diff --git a/.gitignore b/.gitignore
index 3545968..e43b0f9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1 @@
 .DS_Store
-Manifest.toml
diff --git a/Manifest.toml b/Manifest.toml
new file mode 100644
index 0000000..bba0dd7
--- /dev/null
+++ b/Manifest.toml
@@ -0,0 +1,443 @@
+# This file is machine-generated - editing it directly is not advised
+
+julia_version = "1.8.1"
+manifest_format = "2.0"
+project_hash = "fbe0ee936dd5830e6ed140283f15265ec4d07a17"
+
+[[deps.ArgParse]]
+deps = ["Logging", "TextWrap"]
+git-tree-sha1 = "3102bce13da501c9104df33549f511cd25264d7d"
+uuid = "c7e460c6-2fb9-53a9-8c5b-16f535851c63"
+version = "1.1.4"
+
+[[deps.ArgTools]]
+uuid = "0dad84c5-d112-42e6-8d28-ef12dabb789f"
+version = "1.1.1"
+
+[[deps.Arrow]]
+deps = ["ArrowTypes", "BitIntegers", "CodecLz4", "CodecZstd", "DataAPI", "Dates", "Mmap", "PooledArrays", "SentinelArrays", "Tables", "TimeZones", "UUIDs"]
+git-tree-sha1 = "4e7aa2021204bd9456ad3e87372237e84ee2c3c1"
+uuid = "69666777-d1a9-59fb-9406-91d4454c9d45"
+version = "2.3.0"
+
+[[deps.ArrowTypes]]
+deps = ["UUIDs"]
+git-tree-sha1 = "a0633b6d6efabf3f76dacd6eb1b3ec6c42ab0552"
+uuid = "31f734f8-188a-4ce0-8406-c8a06bd891cd"
+version = "1.2.1"
+
+[[deps.Artifacts]]
+uuid = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
+
+[[deps.Base64]]
+uuid = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
+
+[[deps.BitIntegers]]
+deps = ["Random"]
+git-tree-sha1 = "5a814467bda636f3dde5c4ef83c30dd0a19928e0"
+uuid = "c3b6d118-76ef-56ca-8cc7-ebb389d030a1"
+version = "0.2.6"
+
+[[deps.BufferedStreams]]
+git-tree-sha1 = "bb065b14d7f941b8617bc323063dbe79f55d16ea"
+uuid = "e1450e63-4bb3-523b-b2a4-4ffa8c0fd77d"
+version = "1.1.0"
+
+[[deps.CEnum]]
+git-tree-sha1 = "eb4cb44a499229b3b8426dcfb5dd85333951ff90"
+uuid = "fa961155-64e5-5f13-b03f-caf6b980ea82"
+version = "0.4.2"
+
+[[deps.CodecLz4]]
+deps = ["Lz4_jll", "TranscodingStreams"]
+git-tree-sha1 = "59fe0cb37784288d6b9f1baebddbf75457395d40"
+uuid = "5ba52731-8f18-5e0d-9241-30f10d1ec561"
+version = "0.4.0"
+
+[[deps.CodecZlib]]
+deps = ["TranscodingStreams", "Zlib_jll"]
+git-tree-sha1 = "ded953804d019afa9a3f98981d99b33e3db7b6da"
+uuid = "944b1d66-785c-5afd-91f1-9de20f533193"
+version = "0.7.0"
+
+[[deps.CodecZstd]]
+deps = ["CEnum", "TranscodingStreams", "Zstd_jll"]
+git-tree-sha1 = "849470b337d0fa8449c21061de922386f32949d9"
+uuid = "6b39b394-51ab-5f42-8807-6242bab2b4c2"
+version = "0.7.2"
+
+[[deps.Compat]]
+deps = ["Base64", "Dates", "DelimitedFiles", "Distributed", "InteractiveUtils", "LibGit2", "Libdl", "LinearAlgebra", "Markdown", "Mmap", "Pkg", "Printf", "REPL", "Random", "SHA", "Serialization", "SharedArrays", "Sockets", "SparseArrays", "Statistics", "Test", "UUIDs", "Unicode"]
+git-tree-sha1 = "78bee250c6826e1cf805a88b7f1e86025275d208"
+uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
+version = "3.46.0"
+
+[[deps.CompilerSupportLibraries_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "e66e0078-7015-5450-92f7-15fbd957f2ae"
+version = "0.5.2+0"
+
+[[deps.ConfParser]]
+git-tree-sha1 = "db2712392fbf7dd12eff7c2ea620a34b5d0ad7b9"
+uuid = "88353bc9-fd38-507d-a820-d3b43837d6b9"
+version = "0.1.2"
+
+[[deps.DataAPI]]
+git-tree-sha1 = "fb5f5316dd3fd4c5e7c30a24d50643b73e37cd40"
