diff --git a/languages.toml b/languages.toml
index ea6e6893f..d9f6c8fd7 100644
--- a/languages.toml
+++ b/languages.toml
@@ -750,6 +750,7 @@ roots = [ "package.json" ]
 comment-token = "//"
 block-comment-tokens = { start = "/*", end = "*/" }
 language-servers = [ "typescript-language-server" ]
+formatter = { command = "biome", args = ["format"] }
 indent = { tab-width = 2, unit = "  " }
 
 [language.debugger]
@@ -778,6 +779,7 @@ roots = [ "package.json" ]
 comment-token = "//"
 block-comment-tokens = { start = "/*", end = "*/" }
 language-servers = [ "typescript-language-server" ]
+formatter = { command = "biome", args = ["format"] }
 indent = { tab-width = 2, unit = "  " }
 grammar = "javascript"
 
@@ -792,6 +794,7 @@ roots = [ "package.json", "tsconfig.json" ]
 comment-token = "//"
 block-comment-tokens = { start = "/*", end = "*/" }
 language-servers = [ "typescript-language-server" ]
+formatter = { command = "biome", args = ["format"] }
 indent = { tab-width = 2, unit = "  " }
 
 [[grammar]]
@@ -825,6 +828,7 @@ roots = [ "package.json", "tsconfig.json" ]
 comment-token = "//"
 block-comment-tokens = { start = "/*", end = "*/" }
 language-servers = [ "typescript-language-server" ]
+formatter = { command = "biome", args = ["format"] }
 indent = { tab-width = 2, unit = "  " }
 
 [[grammar]]
@@ -882,6 +886,7 @@ shebangs = ["python"]
 roots = ["pyproject.toml", "setup.py", "poetry.lock", "pyrightconfig.json"]
 comment-token = "#"
 language-servers = ["ruff", "jedi", "pylsp"]
+formatter = { command = "black", args = ["-"]}
 # TODO: pyls needs utf-8 offsets
 indent = { tab-width = 4, unit = "    " }
 
@@ -1354,6 +1359,7 @@ roots = ["Setup.hs", "stack.yaml", "cabal.project"]
 comment-token = "--"
 block-comment-tokens = { start = "{-", end = "-}" }
 language-servers = [ "haskell-language-server" ]
+formatter = { command = "ormolu" }
 indent = { tab-width = 2, unit = "  " }
 
 [[grammar]]
@@ -1807,6 +1813,7 @@ auto-format = true
 comment-token = "--"
 block-comment-tokens = { start = "{-", end = "-}" }
 language-servers = [ "elm-language-server" ]
+formatter = { command = "elm-format", args = ["--stdin"] }
 indent = { tab-width = 4, unit = "    " }
 
 [[grammar]]
@@ -3793,6 +3800,7 @@ language-servers = [
     "vscode-eslint-language-server",
     "ember-language-server",
 ]
+formatter = { command = "biome", args = ["format"] }
 indent = { tab-width = 2, unit = "  " }
 grammar = "javascript"
 
@@ -3817,6 +3825,7 @@ language-servers = [
     "vscode-eslint-language-server",
     "ember-language-server",
 ]
+formatter = { command = "biome", args = ["format"] }
 indent = { tab-width = 2, unit = "  " }
 grammar = "typescript"