The JWST NIRSPEC+MIRI spectrum of GRB 221009A as observed at 12 days post-burst. The upper panel shows the observed spectrum (with the black points showing near-simultaneous photometry), while the lower panel is corrected for a foreground extinction of A _V = 4.9. While this has little impact on the mid-IR, the correction factors for the optical are a factor of ∼100. The spectrum appears largely featureless, although some possible absorption features are seen. At this epoch, there are no individual emission features. For comparison, expected lines from iron group elements and possible r − process contributions are marked (Hotokezaka et al. 2022). For comparison, we also plot the best-fit absorbed power-law model and how SN 1998bw at 12 days would appear in addition to that model (the SN should contribute minimally at >5 μm, such that this additive approach is reasonable). The spectrum does not require the presence of any additional component. However, the bluest regions (which are also those most impacted by the extinction correction) do show an upturn, which is apparently also present in GTC observations. This upturn could be indicative of some SN contribution in the blue.