+uuid = "9a962f9c-6df0-11e9-0e5d-c546b8b5ee8a"
+version = "1.10.0"
+
+[[deps.DataValueInterfaces]]
+git-tree-sha1 = "bfc1187b79289637fa0ef6d4436ebdfe6905cbd6"
+uuid = "e2d170a0-9d28-54be-80f0-106bbe20a464"
+version = "1.0.0"
+
+[[deps.Dates]]
+deps = ["Printf"]
+uuid = "ade2ca70-3891-5945-98fb-dc099432e06a"
+
+[[deps.DelimitedFiles]]
+deps = ["Mmap"]
+uuid = "8bb1440f-4735-579b-a4ab-409b98df4dab"
+
+[[deps.Distributed]]
+deps = ["Random", "Serialization", "Sockets"]
+uuid = "8ba89e20-285c-5b6f-9357-94700520ee1b"
+
+[[deps.Downloads]]
+deps = ["ArgTools", "FileWatching", "LibCURL", "NetworkOptions"]
+uuid = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
+version = "1.6.0"
+
+[[deps.EnumX]]
+git-tree-sha1 = "1d2621e1a6246c5cf1116be0055686f305210b80"
+uuid = "4e289a0a-7415-4d19-859d-a7e5c4648b56"
+version = "1.0.2"
+
+[[deps.ExceptionUnwrapping]]
+deps = ["Test"]
+git-tree-sha1 = "f7de69df4c5f0c09b3bde6bdaf618e16900988e3"
+uuid = "460bff9d-24e4-43bc-9d9f-a8973cb893f4"
+version = "0.1.4"
+
+[[deps.ExprTools]]
+git-tree-sha1 = "56559bbef6ca5ea0c0818fa5c90320398a6fbf8d"
+uuid = "e2ba6199-217a-4e67-a87a-7c52f15ade04"
+version = "0.1.8"
+
+[[deps.FileWatching]]
+uuid = "7b1f6079-737a-58dc-b8bc-7a2ca5c1b5ee"
+
+[[deps.Future]]
+deps = ["Random"]
+uuid = "9fa8497b-333b-5362-9e8d-4d0656e87820"
+
+[[deps.HTTP]]
+deps = ["Base64", "CodecZlib", "Dates", "IniFile", "Logging", "LoggingExtras", "MbedTLS", "NetworkOptions", "Random", "SimpleBufferStream", "Sockets", "URIs", "UUIDs"]
+git-tree-sha1 = "59ba44e0aa49b87a8c7a8920ec76f8afe87ed502"
+uuid = "cd3eb016-35fb-5094-929b-558a96fad6f3"
+version = "1.3.3"
+
+[[deps.IniFile]]
+git-tree-sha1 = "f550e6e32074c939295eb5ea6de31849ac2c9625"
+uuid = "83e8ac13-25f8-5344-8a64-a9f2b223428f"
+version = "0.5.1"
+
+[[deps.InlineStrings]]
+deps = ["Parsers"]
+git-tree-sha1 = "d19f9edd8c34760dca2de2b503f969d8700ed288"
+uuid = "842dd82b-1e85-43dc-bf29-5d0ee9dffc48"
+version = "1.1.4"
+
+[[deps.InteractiveUtils]]
+deps = ["Markdown"]
+uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
+
+[[deps.IteratorInterfaceExtensions]]
+git-tree-sha1 = "a3f24677c21f5bbe9d2a714f95dcd58337fb2856"
+uuid = "82899510-4779-5014-852e-03e436cf321d"
+version = "1.0.0"
+
+[[deps.JLLWrappers]]
+deps = ["Preferences"]
+git-tree-sha1 = "abc9885a7ca2052a736a600f7fa66209f96506e1"
+uuid = "692b3bcd-3c85-4b1f-b108-f13ce0eb3210"
+version = "1.4.1"
+
+[[deps.JSON3]]
+deps = ["Dates", "Mmap", "Parsers", "StructTypes", "UUIDs"]
+git-tree-sha1 = "f1572de22c866dc92aea032bc89c2b137cbddd6a"
+uuid = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
+version = "1.10.0"
+
+[[deps.LazyArtifacts]]
+deps = ["Artifacts", "Pkg"]
+uuid = "4af54fe1-eca0-43a8-85a7-787d91b784e3"
+
+[[deps.LibCURL]]
+deps = ["LibCURL_jll", "MozillaCACerts_jll"]
+uuid = "b27032c2-a3e7-50c8-80cd-2d36dbcbfd21"
+version = "0.6.3"
+
+[[deps.LibCURL_jll]]
+deps = ["Artifacts", "LibSSH2_jll", "Libdl", "MbedTLS_jll", "Zlib_jll", "nghttp2_jll"]
+uuid = "deac9b47-8bc7-5906-a0fe-35ac56dc84c0"
+version = "7.84.0+0"
+
+[[deps.LibGit2]]
+deps = ["Base64", "NetworkOptions", "Printf", "SHA"]
+uuid = "76f85450-5226-5b5a-8eaa-529ad045b433"
+
+[[deps.LibSSH2_jll]]
