Supported SDKs

Relay speaks the Conductor executor WebSocket protocol, and it derives that protocol from the public source of the DBOS Transact SDKs. Upstream is moving the Conductor connector out of the MIT-licensed SDK packages and into proprietary ones. Once a connector is proprietary, Relay cannot read it, so the protocol facts it published stay readable but stop being verifiable. This page records the range of SDK versions Relay supports and the evidence behind it.

Supported range

These are upper bounds, not recommendations. Any version at or below the ceiling works, including versions that predate it. An unmodified application built against a supported SDK connects to Relay by pointing its Conductor URL at Relay and needs no code change, no configuration change, and no Relay-side setting.

The ceiling is policy, not a technical limit. Relay is not blocked from talking to a newer SDK; it is blocked from verifying what that SDK does, and the project's rule is that a protocol claim is either cited from a permitted source or proven by a test against a real SDK. The ceiling is revisited whenever upstream publishes, which is what the checks described below are for.

Why the ceiling exists

Three SDKs have already split the connector out of the public package on their main branches. Those commits are unreleased as of 2026-10-11, so the published releases still contain the connector.

Java has no such commit. At commit 85b3f0ed0458b72358fb7554bc20931bd61e7897 on main the whole transact/src/main/java/dev/dbos/transact/conductor/ tree is still present and public, which makes Java the only SDK left that publishes the wire protocol in the open. That is why the loss of the Java connector is watched separately, and why it is worth reacting to quickly rather than at the next release review.

Evidence for each ceiling

Every version claim below names the repository tag it comes from and the package-registry upload date for the same version. Registry timestamps are UTC; repository tag dates are the committer dates of the tagged commits.

Go

• Tag v1.6.0 in dbos-inc/dbos-transact-golang, commit 04337c15667adcdf5cc057be448ed9545d6f06d9, tagged 2026-10-07.
• proxy.golang.org reports @latest as v1.6.0 at 2026-10-07T16:06:46Z.
• git ls-tree -r v1.6.0 lists dbos/conductor.go and dbos/conductor_protocol.go, so the connector is still in the published module.

Python

• Tag 3.2.0 in dbos-inc/dbos-transact-py, commit d324156616281d7d4923bc60851617bdbb70ea5e, tagged 2026-09-28.
• PyPI reports dbos 3.2.0 uploaded 2026-09-29T15:43:49, and it is the latest release on the index.
• The published 3.2.0 distribution contains dbos/_conductor/conductor.py and dbos/_conductor/protocol.py.

TypeScript

• Tag v5.2 in dbos-inc/dbos-transact-ts, commit 3f36908f58fd8b3079cbf5372203c7a2d0ba06cc, tagged 2026-09-29.
• The npm registry reports @dbos-inc/dbos-sdk 5.2.11 published 2026-09-29T15:48:15.957Z, and latest points at 5.2.11.
• The published 5.2.11 tarball contains dist/src/conductor/conductor.js and dist/src/conductor/protocol.js.
• The 5.3.x line exists on the registry only as preview and test dist-tags, so no stable release has shipped past the ceiling.

Java

• origin/main of dbos-inc/dbos-transact-java is at 85b3f0ed0458b72358fb7554bc20931bd61e7897, dated 2026-10-08, and carries 64 files under transact/src/main/java/dev/dbos/transact/conductor/ with no enterprise package anywhere in the tree.
• The latest release tag is 1.2.0, commit 0f4fe187b20bd6f5f735d8f99d810aeb90b8314d, tagged 2026-09-30. Maven Central also serves 1.3.0-m1 through 1.3.0-m7 milestones.
• Because there is no split commit, there is nothing to cap yet.

Protocol pins

The protocol facts in this wiki are pinned in the provenance ledger, which records the repository, commit, and confirmation date for each SDK source. Those pins predate the ceiling and are not bumped by it: the ceiling bounds what an application may run, while the pins bound what Relay's protocol description was derived from. A ceiling bump and a pin refresh are separate changes.

Enforcement

Two checks keep the ceiling from going stale silently.

• tests/verifysdk/sdk_ceiling_test.go reads the manifests of the sample applications in examples/ and fails when a pinned SDK version is above the ceiling recorded in this page. It reads files only, runs offline, and is part of make test.
• make watch/java-connector runs scripts/watch-java-connector.py, which clones the Java SDK and fails when the Conductor connector package is no longer present at the recorded baseline. It needs network access, so it is not part of make check; run it on a schedule or before a release.

Bumping the ceiling

1. Re-verify the upstream state: the newest tag of each SDK, the newest registry upload, and whether the connector is still in that published artefact.
2. Update this page, including the citations, and record the change in the documentation log.
3. Update the constants in tests/verifysdk/sdk_ceiling_test.go so the example pins are checked against the new bound.
4. Bump the sample application pins in examples/ and confirm each still builds. The data-plane client in the root go.mod is deliberately not bumped with them; see ADR 0004.
5. If the Java connector has moved, update the baseline in scripts/watch-java-connector.py and record the new last-known-good commit and file count.