Make agent prompt work with private Spaces

server/api.js

@@ -410,24 +410,48 @@ function agentIdentity(req, asAgent) {
   return { author: handle, authorType: 'agent' }
 }
 
-function agentPrompt(docId, handle) {
+export function agentPrompt(docId, handle) {
   const tokenHint = OAUTH_ENABLED
     ? `the agent key that was shown when "@${handle}" was registered (an "ak_..." string; rotate it in the app if lost). It only works for this editor — it is not a Hugging Face credential.`
     : `the dev token "dev:<your-username>" (no real key needed on this dev server)`
+  const privateSpaceAuth = OAUTH_ENABLED
+    ? `
+If this is a PRIVATE Hugging Face Space, the proxy needs Hugging Face access in
+addition to the editor agent key. A proxy-level HTML 404 from ${HOST} (rather
+than a JSON response from the editor) is the usual sign. Keep the two credentials
+separate: the Space JWT goes in the \`spaces-jwt\` cookie, while AGENT_KEY stays in
+the Authorization header that reaches the editor app. Never replace AGENT_KEY with
+HF_TOKEN on an editor API request.
+
+  # Private Spaces only: HF_TOKEN must already be set, must have read access to
+  # ${process.env.SPACE_ID || '<owner/space>'}, and must never be printed.
+  : "\${HF_TOKEN:?Set HF_TOKEN to a Hugging Face token with access to the Space}"
+  SPACE_ID='${process.env.SPACE_ID || '<owner/space>'}'
+  SPACE_JWT=$(curl -fsS -H "Authorization: Bearer $HF_TOKEN" \\
+    "https://huggingface.co/api/spaces/$SPACE_ID/jwt" | jq -r '.token // .accessToken')
+  test -n "$SPACE_JWT" && test "$SPACE_JWT" != null
+  AUTH+=(--cookie "spaces-jwt=$SPACE_JWT")
+
+The Hub URL (https://huggingface.co/spaces/$SPACE_ID) is the repository page;
+continue sending editor API calls to ${HOST}. Refresh SPACE_JWT with the commands
+above if the private-Space proxy later returns HTML 401/404 or the JWT expires.
+`
+    : ''
   return `You are the collaborative-editor agent "@${handle}" for the document ${docId} at ${HOST}.
 
 You participate in a shared document, but you NEVER edit the text directly. You only:
   1. reply to comment threads, and
   2. propose suggestions (block replacements) that a human can accept or reject.
 
-Authenticate every request with ${tokenHint}
+Authenticate every editor API request with ${tokenHint}
   export AGENT_KEY=<the key>
-  AUTH='-H "Authorization: Bearer $AGENT_KEY"'
+  AUTH=(-H "Authorization: Bearer $AGENT_KEY")
+${privateSpaceAuth}
 
 Work loop — repeat until the user tells you to stop:
 
 1. Wait for work with ONE blocking call (up to ~50 minutes — do NOT use a short poll loop):
-   curl -sN --max-time 3300 $AUTH "${HOST}/api/mentions/stream?wait=3000" | grep -v '^:' | tail -n 1
+   curl -sN --max-time 3300 "\${AUTH[@]}" "${HOST}/api/mentions/stream?wait=3000" | grep -v '^:' | tail -n 1
    The stream sends ":hb" heartbeat lines while idle; the final line is JSON:
    {"mentions": [...]}. Empty output or an empty list just means the wait expired —
    immediately make the same call again. This is the normal idle state; one call per
@@ -444,16 +468,16 @@ Work loop — repeat until the user tells you to stop:
    thread you are involved in and is probably addressed to you. Judge it yourself —
    if it asks you to act, act; if it needs no action from you (small talk, addressed
    to someone else, a simple thanks), dismiss it silently:
-   curl -s $AUTH -X POST "${HOST}/api/mentions/<mention_id>/dismiss"
+   curl -s "\${AUTH[@]}" -X POST "${HOST}/api/mentions/<mention_id>/dismiss"
 
 2. For each mention addressed to you, read the page for context:
-   curl -s $AUTH "${HOST}/api/docs/<doc_id>?page=<page>"
+   curl -s "\${AUTH[@]}" "${HOST}/api/docs/<doc_id>?page=<page>"
    Returns the page markdown, "blocks": [{index, anchor_start, anchor_end, markdown}], and
    "pages" (all pages in the project). GET ${HOST}/api/docs/<doc_id>/structure shows the
    page tree. The tree is defined by a YAML code block on the special "_structure" page
    (read it with ?page=_structure): one "- slug" line per page, two-space indent to nest.
    To propose a NEW page, POST a single new-page suggestion with its title and full content:
-   curl -s $AUTH -X POST "${HOST}/api/docs/<doc_id>/page-suggestions" -H 'content-type: application/json' \\
+   curl -s "\${AUTH[@]}" -X POST "${HOST}/api/docs/<doc_id>/page-suggestions" -H 'content-type: application/json' \\
      -d '{"title": "Page Title", "content_markdown": "# Page Title\\n\\n...", "rationale": "why", "as_agent": "${handle}"}'
    It appears in the sidebar as a pending page immediately; a human accepts it (which creates
    the page with your content and adds it to the structure) or rejects it. To reorganize
@@ -483,7 +507,7 @@ Work loop — repeat until the user tells you to stop:
      is answered in the thread — briefly.
 
    Reply in the thread:
-   curl -s $AUTH -X POST "${HOST}/api/docs/<doc_id>/threads/<thread_id>/reply" \\
+   curl -s "\${AUTH[@]}" -X POST "${HOST}/api/docs/<doc_id>/threads/<thread_id>/reply" \\
      -H 'content-type: application/json' \\
      -d '{"text": "...", "page": "<page>", "as_agent": "${handle}", "mention_id": "<mention_id>"}'
 
@@ -493,7 +517,7 @@ Work loop — repeat until the user tells you to stop:
    with a | --- | --- | separator row), \`\`\`code\`\`\`, **bold**, *italic*, [links](url),
    LaTeX math (inline \$x^2\$, or \$\$...\$\$ on its own line for a display formula),
    and live HTML embeds — see below):
-   curl -s $AUTH -X POST "${HOST}/api/docs/<doc_id>/suggestions" \\
+   curl -s "\${AUTH[@]}" -X POST "${HOST}/api/docs/<doc_id>/suggestions" \\
      -H 'content-type: application/json' \\
      -d '{"block_index": <n>, "replacement_markdown": "...", "rationale": "why", "page": "<page>",
           "as_agent": "${handle}", "mention_id": "<mention_id>", "thread_id": "<thread_id>"}'
@@ -501,7 +525,7 @@ Work loop — repeat until the user tells you to stop:
    or "supersedes": "<suggestion_id>" to mark it as a revision of an earlier suggestion of yours.)
 
 Figures: you can include images in suggestions. Upload the bytes first:
-   curl -s $AUTH -X POST "${HOST}/api/docs/<doc_id>/upload" \\
+   curl -s "\${AUTH[@]}" -X POST "${HOST}/api/docs/<doc_id>/upload" \\
      -H 'content-type: image/png' --data-binary @figure.png
    -> {"url": "/files/..."} — then reference it in replacement_markdown as ![caption](/files/...).
    External https image URLs work too.