Choose an indexer

OpenWeights reaches the Sia network through an indexer. It does not bundle one: you supply the URL, and both openweights-cas and openweights-gateway use it.

Set it once in .env:

OPENWEIGHTS_INDEXER_URL=https://sia.storage

https://sia.storage is the default the setup wizard offers and the default the Compose file falls back to when the variable is unset.

Hosted: https://sia.storage

A hosted indexer, so you do not run one or fund its wallet yourself.

A hosted indexer exposes no admin API. Two console panels read that API for host-level detail, so with https://sia.storage they have nothing to show:

• the host map on /stats/map
• the "on Sia network" section of the setup page

Everything else in the console, and both the upload and download paths, work normally.

Your own indexd

Run indexd yourself and point at it:

OPENWEIGHTS_INDEXER_URL=http://my-indexd:9982

Running your own indexer means you also fund its wallet and it forms its own storage contracts. To light up the console's host map and setup panels, also set the admin API:

INDEXD_ADMIN_URL=<your indexd admin API base URL, no trailing slash>
INDEXD_ADMIN_PASSWORD=<your indexd admin password>

INDEXD_ADMIN_URL points at indexd's admin API, which is separate from the app API in OPENWEIGHTS_INDEXER_URL. The CAS reads both.

Redundancy

Uploads are erasure-coded before they reach Sia. Two variables control the scheme:

The defaults need enough usable hosts to satisfy a 10-of-30 scheme. Lowering them lets a smaller host set form contracts. Set either to a value that is not a valid number in the range 0 to 255 and the CAS fails at startup rather than falling back to the default.

After changing the indexer

The App Key is derived per indexer, so switching means re-registering:

1. Update OPENWEIGHTS_INDEXER_URL in .env.
2. Re-run openweights-cas-register and replace OPENWEIGHTS_APP_KEY with the new base64 value it prints.
3. make up to restart the services with the new key.

See Run the stack for the registration steps.

The first pin takes time

On a fresh indexer, the first upload forms on-chain storage contracts across many hosts, which takes minutes. OpenWeights accepts the upload immediately and a background reconciler finishes the pin. Two variables bound that work:

The shipped Compose file sets these to 20 and 3600: return to the client fast, and give the background pin an hour to land.

A download attempted before the pin lands returns 404 at reconstruction. Retry until it succeeds. See Verify a round-trip, whose harness does this for you.