+deps = ["Artifacts", "Libdl", "MbedTLS_jll"]
+uuid = "29816b5a-b9ab-546f-933c-edad1886dfa8"
+version = "1.10.2+0"
+
+[[deps.Libdl]]
+uuid = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+
+[[deps.LinearAlgebra]]
+deps = ["Libdl", "libblastrampoline_jll"]
+uuid = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+
+[[deps.Logging]]
+uuid = "56ddb016-857b-54e1-b83d-db4d58db5568"
+
+[[deps.LoggingExtras]]
+deps = ["Dates", "Logging"]
+git-tree-sha1 = "5d4d2d9904227b8bd66386c1138cf4d5ffa826bf"
+uuid = "e6f89c97-d47a-5376-807f-9c37f3926c36"
+version = "0.4.9"
+
+[[deps.Lz4_jll]]
+deps = ["Artifacts", "JLLWrappers", "Libdl", "Pkg"]
+git-tree-sha1 = "5d494bc6e85c4c9b626ee0cab05daa4085486ab1"
+uuid = "5ced341a-0733-55b8-9ab6-a4889d929147"
+version = "1.9.3+0"
+
+[[deps.Markdown]]
+deps = ["Base64"]
+uuid = "d6f4376e-aef5-505a-96c1-9c027394607a"
+
+[[deps.MbedTLS]]
+deps = ["Dates", "MbedTLS_jll", "MozillaCACerts_jll", "Random", "Sockets"]
+git-tree-sha1 = "ae6676d5f576ccd21b6789c2cbe2ba24fcc8075d"
+uuid = "739be429-bea8-5141-9913-cc70e7f3736d"
+version = "1.1.5"
+
+[[deps.MbedTLS_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "c8ffd9c3-330d-5841-b78e-0817d7145fa1"
+version = "2.28.0+0"
+
+[[deps.Mmap]]
+uuid = "a63ad114-7e13-5084-954f-fe012c677804"
+
+[[deps.Mocking]]
+deps = ["Compat", "ExprTools"]
+git-tree-sha1 = "29714d0a7a8083bba8427a4fbfb00a540c681ce7"
+uuid = "78c3b35d-d492-501b-9361-3d52fe80e533"
+version = "0.7.3"
+
+[[deps.MozillaCACerts_jll]]
+uuid = "14a3606d-f60d-562e-9121-12d972cd8159"
+version = "2022.2.1"
+
+[[deps.NetworkOptions]]
+uuid = "ca575930-c2e3-43a9-ace4-1e988b2c1908"
+version = "1.2.0"
+
+[[deps.Nullables]]
+git-tree-sha1 = "8f87854cc8f3685a60689d8edecaa29d2251979b"
+uuid = "4d1e1d77-625e-5b40-9113-a560ec7a8ecd"
+version = "1.0.0"
+
+[[deps.OpenBLAS_jll]]
+deps = ["Artifacts", "CompilerSupportLibraries_jll", "Libdl"]
+uuid = "4536629a-c528-5b80-bd46-f80d51c5b363"
+version = "0.3.20+0"
+
+[[deps.OrderedCollections]]
+git-tree-sha1 = "85f8e6578bf1f9ee0d11e7bb1b1456435479d47c"
+uuid = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
+version = "1.4.1"
+
+[[deps.Parsers]]
+deps = ["Dates"]
+git-tree-sha1 = "3d5bf43e3e8b412656404ed9466f1dcbf7c50269"
+uuid = "69de0a69-1ddd-5017-9359-2bf0b02dc9f0"
+version = "2.4.0"
+
+[[deps.Pkg]]
+deps = ["Artifacts", "Dates", "Downloads", "LibGit2", "Libdl", "Logging", "Markdown", "Printf", "REPL", "Random", "SHA", "Serialization", "TOML", "Tar", "UUIDs", "p7zip_jll"]
+uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+version = "1.8.0"
+
+[[deps.PooledArrays]]
+deps = ["DataAPI", "Future"]
+git-tree-sha1 = "a6062fe4063cdafe78f4a0a81cfffb89721b30e7"
+uuid = "2dfb63ee-cc39-5dd5-95bd-886bf059d720"
+version = "1.4.2"
+
+[[deps.Preferences]]
+deps = ["TOML"]
+git-tree-sha1 = "47e5f437cc0e7ef2ce8406ce1e7e24d44915f88d"
+uuid = "21216c6a-2e73-6563-6e65-726566657250"
+version = "1.3.0"
+
+[[deps.Printf]]
+deps = ["Unicode"]
+uuid = "de0858da-6303-5e67-8744-51eddeeeb8d7"
+
+[[deps.ProtoBuf]]
+deps = ["BufferedStreams", "Dates", "EnumX", "TOML", "TranscodingStreams"]
+git-tree-sha1 = "32f6c63fb3b5685bf83512b597bae55a5628cc87"
+uuid = "3349acd9-ac6a-5e09-bcdb-63829b23a429"
+version = "1.0.6"
