Add shared LNURL types, indexing helpers, and warnings.

Introduce lnurl as a first-class mint type with probe/announcement fields
and shared helpers the API and web can both rely on.

Co-authored-by: Cursor <cursoragent@cursor.com>

shared/src/fedimint.ts

@@ -300,3 +300,201 @@ export function shortInviteCode(code: string, head = 14, tail = 8): string {
   if (code.length <= head + tail + 1) return code;
   return `${code.slice(0, head)}…${code.slice(-tail)}`;
 }
+
+/* ---------- decoding an invite code ---------- */
+
+/**
+ * Decoding one, which until now nothing in this codebase did.
+ *
+ * `isInviteCode` above is a shape check, and a shape check is all the *display* side
+ * has ever needed: a code arrives inside an announcement that already carries the
+ * federation id in its `d` tag, and the code itself is handed to a wallet verbatim.
+ *
+ * On-demand indexing changes that. A reader pasting an invite code into the review
+ * dialog hands over the only thing they have, and there is no announcement beside it
+ * to read an id off — so the id has to come out of the code, or the federation cannot
+ * be keyed, deduped against what is already indexed, or given a page.
+ *
+ * Two layers, both small and both self-contained (a bech32 dependency for one function
+ * would be the tail wagging the dog):
+ *
+ *   1. **bech32m**, per BIP-350: the same alphabet and checksum as bech32 with a
+ *      different constant. Fedimint uses bech32m, so a code that verifies under the
+ *      *bech32* constant is rejected rather than accepted — it would mean the code was
+ *      produced by something else.
+ *   2. **fedimint's consensus encoding** of `Vec<InviteCodePart>`: a BigSize count, then
+ *      per part a BigSize tag, a BigSize length and that many bytes. Tag 1 is the
+ *      federation id, 32 bytes. Everything else — guardian API URLs (tag 0), an API
+ *      secret (tag 2), anything a later fedimint adds — is skipped by its length
+ *      without being understood, which is what the tag/length framing is for.
+ *
+ * Written against real codes off the relay pool, not against a reading of the Rust, and
+ * `check-index.ts` asserts it still decodes them.
+ */
+
+/** bech32's alphabet, and its two checksum constants. `1` is deliberately not in it. */
+const BECH32_CHARSET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';
+const BECH32M_CONST = 0x2bc830a3;
+const GENERATOR = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3];
+
+function bech32Polymod(values: readonly number[]): number {
+  let chk = 1;
+  for (const value of values) {
+    const top = chk >> 25;
+    chk = ((chk & 0x1ffffff) << 5) ^ value;
+    for (let i = 0; i < 5; i++) if ((top >> i) & 1) chk ^= GENERATOR[i]!;
+  }
+  return chk >>> 0;
+}
+
+function hrpExpand(hrp: string): number[] {
+  const out: number[] = [];
+  for (const char of hrp) out.push(char.charCodeAt(0) >> 5);
+  out.push(0);
+  for (const char of hrp) out.push(char.charCodeAt(0) & 31);
+  return out;
+}
+
+/**
+ * The payload bytes of a bech32m string, or null if it is not a valid one.
+ *
+ * Length capped well above any real invite code: the checksum is only meaningful over
+ * a string somebody could plausibly have produced, and an unbounded input here would
+ * be an unbounded loop below.
+ */
+function decodeBech32m(input: string): { hrp: string; bytes: Uint8Array } | null {
+  if (input.length < 8 || input.length > 4000) return null;
+  // Mixed case is invalid in bech32; one case throughout is not.
+  if (input !== input.toLowerCase() && input !== input.toUpperCase()) return null;
+
+  const value = input.toLowerCase();
+  const split = value.lastIndexOf('1');
+  if (split < 1 || split + 7 > value.length) return null;
+
+  const hrp = value.slice(0, split);
+  for (const char of hrp) {
+    const code = char.charCodeAt(0);
+    if (code < 33 || code > 126) return null;
+  }
+
+  const data: number[] = [];
+  for (const char of value.slice(split + 1)) {
+    const index = BECH32_CHARSET.indexOf(char);
+    if (index === -1) return null;
+    data.push(index);
+  }
+
+  if (bech32Polymod([...hrpExpand(hrp), ...data]) !== BECH32M_CONST) return null;
+
+  // Five-bit groups to eight, dropping the checksum and the final partial group.
+  const payload = data.slice(0, -6);
+  const bytes: number[] = [];
+  let acc = 0;
+  let bits = 0;
+  for (const group of payload) {
+    acc = (acc << 5) | group;
+    bits += 5;
+    while (bits >= 8) {
+      bits -= 8;
+      bytes.push((acc >> bits) & 0xff);
+    }
+  }
+  // Leftover bits must be zero padding, and there must be fewer than five of them.
+  if (bits >= 5 || ((acc << (8 - bits)) & 0xff) !== 0) return null;
+
+  return { hrp, bytes: Uint8Array.from(bytes) };
+}
+
+/** A cursor over the decoded bytes, reading fedimint's BigSize integers and blobs. */
+class ByteReader {
+  private at = 0;
+  constructor(private readonly bytes: Uint8Array) {}
+
+  get done(): boolean {
+    return this.at >= this.bytes.length;
+  }
+
+  /**
+   * Lightning's BigSize, which is what fedimint encodes a `u64` as: one byte under
+   * 0xfd, otherwise a marker and 2, 4 or 8 big-endian bytes.
+   *
+   * Returns null rather than throwing when the buffer runs out, so a truncated code is
+   * a rejected code and not an exception a caller has to catch.
+   */
+  bigSize(): number | null {
+    const first = this.byte();
+    if (first === null) return null;
+    if (first < 0xfd) return first;
+
+    const width = first === 0xfd ? 2 : first === 0xfe ? 4 : 8;
+    let value = 0;
+    for (let i = 0; i < width; i++) {
+      const next = this.byte();
+      if (next === null) return null;
+      // Above 2^53 nothing here is a real length or tag anyway, and the arithmetic
+      // stops being exact, so an absurd value is refused rather than rounded.
+      value = value * 256 + next;
+      if (value > Number.MAX_SAFE_INTEGER) return null;
+    }
+    return value;
+  }
+
+  bytesOf(length: number): Uint8Array | null {
+    if (length < 0 || this.at + length > this.bytes.length) return null;
+    const slice = this.bytes.subarray(this.at, this.at + length);
+    this.at += length;
+    return slice;
+  }
+
+  private byte(): number | null {
+    return this.at < this.bytes.length ? this.bytes[this.at++]! : null;
+  }
+}
+
+/** The tag fedimint gives the federation id inside an invite code. */
+const INVITE_PART_FEDERATION_ID = 1;
+/** A federation id is a 32 byte hash. A part of any other length is not one. */
+const FEDERATION_ID_BYTES = 32;
+/** Real codes carry two or three parts. This only has to stop a hostile count. */
+const MAX_INVITE_PARTS = 64;
+
+function toHex(bytes: Uint8Array): string {
+  let out = '';
+  for (const byte of bytes) out += byte.toString(16).padStart(2, '0');
+  return out;
+}
+
+/**
+ * The federation id inside an invite code, or null if the code is not one.
+ *
+ * Null covers every way a pasted string can fail — wrong prefix, a typo the checksum
+ * catches, valid bech32m that is not an invite code, an invite code with no federation
+ * id part — because a caller has exactly one thing to say about all of them ("that is
+ * not an invite code") and telling them apart would be telling a stranger which of
+ * their guesses was closest.
+ */
+export function federationIdFromInviteCode(code: string): string | null {
+  const raw = code?.trim();
+  if (!raw || !/^fed1[a-z0-9]+$/i.test(raw)) return null;
+
+  const decoded = decodeBech32m(raw);
+  // `fed1` is the human-readable part; the `1` after it is bech32's separator.
+  if (!decoded || decoded.hrp !== 'fed1') return null;
+
+  const reader = new ByteReader(decoded.bytes);
+  const parts = reader.bigSize();
+  if (parts === null || parts === 0 || parts > MAX_INVITE_PARTS) return null;
+
+  for (let i = 0; i < parts; i++) {
+    const tag = reader.bigSize();
+    const length = tag === null ? null : reader.bigSize();
+    const value = length === null ? null : reader.bytesOf(length);
+    if (value === null) return null;
+
+    if (tag === INVITE_PART_FEDERATION_ID && value.length === FEDERATION_ID_BYTES) {
+      return toHex(value);
+    }
+  }
+
+  return null;
+}

shared/src/index.ts

@@ -5,3 +5,5 @@ export * from './score.js';
 export * from './nuts.js';
 export * from './warnings.js';
 export * from './fedimint.js';
+export * from './lnurl.js';
+export * from './indexing.js';

