows": 120352,
+    "bitwise_rows": 416,
+    "memory_rows": 2297,
+    "kernel_rom_rows": 63,
+    "ace_rows": 0
+  }
+}

bin/bench-transaction/snapshots/consume-two-p2id.json

@@ -0,0 +1,18 @@
+{
+  "schema_version": "0",
+  "source": "protocol/bench-transaction:consume-two-p2id",
+  "timestamp": "unix-1776687994",
+  "miden_vm_version": "0.22",
+  "trace": {
+    "core_rows": 80522,
+    "chiplets_rows": 141260,
+    "range_rows": 20121
+  },
+  "shape": {
+    "hasher_rows": 138208,
+    "bitwise_rows": 592,
+    "memory_rows": 2392,
+    "kernel_rom_rows": 67,
+    "ace_rows": 0
+  }
+}