+
+[[deps.REPL]]
+deps = ["InteractiveUtils", "Markdown", "Sockets", "Unicode"]
+uuid = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
+
+[[deps.Random]]
+deps = ["SHA", "Serialization"]
+uuid = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+
+[[deps.RecipesBase]]
+git-tree-sha1 = "6bf3f380ff52ce0832ddd3a2a7b9538ed1bcca7d"
+uuid = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
+version = "1.2.1"
+
+[[deps.SHA]]
+uuid = "ea8e919c-243c-51af-8825-aaa63cd721ce"
+version = "0.7.0"
+
+[[deps.Scratch]]
+deps = ["Dates"]
+git-tree-sha1 = "f94f779c94e58bf9ea243e77a37e16d9de9126bd"
+uuid = "6c6a2e73-6563-6170-7368-637461726353"
+version = "1.1.1"
+
+[[deps.Select]]
+deps = ["Nullables"]
+git-tree-sha1 = "eedc12abb6c7fecd172b698d15de543e7a833ed1"
+repo-rev = "master"
+repo-url = "https://github.com/NHDaly/Select.jl"
+uuid = "ac7b3b08-bf78-4e82-aa6e-b038cb67d740"
+version = "0.1.0"
+
+[[deps.SentinelArrays]]
+deps = ["Dates", "Random"]
+git-tree-sha1 = "db8481cf5d6278a121184809e9eb1628943c7704"
+uuid = "91c51154-3ec4-41a3-a24f-3f23e20d615c"
+version = "1.3.13"
+
+[[deps.Serialization]]
+uuid = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
+
+[[deps.SharedArrays]]
+deps = ["Distributed", "Mmap", "Random", "Serialization"]
+uuid = "1a1011a3-84de-559e-8e89-a11a2f7dc383"
+
+[[deps.SimpleBufferStream]]
+git-tree-sha1 = "874e8867b33a00e784c8a7e4b60afe9e037b74e1"
+uuid = "777ac1f9-54b0-4bf8-805c-2214025038e7"
+version = "1.1.0"
+
+[[deps.Sockets]]
+uuid = "6462fe0b-24de-5631-8697-dd941f90decc"
+
+[[deps.SparseArrays]]
+deps = ["LinearAlgebra", "Random"]
+uuid = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
+
+[[deps.Statistics]]
+deps = ["LinearAlgebra", "SparseArrays"]
+uuid = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
+
+[[deps.StructTypes]]
+deps = ["Dates", "UUIDs"]
+git-tree-sha1 = "ca4bccb03acf9faaf4137a9abc1881ed1841aa70"
+uuid = "856f2bd8-1eba-4b0a-8007-ebc267875bd4"
+version = "1.10.0"
+
+[[deps.TOML]]
+deps = ["Dates"]
+uuid = "fa267f1f-6049-4f14-aa54-33bafae1ed76"
+version = "1.0.0"
+
+[[deps.TableTraits]]
+deps = ["IteratorInterfaceExtensions"]
+git-tree-sha1 = "c06b2f539df1c6efa794486abfb6ed2022561a39"
+uuid = "3783bdb8-4a98-5b6b-af9a-565f29a5fe9c"
+version = "1.0.1"
+
+[[deps.Tables]]
+deps = ["DataAPI", "DataValueInterfaces", "IteratorInterfaceExtensions", "LinearAlgebra", "OrderedCollections", "TableTraits", "Test"]
+git-tree-sha1 = "5ce79ce186cc678bbb5c5681ca3379d1ddae11a1"
+uuid = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
+version = "1.7.0"
+
+[[deps.Tar]]
+deps = ["ArgTools", "SHA"]
+uuid = "a4e569a6-e804-4fa4-b0f3-eef7a1d5b13e"
+version = "1.10.0"
+
+[[deps.Test]]
+deps = ["InteractiveUtils", "Logging", "Random", "Serialization"]
+uuid = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[[deps.TextWrap]]
+git-tree-sha1 = "9250ef9b01b66667380cf3275b3f7488d0e25faf"
+uuid = "b718987f-49a8-5099-9789-dcd902bef87d"
+version = "1.0.1"
+
+[[deps.TimeZones]]
+deps = ["Dates", "Downloads", "InlineStrings", "LazyArtifacts", "Mocking", "Printf", "RecipesBase", "Scratch", "Unicode"]
+git-tree-sha1 = "d634a3641062c040fc8a7e2a3ea17661cc159688"
+uuid = "f269a46b-ccf7-5d73-abea-4c690281aa53"