shared/src/indexing.ts

@@ -0,0 +1,208 @@
+/**
+ * On-demand indexing: the contract `POST /api/index` speaks.
+ *
+ * Both ends of that request are in this repository — the API answers it, the 404
+ * resolver and the review-by-URL dialog send it — so the shapes live here rather than
+ * being written out twice and drifting. The reason codes in particular are the whole
+ * point of this file: the API decides *what happened*, the browser decides *what to
+ * say about it*, and a typo in a string literal must not be the thing that silently
+ * turns a precise sentence into a generic one.
+ *
+ * The endpoint itself is documented in BACKEND.md. What is here is only what both
+ * sides need to agree on: which types are indexable, what a valid submission looks
+ * like before any network call, and what comes back.
+ */
+import { federationIdFromInviteCode, isInviteCode } from './fedimint.js';
+import { normalizeMintUrl } from './normalize.js';
+import type { MintDetail, MintInfo } from './types.js';
+
+/** The three ecosystems a reader can hand this site an identifier for. */
+export const INDEXABLE_TYPES = ['cashu', 'fedimint', 'lnurl'] as const;
+export type IndexType = (typeof INDEXABLE_TYPES)[number];
+
+export function isIndexType(value: unknown): value is IndexType {
+  return typeof value === 'string' && (INDEXABLE_TYPES as readonly string[]).includes(value);
+}
+
+/**
+ * Why a submission did not become a row.
+ *
+ * Every one of these is a different sentence to a reader, which is why they are not
+ * collapsed into a generic failure:
+ *
+ *   `bad_type`         the `type` field was not one of the three
+ *   `bad_input`        the input is not a URL (or an invite code) at all
+ *   `blocked_host`     it resolves somewhere this server will not fetch from
+ *   `wrong_type`       the host answered, as a *different* ecosystem's mint
+ *   `invalid_response` the host answered, as nothing this site recognises
+ *   `invalid_invite`   the invite code does not decode
+ *   `unverifiable`     nothing answered, and Nostr has never heard of it either
+ *   `rate_limited`     too many submissions from one address this hour
+ */
+export type IndexFailureReason =
+  | 'bad_type'
+  | 'bad_input'
+  | 'blocked_host'
+  | 'wrong_type'
+  | 'invalid_response'
+  | 'invalid_invite'
+  | 'unverifiable'
+  | 'rate_limited';
+
+/** How a row that did not already exist came to be written. */
+export type IndexSource = 'probe' | 'announcement' | 'invite';
+
+export interface IndexFailure {
+  error: IndexFailureReason;
+  /** English, for a log or a `curl`. The browser renders its own translated copy. */
+  message: string;
+  /**
+   * The ecosystem this address *does* look like, when the answer said so.
+   *
+   * Only ever set beside `wrong_type`, and it is what lets the dialog offer "this looks
+   * like a Cashu mint, review it there instead" with a button rather than making the
+   * reader work out which page they wanted.
+   */
+  detected_type?: IndexType;
+  /** Seconds until the next submission is accepted. Only beside `rate_limited`. */
+  retry_after?: number;
+}
+
+/** 200 or 201: the same payload `GET /api/mints/:host` returns, plus how it got there. */
+export type IndexSuccess = MintDetail & {
+  /** True when the identifier was already indexed and nothing was probed. */
+  existing: boolean;
+  /** Absent on an `existing` hit: nothing was written, so nothing wrote it. */
+  indexed_from?: IndexSource;
+};
+
+export type IndexResponse = IndexSuccess | IndexFailure;
+
+export function isIndexFailure(body: IndexResponse): body is IndexFailure {
+  return typeof (body as IndexFailure).error === 'string';
+}
+
+/**
+ * The client-side pre-check, run before any network call.
+ *
+ * Deliberately shallow: it answers "could this possibly be an address of this kind?"
+ * and nothing more. Whether the mint exists, answers, or is what it claims is the
+ * server's question, and asking the browser to guess would only produce a second
+ * opinion to disagree with. What it does catch is the common typo — an empty box, a
+ * sentence, a `fed1…` pasted into the Cashu field — before a request goes out.
+ *
+ * Returns the value to submit, which is the input with the scheme the normalizer would
+ * add, so the dialog can show the reader what it is about to check.
+ */
+export function checkIndexInput(
+  type: IndexType,
+  input: string,
+): { ok: true; value: string } | { ok: false; reason: 'empty' | 'bad_url' | 'bad_invite' } {
+  const raw = input.trim();
+  if (!raw) return { ok: false, reason: 'empty' };
+
+  if (type === 'fedimint') {
+    return isInviteCode(raw) && federationIdFromInviteCode(raw) !== null
+      ? { ok: true, value: raw.toLowerCase() }
+      : { ok: false, reason: 'bad_invite' };
+  }
+
+  // A pasted invite code in a URL field is a wrong-field mistake, not a malformed URL,
+  // and saying "that is an invite code" is more use than "that is not a URL".
+  if (isInviteCode(raw)) return { ok: false, reason: 'bad_invite' };
+
+  const normalized = normalizeMintUrl(raw);
+  return normalized ? { ok: true, value: normalized.url } : { ok: false, reason: 'bad_url' };
+}
+
+/**
+ * Is this body a NUT-06 mint info document?
+ *
+ * The probe needs a test that a Cashu mint passes and an arbitrary JSON endpoint fails,
+ * because `/v1/info` on a host that is not a mint is very often a 200 with *something*
+ * on it — an API index, a health check, a framework's error object. NUT-06 makes every
+ * field optional, so the test is "does it carry any of the things only a mint has":
+ * a `nuts` object, or a mint pubkey, or the name/version pair a mint's info always has.
+ *
+ * Kept here rather than in the prober because the wrong-type detection on the LNURL
+ * path runs the same test against the same document, and two spellings of "is this a
+ * Cashu mint" is exactly how a submission ends up filed under both ecosystems.
+ */
+export function isNut06Info(body: unknown): body is MintInfo {
+  if (!body || typeof body !== 'object' || Array.isArray(body)) return false;
+  const info = body as Record<string, unknown>;
+
+  const nuts = info['nuts'];
+  if (nuts && typeof nuts === 'object' && !Array.isArray(nuts) && Object.keys(nuts).length > 0) {
+    return true;
+  }
+  // A mint pubkey is 33 compressed bytes, exactly as an LNURL mint's is.
+  if (typeof info['pubkey'] === 'string' && /^0[23][0-9a-f]{64}$/i.test(info['pubkey'])) {
+    return true;
+  }
+  return typeof info['name'] === 'string' && typeof info['version'] === 'string';
+}
+
+/**
+ * The route a page for this listing lives at, given its type and routing slug.
+ *
+ * One table, because three pages, the 404 resolver, the review dialog and the sitemap
+ * all have to agree on it, and the failure mode of disagreeing is a link to a page that
+ * does not exist. Locale prefixing is the caller's job (`localePath`).
+ */
+export const MINT_ROUTES: Record<IndexType, string> = {
+  cashu: '/mint',
+  fedimint: '/fedimint',
+  lnurl: '/lnurl-mint',
+};
+
+/** `/mint/mint.example.com`, unprefixed. */
+export function mintPath(type: string, host: string): string {
+  const base = MINT_ROUTES[type as IndexType] ?? MINT_ROUTES.cashu;
+  return `${base}/${host}`;
+}
+
+/**
+ * Which ecosystem a page path belongs to, or null when it is not a listing page.
+ *
+ * The 404 resolver's first question: the reader asked for *something*, and whether
+ * this build has any business indexing it on their behalf is decided entirely by the
+ * shape of the path they used.
+ */
+export function typeForPath(path: string): { type: IndexType; host: string } | null {
+  const match = /^\/(mint|fedimint|lnurl-mint)\/([^/]+)\/?$/.exec(path);
+  if (!match?.[1] || !match[2]) return null;
+
+  const type: IndexType =
+    match[1] === 'fedimint' ? 'fedimint' : match[1] === 'lnurl-mint' ? 'lnurl' : 'cashu';
+  return { type, host: decodeURIComponent(match[2]) };
+}
+
+/**
+ * The address a `/mint/{slug}` or `/lnurl-mint/{slug}` deep link implies, or null when
+ * the slug cannot be turned back into one.
+ *
+ * Routing slugs are deterministic but not reversible: `mint.example.com/Bitcoin` becomes
+ * `mint.example.com-bitcoin`, and so would a mint at `mint.example.com-bitcoin` if one
+ * existed. Looking a row up by slug is unaffected — that is what the column is for — but
+ * *indexing* from a slug means fetching an address, and guessing which of two readings a
+ * hyphen had would mean probing the wrong host and possibly indexing it.
+ *
+ * So only the unambiguous shape is derived: a plain hostname, optionally with the port
+ * suffix the slug spells `-3338`. Everything else returns null, and the caller says it
+ * cannot look this one up from the link alone and offers the dialog, where the reader
+ * can paste the address including its path.
+ *
+ * The `lnurl-` collision prefix is deliberately *not* stripped. A slug only takes that
+ * prefix at insert time, so a link carrying one describes a row that exists and never
+ * reaches this function; a slug that merely starts with those characters is far more
+ * likely to be a mint whose hostname begins `lnurl-`, and turning it into a different
+ * host would mean probing — and possibly indexing — somebody else's server.
+ */
+export function addressFromSlug(slug: string): string | null {
+  const value = slug.trim().toLowerCase();
+  const match = /^([a-z0-9-]+(?:\.[a-z0-9-]+)*\.[a-z]{2,})(?:-(\d{2,5}))?$/.exec(value);
+  if (!match?.[1]) return null;
+
+  return `https://${match[1]}${match[2] ? `:${match[2]}` : ''}`;
+}

