# Run commands from custom item data!
\nCobalt core is a datapack that allows for items to run commands from custom data!<\/p>\n
**To Use**:
\nEnter the command you want to run into the proper custom data path:
\n“`json
\n{
\n “components”: {
\n “custom_data”: {
\n “cobalt”: {
\n “onUse”: {
\n “command”: “say Hello World!”
\n }
\n }
\n }
\n }
\n}
\n“`
\n#
\nBelow are all current uses for Cobalt Core, along with example commands:<\/p>\n
`onUse`: runs on item use when in mainhand (item must have `consumable` component with `consume_seconds:2147483647,animation:”block”`)
\n“`mcfunction
\n\/give @s stick[consumable={consume_seconds:2147483647,animation:”block”},custom_data={cobalt:{onUse:{command:”say Hello world!”}}}]
\n“`
\n`onShiftUse`: runs on item use when in mainhand while sneaking (same requirements as `onUse`)
\n“`mcfunction
\n\/give @s nether_star[consumable={consume_seconds:2147483647,animation:”block”},custom_data={cobalt:{onShiftUse:{command:”say Goodbye world!”}}}]
\n“`
\n`onAttack`: runs upon successfully attacking a mob when in mainhand
\n“`mcfunction
\n\/give @s iron_sword[custom_data={cobalt:{onAttack:{command:”effect give @n[nbt={HurtTime:10s},distance=..8] poison”}}}]
\n“`
\n`onBlock`: runs upon successfully blocking damage when held (item must have `blocks_attack` component (1.21.5+) or be a shield)
\n“`mcfunction
\n\/give @s shield[custom_data={cobalt:{onBlock:{command:”execute on attacker at @s run summon lightning_bolt”}}}]
\n“`
\n`onDamage`: runs upon taking damage from a mob when held or worn
\n“`mcfunction
\n\/give @s diamond_chestplate[custom_data={cobalt:{onDamage:{command:”execute on attacker run damage @s 2″}}}]
\n“`
\n`projectile.onHitMob`: runs when a thrown or shot projectile from this item hits a mob
\n“`mcfunction
\n\/give @s crossbow[custom_data={cobalt:{projectile:{onHitMob:{command:”summon tnt ~ ~ ~ {fuse:0}”}}}}]
\n“`
\n`projectile.onHitBlock`: runs when a thrown or shot projectile from this item hits a block
\n“`mcfunction
\n\/give @s bow[custom_data={cobalt:{projectile:{onHitBlock:{command:”execute on origin run tp @s ~ ~ ~”}}}}]
\n“`
\n`onHold`: runs every tick when held or worn
\n“`mcfunction
\n\/give @s lantern[custom_data={cobalt:{onHold:{command:”effect give @e[distance=..50] glowing 1 0 true”}}}]
\n“`
\n`projectile.onSpawn`: runs for a single tick when the projectile is spawned
\n“`mcfunction
\n\/give @s trident[custom_data={cobalt:{projectile:{onSpawn:{command:”summon lightning_bolt”}}}}]
\n“`
\n`projectile.onTravel`: runs for every tick the projectile is travelling
\n“`mcfunction
\n\/give @s bow[custom_data={cobalt:{projectile:{onTravel:{command:”execute on origin run tp @s ~ ~ ~”}}}}]
\n“`<\/p>\n","protected":false},"excerpt":{"rendered":"
Run commands from items<\/p>\n","protected":false},"featured_media":41910,"template":"","meta":{"_minecraft_slug":"cobalt-core","_minecraft_project_id":"scp3dIqS","_minecraft_author":"TheCodingFlygon","_minecraft_license":"MIT","_minecraft_downloads":31,"_minecraft_follows":1,"_minecraft_client_side":"optional","_minecraft_server_side":"required","_minecraft_storage_type":"zip","_minecraft_archive_name":"cobalt-core.zip","_minecraft_size_bytes":1197861,"_minecraft_version_count":3,"_minecraft_updated_at":"2026-05-15T23:50:38.725391Z","_minecraft_date_created":"2025-05-08T06:13:35.280910Z","_minecraft_date_modified":"2025-05-17T16:20:24.745887Z","_minecraft_project_url":"https:\/\/modrinth.com\/mod\/cobalt-core","_minecraft_icon_attachment_id":41910,"_minecraft_imported_at":"2026-06-01T23:18:59+00:00","_minecraft_import_hash":"f92dad5d77f66c571f2822de59475974","_minecraft_versions":"","_minecraft_links":"","_minecraft_gallery":"","_minecraft_api_metadata":""},"mod_category":[84,88,89,873,92],"mod_loader":[86],"minecraft_version":[40,41,73,74,38,78,79,80,81,82],"class_list":["post-41909","mod","type-mod","status-publish","has-post-thumbnail","hentry","mod_category-datapack","mod_category-equipment","mod_category-game-mechanics","mod_category-library","mod_category-utility","mod_loader-datapack","minecraft_version-1-21-10","minecraft_version-1-21-11","minecraft_version-1-21-2","minecraft_version-1-21-3","minecraft_version-1-21-4","minecraft_version-1-21-5","minecraft_version-1-21-6","minecraft_version-1-21-7","minecraft_version-1-21-8","minecraft_version-1-21-9"],"yoast_head":"\n