+version = "1.9.0"
+
+[[deps.TranscodingStreams]]
+deps = ["Random", "Test"]
+git-tree-sha1 = "8a75929dcd3c38611db2f8d08546decb514fcadf"
+uuid = "3bb67fe8-82b1-5028-8e26-92a6c54297fa"
+version = "0.9.9"
+
+[[deps.URIs]]
+git-tree-sha1 = "e59ecc5a41b000fa94423a578d29290c7266fc10"
+uuid = "5c2747f8-b7ea-4ff2-ba2e-563bfd36b1d4"
+version = "1.4.0"
+
+[[deps.UUIDs]]
+deps = ["Random", "SHA"]
+uuid = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
+
+[[deps.Unicode]]
+uuid = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"
+
+[[deps.Zlib_jll]]
+deps = ["Libdl"]
+uuid = "83775a58-1f1d-513f-b197-d71354ab007a"
+version = "1.2.12+3"
+
+[[deps.Zstd_jll]]
+deps = ["Artifacts", "JLLWrappers", "Libdl", "Pkg"]
+git-tree-sha1 = "e45044cd873ded54b6a5bac0eb5c971392cf1927"
+uuid = "3161d3a3-bdf6-5164-811a-617609db77b4"
+version = "1.5.2+0"
+
+[[deps.libblastrampoline_jll]]
+deps = ["Artifacts", "Libdl", "OpenBLAS_jll"]
+uuid = "8e850b90-86db-534c-a0d3-1478176c7d93"
+version = "5.1.1+0"
+
+[[deps.nghttp2_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "8e850ede-7688-5339-a07c-302acd2aaf8d"
+version = "1.48.0+0"
+
+[[deps.p7zip_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "3f19e933-33d8-53b3-aaab-bd5110c3b7a0"
+version = "17.4.0+0"
diff --git a/Project.toml b/Project.toml
index 716f99e..7a40869 100644
--- a/Project.toml
+++ b/Project.toml
@@ -9,11 +9,15 @@ ConfParser = "88353bc9-fd38-507d-a820-d3b43837d6b9"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 EnumX = "4e289a0a-7415-4d19-859d-a7e5c4648b56"
 ExceptionUnwrapping = "460bff9d-24e4-43bc-9d9f-a8973cb893f4"
+FileWatching = "7b1f6079-737a-58dc-b8bc-7a2ca5c1b5ee"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
+Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 Mocking = "78c3b35d-d492-501b-9361-3d52fe80e533"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 ProtoBuf = "3349acd9-ac6a-5e09-bcdb-63829b23a429"
+REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
+Select = "ac7b3b08-bf78-4e82-aa6e-b038cb67d740"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
 
 [compat]
diff --git a/src/RAI.jl b/src/RAI.jl
index 7abf9ee..1af29ac 100644
--- a/src/RAI.jl
+++ b/src/RAI.jl
@@ -104,5 +104,6 @@ include("metadata.jl")
 include("response.jl")
 include("api.jl")
 include("results.jl")
+include("repl/REPLMode.jl")
 
 end
diff --git a/src/repl/REPLMode.jl b/src/repl/REPLMode.jl
new file mode 100644
index 0000000..ede5fa4
--- /dev/null
+++ b/src/repl/REPLMode.jl
@@ -0,0 +1,36 @@
+module REPLMode
+
+using Markdown
+using ..RAI
+# using RelationalAIProtocol: OPEN_OR_CREATE, CREATE_OVERWRITE
+import REPL: REPL, LineEdit, REPLCompletions
+
+include("show.jl")
+include("watch.jl")
+include("install.jl")
+include("command.jl")
+include("repl.jl")
+
+islocal(ctx::Context) = ctx.host in ("127.0.0.1", "localhost")
+
+struct Connection
+    ctx::Context
+    db::String
+    engine::String
+end
+
+function connect(db)
+    global conn = Connection(Context(load_config()), db, "")
+end
+
+function __init__()
+    db = get(ENV, "RAI_REPL_DB", "repl")
+    connect(db)
+    if islocal(conn.ctx)
+        julia_repl_hook()
+    else
+        warn("REPL not initialised on remote connection.")