shared/src/lnurl.ts

@@ -0,0 +1,714 @@
+/**
+ * LNURL mints: what a `kind:38174` announcement contains, what the mint's own endpoints
+ * return, and the handful of derived values the API, the pages and the islands all have
+ * to agree on.
+ *
+ * The kind is this site's own proposed NIP-87 extension, specified in
+ * `docs/KIND-LNURL-MINT.md`. That document and this file are meant to be read together:
+ * every rule below is stated there normatively, and `api/src/check-lnurl.ts` asserts the
+ * two have not drifted apart.
+ *
+ * The endpoint parsing was written against the live reference instance and against a
+ * locally run build of the mint software, not against a reading of the README — the same
+ * rule NOTES.md sets for the Cashu side. `NOTES-LNURL.md` records what was actually on
+ * the wire. Four places where the wire and the prose disagreed, all resolved for the wire:
+ *
+ *   - There is no bare `/p`. The payRequest lives only at `/.well-known/lnurlp/{username}`,
+ *     and `/p` is a hard 404. The mint advertisement — limits, description, pubkey, node
+ *     identity — is on the *withdraw* side, `/.well-known/lnurlw/{username}`.
+ *   - Every registered route answers its errors with **HTTP 200** and an LNURL
+ *     `{"status":"ERROR"}` body. A status code proves nothing; only the parsed body does.
+ *   - `None` fields are dropped from responses entirely, so "no funding source" shows up
+ *     as `mintPubkey` and the node fields being *absent*, not null.
+ *   - LUD-21 verify cannot be distinguished from an unknown payment hash. It is
+ *     announcement-only; nothing here infers it.
+ *
+ * Every amount on the wire is millisatoshi. Nothing in this file rounds; `msatToSat`
+ * is where that decision is made once.
+ */
+import {
+  sanitizeDisplayText, sanitizePictureUrl, tagValue, tagValues, type NostrEventLike,
+} from './nostr.js';
+import { displayDomain, normalizeMintUrl } from './normalize.js';
+
+/** The scheme on the synthetic `mints.url` an LNURL row is keyed by. */
+export const LNURL_KEY_SCHEME = 'lnurl:';
+
+/**
+ * Routing-slug prefix, used **only** on collision.
+ *
+ * `mints.host` is globally unique across every ecosystem, so an LNURL mint and a Cashu
+ * mint on the same hostname would fight over one slug and the loser would silently not
+ * be tracked. Almost always they do not collide, and the LNURL mint keeps the clean
+ * `lnurl.21mint.me` slug; when one does, the row takes `lnurl-` in front rather than
+ * vanishing. See `insertLnurlMint` for why that is decided at insert time and then never
+ * revisited.
+ */
+export const LNURL_SLUG_PREFIX = 'lnurl-';
+
+/**
+ * The primary key an LNURL row uses.
+ *
+ * Namespaced rather than storing the bare URL, for the same reason `fedimint:` is: the
+ * column is the table's primary key across all three ecosystems, and one host serving
+ * both a Cashu mint and an LNURL mint must produce two rows, not a collision. The base
+ * URL is recoverable in full, so nothing is lost by the prefix.
+ */
+export function lnurlKey(baseUrl: string): string {
+  return LNURL_KEY_SCHEME + baseUrl;
+}
+
+/** The base URL inside an `lnurl:` key, or null if that is not what this is. */
+export function baseUrlFromKey(key: string): string | null {
+  if (!key.startsWith(LNURL_KEY_SCHEME)) return null;
+  const url = key.slice(LNURL_KEY_SCHEME.length);
+  return url.startsWith('https://') ? url : null;
+}
+
+/* ---------- identity ---------- */
+
+/**
+ * A mint pubkey: the funding node's identity key, 33 bytes compressed, 66 hex characters
+ * beginning `02` or `03`.
+ *
+ * Strict about the length and the prefix on purpose. This value becomes the `d` tag, and
+ * the whole reason the two `d` forms are unambiguous is that one of them is exactly this
+ * shape and the other never is.
+ */
+export function isMintPubkey(value: unknown): value is string {
+  return typeof value === 'string' && /^0[23][0-9a-f]{64}$/i.test(value);
+}
+
+/**
+ * The `d` fallback: a mint's normalized host, with no scheme and no trailing slash.
+ *
+ * `https://mint.example.com/lnurl/` becomes `mint.example.com/lnurl`. Always contains a
+ * dot and never matches `isMintPubkey`, which is what keeps the two forms apart.
+ */
+export function hostIdentifier(baseUrl: string): string {
+  return displayDomain(baseUrl).toLowerCase();
+}
+
+/**
+ * The canonical `d` for a mint, given whatever is known about it.
+ *
+ * Pubkey when there is one, host otherwise — and the pubkey is *sticky*: a caller
+ * passing a previously known pubkey keeps it even when the current probe found none,
+ * because a node being unreachable for one request is not a change of identity. See
+ * "When a mint gains a pubkey after being announced by host" in the kind document.
+ */
+export function lnurlIdentifier(baseUrl: string, mintPubkey: string | null | undefined): string {
+  return isMintPubkey(mintPubkey) ? mintPubkey.toLowerCase() : hostIdentifier(baseUrl);
+}
+
+/**
+ * Both identifiers a review of this mint could carry, for a `#d` relay filter and for
+ * resolution.
+ *
+ * A mint announced by host before it had a funding source, and by pubkey afterwards, has
+ * reviews pointing at both. Asking for only the current one strands the older half.
+ */
+export function lnurlIdentifiers(
+  baseUrl: string,
+  mintPubkey: string | null | undefined,
+): string[] {
+  const host = hostIdentifier(baseUrl);
+  return isMintPubkey(mintPubkey) ? [mintPubkey.toLowerCase(), host] : [host];
+}
+
+/* ---------- features ---------- */
+
+/**
+ * Note operations: the four branches of LUD-25's `/w/cb`, plus minting.
+ *
+ * Split into two groups because that is where a missing funding source cuts. `mint` and
+ * `melt` both need the node — one issues an invoice, the other pays one — while
+ * `rotate`, `split` and `merge` only rewrite this mint's own book and keep working with
+ * no node at all. That distinction is the whole reason the degraded state is worth
+ * rendering rather than collapsing into "offline".
+ */
+export const FUNDED_FEATURES = ['mint', 'melt'] as const;
+export const NOTE_FEATURES = ['rotate', 'split', 'merge'] as const;
+
+/** The LNURL sub-specifications a mint can speak. */
+export const SPEC_FEATURES = ['lud06', 'lud03', 'lud16', 'lud21'] as const;
+
+/** Optional extras, both of which are genuinely visible from outside. */
+export const EXTRA_FEATURES = ['signed-notes', 'onion'] as const;
+
+/**
+ * The whole vocabulary, and the only values this build has an opinion about.
+ *
+ * Anything else in a `features` tag is kept and shown as its own chip rather than
+ * dropped: the kind document requires consumers to ignore tokens they do not recognise,
+ * and rendering an unknown capability under its published name says exactly as much as
+ * it should.
+ */
+export const FEATURE_VOCABULARY: readonly string[] = [
+  ...FUNDED_FEATURES, ...NOTE_FEATURES, ...SPEC_FEATURES, ...EXTRA_FEATURES,
+];
+
+/**
+ * The named rows on the mint page's Features panel, in display order.
+ *
+ * `notes` is a row and not a feature: the three note-rewriting operations are one thing
+ * to a reader ("can I reshape what I hold?") and always ship together, so one row
+ * satisfied by any of them beats three rows that are always identical. Every other row
+ * is one vocabulary value.
+ */
+export const HIGHLIGHT_FEATURES = [
+  'mint', 'melt', 'notes', 'lud16', 'lud21', 'signed-notes', 'onion',
+] as const;
+export type HighlightFeature = (typeof HIGHLIGHT_FEATURES)[number];
+
+/** Which vocabulary values satisfy each named row. */
+export const FEATURE_ALIASES: Record<string, readonly string[]> = {
+  mint: ['mint'],
+  melt: ['melt'],
+  notes: ['rotate', 'split', 'merge'],
+  lud16: ['lud16'],
+  lud21: ['lud21'],
+  'signed-notes': ['signed-notes'],
+  onion: ['onion'],
+};
+
+/**
+ * Rows whose row is only as good as the funding source behind it.
+ *
+ * A mint that implements minting, melting and note signing still cannot do any of them
+ * while its node is unreachable, and the panel says so rather than showing a tick that
+ * is not true today. `rotate`/`split`/`merge` are deliberately absent from this set:
+ * they are exactly what still works.
+ */
+export const FUNDING_DEPENDENT: readonly HighlightFeature[] = ['mint', 'melt', 'signed-notes'];
+
+/**
+ * Plain-language names, and the English source of truth for them.
+ *
+ * The catalogs carry a translation per key under `lnurl.feature.`; anything neither
+ * knows renders as its own published token, which is still a true label.
+ */
+export const FEATURE_NAMES_EN: Record<string, string> = {
+  mint: 'Mint via Lightning (LUD-06)',
+  melt: 'Melt to Lightning',
+  notes: 'Rotate / split / merge notes',
+  lud16: 'Lightning address',
+  lud21: 'Payment verification (LUD-21)',
+  'signed-notes': 'Signed notes (offline verification)',
+  onion: 'Tor address',
+  rotate: 'Rotate a note',
+  split: 'Split a note',
+  merge: 'Merge notes',
+  lud06: 'LUD-06 payRequest',
+  lud03: 'LUD-03 withdrawRequest',
+};
+
+/**
+ * Split a `features` tag: `"mint,melt,rotate,lud06"`.
+ *
+ * Comma separated, but whitespace is tolerated because a publisher writing
+ * `"mint, melt"` meant the same thing — the same latitude `parseModules` gives a
+ * `modules` tag. Lowercased, deduped, order preserved, and bounded so a hostile tag
+ * cannot become a thousand chips on a page.
+ */
+export function parseFeatures(value: string | null | undefined): string[] {
+  if (!value) return [];
+  const out: string[] = [];
+  const seen = new Set<string>();
+  for (const part of value.split(/[,\s]+/)) {
+    const feature = part.trim().toLowerCase();
+    if (!feature || feature.length > 32 || seen.has(feature)) continue;
+    if (!/^[a-z0-9_-]+$/.test(feature)) continue;
+    seen.add(feature);
+    out.push(feature);
+    if (out.length >= 40) break;
+  }
+  return out;
+}
+
+/** Which named row a vocabulary value belongs to, or null for the chip list. */
