Files
Cyrene_v2/plugins/tools/io/web_fetch.go
T

110 lines
2.9 KiB
Go

package io
import (
"context"
"fmt"
"log/slog"
"mime"
"net/http"
"strings"
"git.yeij.top/AskaEth/Cyrene_v2/pkg/plugins/sdk"
)
// Compile-time assertion that webFetchTool implements sdk.Tool.
var _ sdk.Tool = (*webFetchTool)(nil)
// webFetchTool fetches a URL over HTTP and returns its readable text, limited by
// size and content type, extracting text from HTML when appropriate.
type webFetchTool struct {
client *http.Client
allowedHosts []string
maxBytes int64
log *slog.Logger
}
func newWebFetchTool(t *tools) *webFetchTool {
return &webFetchTool{
client: t.client,
allowedHosts: t.allowedHosts,
maxBytes: t.maxFetchBytes,
log: t.log,
}
}
// Name implements sdk.Tool.
func (w *webFetchTool) Name() string { return "web-fetch" }
// Description implements sdk.Tool.
func (w *webFetchTool) Description() string {
return "Fetch a URL and return its readable text, limited by size and content type."
}
// Parameters implements sdk.Tool.
func (w *webFetchTool) Parameters() (map[string]any, error) {
return map[string]any{
"type": "object",
"properties": map[string]any{
"url": map[string]any{"type": "string", "description": "Absolute http(s) URL."},
"max_bytes": map[string]any{"type": "integer", "description": "Response size cap in bytes."},
},
"required": []any{"url"},
}, nil
}
// Execute implements sdk.Tool.
func (w *webFetchTool) Execute(ctx context.Context, args any) (any, error) {
m, ok := args.(map[string]any)
if !ok {
return nil, fmt.Errorf("io: web-fetch: args must be an object")
}
rawURL := argString(m, "url")
if strings.TrimSpace(rawURL) == "" {
return nil, fmt.Errorf("io: web-fetch: url is required")
}
if _, err := validateRequestURL(ctx, rawURL, w.allowedHosts); err != nil {
return nil, err
}
if w.client == nil {
return nil, fmt.Errorf("io: web-fetch: no underlying client")
}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
if err != nil {
return nil, fmt.Errorf("io: web-fetch: build request: %w", err)
}
resp, err := w.client.Do(req)
if err != nil {
return nil, fmt.Errorf("io: web-fetch: do: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("io: web-fetch: url returned status %d", resp.StatusCode)
}
mt := "text/plain"
if rawCT := resp.Header.Get("Content-Type"); rawCT != "" {
var err error
mt, _, err = mime.ParseMediaType(rawCT)
if err != nil || !isTextContentType(mt) {
return nil, fmt.Errorf("io: web-fetch: unexpected content type %q", rawCT)
}
}
max := w.maxBytes
if v, ok := argInt(m, "max_bytes"); ok && v > 0 {
max = int64(v)
}
data, truncated, err := readLimited(resp.Body, max)
if err != nil {
return nil, fmt.Errorf("io: web-fetch: read: %w", err)
}
text := string(data)
if isHTML(mt) {
text = htmlToText(text)
}
return map[string]any{
"url": rawURL,
"content_type": mt,
"text": text,
"truncated": truncated,
}, nil
}