## Motivation

The JSON-RPC server already returns `x-aztec-*` headers for protocol
component versions (chain id, rollup address, etc.), but does not
include the node's package version. This makes it harder to identify
which software version a node is running when debugging or monitoring.

## Approach

Extended `getVersioningMiddleware` to accept an optional
`packageVersion` parameter and emit it as an `x-aztec-packageVersion`
response header alongside existing versioning headers.

## Example

```
$ curl -s -D- http://localhost:8090 -H 'content-type: application/json' -d '[{"jsonrpc":"2.0","id":1,"method":"node_getNodeVersion","params":[]}]'
HTTP/1.1 200 OK
Vary: Accept-Encoding, Origin
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
x-aztec-l2CircuitsVkTreeRoot: 0x06624799e2080c43aba671cdece34d5f4cdff2122bc6be41d80bd903ca0975cc
x-aztec-l2ProtocolContractsHash: 0x23c2022f0b69b29e354b4f7612d5db3ba0bc4259d71ac9186ed272945a644b9c
x-aztec-packageVersion: 5.0.0
Content-Length: 43
Date: Fri, 13 Mar 2026 16:04:31 GMT
Connection: keep-alive
Keep-Alive: timeout=5

[{"jsonrpc":"2.0","id":1,"result":"5.0.0"}]
```

## Changes

- **stdlib**: Updated `getVersioningMiddleware` to accept an optional
`opts` bag with `packageVersion`, setting `x-aztec-packageVersion`
header when provided
- **aztec**: Wired `getPackageVersion()` into both the main and admin
RPC server middleware calls

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

BEGIN_COMMIT_OVERRIDE
fix: orchestrator enqueue yield (#21286)
chore: default multiplier (#21482)
chore: update yarn.lock (#21479)
chore: backport #21231 feat!: improve L2ToL1MessageWitness API to v4
(#21463)
feat(rpc): add package version to RPC response headers (#21526)
feat(ethereum): check VK tree root and protocol contracts hash in rollup
compatibility (#21537)
feat: add public log filtering by tag (#21561)
END_COMMIT_OVERRIDE

BEGIN_COMMIT_OVERRIDE
feat: add ETHEREUM_HTTP_TIMEOUT_MS env var for viem HTTP transport
(#20919)
fix(archiver): filter tagged log queries by block number (#21388)
fix(node): handle slot zero in getL2ToL1Messages (#21386)
feat(sequencer): redistribute checkpoint budget evenly across remaining
blocks (#21378)
fix: fall back to package.json for CLI version detection (#21382)
chore: Removed multiplier config (#21412)
chore: Removed default snapshot url config (#21413)
chore: Read tx filestores from network config (#21416)
fix(node): check world state against requested block hash (#21385)
feat(p2p): use l2 priority fee only for tx priority (#21420)
feat(p2p): reject and evict txs with insufficient max fee per gas
(#21281)
revert "feat(p2p): reject and evict txs with insufficient max fee per
gas (#21281)" (#21432)
chore: Reduce log spam (#21436)
fix(tx): reject txs with invalid setup when unprotecting (#21224)
fix: orchestrator enqueue yield (#21286)
chore(builder): check archive tree next leaf index during block building
(#21457)
fix: scenario deployment (#21428)
chore: add claude skill to read network-logs (#21495)
chore: update claude network-logs skill (#21523)
feat(rpc): add package version to RPC response headers (#21526)
chore(prover): silence "epoch to prove" debug logs (#21527)
chore(sequencer): do not log blob data (#21530)
fix: dependabot alerts (#21531)
docs(p2p): nicer READMEs (#21456)
fix(archiver): guard getL1ToL2Messages against incomplete message sync
(#21494)
fix(sequencer): await syncing proposed block to archiver (#21554)
feat(ethereum): check VK tree root and protocol contracts hash in rollup
compatibility (#21537)
fix: marking peer as dumb on failed responses (#21316)
fix(kv-store): make LMDB clear and drop operations atomic across
sub-databases (#21539)
feat(world-state): add blockHash verification to syncImmediate (#21556)
chore(monitor): print out l2 fees components (#21559)
chore: rm faucet (#21538)
chore: remove old merkle trees (#21577)
feat: Implement commit all and revert all for world state checkpoints
(#21532)
chore: skip flaky browser acir tests in CI (#21596)
fix: Better detection for epoch prune (#21478)
chore: logging (#21604)
fix: Don't update state if we failed to execute sufficient transactions
(#21443)
END_COMMIT_OVERRIDE