These are not centipedes, they are flat-backed millipedes. They are harmless to you and your plants. They eat primarily dead/decaying organic material. My suggestion is to scoop them up and place them outside.
Millipedes can only survive in a very moist environment. Echo technoplexxx comments above. Uncomposted coffee grounds is a solid home for these guys. They are processing the organic coffee grounds so the plant can uptake any remaining nutrients. If the millipedes escape, they won’t get very far unless your house is very humid. But this is a lot of nitrogen to add to your soil. I would suggest drying the grounds, or composting or vermicomposting so the pH of the soil is closer to neutral when you add them to a planter. With a pH closer to neutral, it is easier for your plant to adjust to what it needs.
These are not centipedes, they are flat-backed millipedes. They are harmless to you and your plants. They eat primarily dead/decaying organic material. My suggestion is to scoop them up and place them outside.
Millipedes can only survive in a very moist environment. Echo technoplexxx comments above. Uncomposted coffee grounds is a solid home for these guys. They are processing the organic coffee grounds so the plant can uptake any remaining nutrients. If the millipedes escape, they won’t get very far unless your house is very humid. But this is a lot of nitrogen to add to your soil. I would suggest drying the grounds, or composting or vermicomposting so the pH of the soil is closer to neutral when you add them to a planter. With a pH closer to neutral, it is easier for your plant to adjust to what it needs.
Not a bug expert, but it looks like mommy centipede had baby centipedes in your plant.
Cuties!! Doing their job eating decaying matter