+export function highlightFeatureFor(feature: string): HighlightFeature | null {
+  const name = feature.toLowerCase();
+  for (const key of HIGHLIGHT_FEATURES) {
+    if (FEATURE_ALIASES[key]?.includes(name)) return key;
+  }
+  return null;
+}
+
+/** True when this mint claims anything satisfying one of the named rows. */
+export function hasFeature(features: readonly string[], key: HighlightFeature): boolean {
+  const aliases = FEATURE_ALIASES[key] ?? [];
+  return features.some((feature) => aliases.includes(feature.toLowerCase()));
+}
+
+/** Features with no named row of their own, for the chip list under the seven. */
+export function otherFeatures(features: readonly string[]): string[] {
+  return features.filter((feature) => highlightFeatureFor(feature) === null);
+}
+
+/**
+ * What one row of the Features panel says.
+ *
+ * Three states rather than two, which is the one place this panel is richer than the
+ * Fedimint Modules panel it is modelled on: a capability can be published, and still be
+ * unavailable this minute because the node behind it is unreachable. Collapsing that
+ * into "supported" would show a tick beside something that would fail if tried.
+ */
+export type FeatureState = 'ok' | 'unavailable' | 'none';
+
+/**
+ * The state of every named row, given what was announced and what the probe saw.
+ *
+ * The announcement decides whether a capability exists at all; the probe can only take
+ * one away, and only the three that depend on a funding source. That asymmetry is
+ * normative in the kind document: a prober never rewrites an operator's `features`.
+ *
+ * `fundingAvailable` is null when nothing has probed yet, which reads as "no reason to
+ * doubt it" rather than as a failure.
+ */
+export function featureStates(
+  features: readonly string[],
+  fundingAvailable: boolean | null,
+): Record<HighlightFeature, FeatureState> {
+  const out = {} as Record<HighlightFeature, FeatureState>;
+  for (const key of HIGHLIGHT_FEATURES) {
+    if (!hasFeature(features, key)) {
+      out[key] = 'none';
+      continue;
+    }
+    out[key] =
+      fundingAvailable === false && FUNDING_DEPENDENT.includes(key) ? 'unavailable' : 'ok';
+  }
+  return out;
+}
+
+/**
+ * The features a probe can honestly claim, from what it observed.
+ *
+ * Every entry has an observation behind it, and the four that are missing are the
+ * point. `rotate`, `split` and `merge` are only provable by calling `/w/cb`, which
+ * mutates or destroys a stranger's note; `lud21` is genuinely undetectable, because a
+ * disabled verify endpoint and an unknown payment hash return byte-identical responses
+ * (NOTES-LNURL.md §5). None of the four is inferred from a version string.
+ *
+ * Two callers, one definition, deliberately: the page renders this beside an operator's
+ * announced list, and the publisher signs it into a `kind:38174`. Those must not be
+ * able to disagree about what this site claims to have seen.
+ *
+ * The order is the vocabulary's own, so two runs over one mint produce identical
+ * output and the publisher's change detector does not fire on a reordering.
+ */
+export function observedFeatures(probe: {
+  fundingAvailable: boolean | null;
+  maxWithdrawableMsat: number | null;
+  maxSendableMsat: number | null;
+  lightningAddress: string | null;
+  mintPubkey: string | null;
+  onionUrl: string | null;
+}): string[] {
+  const features: string[] = [];
+
+  /*
+   * `mint` and `melt` each need two things: the mint advertising the relevant side,
+   * and a funding source that can actually perform it. A mint whose node is unreachable
+   * implements both and can do neither, and this site only ever saw it in the state
+   * where it could not — so it does not say otherwise.
+   */
+  const funded = probe.fundingAvailable === true;
+  if (funded && probe.maxSendableMsat !== null) features.push('mint');
+  if (funded && (probe.maxWithdrawableMsat ?? 0) > 0) features.push('melt');
+
+  if (probe.maxSendableMsat !== null) features.push('lud06');
+  // The advertisement's `callback` is `/w`, the LUD-03 withdrawRequest, and parsing the
+  // advertisement at all is what proves it was served.
+  if (probe.maxWithdrawableMsat !== null) features.push('lud03');
+  if (probe.lightningAddress) features.push('lud16');
+  if (probe.mintPubkey && funded) features.push('signed-notes');
+  if (probe.onionUrl) features.push('onion');
+
+  return features;
+}
+
+/**
+ * What the Features panel renders: what the operator announced, plus what was observed.
+ *
+ * A union, and it has to be one. The announcement is the operator's claim about what
+ * they built and is the richer list — only they can tell you that notes rotate. The
+ * probe is this site's own observation and is the *only* list for a mint nobody has
+ * announced yet, which today is every LNURL mint on the network.
+ *
+ * Announced values come first so an operator's own ordering survives. Note that this is
+ * a display concern and nothing else: `LnurlFields.features` still holds the
+ * announcement verbatim, and the publisher still signs only `observedFeatures`. The
+ * kind document's rule is that a prober never rewrites an operator's list, and nothing
+ * here does — it renders two lists side by side.
+ */
+export function displayFeatures(
+  announced: readonly string[] | null | undefined,
+  observed: readonly string[] | null | undefined,
+): string[] {
+  return [...new Set([...(announced ?? []), ...(observed ?? [])])];
+}
+
+/* ---------- amounts ---------- */
+
+/**
+ * Millisatoshi to satoshi, floored.
+ *
+ * Floored rather than rounded because both of the numbers this converts are *bounds*: a
+ * `maxWithdrawable` rounded up advertises a note larger than the mint will ever issue,
+ * and a `minWithdrawable` rounded down advertises one it will refuse. Flooring keeps the
+ * displayed range inside the real one at both ends, which is the safe direction to be
+ * wrong in. Sub-sat amounts floor to 0, which is true and is what the "withdrawals
+ * disabled" warning keys on.
+ */
+export function msatToSat(msat: number | null | undefined): number | null {
+  if (typeof msat !== 'number' || !Number.isFinite(msat) || msat < 0) return null;
+  return Math.floor(msat / 1000);
+}
+
+/* ---------- the mint's own endpoints ---------- */
+
+/** The path the mint advertisement lives on. `_` is LUD-16's reserved bare-domain name. */
+export const WITHDRAW_INFO_PATH = '/.well-known/lnurlw/_';
+/** The LUD-06 payRequest, used as a fallback when the withdraw side does not answer. */
+export const PAY_INFO_PATH = '/.well-known/lnurlp/_';
+
+/**
+ * What a mint advertisement yields once parsed.
+ *
+ * Everything is optional except the two limits and the tag, because that is genuinely
+ * what varies: a mint with no funding source omits its whole node section, and the
+ * response is still valid and still worth rendering.
+ */
+export interface LnurlAdvertisement {
+  minWithdrawableMsat: number;
+  maxWithdrawableMsat: number;
+  defaultDescription: string | null;
+  mintPubkey: string | null;
+  payLink: string | null;
+  nodeAlias: string | null;
+  nodeUri: string | null;
+  nodeCapacityMsat: number | null;
+  nodeChannels: number | null;
+  nodePeers: number | null;
+  /**
+   * Whether the mint's funding source answered.
+   *
+   * Derived, not read: `mintPubkey` is populated only when a funding source is both
+   * configured and reachable, and is dropped from the response otherwise. One bit, and
+   * it is the only HTTP-visible signal there is — see NOTES-LNURL.md for why it is not
+   * possible to separate "never configured" from "unreachable right now", and why the
+   * site does not try.
+   */
+  fundingAvailable: boolean;
+}
+
+function num(value: unknown): number | null {
+  return typeof value === 'number' && Number.isFinite(value) ? value : null;
+}
+
+function str(value: unknown, max = 400): string | null {
+  if (typeof value !== 'string') return null;
+  const text = value.trim();
+  if (!text || text.length > max) return null;
+  return text;
+}
+
+/**
+ * Parse `/.well-known/lnurlw/_`.
+ *
+ * Returns null for anything that is not a withdrawRequest carrying both limits — which
+ * includes the mint's own `{"status":"ERROR"}` bodies, since those arrive with HTTP 200
+ * and would otherwise read as a successful probe. The caller turns null into the
+ * "responding but invalid" state, which is neither online nor offline.
+ */
+export function parseAdvertisement(body: unknown): LnurlAdvertisement | null {
+  if (!body || typeof body !== 'object' || Array.isArray(body)) return null;
+  const raw = body as Record<string, unknown>;
+
+  if (raw['tag'] !== 'withdrawRequest') return null;
+
+  const min = num(raw['minWithdrawable']);
+  const max = num(raw['maxWithdrawable']);
+  // Both bounds are required, and inverted bounds are not a mint advertisement.
+  if (min === null || max === null || min < 0 || max < 0 || min > max) return null;
+
+  const mintPubkey = isMintPubkey(raw['mintPubkey']) ? String(raw['mintPubkey']).toLowerCase() : null;
+
+  return {
+    minWithdrawableMsat: min,
+    maxWithdrawableMsat: max,
+    defaultDescription: str(raw['defaultDescription']),
+    mintPubkey,
+    payLink: str(raw['payLink']),
+    nodeAlias: sanitizeDisplayText(raw['nodeAlias'], 64) ?? null,
+    nodeUri: str(raw['nodeUri'], 200),
+    nodeCapacityMsat: num(raw['nodeCapacity']),
+    nodeChannels: num(raw['nodeNumChannels']),
+    nodePeers: num(raw['nodeNumPeers']),
+    fundingAvailable: mintPubkey !== null,
+  };
+}
+
+/** What the LUD-06 payRequest yields. Fetched for the fee, the address and the limits. */
+export interface LnurlPayInfo {
+  minSendableMsat: number;
+  maxSendableMsat: number;
+  /** The `text/plain` entry: the closest thing to an operator-written description. */
+  description: string | null;
+  /** The `text/identifier` entry, a LUD-16 lightning address. */
+  identifier: string | null;
+  /** `Mint fees: <base>,<ppm>`, absent when the mint is fee-free. */