+    end
+end
+
+end
diff --git a/src/repl/command.jl b/src/repl/command.jl
new file mode 100644
index 0000000..66663fc
--- /dev/null
+++ b/src/repl/command.jl
@@ -0,0 +1,76 @@
+using Markdown
+
+const helpmd = md"""
+Welcome to the Rel REPL. These are the commands you can use to manage your
+session.
+
+    %help
+
+List this help message.
+
+    %db
+
+See all available databases. The currently attached database will be listed in
+bold.
+
+    %db foo
+
+Connect to the database `foo`, creating it if necessary.
+
+    %install foo
+
+Install the source code at the path `foo`. `foo` can be a `.rel` file or a
+directory containing `.rel` files.
+
+    %install
+
+List all installed Rel code.
+
+    %install -
+
+Clear all installed Rel code.
+
+    %clear
+
+Clear installed Rel code and the EDB, resetting the database.
+"""
+
+parsecommand(s) = match(r"%(\w+)\b\s*(.+)?", s)
+
+function printerr(e)
+    printstyled("error: ", color = :red, bold = true)
+    print(e)
+    println()
+end
+
+function hidepwd(path)
+    replace(path, pwd() => ".")
+end
+
+function command(m::RegexMatch)
+    type = m.captures[1]
+    arg = m.captures[2]
+    if type in ("help", "h")
+        println()
+        display(helpmd)
+    elseif type in ("install", "i")
+        if arg == nothing
+            list_sources()
+        elseif arg == "-"
+            reset_sources()
+        else
+            install(arg)
+        end
+    elseif type == "db"
+        if arg == nothing
+            # TODO: list of dbs
+            println(conn.db)
+        else
+            connect(arg)
+        end
+    elseif type == "clear"
+        clear_db()
+    else
+        display(md"Unrecognised command. Use `%help` to see all options.")
+    end
+end
diff --git a/src/repl/install.jl b/src/repl/install.jl
new file mode 100644
index 0000000..6649992
--- /dev/null
+++ b/src/repl/install.jl
@@ -0,0 +1,87 @@
+function install_source(conn, name, src)
+    load_model(conn.ctx, conn.db, conn.engine, Dict(name => src))
+end
+
+function relfiles(dir, files = String[])
+    for f in readdir(dir)
+        path = joinpath(dir, f)
+        if isdir(path)
+            relfiles(path, files)
+        elseif endswith(path, ".rel") && isfile(path)
+            push!(files, path)
+        end
+    end
+    return files
+end
+
+function install_folder(path)
+    for file in relfiles(path)
+        install_source(conn, abspath(file), String(read(file)))
+    end
+end
+
+const watchers = Dict{String,Union{FileWatcher,RecursiveWatcher}}()
+
+function is_watched_src(src)
+    for (path, _) in watchers
+        startswith(src, path) && return true
+    end
+    return false
+end
+
+function updatefile(src)
+    if isfile(src)
+        install_source(conn, src, String(read(src)))
+    else
+        delete_source(conn, src)
+    end
+end
+
+function install(src)
+    src = abspath(src)
+    haskey(watchers, src) && return
+    if isfile(src)
+        install_source(conn, src, String(read(src)))
+        watchers[src] = FileWatcher(src) do e
+            updatefile(src)
+        end
+    elseif isdir(src)
+        install_folder(src)
+        watchers[src] = RecursiveWatcher(src) do e
+            file, _ = e
+            file = abspath(joinpath(src, file))
+            endswith(file, ".rel") || return
+            updatefile(file)
+        end
+    else
+        printerr("path doesn't exist: $(src)")
+    end
+    return
+end
+
+function reset_sources()
+    for (src, _) in list_source(conn)
+        is_watched_src(src) && delete_source(conn, src)
+    end
+    foreach(stop!, values(watchers))
+    empty!(watchers)
+    return
+end
+
+function list_sources()
+    ss = list_source(conn)
+    for (name, src) in ss
+        is_watched_src(name) || println(hidepwd(name))
+    end
+    for (src, _) in watchers
+        println(hidepwd(src))
+    end
+end
+
+function clear_db()
+    # If we replace the global connection, the DB gets reset on every subsequent
+    # query. So just create a temporary overwriting connection, and make a
+    # single dummy query to carry out the reset.
