Project · developer-tool
migration-service
- How you run it
- not recorded
- Holochain version
- not recorded
- Activity
- active
- Checked
- 30 October 2026
What is migration-service and what is it for?
migration-service is a set of off-chain programs that help a Holochain app carry a participant's committed history from an older version of its application rules to a newer one. It lets the app fetch that participant's sealed closing record over HTTP, so the app can open on the successor version instead of an operator having to drive that step by hand.
The project is an off-chain pipeline for moving a participant's committed history from a closing version of a Holochain app to its successor. When an app version is retired, the participant's chain is sealed with a closing summary that several notaries have signed; migration-service carries that sealed package from the old network to the new one so the participant's own history comes along. It is maintained in the unytco organisation, alongside that organisation's peer-to-peer payments and accounting tools.
The service has three parts. A router is the public HTTP entry point: it checks that the move is a legitimate step along a version chain and returns the closing package to the app, holding no keys and never reading what the package contains. Beside an older network that is still running, a daemon reads that network's committed closes — it signs only its own calls through the node it runs next to, and has no way to sign on anyone else's behalf. A third program does the same work headlessly for agents running on servers rather than on a person's computer.
A concrete example is an operator running such a server-side agent: they download the released binaries and run them as supervised services, one on the old host to close the chain and one on the new host to open it, checking each step with the status and verify commands. The repository README documents the three components, how to build and test each, and the release file names.
How to get it
From the command line
- Download the release binaries from the project's GitHub releases — the assets are named headless-migrator and migration-notary, each with a matching .sha256 digest, and a latest-download URL resolves to the newest non-prerelease.
- Verify each download against its published .sha256 digest and mark the binary executable.
- Use the close service on the old host and the open service on the new host as supervised services, and the status and verify one-shots to check progress; each exits 0 only on success, so a restart-on-failure policy drives the loop.
Questions people ask
- Does migration-service hold a participant's keys or sign on their behalf?
- No. The README states the router holds no keys and never interprets the payload, and that the daemon beside the old network signs only its own calls and has no notarization path for other agents. source
- Can the off-chain service open a chain on the new app version by itself?
- No. The README says the app — or the headless migrator's open service — installs the new version with the package as the successor role's initial properties so that version's init opens the agent's own chain, a step no off-chain service can take. source
- Where do the released binaries come from, and how are they identified?
- They are published as GitHub release assets with fixed names — headless-migrator and migration-notary — each accompanied by a .sha256 digest, so a provisioning script can reference a stable URL. source
From 3 public sources, checked 23 September 2026.
Try migration-service
- Code on GitHubOpen on GitHub ↗Last change 16 October 2026.
- Releasev0.4.0Published 16 October 2026.
- The project's own files do not say how it is run.
Details & sources
- Source
- unytco/migration-service
Evidence
- Release
- github.com/unytco/migration-service/releases/tag/v0.4.0shipped in a release · seen since 20 October 2026 · github.release@1
- Last change
- api.github.com/repos/unytco/migration-servicelisted by a third party · seen since 20 October 2026 · github.repository@1
- Activity
- github.com/unytco/migration-service/releases/tag/v0.4.0shipped in a release · seen since 20 October 2026 · liveness@1
Compatibility
- hdk
- —
- hdi
- 0.8.1 · headless-migrator/Cargo.toml @ d8a244d
- holochain-client
- —
- happ.yaml
- absent
- web-happ.yaml
- absent