+  feeBaseMsat: number | null;
+  feePpm: number | null;
+  /** The `withdrawLink` extension: lnurlcash's pointer back to the withdraw side. */
+  withdrawLink: string | null;
+}
+
+/**
+ * Parse `/.well-known/lnurlp/_`.
+ *
+ * `metadata` is a JSON *string* holding a JSON array of `[mime, value]` pairs, so it is
+ * parsed twice. A metadata blob that will not parse costs the description and the
+ * address and nothing else: the limits above it are still good.
+ */
+export function parsePayInfo(body: unknown): LnurlPayInfo | null {
+  if (!body || typeof body !== 'object' || Array.isArray(body)) return null;
+  const raw = body as Record<string, unknown>;
+
+  if (raw['tag'] !== 'payRequest') return null;
+
+  const min = num(raw['minSendable']);
+  const max = num(raw['maxSendable']);
+  if (min === null || max === null || min < 0 || max < 0 || min > max) return null;
+
+  let description: string | null = null;
+  let identifier: string | null = null;
+  let feeBaseMsat: number | null = null;
+  let feePpm: number | null = null;
+
+  try {
+    const entries: unknown = JSON.parse(typeof raw['metadata'] === 'string' ? raw['metadata'] : '[]');
+    if (Array.isArray(entries)) {
+      for (const entry of entries) {
+        if (!Array.isArray(entry) || typeof entry[0] !== 'string' || typeof entry[1] !== 'string') {
+          continue;
+        }
+        const [mime, value] = entry as [string, string];
+        // `Mint fees: <base_msat>,<ppm>` shares the `text/plain` mime with the
+        // description, so it is recognised by its prefix and taken out of the running
+        // for one — otherwise a fee-charging mint's description would be its fee line.
+        const fees = /^Mint fees:\s*(\d+)\s*,\s*(\d+)\s*$/i.exec(value);
+        if (mime === 'text/plain' && fees) {
+          feeBaseMsat = Number.parseInt(fees[1]!, 10);
+          feePpm = Number.parseInt(fees[2]!, 10);
+          continue;
+        }
+        if (mime === 'text/plain' && description === null) {
+          description = sanitizeDisplayText(value, 400) ?? null;
+        }
+        if (mime === 'text/identifier' && identifier === null) {
+          identifier = isLightningAddress(value) ? value.trim().toLowerCase() : null;
+        }
+      }
+    }
+  } catch {
+    // Unparseable metadata. The limits are still real, so this is not a failed probe.
+  }
+
+  return {
+    minSendableMsat: min,
+    maxSendableMsat: max,
+    description,
+    identifier,
+    feeBaseMsat,
+    feePpm,
+    withdrawLink: str(raw['withdrawLink']),
+  };
+}
+
+/** `name@domain`, and only that. Same shape rule the review cards apply to a NIP-05. */
+export function isLightningAddress(value: unknown): value is string {
+  if (typeof value !== 'string') return false;
+  const text = value.trim();
+  return text.length <= 128 && /^[a-z0-9._+-]+@[a-z0-9-]+(\.[a-z0-9-]+)+$/i.test(text);
+}
+
+/**
+ * The mint's lightning address, derived from `payLink`.
+ *
+ * Not read off the payRequest's own `text/identifier`, which echoes back whatever
+ * username was queried — probing `_` gets `_@host`, which is LUD-16's bare-domain form
+ * and not something to render at a reader. `payLink` is built from the operator's
+ * configured username unconditionally, so it is the one place the real name appears.
+ */
+export function addressFromPayLink(payLink: string | null | undefined): string | null {
+  if (!payLink) return null;
+  let url: URL;
+  try {
+    url = new URL(payLink);
+  } catch {
+    return null;
+  }
+  const username = /\/\.well-known\/lnurlp\/([^/?#]+)$/.exec(url.pathname)?.[1];
+  if (!username || username === '_') return null;
+  const address = `${decodeURIComponent(username)}@${url.hostname.toLowerCase()}`;
+  return isLightningAddress(address) ? address : null;
+}
+
+/**
+ * A `*.onion` host in the one-pager, or null.
+ *
+ * Deliberately looser than base32's alphabet. A v3 address is 56 characters of `a-z2-7`,
+ * but the mint software's own test fixture is not valid base32, and a real address that
+ * does not fit the expected shape is still the operator's address. Nothing is ever
+ * fetched over Tor by this site, so the cost of a wrong match is one displayed string.
+ */
+export function onionFromHtml(html: string): string | null {
+  const match = /\b([a-z0-9]{16,60}\.onion)\b/i.exec(html);
+  return match?.[1]?.toLowerCase() ?? null;
+}
+
+/**
+ * The software version, from `GET /openapi.json`.
+ *
+ * `0.0.0+unknown` is the package's own "I could not find my metadata" sentinel, not a
+ * release, so it is treated as no version at all rather than printed at a reader. The
+ * title is checked too: an arbitrary FastAPI app on the same host would otherwise
+ * contribute its version to a mint's page.
+ */
+export function parseSoftware(body: unknown): string | null {
+  if (!body || typeof body !== 'object') return null;
+  const info = (body as Record<string, unknown>)['info'];
+  if (!info || typeof info !== 'object') return null;
+
+  const record = info as Record<string, unknown>;
+  const title = str(record['title'], 64);
+  const version = str(record['version'], 64);
+  if (!title || !version) return null;
+  if (!/^[\w.+-]+$/.test(version) || version.startsWith('0.0.0+unknown')) return null;
+  if (!/^[\w.@/ -]+$/.test(title)) return null;
+
+  return `${title}/${version}`;
+}
+
+/* ---------- the announcement ---------- */
+
+export interface LnurlAnnouncement {
+  /** The `d` tag: a mint pubkey, or a normalized host. */
+  identifier: string;
+  /** The `d` tag when it was a pubkey, else null. Feeds the sticky identity rule. */
+  mintPubkey: string | null;
+  /** The canonical `u` tag, normalized. This is what rows are deduped by. */
+  baseUrl: string;
+  /** The routing slug the normalizer derived from that URL. */
+  slug: string;
+  /** The `features` tag, split. */
+  features: string[];
+  /** The `n` tag, normalized. */
+  network: string | null;
+  /** From `content`, which is kind-0-shaped metadata. */
+  name: string | null;
+  picture: string | null;
+  about: string | null;
+  announcerPubkey: string;
+  announcedAt: number;
+}
+
+/**
+ * Read a kind 38174 event, or return null if it is not one this site can use.
+ *
+ * `u` is required here where NIP-87 makes it a SHOULD for 38172, and the kind document
+ * says why: an LNURL mint's `d` may be a bare host with no scheme, which is not
+ * something to fetch, so an announcement with no usable `u` carries no address at all
+ * and there is nothing to probe, key a row by, or link to.
+ *
+ * The `d` tag is *not* required to match the `u` tag's host. A mint that has a pubkey
+ * announces under it, and checking the two against each other would reject exactly the
+ * events the identity rule exists to allow.
+ */
+export function parseLnurlAnnouncement(event: NostrEventLike): LnurlAnnouncement | null {
+  const d = tagValue(event.tags, 'd')?.trim().toLowerCase();
+  if (!d || d.length > 200) return null;
+
+  // A `d` that is neither a pubkey nor host-shaped is not an identifier this build can
+  // resolve a review against, so the announcement is not usable even if `u` is fine.
+  if (!isMintPubkey(d) && !/^[a-z0-9.-]+\.[a-z]{2,}(:\d+)?(\/[\w./~-]*)?$/.test(d)) return null;
+
+  let normalized: ReturnType<typeof normalizeMintUrl> = null;
+  for (const raw of tagValues(event.tags, 'u')) {
+    normalized = normalizeMintUrl(raw);
+    if (normalized) break;
+  }
+  if (!normalized) return null;
+
+  const meta = parseLnurlMetadata(event.content);
+
+  return {
+    identifier: d,
+    mintPubkey: isMintPubkey(d) ? d : null,
+    baseUrl: normalized.url,
+    slug: normalized.host,
+    features: parseFeatures(tagValue(event.tags, 'features')),
+    network: normalizeLnurlNetwork(tagValue(event.tags, 'n')),
+    name: meta.name,
+    picture: meta.picture,
+    about: meta.about,
+    announcerPubkey: event.pubkey,
+    announcedAt: event.created_at,
+  };
+}
+
+/**
+ * The `content` of a 38174, which the kind document defines as kind-0-style metadata.
+ *
+ * Same defensive posture as the Fedimint parser: this is arbitrary text written by
+ * anyone with a relay connection, so unparseable JSON, wrong types and junk fields all
+ * degrade to "no metadata" rather than throwing.
+ */
+export function parseLnurlMetadata(content: string): {
+  name: string | null;
+  picture: string | null;
+  about: string | null;
+} {
+  const empty = { name: null, picture: null, about: null };
+  if (!content.trim()) return empty;
+
+  let meta: Record<string, unknown>;
+  try {
+    const parsed: unknown = JSON.parse(content);
+    if (!parsed || typeof parsed !== 'object' || Array.isArray(parsed)) return empty;
+    meta = parsed as Record<string, unknown>;
+  } catch {
+    return empty;
+  }
+
+  const first = (...keys: string[]): unknown => {
+    for (const key of keys) if (meta[key] !== undefined && meta[key] !== null) return meta[key];
+    return undefined;
+  };
+
+  return {
+    name: sanitizeDisplayText(first('name', 'display_name', 'mint_name'), 64) ?? null,
+    picture: sanitizePictureUrl(first('picture', 'icon_url', 'image')) ?? null,
+    about: sanitizeDisplayText(first('about', 'description'), 400) ?? null,
+  };
+}
+
+/**
+ * Normalize an `n` tag.
+ *
+ * The same mapping the Fedimint side applies, and for the same reason: NIP-87 names the
+ * value `mainnet`, publishers copy each other, and `bitcoin` is what they write. Kept
+ * separate from `normalizeNetwork` only so the two ecosystems' rules can diverge later
+ * without one quietly changing the other; today they agree, and `check-lnurl.ts` asserts
+ * that they still do.
+ */
+export function normalizeLnurlNetwork(value: string | null | undefined): string | null {
+  const raw = value?.trim().toLowerCase();
+  if (!raw) return null;
+  if (raw === 'bitcoin' || raw === 'main' || raw === 'mainnet') return 'mainnet';
+  if (!/^[a-z0-9]{1,20}$/.test(raw)) return null;
+  return raw;
+}