+    tmp = LocalConnection(dbname = conn.dbname, default_open_mode = CREATE_OVERWRITE)
+    query(tmp, "")
+end
diff --git a/src/repl/repl.jl b/src/repl/repl.jl
new file mode 100644
index 0000000..12a16ea
--- /dev/null
+++ b/src/repl/repl.jl
@@ -0,0 +1,104 @@
+function julia_repl_hook()
+    if isdefined(Base, :active_repl)
+        repl_init(Base.active_repl)
+    else
+        atreplinit() do repl
+            if isinteractive() && repl isa REPL.LineEditREPL
+                isdefined(repl, :interface) || (repl.interface = REPL.setup_interface(repl))
+                repl_init(repl)
+            end
+        end
+    end
+end
+
+function repl_init(repl)
+    main_mode = repl.interface.modes[1]
+    rel_mode = create_mode(repl, main_mode)
+    push!(repl.interface.modes, rel_mode)
+    keymap = Dict{Any,Any}(
+        '=' => function (s,args...)
+            if isempty(s) || position(LineEdit.buffer(s)) == 0
+                buf = copy(LineEdit.buffer(s))
+                LineEdit.transition(s, rel_mode) do
+                    LineEdit.state(s, rel_mode).input_buffer = buf
+                end
+            else
+                LineEdit.edit_insert(s, '=')
+            end
+        end
+    )
+    main_mode.keymap_dict = LineEdit.keymap_merge(main_mode.keymap_dict, keymap)
+    return
+end
+
+function create_mode(repl, main)
+    rel_mode = LineEdit.Prompt("query> ";
+    prompt_prefix = repl.options.hascolor ? Base.text_colors[:magenta] : "",
+    prompt_suffix = "",
+    on_enter = return_callback,
+    sticky = true)
+
+    rel_mode.repl = repl
+    hp = main.hist
+    hp.mode_mapping[:rel] = rel_mode
+    rel_mode.hist = hp
+
+    search_prompt, skeymap = LineEdit.setup_search_keymap(hp)
+    prefix_prompt, prefix_keymap = LineEdit.setup_prefix_keymap(hp, rel_mode)
+
+    rel_mode.on_done = (s, buf, ok) -> begin
+        ok || return REPL.transition(s, :abort)
+        input = String(take!(buf))
+        REPL.reset(repl)
+        repl_eval(repl, input)
+        REPL.prepare_next(repl)
+        REPL.reset_state(s)
+        s.current_mode.sticky || REPL.transition(s, main)
+    end
+
+    mk = REPL.mode_keymap(main)
+
+    b = Dict{Any,Any}[
+        skeymap, mk, prefix_keymap, LineEdit.history_keymap,
+        LineEdit.default_keymap, LineEdit.escape_defaults
+    ]
+    rel_mode.keymap_dict = LineEdit.keymap(b)
+    return rel_mode
+end
+
+# This function determines whether we should evaluate or just add a new line
+# when the user presses `enter`.
+# Ideally, we'd invoke the parser to see if it needs more input.
+# For now we have a fairly dumb bracket-based heuristic.
