1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE NoImplicitPrelude #-}
-- | Web page reader tool - fetches and summarizes web pages.
--
-- : out omni-agent-tools-webreader
-- : dep aeson
-- : dep http-conduit
module Omni.Agent.Tools.WebReader
( -- * Tool
webReaderTool,
-- * Direct API
fetchWebpage,
extractText,
-- * Testing
main,
test,
)
where
import Alpha
import Data.Aeson ((.=))
import qualified Data.Aeson as Aeson
import qualified Data.ByteString.Lazy as BL
import qualified Data.Text as Text
import qualified Data.Text.Encoding as TE
import qualified Network.HTTP.Client as HTTPClient
import qualified Network.HTTP.Simple as HTTP
import qualified Omni.Agent.Engine as Engine
import qualified Omni.Agent.Provider as Provider
import qualified Omni.Test as Test
main :: IO ()
main = Test.run test
test :: Test.Tree
test =
Test.group
"Omni.Agent.Tools.WebReader"
[ Test.unit "extractText removes HTML tags" <| do
let html = "<html><body><p>Hello world</p></body></html>"
result = extractText html
("Hello world" `Text.isInfixOf` result) Test.@=? True,
Test.unit "extractText removes script tags" <| do
let html = "<html><script>alert('hi')</script><p>Content</p></html>"
result = extractText html
("alert" `Text.isInfixOf` result) Test.@=? False
("Content" `Text.isInfixOf` result) Test.@=? True,
Test.unit "webReaderTool has correct schema" <| do
let tool = webReaderTool "test-key"
Engine.toolName tool Test.@=? "read_webpage"
]
fetchWebpage :: Text -> IO (Either Text Text)
fetchWebpage url = do
result <-
try <| do
req0 <- HTTP.parseRequest (Text.unpack url)
let req =
HTTP.setRequestMethod "GET"
<| HTTP.setRequestHeader "User-Agent" ["Mozilla/5.0 (compatible; OmniBot/1.0)"]
<| HTTP.setRequestHeader "Accept" ["text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"]
<| HTTP.setRequestResponseTimeout (HTTPClient.responseTimeoutMicro (30 * 1000000))
<| req0
HTTP.httpLBS req
case result of
Left (e :: SomeException) ->
pure (Left ("Failed to fetch URL: " <> tshow e))
Right response -> do
let status = HTTP.getResponseStatusCode response
if status >= 200 && status < 300
then do
let body = HTTP.getResponseBody response
text = TE.decodeUtf8With (\_ _ -> Just '?') (BL.toStrict body)
pure (Right text)
else pure (Left ("HTTP error: " <> tshow status))
extractText :: Text -> Text
extractText html =
let noScript = removeTagContent "script" html
noStyle = removeTagContent "style" noScript
noNoscript = removeTagContent "noscript" noStyle
noTags = stripTags noNoscript
in collapseWhitespace noTags
where
removeTagContent :: Text -> Text -> Text
removeTagContent tag txt =
let openTag = "<" <> tag
closeTag = "</" <> tag <> ">"
in removeMatches openTag closeTag txt
removeMatches :: Text -> Text -> Text -> Text
removeMatches open close txt =
case Text.breakOn open (Text.toLower txt) of
(_, "") -> txt
(before, _) ->
let actualBefore = Text.take (Text.length before) txt
rest = Text.drop (Text.length before) txt
in case Text.breakOn close (Text.toLower rest) of
(_, "") -> actualBefore
(_, afterClose) ->
let skipLen = Text.length close
remaining = Text.drop (Text.length rest - Text.length afterClose + skipLen) txt
in actualBefore <> removeMatches open close remaining
stripTags :: Text -> Text
stripTags txt = go txt ""
where
go :: Text -> Text -> Text
go remaining acc =
case Text.breakOn "<" remaining of
(before, "") -> acc <> before
(before, rest) ->
case Text.breakOn ">" rest of
(_, "") -> acc <> before
(_, afterTag) -> go (Text.drop 1 afterTag) (acc <> before <> " ")
collapseWhitespace = Text.unwords <. Text.words
summarizeContent :: Text -> Text -> Text -> IO (Either Text Text)
summarizeContent apiKey url content = do
let truncatedContent = Text.take 50000 content
gemini = Provider.defaultOpenRouter apiKey "google/gemini-2.0-flash-001"
result <-
Provider.chat
gemini
[]
[ Provider.Message
Provider.System
"You are a webpage summarizer. Provide a concise summary of the webpage content. Focus on the main points and key information. Be brief but comprehensive."
Nothing
Nothing,
Provider.Message
Provider.User
("Summarize this webpage (" <> url <> "):\n\n" <> truncatedContent)
Nothing
Nothing
]
case result of
Left err -> pure (Left ("Summarization failed: " <> err))
Right msg -> pure (Right (Provider.msgContent msg))
webReaderTool :: Text -> Engine.Tool
webReaderTool apiKey =
Engine.Tool
{ Engine.toolName = "read_webpage",
Engine.toolDescription =
"Fetch and summarize a webpage. Use this when the user shares a URL or link "
<> "and wants to know what it contains. Returns a summary of the page content.",
Engine.toolJsonSchema =
Aeson.object
[ "type" .= ("object" :: Text),
"properties"
.= Aeson.object
[ "url"
.= Aeson.object
[ "type" .= ("string" :: Text),
"description" .= ("The URL of the webpage to read" :: Text)
]
],
"required" .= (["url"] :: [Text])
],
Engine.toolExecute = executeWebReader apiKey
}
executeWebReader :: Text -> Aeson.Value -> IO Aeson.Value
executeWebReader apiKey v =
case Aeson.fromJSON v of
Aeson.Error e -> pure (Aeson.object ["error" .= Text.pack e])
Aeson.Success (args :: WebReaderArgs) -> do
fetchResult <- fetchWebpage (wrUrl args)
case fetchResult of
Left err ->
pure (Aeson.object ["error" .= err])
Right html -> do
let textContent = extractText html
if Text.null (Text.strip textContent)
then pure (Aeson.object ["error" .= ("Page appears to be empty or JavaScript-only" :: Text)])
else do
summaryResult <- summarizeContent apiKey (wrUrl args) textContent
case summaryResult of
Left err ->
pure
( Aeson.object
[ "error" .= err,
"raw_content" .= Text.take 2000 textContent
]
)
Right summary ->
pure
( Aeson.object
[ "success" .= True,
"url" .= wrUrl args,
"summary" .= summary
]
)
newtype WebReaderArgs = WebReaderArgs
{ wrUrl :: Text
}
deriving (Generic)
instance Aeson.FromJSON WebReaderArgs where
parseJSON =
Aeson.withObject "WebReaderArgs" <| \v ->
WebReaderArgs </ (v Aeson..: "url")
|