shared/src/normalize.ts

@@ -28,6 +28,9 @@ function isDisallowedHost(hostname: string): boolean {
   if (hostname.endsWith('.local')) return true;
   if (PRIVATE_IPV4.test(hostname)) return true;
   if (isPrivateIpv6(hostname)) return true;
+  // Anything that parses as an IP literal is judged by the resolved-address rule too,
+  // so the two checks cannot disagree about, say, 100.64.0.1 or 224.0.0.1.
+  if (/^\d{1,3}(\.\d{1,3}){3}$/.test(hostname) && isPrivateIpAddress(hostname)) return true;
   // A bare label with no dot cannot be a public host.
   if (!hostname.includes('.') && !hostname.includes(':')) return true;
   return false;
@@ -50,6 +53,67 @@ function isPrivateIpv6(hostname: string): boolean {
   return false;
 }
 
+/**
+ * Is this literal IP address one the indexer must never connect to?
+ *
+ * Written against a *resolved* address rather than a hostname, which is the difference
+ * between this and `isDisallowedHost` above: `mint.example.com` looks like an ordinary
+ * public name and can resolve to `127.0.0.1`, and only the answer DNS gave can tell you
+ * so. `POST /api/index` fetches URLs a stranger typed, so it resolves first and checks
+ * every address here before a socket is opened.
+ *
+ * Broader than the hostname rule on purpose. Beyond loopback, link-local and the three
+ * RFC-1918 ranges it also refuses carrier-grade NAT (100.64/10), `0.0.0.0/8`, the
+ * benchmarking and documentation ranges, multicast and the broadcast address: none of
+ * them is a public mint, and each of them is somewhere on a network this server can see
+ * and a stranger should not be able to point it at.
+ */
+export function isPrivateIpAddress(value: string): boolean {
+  const ip = value.trim().toLowerCase().replace(/^\[|\]$/g, '');
+  if (!ip) return true;
+
+  const v4 = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/.exec(ip);
+  if (v4) {
+    const [a, b] = [Number(v4[1]), Number(v4[2])];
+    if (a === undefined || b === undefined || a > 255 || b > 255) return true;
+    if (a === 0 || a === 10 || a === 127) return true;              // this-network, RFC1918, loopback
+    if (a === 169 && b === 254) return true;                        // link-local
+    if (a === 172 && b >= 16 && b <= 31) return true;               // RFC1918
+    if (a === 192 && b === 168) return true;                        // RFC1918
+    if (a === 192 && b === 0) return true;                          // IETF protocol assignments / 192.0.2.0 docs
+    if (a === 198 && (b === 18 || b === 19)) return true;           // benchmarking
+    if (a === 198 && b === 51) return true;                         // documentation
+    if (a === 203 && b === 0) return true;                          // documentation
+    if (a === 100 && b >= 64 && b <= 127) return true;              // carrier-grade NAT
+    if (a >= 224) return true;                                      // multicast, reserved, broadcast
+    return false;
+  }
+
+  if (!ip.includes(':')) return true; // Not an address this function understands.
+
+  // An IPv4-mapped or IPv4-compatible address is judged on its IPv4 half.
+  const mapped = /:((?:\d{1,3}\.){3}\d{1,3})$/.exec(ip);
+  if (mapped?.[1]) return isPrivateIpAddress(mapped[1]);
+
+  if (ip === '::' || ip === '::1') return true;
+  if (/^f[cd]/.test(ip)) return true;   // unique local, fc00::/7
+  if (/^fe[89ab]/.test(ip)) return true; // link-local, fe80::/10
+  if (/^ff/.test(ip)) return true;       // multicast
+  return false;
+}
+
+/**
+ * Is this hostname one the indexer must never fetch, before DNS is consulted at all?
+ *
+ * The cheap half of the check: `localhost`, `.onion`, `.local`, a bare label with no
+ * dot, and an IP literal that is already disqualified by `isPrivateIpAddress`. Exported
+ * so the on-demand indexer can refuse the obvious cases without paying for a lookup,
+ * and so a redirect hop can be judged by the same rule its origin was.
+ */
+export function isBlockedHostname(hostname: string): boolean {
+  return isDisallowedHost(hostname.toLowerCase());
+}
+
 /**
  * May the indexer fetch this URL? http(s) only, and never a private or local host.
  *

shared/src/nostr.ts

@@ -13,6 +13,15 @@ export const KIND_REVIEW = 38000;
 export const KIND_MINT_ANNOUNCEMENT = 38172;
 /** NIP-87 Fedimint federation announcement. */
 export const KIND_FEDIMINT_ANNOUNCEMENT = 38173;
+/**
+ * LNURL mint announcement.
+ *
+ * Not in NIP-87: this site's own proposed extension to it, specified in
+ * `docs/KIND-LNURL-MINT.md` and intended for a PR to nostr-protocol/nips. 38174 is the
+ * next free slot in the family — checked against the kind index in the nips README and
+ * against every issue and PR in that repository before it was claimed.
+ */
+export const KIND_LNURL_ANNOUNCEMENT = 38174;
 /** Profile metadata. */
 export const KIND_PROFILE = 0;
 
@@ -30,6 +39,7 @@ export const KIND_PROFILE = 0;
 export const ANNOUNCEMENT_KINDS = {
   cashu: KIND_MINT_ANNOUNCEMENT,
   fedimint: KIND_FEDIMINT_ANNOUNCEMENT,
+  lnurl: KIND_LNURL_ANNOUNCEMENT,
 } as const;
 
 /**
@@ -224,6 +234,11 @@ export function isFedimintReview(event: NostrEventLike): boolean {
   return tagValue(event.tags, 'k') === String(KIND_FEDIMINT_ANNOUNCEMENT);
 }
 
+/** True when the event's `k` tag marks it as being about an LNURL mint. */
+export function isLnurlReview(event: NostrEventLike): boolean {
+  return tagValue(event.tags, 'k') === String(KIND_LNURL_ANNOUNCEMENT);
+}
+
 /**
  * The kind a review says it is about, from its `k` tag, as a number.
  *

shared/src/types.ts

@@ -18,7 +18,7 @@ export type MintStatus = 'online' | 'degraded' | 'offline' | 'unknown' | 'announ
  * has to be able to hold a value it does not have a page for. Compare against
  * `ANNOUNCEMENT_KINDS` rather than switching exhaustively on this.
  */
-export type MintType = 'cashu' | 'fedimint' | (string & {});
+export type MintType = 'cashu' | 'fedimint' | 'lnurl' | (string & {});
 
 /** One item of `GET /api/mints`. */
 export interface MintListItem {
@@ -26,7 +26,7 @@ export interface MintListItem {
   host: string;
   name: string | null;
   icon: string | null;
-  /** 'cashu' or 'fedimint'. Rows written before the column existed read as 'cashu'. */
+  /** 'cashu', 'fedimint' or 'lnurl'. Rows written before the column existed read as 'cashu'. */
   type: MintType;
   status: MintStatus;
   last_online: number | null;
@@ -48,10 +48,14 @@ export type RatingDistribution = Record<'1' | '2' | '3' | '4' | '5', number>;
 /**
  * `GET /api/mints/:host`.
  *
- * The Fedimint keys are optional and absent on a Cashu mint, which is what keeps the
- * Cashu payload unchanged. Read them through `FedimintDetail` after checking `type`.
+ * The Fedimint and LNURL keys are optional and absent on a Cashu mint, which is what
+ * keeps the Cashu payload unchanged. Read them through `FedimintDetail` or
+ * `LnurlDetail` after checking `type`.
  */
-export interface MintDetail extends MintListItem, Partial<FedimintFields> {
+export interface MintDetail
+  extends MintListItem,
+    Partial<FedimintFields>,
+    Partial<LnurlFields> {
   description: string | null;
   pubkey: string | null;
   info: MintInfo | null;
@@ -100,6 +104,97 @@ export interface FedimintFields {
 /** `GET /api/mints/:host` for a Fedimint federation: the detail plus its own fields. */
 export type FedimintDetail = MintDetail & FedimintFields;
 
