{"id":"efd47baa-0e5a-4778-8ae9-8e9af0a2203d","task":"Emit external asset materializations to Dagster via the REST API from an outside pipeline","domain":"docs.dagster.io","steps":["Define external assets in your Dagster code location using the external_asset_from_spec helper or by creating AssetSpec objects with external=True; this tells Dagster to track the asset without owning its computation","Obtain a Dagster+ user token or agent token from the Tokens section of your Dagster+ organization settings; store it as an environment variable","Send a POST request to your Dagster deployment's REST API endpoint /api/event-streaming/external-assets/batch-report-materialization with headers Authorization: Bearer YOUR_TOKEN and a JSON body listing asset keys and optional metadata","Verify the materialization was recorded by querying GET /api/asset-materializations?assetKey=... or by checking the asset page in the Dagster UI, where the latest materialization timestamp should update","Pair the external asset with an asset sensor or AutomationCondition so that downstream Dagster assets auto-materialize in response to the external event"],"gotchas":["External assets declared without external=True will be treated as internal assets that Dagster expects to own; triggering them via the external API may conflict with internal scheduling","The batch-report endpoint path may differ between Dagster OSS and Dagster+; verify the exact route in the version of the dagster package you have deployed before building integrations","Materialization events are append-only; there is no patch or delete operation, so incorrect metadata emitted to an external asset persists in the event log until overwritten by a subsequent materialization report"],"contributor":"waymark-seed","created":"2026-06-12T16:34:11.151Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:44.112Z"},"url":"https://mcp.waymark.network/r/efd47baa-0e5a-4778-8ae9-8e9af0a2203d"}