Serve the OpenAccess descriptor at /.well-known/openaccess.json (#127)

Spec: https://logicsrc.com/openaccess

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Claude-Session: https://claude.ai/code/session_01SWRffW4ifQPUrGXJtgYWMd

internal/files/openaccess.json

@@ -0,0 +1,29 @@
+{
+  "openaccess": "0.1",
+  "name": "AgentBBS",
+  "url": "https://bbs.profullstack.com",
+  "operator": "https://logicsrc.com/.well-known/openprofile.md",
+  "redirect_uris": [
+    "https://bbs.profullstack.com/api/v1/openaccess/callback"
+  ],
+  "jwks": {
+    "keys": [
+      {
+        "kty": "OKP",
+        "crv": "Ed25519",
+        "kid": "Vg7JJd0byYl3",
+        "x": "bck0ITevVM5tl-uMt-IAzuD_4DBuTpn9zlE0WKimdxw",
+        "alg": "EdDSA",
+        "use": "sig"
+      }
+    ]
+  },
+  "scopes": {},
+  "honours": [
+    "profullstack.com/all-access"
+  ],
+  "webhooks": "https://bbs.profullstack.com/api/v1/openaccess/events",
+  "hubs": [
+    "https://openaccess.logicsrc.com"
+  ]
+}

internal/files/web.go

@@ -2,6 +2,7 @@ package files
 
 import (
 	"crypto/rand"
+	_ "embed"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -71,9 +72,40 @@ func (s *Service) WebHandler(cfg WebConfig) http.Handler {
 	mux.HandleFunc("/mkdir", h.handleMkdir)
 	mux.HandleFunc("/delete", h.handleDelete)
 	mux.HandleFunc("/healthz", func(w http.ResponseWriter, _ *http.Request) { _, _ = w.Write([]byte("ok")) })
+	mux.Handle(OpenAccessPath, OpenAccessHandler())
 	return mux
 }
 
+// OpenAccessPath is the well-known location of the OpenAccess descriptor
+// (https://logicsrc.com/openaccess). Hubs such as openaccess.logicsrc.com fetch
+// it to list the BBS and to link accounts with OAuth 2.1 + PKCE.
+const OpenAccessPath = "/.well-known/openaccess.json"
+
+// openAccessDescriptor is the static descriptor served verbatim. It names the
+// public signing key (JWKS), the redirect URI and the hubs the BBS trusts.
+//
+//go:embed openaccess.json
+var openAccessDescriptor []byte
+
+// OpenAccessHandler serves the embedded OpenAccess descriptor as JSON with a
+// short public cache. It needs no session: hubs fetch it anonymously.
+func OpenAccessHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet && r.Method != http.MethodHead {
+			w.Header().Set("Allow", "GET, HEAD")
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Cache-Control", "public, max-age=300")
+		w.Header().Set("Content-Length", strconv.Itoa(len(openAccessDescriptor)))
+		if r.Method == http.MethodHead {
+			return
+		}
+		_, _ = w.Write(openAccessDescriptor)
+	})
+}
+
 // --- session helpers --------------------------------------------------------
 
 func (h *webSrv) lookup(r *http.Request) (string, bool) {

internal/files/web_test.go

@@ -2,6 +2,7 @@ package files
 
 import (
 	"bytes"
+	"encoding/json"
 	"io"
 	"mime"
 	"mime/multipart"
@@ -394,3 +395,33 @@ func TestWebPublicReadOnlyByDefault(t *testing.T) {
 		t.Fatalf("public upload: want redirect, got %d", rr.Code)
 	}
 }
+
+func TestWebOpenAccessDescriptor(t *testing.T) {
+	h, _ := webTestHandler(t)
+	rr := httptest.NewRecorder()
+	h.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, OpenAccessPath, nil))
+	if rr.Code != http.StatusOK {
+		t.Fatalf("status: want 200, got %d", rr.Code)
+	}
+	if ct := rr.Header().Get("Content-Type"); ct != "application/json" {
+		t.Fatalf("content-type: got %q", ct)
+	}
+	if cc := rr.Header().Get("Cache-Control"); cc != "public, max-age=300" {
+		t.Fatalf("cache-control: got %q", cc)
+	}
+	var doc struct {
+		OpenAccess string `json:"openaccess"`
+		URL        string `json:"url"`
+	}
+	if err := json.Unmarshal(rr.Body.Bytes(), &doc); err != nil {
+		t.Fatalf("descriptor is not JSON: %v", err)
+	}
+	if doc.OpenAccess == "" || doc.URL == "" {
+		t.Fatalf("descriptor missing openaccess/url: %s", rr.Body.String())
+	}
+	rr = httptest.NewRecorder()
+	h.ServeHTTP(rr, httptest.NewRequest(http.MethodPost, OpenAccessPath, nil))
+	if rr.Code != http.StatusMethodNotAllowed {
+		t.Fatalf("POST: want 405, got %d", rr.Code)
+	}
+}