+/**
+ * What `ecosystem_json` holds for an LNURL row.
+ *
+ * Two sources, never mixed: `features` is what the operator *announced* on Nostr, and
+ * everything under "probed" is what the mint's own endpoints said when they were last
+ * reached. The kind document makes that separation normative — a prober never rewrites
+ * an operator's capability list — and keeping the two in different fields is what makes
+ * it impossible to do by accident.
+ *
+ * Every millisatoshi field is stored exactly as the wire gave it. Conversion to sats
+ * happens once, at render, through `msatToSat`.
+ */
+export interface LnurlFields {
+  /** The `d` tag: the mint pubkey when it has one, else the normalized host. */
+  lnurl_id: string;
+  /** The https base URL. `host` is the routing slug derived from it. */
+  base_url: string;
+  /** The `features` tag, split. The operator's claim, never edited by a probe. */
+  features: string[];
+  /**
+   * What the last probe actually observed this mint serving.
+   *
+   * Kept apart from `features` above rather than merged into it, because the two are
+   * different kinds of statement — a claim and an observation — and the kind document
+   * makes it normative that a prober never rewrites the first. The page renders their
+   * union through `displayFeatures`; the publisher signs only this one.
+   */
+  observed_features: string[];
+  /** The `n` tag, normalized — `bitcoin` and `mainnet` both arrive as `mainnet`. */
+  network: string | null;
+  /** `created_at` of the newest announcement seen. null for a seeded row. */
+  announced_at: number | null;
+  /** Who published that announcement. The `a` tag of a review points back at them. */
+  announcer_pubkey: string | null;
+
+  /* ---- probed: from the mint's own endpoints ---- */
+
+  /**
+   * The funding node's identity key, from the mint advertisement.
+   *
+   * Sticky once learned: a probe that finds none does not clear it, because a node
+   * being unreachable for one request is not a change of identity. Its *absence from
+   * the latest probe* is recorded separately, in `funding_available`.
+   */
+  mint_pubkey: string | null;
+  /**
+   * Whether the last probe found a reachable funding source.
+   *
+   * null before anything has probed. false is the degraded-but-online state: the mint
+   * answers, its limits are real, and `rotate`/`split`/`merge` still work, but nothing
+   * moves in or out over Lightning. See NOTES-LNURL.md for why this one bit cannot
+   * distinguish "never configured" from "unreachable right now", and why that is fine.
+   */
+  funding_available: boolean | null;
+  /** Which endpoint answered: the withdraw advertisement, or the payRequest fallback. */
+  probe_endpoint: string | null;
+  /**
+   * Set when the host answered but with something that is not a mint advertisement.
+   *
+   * A distinct outcome from both online and offline, and it has to be: these endpoints
+   * return HTTP 200 for their errors, so "responding" and "working" are different
+   * questions. Carries the short reason, for the banner.
+   */
+  invalid_reason: string | null;
+
+  /** Withdraw bounds, millisatoshi: what a note's value can actually be. */
+  min_withdrawable_msat: number | null;
+  max_withdrawable_msat: number | null;
+  /** Pay bounds, millisatoshi: what a minter can actually send. Not the same numbers. */
+  min_sendable_msat: number | null;
+  max_sendable_msat: number | null;
+  /** `Mint fees: <base>,<ppm>` from the payRequest metadata. Absent means fee-free. */
+  fee_base_msat: number | null;
+  fee_ppm: number | null;
+
+  /** The LUD-16 address, derived from `payLink` rather than the echoed identifier. */
+  lightning_address: string | null;
+  /** The Tor address from the one-pager, when one is advertised. */
+  onion_url: string | null;
+
+  /** The funding node, as the mint chooses to describe it. All optional, all msat. */
+  node_alias: string | null;
+  node_uri: string | null;
+  node_capacity_msat: number | null;
+  node_channels: number | null;
+  node_peers: number | null;
+}
+
+/** `GET /api/mints/:host` for an LNURL mint: the detail plus its own fields. */
+export type LnurlDetail = MintDetail & LnurlFields;
+
 /**
  * `GET /api/stats`.
  *
@@ -127,6 +222,18 @@ export interface Stats {
   fedimint_announced: number;
   /** Reviews of federations (`k` = 38173), included in `reviews_total`. */
   fedimint_reviews: number;
+  lnurl_total: number;
+  /** LNURL mints a probe reached. Online includes the degraded-funding ones. */
+  lnurl_online: number;
+  lnurl_offline: number;
+  /**
+   * Online mints whose funding source was unreachable at the last probe: up and
+   * serving, but nothing moves in or out over Lightning. A subset of `lnurl_online`,
+   * never added to it.
+   */
+  lnurl_degraded_funding: number;
+  /** Reviews of LNURL mints (`k` = 38174), included in `reviews_total`. */
+  lnurl_reviews: number;
 }
 
 /** `GET /api/health`. */

shared/src/warnings.ts

@@ -88,7 +88,14 @@ export type MintWarningKind =
   | 'offline'       // offline under 7 days
   // Fedimint
   | 'fedimint-offline'  // a real check reported the guardians down
-  | 'never-confirmed';  // announced on Nostr, and nothing has ever confirmed it
+  | 'never-confirmed'   // announced on Nostr, and nothing has ever confirmed it
+  // LNURL. The offline tiers above are shared verbatim rather than twinned: `gone`,
+  // `offline-long` and `offline` are about reachability, which means exactly the same
+  // thing for an LNURL mint as for a Cashu one, and their copy already reads correctly
+  // for both. Only the states with no Cashu equivalent are new.
+  | 'lnurl-withdrawals-disabled' // maxWithdrawable is zero: nothing can be redeemed
+  | 'lnurl-invalid'              // the host answers, but not with a mint advertisement
+  | 'lnurl-no-funding';          // up and serving, but its Lightning node is unreachable
 
 export interface MintWarning {
   kind: MintWarningKind;
@@ -139,6 +146,19 @@ export interface MintWarningInput {
   capabilities?: Pick<MintCapabilities, 'mintDisabled' | 'meltDisabled'> | null;
   /** Only used to date "never answered a single check". */
   first_seen?: number;
+
+  /* ---- LNURL ---- */
+
+  /**
+   * The advertised withdraw ceiling, millisatoshi. Zero is the disabling value, and it
+   * is checked as `=== 0` rather than as falsy: `null` means nothing has probed, which
+   * is not the same claim at all.
+   */
+  max_withdrawable_msat?: number | null;
+  /** false when the last probe found the mint's Lightning node unreachable. */
+  funding_available?: boolean | null;
+  /** Set when the host answered with something that is not a mint advertisement. */
+  invalid_reason?: string | null;
 }
 
 export interface MintWarningOptions {
@@ -218,9 +238,28 @@ export const WARNING_COPY_EN: Record<string, string> = {
     'This federation was announced on Nostr on {date}, {days} ago, nothing has confirmed since then that it is running, and nobody has reviewed it recently. Everything below came from the announcement.',
   'neverConfirmed.meta': 'Announced {date}, never confirmed',
 
+  'lnurlWithdrawalsDisabled.lead': 'Withdrawals disabled.',
+  'lnurlWithdrawalsDisabled.body.online':
+    'This mint advertises a maximum withdrawal of zero, so no note it issues can be redeemed for anything. Do not mint here until that changes.',
+  'lnurlWithdrawalsDisabled.body.offline':
+    'This mint advertised a maximum withdrawal of zero when it was last reached, so no note it issued could be redeemed for anything. Do not mint here until that changes.',
+  'lnurlWithdrawalsDisabled.meta.online': 'Withdrawals currently disabled',
+  'lnurlWithdrawalsDisabled.meta.offline': 'Withdrawals were disabled when last seen',
+
+  'lnurlInvalid.lead': 'Endpoint responding but invalid.',
+  'lnurlInvalid.body':
+    'The host answers, but not with a mint advertisement this site can read, so withdrawals may not work. Anything below is the last state that did parse, and reviews still work.',
+  'lnurlInvalid.meta': 'Responding, but not with a valid mint advertisement',
+
+  'lnurlNoFunding.lead': 'Minting and melting unavailable.',
+  'lnurlNoFunding.body':
+    'Existing notes can still be rotated, split, or merged, but nothing moves in or out via Lightning right now. The mint itself is up and answering; the Lightning node behind it is not reachable from it.',
+  'lnurlNoFunding.meta': 'Minting and melting unavailable',
+
   'also.meltDisabled': 'Before going offline it had also disabled withdrawals.',
   'also.mintDisabled': 'Before going offline it had also disabled new minting.',
   'also.offline': 'It has also been offline since {date} ({days}).',
+  'also.noFunding': 'Its Lightning node was also unreachable, so nothing could be minted or melted.',
 };
 
 /**
@@ -247,12 +286,24 @@ const englishStrings: WarningStrings = (key, vars) => {
 
 /** Severity order, highest first. Index 0 of the returned list is the one to show. */
 const ORDER: MintWarningKind[] = [
-  'gone', 'melt-disabled', 'frozen', 'offline-long', 'melt-only', 'offline',
+  'gone',
+  'melt-disabled', 'frozen', 'lnurl-withdrawals-disabled',
+  'offline-long',
+  'melt-only', 'lnurl-invalid', 'lnurl-no-funding',
+  'offline',
   // Appended rather than interleaved. The Fedimint kinds never share a list with the
   // Cashu ones (the two branches are exclusive), so their position relative to those
   // is arbitrary — and appending leaves every existing rank exactly where it was.
   'fedimint-offline', 'never-confirmed',
 ];
+/*
+ * The LNURL kinds *are* interleaved, unlike the Fedimint ones, and they have to be:
+ * that branch reuses `gone`, `offline-long` and `offline`, so its warnings genuinely
+ * share a list with those ranks and appending would put a critical
+ * "withdrawals disabled" below a mild "offline since yesterday". The relative order of
+ * everything that existed before is unchanged, which is what `check-warnings.ts`
+ * asserts.
+ */
 
 /**
  * How stale an unconfirmed announcement has to be before it is worth saying so.
@@ -284,6 +335,7 @@ export function getMintWarnings(
   options: MintWarningOptions = {},
 ): MintWarning[] {
   if (mint.type === 'fedimint') return fedimintWarnings(mint, options);
+  if (mint.type === 'lnurl') return lnurlWarnings(mint, options);
   return cashuWarnings(mint, options);
 }
 
