## Queue a backfill over a block range `POST /api/subgraphs/{name}/backfill` (self-hosted instances only) Re-runs handlers over `fromBlock` to `toBlock`, inclusive, without dropping data. A backfill that overlaps an earlier failed or cancelled one resumes from its last committed block. Refused when the handlers apply deltas (`ctx.increment`, `ctx.update`) or read-modify-write rows (`ctx.findOne`, `ctx.findMany`), which would double-count blocks already processed; reindex those instead. ### Path parameters | Name | Type | Description | | --- | --- | --- | | `name` | string, required | Subgraph name, as deployed. Lowercase letters, digits and hyphens. | ### Body | Field | Type | Description | | --- | --- | --- | | `fromBlock` | integer, required | First block height to re-run, inclusive. | | `toBlock` | integer, required | Last block height to re-run, inclusive. | ### Returns One `SubgraphOperationQueued` object. ### Responses - `200` Backfill queued - `400` `fromBlock` or `toBlock` is missing, not a number, or 0 (`VALIDATION_ERROR`) - `401` This bind requires the instance token, and it was missing or wrong - `404` No subgraph by this name on this instance (`SUBGRAPH_NOT_FOUND`) - `409` A reindex or backfill is already queued or running for this subgraph (`OPERATION_IN_PROGRESS`). Wait for it, or stop it first. - `415` Missing or non-JSON `Content-Type` (`UNSUPPORTED_MEDIA_TYPE`) — writes must send `Content-Type: application/json` - `422` The handlers apply deltas and cannot be replayed (`BACKFILL_NON_REPLAYABLE_HANDLER`) ### Example ```bash curl -X POST http://127.0.0.1:3800/api/subgraphs/{name}/backfill \ -H "Authorization: Bearer $INSTANCE_TOKEN" \ --json '{ "fromBlock": 8950000, "toBlock": 9000000 }' ``` ```json { "message": "Backfill queued for subgraph \"sbtc-flows\"", "fromBlock": 8950000, "toBlock": 9000000, "operationId": "9a4e7c21-0b3d-4f6a-8c15-e2d7b9f0a461", "status": "queued" } ```