| 1 | package agents |
| 2 | |
| 3 | // The pure half of the bridge: one stream-json line from a headless Claude |
| 4 | // Code session (`claude -p --input-format stream-json --output-format |
| 5 | // stream-json --verbose`) in, zero or more Acts out. Kept free of I/O so the |
| 6 | // translation is table-testable against fixture lines (translate_test.go) — |
| 7 | // the same pure-logic-out-of-the-plumbing split as format.js/ui.js. |
| 8 | |
| 9 | import ( |
| 10 | "encoding/json" |
| 11 | "fmt" |
| 12 | "strings" |
| 13 | ) |
| 14 | |
| 15 | // Act is one thing the bridge should do in response to a stream line. |
| 16 | type Act struct { |
| 17 | Kind string // "init" | "turn" | "tool" | "error" |
| 18 | // init: the CLI's own session id (what `claude --resume` takes later). |
| 19 | ClaudeSessionID string |
| 20 | // turn: the assistant's final text for the completed turn; error: detail. |
| 21 | Text string |
| 22 | // tool: a one-line activity description ("Ran `go test ./...`"). |
| 23 | Tool string |
| 24 | } |
| 25 | |
| 26 | // streamLine is the envelope every stream-json stdout line shares. |
| 27 | type streamLine struct { |
| 28 | Type string `json:"type"` |
| 29 | Subtype string `json:"subtype"` |
| 30 | SessionID string `json:"session_id"` |
| 31 | Result string `json:"result"` |
| 32 | IsError bool `json:"is_error"` |
| 33 | Message struct { |
| 34 | Content []contentBlock `json:"content"` |
| 35 | } `json:"message"` |
| 36 | } |
| 37 | |
| 38 | type contentBlock struct { |
| 39 | Type string `json:"type"` |
| 40 | Text string `json:"text"` |
| 41 | Name string `json:"name"` |
| 42 | Input json.RawMessage `json:"input"` |
| 43 | } |
| 44 | |
| 45 | // Translate parses one stdout line. Unknown or partial event types translate |
| 46 | // to nothing — the stream carries plenty a fleet board doesn't need, and an |
| 47 | // unrecognised future event must never wedge a session. |
| 48 | func Translate(line []byte) []Act { |
| 49 | var sl streamLine |
| 50 | if json.Unmarshal(line, &sl) != nil { |
| 51 | return nil |
| 52 | } |
| 53 | switch sl.Type { |
| 54 | case "system": |
| 55 | if sl.Subtype == "init" && sl.SessionID != "" { |
| 56 | return []Act{{Kind: "init", ClaudeSessionID: sl.SessionID}} |
| 57 | } |
| 58 | case "assistant": |
| 59 | var acts []Act |
| 60 | for _, b := range sl.Message.Content { |
| 61 | if b.Type == "tool_use" && b.Name != "" { |
| 62 | acts = append(acts, Act{Kind: "tool", Tool: toolLine(b)}) |
| 63 | } |
| 64 | } |
| 65 | return acts |
| 66 | case "result": |
| 67 | text := strings.TrimSpace(sl.Result) |
| 68 | if sl.IsError { |
| 69 | if text == "" { |
| 70 | text = "the turn failed" |
| 71 | } |
| 72 | return []Act{{Kind: "error", Text: text}} |
| 73 | } |
| 74 | if text != "" { |
| 75 | return []Act{{Kind: "turn", Text: text}} |
| 76 | } |
| 77 | } |
| 78 | return nil |
| 79 | } |
| 80 | |
| 81 | // toolLine renders one tool_use block as the activity line members see. |
| 82 | // Bash gets its command surfaced (that's the line a room actually wants to |
| 83 | // read); everything else names the tool and, when short, its primary input. |
| 84 | func toolLine(b contentBlock) string { |
| 85 | var input map[string]any |
| 86 | _ = json.Unmarshal(b.Input, &input) |
| 87 | if b.Name == "Bash" { |
| 88 | if cmd, _ := input["command"].(string); cmd != "" { |
| 89 | return "Ran " + clampLine(cmd, 160) |
| 90 | } |
| 91 | } |
| 92 | for _, k := range []string{"file_path", "path", "pattern", "url", "query", "description"} { |
| 93 | if v, _ := input[k].(string); v != "" { |
| 94 | return fmt.Sprintf("%s %s", b.Name, clampLine(v, 120)) |
| 95 | } |
| 96 | } |
| 97 | return b.Name |
| 98 | } |
| 99 | |
| 100 | // clampLine flattens newlines and truncates — activity lines are one line by |
| 101 | // contract (the fold clamps to 200 chars; we stay under it). |
| 102 | func clampLine(s string, max int) string { |
| 103 | s = strings.Join(strings.Fields(s), " ") |
| 104 | if len(s) > max { |
| 105 | s = s[:max] + "…" |
| 106 | } |
| 107 | return s |
| 108 | } |
| 109 | |
amadan