@@ -373,13 +425,7 @@ function cashuWarnings(
   const caps = mint.capabilities ?? readCapabilities(mint.info?.nuts);
   const { mintDisabled, meltDisabled } = caps;
 
-  const offline = mint.status === 'offline';
-  const since = mint.last_online;
-  const days = offline && since !== null ? Math.max(0, Math.floor((now - since) / 86400)) : null;
-
-  // Offline with no last_online means it has never once answered, which is at least
-  // as bad as a month of silence, so it lands in the top tier rather than the bottom.
-  const tier = !offline ? 0 : days === null ? 3 : days >= 30 ? 3 : days >= 7 ? 2 : 1;
+  const { offline, since, days, tier } = offlineTier(mint, now);
 
   /*
    * Cached flags describe the last configuration seen, not the current one, and the
@@ -468,6 +514,183 @@ function cashuWarnings(
   return out;
 }
 
+/**
+ * How long a listing has been unreachable, in the four bands the banners key on.
+ *
+ * Shared by the Cashu and LNURL branches, which apply exactly the same thresholds —
+ * being unreachable means the same thing whether the endpoint that stopped answering
+ * was `/v1/info` or a mint advertisement, and two copies of "is 7 days long?" is two
+ * places for it to become 8 in one of them.
+ *
+ * Tier 3 covers both a month of silence and never having answered at all: offline with
+ * no `last_online` means it has never once answered, which is at least as bad as a
+ * month of it, so it lands in the top tier rather than the bottom.
+ */
+function offlineTier(
+  mint: Pick<MintWarningInput, 'status' | 'last_online'>,
+  now: number,
+): { offline: boolean; since: number | null; days: number | null; tier: 0 | 1 | 2 | 3 } {
+  const offline = mint.status === 'offline';
+  const since = mint.last_online;
+  const days = offline && since !== null ? Math.max(0, Math.floor((now - since) / 86400)) : null;
+  const tier = !offline ? 0 : days === null ? 3 : days >= 30 ? 3 : days >= 7 ? 2 : 1;
+  return { offline, since, days, tier };
+}
+
+/**
+ * What can be said about an LNURL mint.
+ *
+ * Between the two extremes of the other ecosystems. A federation publishes no switches
+ * at all, so its page can only talk about reachability; a Cashu mint publishes NUT-04
+ * and NUT-05 flags, so its page can be specific about which direction is broken. An
+ * LNURL mint sits in between: two things about it are genuinely checkable over HTTP,
+ * and both get a banner.
+ *
+ *   - `maxWithdrawable` of zero. A mint advertising that no note can be redeemed for
+ *     anything is the closest analogue this ecosystem has to "withdrawals disabled",
+ *     and it is read from the advertisement rather than inferred, so it ranks with the
+ *     Cashu capability banners.
+ *   - A funding source the mint cannot reach. Distinctive to lnurlcash and worth its
+ *     own sentence, because it is *partial*: the mint is up, its notes still rotate,
+ *     split and merge, and only the two operations that need a Lightning node are
+ *     unavailable. Calling that "offline" would be wrong in both directions.
+ *
+ * The third, `lnurl-invalid`, is about this site's own reading rather than the mint's
+ * configuration: these endpoints answer their errors with HTTP 200, so a host that
+ * responds with something unparseable is a state that has to be named rather than
+ * silently counted as either up or down.
+ *
+ * Note what is deliberately missing: nothing here reads `features`. That tag is the
+ * operator's claim about what they built, and a banner derived from a claim rather than
+ * from an observation would be the same invention the Fedimint branch refuses to make.
+ */
+function lnurlWarnings(
+  mint: MintWarningInput,
+  options: MintWarningOptions = {},
+): MintWarning[] {
+  const now = options.now ?? Math.floor(Date.now() / 1000);
+  const date = options.formatDate ?? defaultDate;
+  const month = options.formatMonth ?? defaultMonth;
+  const s = options.strings ?? englishStrings;
+
+  const { offline, since, days, tier } = offlineTier(mint, now);
+  const tense = offline ? 'offline' : 'online';
+  const dayCount = s('dayCount', { n: days ?? 0 });
+
+  // `=== 0`, never falsy: null means nothing has probed this mint yet, and "we have not
+  // looked" must not render as "withdrawals are disabled".
+  const withdrawalsDisabled = mint.max_withdrawable_msat === 0;
+  const invalid = Boolean(mint.invalid_reason);
+  const noFunding = mint.funding_available === false;
+
+  const out: MintWarning[] = [];
+
+  // Pushed in ORDER, so the first one added is the one that wins.
+  if (tier === 3) {
+    out.push({
+      kind: 'gone',
+      severity: 'critical',
+      lead: s('gone.lead'),
+      body:
+        since !== null
+          ? s('gone.body.since', { date: date(since), days: dayCount })
+          : mint.first_seen
+            ? s('gone.body.neverDated', { month: month(mint.first_seen) })
+            : s('gone.body.never'),
+      meta: since !== null ? s('gone.meta.since', { date: date(since) }) : s('gone.meta.never'),
+    });
+  }
+
+  if (withdrawalsDisabled) {
+    out.push({
+      kind: 'lnurl-withdrawals-disabled',
+      severity: 'critical',
+      lead: s('lnurlWithdrawalsDisabled.lead'),
+      body: s(`lnurlWithdrawalsDisabled.body.${tense}`),
+      meta: s(`lnurlWithdrawalsDisabled.meta.${tense}`),
+    });
+  }
+
+  if (tier === 2 && since !== null) {
+    out.push({
+      kind: 'offline-long',
+      severity: 'critical',
+      lead: s('offlineLong.lead', { days: dayCount, date: date(since) }),
+      body: s('offlineLong.body'),
+      meta: s('offlineLong.meta', { date: date(since) }),
+    });
+  }
+
+  if (invalid) {
+    out.push({
+      kind: 'lnurl-invalid',
+      severity: 'warning',
+      lead: s('lnurlInvalid.lead'),
+      body: s('lnurlInvalid.body'),
+      meta: s('lnurlInvalid.meta'),
+    });
+  }
+
+  if (noFunding) {
+    out.push({
+      kind: 'lnurl-no-funding',
+      severity: 'warning',
+      lead: s('lnurlNoFunding.lead'),
+      body: s('lnurlNoFunding.body'),
+      meta: s('lnurlNoFunding.meta'),
+    });
+  }
+
+  if (tier === 1 && since !== null) {
+    out.push({
+      kind: 'offline',
+      severity: 'warning',
+      lead: s('offline.lead', { date: date(since) }),
+      body: s('offline.body'),
+      meta: s('offline.meta', { date: date(since) }),
+    });
+  }
+
+  const primary = out[0];
+  if (primary) {
+    const extra = lnurlCollapsed(primary.kind, { noFunding, offline, since, dayCount, date, s });
+    if (extra) primary.body += ` ${extra}`;
+  }
+
+  return out;
+}
+
+/**
+ * The one sentence a losing LNURL condition earns inside the winner's text.
+ *
+ * Same contract as `collapsed`, and separate from it because the conditions being
+ * folded in are different ones: there is no NUT-04 or NUT-05 here, and the fact worth
+ * rescuing from an offline banner is that the mint's Lightning node was down too.
+ */
+function lnurlCollapsed(
+  kind: MintWarningKind,
+  ctx: {
+    noFunding: boolean;
+    offline: boolean;
+    since: number | null;
+    dayCount: string;
+    date: (unix: number) => string;
+    s: WarningStrings;
+  },
+): string | null {
+  if (kind === 'gone' || kind === 'offline-long' || kind === 'offline') {
+    return ctx.noFunding ? ctx.s('also.noFunding') : null;
+  }
+
+  // A capability banner outranked an offline one: say the mint is also unreachable,
+  // otherwise the page reads as if it were up and merely misconfigured.
+  if (kind === 'lnurl-withdrawals-disabled' && ctx.offline && ctx.since !== null) {
+    return ctx.s('also.offline', { date: ctx.date(ctx.since), days: ctx.dayCount });
+  }
+
+  return null;
+}
+
 /**
  * The one sentence a losing condition earns inside the winner's text. Banners never
  * stack, but a mint that is both gone and had stopped paying out is a worse story
@@ -533,6 +756,8 @@ export const CHIP_COPY_EN: Record<string, string> = {
   frozen: 'Frozen',
   noWithdrawals: 'No withdrawals',
   meltOnly: 'Melt only',
+  /** LNURL: up and serving, but nothing moves in or out over Lightning. */
+  noFunding: 'No mint / melt',
 };
 
 export function mintChip(warnings: MintWarning[], strings?: WarningStrings): MintChip | null {
@@ -541,7 +766,13 @@ export function mintChip(warnings: MintWarning[], strings?: WarningStrings): Min
   if (kinds.has('frozen')) return { label: s('frozen'), severity: 'critical' };
   // "Melt only" is the other direction, so it cannot double as the label here.
   if (kinds.has('melt-disabled')) return { label: s('noWithdrawals'), severity: 'critical' };
+  // An LNURL mint advertising a zero withdraw ceiling is the same statement to a
+  // reader as a Cashu mint with melting off, so it earns the same two words.
+  if (kinds.has('lnurl-withdrawals-disabled')) {
+    return { label: s('noWithdrawals'), severity: 'critical' };
+  }
   if (kinds.has('melt-only')) return { label: s('meltOnly'), severity: 'warning' };
+  if (kinds.has('lnurl-no-funding')) return { label: s('noFunding'), severity: 'warning' };
   return null;
 }