+# (which could of course break in the presence of quotes)
+function return_callback(s)
+    input = String(take!(copy(LineEdit.buffer(s))))
+    if count(x -> x in ('(', '['), input) > count(x -> x in (')', ']'), input)
+        return false
+    end
+    return true
+end
+
+function evalrel(input; readonly = false)
+    try
+        result = exec(conn.ctx, conn.db, conn.engine, input; readonly)
+        # Disabled until we decide the representation
+        # Base.eval(Main, :(ans = $result))
+        replshow(stdout, result)
+    catch
+        Base.display_error(stdout, Base.catch_stack())
+    end
+end
+
+function repl_eval(repl, input)
+    c = parsecommand(input)
+    if c != nothing
+        try # TODO: shouldn't error
+            command(c)
+        catch
+            Base.display_error(stdout, Base.catch_stack())
+        end
+        return
+    end
+    evalrel(input)
+end
diff --git a/src/repl/show.jl b/src/repl/show.jl
new file mode 100644
index 0000000..079284f
--- /dev/null
+++ b/src/repl/show.jl
@@ -0,0 +1,40 @@
+function collectresult(result)
+    keys = result.metadata.relations
+    keys = [sprint.(RAI.show_rel_type, key.relation_id.arguments) for key in keys]
+    vals = [isempty(v) ? [()] : collect(zip(v...)) for (k, v) in result.results]
+    return Dict(zip(keys, vals))
+end
+
+replshow(io, result::RAI.TransactionResponse) = replshow(io, collectresult(result))
+
+function replshow(io, result)
+    first = true
+    isempty(result) && println("{}") # false / empty relation
+    for (key, values) in result
+        key[1] == ":output" || continue
+        first || println(io)
+        first = false
+        showkey(io, key[2:end])
+        showrelation(io, values)
+    end
+end
+
+function showkey(io, ks)
+    isempty(ks) && (ks = ["Unit"]) # single empty tuple
+    for k in ks
+        printstyled(io, string("/", k), bold = true)
+    end
+    println(io)
+end
+
+function showrelation(io, rel)
+    for row in rel
+        print(io, "  ")
+        isempty(row) && print(io, "()")
+        for i = 1:length(row)
+            i != 1 && printstyled(io, ", ", color=:light_blue)
+            show(io, row[i])
+        end
+        println(io)
+    end
+end
diff --git a/src/repl/watch.jl b/src/repl/watch.jl
new file mode 100644
index 0000000..243c232
--- /dev/null
+++ b/src/repl/watch.jl
@@ -0,0 +1,91 @@
+# Generic file watching utlities
+
+using Select, FileWatching
+
+mutable struct CallbackLoop
+    task::Task
+    done::Channel{Nothing}
+    isdone::Bool
+end
+
+function CallbackLoop(func, callback)
+    done = Channel{Nothing}()
+    task = @async begin
+        while true
+            @select begin
+                (@async func()) |> e => callback(e)
+                done => break
+            end
+        end
+    end
+    return CallbackLoop(task, done, false)
+end
+
+function stop!(cb::CallbackLoop)
+    cb.isdone && return
+    put!(cb.done, nothing)
+    wait(cb.task)
+    cb.isdone = true
+    return
+end
+
+struct FileWatcher
+    cb::CallbackLoop
+end
+
+FileWatcher(callback, path::AbstractString) =
+    FileWatcher(CallbackLoop(() -> watch_file(path), callback))
+
+stop!(fw::FileWatcher) = stop!(fw.cb)
+
+struct DirWatcher
+    dir::AbstractString
+    cb::CallbackLoop
+end
+
+DirWatcher(callback, path::AbstractString) =
+    DirWatcher(path, CallbackLoop(() -> watch_folder(path), callback))
+
+function stop!(dw::DirWatcher)
+    stop!(dw.cb)
+    unwatch_folder(dw.dir)
+    return
+end
+
+struct RecursiveWatcher
+    root::AbstractString
+    watcher::DirWatcher
+    children::Dict{String,RecursiveWatcher}
+end
+
+function RecursiveWatcher(callback, path::AbstractString, root::AbstractString = "")
+    children = Dict{String,RecursiveWatcher}()
+    for f in readdir(path)
+        child = joinpath(path, f)
+        if isdir(child)
+            children[f] = RecursiveWatcher(callback, child, joinpath(root, f))
+        end
+    end
+    watcher = DirWatcher(path) do e
+        f, event = e
+        watched = haskey(children, f)
+        dir = isdir(joinpath(path, f))
+        if watched || dir
+            if watched && !dir
+                stop!(children[f])
+                delete!(children, f)
+            elseif dir && !watched
+                children[f] = RecursiveWatcher(callback, joinpath(path, f), joinpath(root, f))
+            end
+        else
+            callback(joinpath(root, f) => event)
+        end
+    end
+    return RecursiveWatcher(root, watcher, children)
+end
+
+function stop!(rw::RecursiveWatcher)
+    stop!(rw.watcher)
+    foreach(stop!, values(rw.children))
+    return
+end