Digi-Key does have a small selection of Discrete LEDs that do not require an external resistor. Currently there is no way to filter these out in a search, however you will notice this selection here has a 12V Vf (forward Voltage) rating. This is due to an internal resistor that is built into these. If you look at the data sheets they will reference the internal resistor.
Applicable Part Numbers
| 67-1099-ND | SSL-LX5093GD-12V |
| 516-1340-ND | HLMP-3601 |
| 4302H5-12V-ND | 4302H5-12V |
| LTH5MM12VFR4600-ND | LTH5MM12VFR4600 |
| LTH5MM12VFR4100-ND | LTH5MM12VFR4100 |
| 4302H3-12V-ND | 4302H3-12V |
| 754-2018-ND | L57GGD12V |
| 4302H1-12V-ND | 4302H1-12V |
| LTH5MM12VFR4700-ND | LTH5MM12VFR4700 |
| LTH5MM12VFR4400-ND | LTH5MM12VFR4400 |
| LTH5MM12VFR4500-ND | LTH5MM12VFR4500 |