simplex-chat/apps/simplex-badge-service

SimpleX badge service

simplex-badge-service runs the whole supporter-badge service as one process, two lanes: a SimpleX chat bot that answers service RPC over a double-ratchet contact address, and — only when --service-config names a badge_service.ini — the badge-codes web checkout (BTCPay and Stripe payment, code issuance, the poller). Without --service-config the web listener does not start at all; the process still runs the chat side and nothing else.

The wire protocol for the RPC side is docs/protocol/badges-rpc.md. The web checkout is specified in plans/badges-codes/2026-08-27-badge-codes.md, whose §9 is the badge_service.ini reference, with the implementation plan in plans/badges-codes/2026-08-31-service-btcpay.md. Earlier plans (2026-07-30-supporter-badges-v3-ux.md, 2026-07-31-badges-core-implementation.md, 2026-08-04-badges-mvp-scope.md) predate the web checkout and describe the RPC-only scaffold this service started as.

At this stage the service:

• creates a double-ratchet contact address on first start (service RPC requires DR, see docs/protocol/badges-rpc.md),
• listens for service requests (CEvtServiceRequest) on that address, rejects a request whose purchaseKey is not the key the agent verified the signature against, and answers redeemBadgeCode,
• issues redemption codes, storing only their SHA-256 and printing each code once,
• does not accept contact requests unless [dev] chat_redeem is on: the address is for RPC only,
• in service mode with --service-config, also serves the built web app (npm run build in web/), POST /api/invoice and GET /api/invoice/:id, the BTCPay and Stripe webhook routes, and a payment poller, seeding its price/offer catalog on every start,
• owns the sx_badge_service_-prefixed tables and its own migrations table (sx_badge_service_migrations).

Every other command answers unsupported_version, or unknown_purchase_key when the key that signed it is not one the service has stored — every command but redeemBadgeCode needs a purchase that already exists.

Build

Build prerequisites and the general contribution flow are in docs/CONTRIBUTING.md.

cabal build exe:simplex-badge-service

Run

simplex-badge-service --help

• default (no --run-cli): background service mode, no interactive terminal.

• --run-cli: interactive CLI that also processes service requests (mirrors simplex-directory-service --run-cli). This mode is the chat/RPC side and the // commands below: it starts no web listener and no poller, and [dev] chat_redeem does not apply to it, whatever --service-config says.

• --no-address: skip address creation on start-up (for operators who provision the address themselves). The service cannot sign credentials without an issuer key and refuses to start without one:

• --issuer-key-idx IDX — the index the apps find the matching public key under (badgePublicKeys in ChatConfig).

• --issuer-secret SECRET — the issuer secret from simplex-chat badge keygen.

The service checks the secret against the configured public key at that index and refuses to start if they disagree: credentials signed with the wrong key cannot be verified by any client, and the codes redeemed against them would be spent for nothing.

The key can come from badge_service.ini instead:

[issuer]
index = 1
private_key = <secret from `simplex-chat badge keygen`>

index is the index clients verify against (badgePublicKeys in ChatConfig), and private_key is the secret that signs. Both are required, and the key is checked at startup like the flags. Rotating is a change to both and a restart, once clients trust the new index.

The command line wins over the file when both --issuer-key-idx and --issuer-secret are given. Note that a secret passed as a flag is visible to every user on the machine through ps, where one in the ini is only as readable as the file: badge_service.ini is gitignored and already holds the provider API keys and webhook secrets.

Other options:

• --service-config INI_FILE: path to badge_service.ini. Omit it to run the chat/RPC side only; the process never starts a web listener without it, and never starts one under --run-cli, which parses and validates the whole file ([listener] static_dir included) but uses only its [issuer] section. An issuer key is still required either way.
• --service-name NAME: the bot's display name, without *s or spaces (default SimpleX Badges).
• --client-service: use the client service certificate.
• also accepts the standard SimpleX Chat core options — database path, SMP/XFTP servers, --socks-proxy, --log-level/-l, and the rest — run simplex-badge-service --help for the complete list.

Running the web checkout

badge_service.ini holds the listener bind address and static_dir, an optional [btcpay] section (omitting it disables Bitcoin and Monero), an optional [stripe] section (omitting it disables card payments) and the poll cadence. badge_service.ini.example is the committed template; badge_service.ini itself is gitignored, since a real one holds API keys and webhook secrets.

The full walkthrough is in web/README.md. Short version:

cd apps/simplex-badge-service/web && npm install && npm run build && cd ../../..
cp apps/simplex-badge-service/badge_service.ini.example apps/simplex-badge-service/badge_service.ini
cabal run simplex-badge-service -- \
  --issuer-key-idx IDX --issuer-secret SECRET \
  --service-config apps/simplex-badge-service/badge_service.ini

IDX and SECRET must be one of the issuer keys clients already ship, not a fresh simplex-chat badge keygen pair: startup refuses a key no client could verify against.

trust_forwarded_for decides what the rate limiter counts. Behind a reverse proxy it must be on, or every request keys on the proxy's address and the whole service shares one bucket of 60 reads and 5 checkouts a minute. Where the listener is reached directly it must be off, because then the header is whatever the caller wrote. The last entry is the one read, which is the one a proxy appends.

The BTCPay API key needs four permissions, each scoped to the one store: cancreateinvoice and canviewinvoices for checkout and the poller, canviewstoresettings to log the store's live payment methods at startup, and canmodifyinvoices so POST /api/invoice/:id/cancel can invalidate an invoice at BTCPay rather than only in this store.

Card payments (Stripe)

An optional [stripe] section enables the card lane; omitting it disables card payments and POST /api/invoice answers provider_unavailable for a card order, the same as an absent [btcpay] does for Bitcoin and Monero. Its keys:

• secret_key — a restricted key (rk_...), never a full secret key (sk_...). Grant it PaymentIntents: write, to create and cancel intents, plus Charges: read — the poller reads an intent with expand[]=latest_charge, and Stripe rejects the whole read if the key lacks read on an expanded object (settlement then falls back to the slower list pass).
• publishable_key (pk_...) — the public key the browser mounts the Payment Element with.
• webhook_secret (whsec_...) — the signing secret of the /webhooks/stripe endpoint, configured in the Stripe Dashboard alongside it.
• session_minutes — how many minutes an unpaid card order stays open (1 to 1440, default 60). Ten minutes after that, the service cancels the payment at Stripe, and retries if that fails. If the order is over 72 hours old and the cancel has kept failing for an hour, the service marks it expired and logs an error. Check such orders in the Stripe Dashboard. After a restart, the hour starts again.

The service fills publishable_key into the shell at boot: the built index.html ships with an empty <meta id="stripe-publishable-key" name="stripe-publishable-key" content=""> (web/public/index.html), and the listener serves a copy with the configured key substituted in, so the ini is the only place the key is set. With no [stripe] section the pristine (empty) shell is served and the page shows its development stand-in card form. The dev mock (web/mock/server.py) does the same substitution from $STRIPE_PUBLISHABLE_KEY, since it runs without an ini.

POST /webhooks/stripe verifies Stripe-Signature against webhook_secret and queues a read, the same hint-only role as POST /webhooks/btcpay: the poller carries authority, so an unverified or unreadable delivery costs nothing but a log line. A delivery signed more than 15 minutes away from the server's clock is refused with a warning, so keep the clock synced (NTP).

The reverse proxy in front of this service must send a Content-Security-Policy that allows Stripe.js and its iframes, since Stripe forbids bundling or self-hosting its script:

script-src 'self' https://js.stripe.com https://*.js.stripe.com;
frame-src https://js.stripe.com https://*.js.stripe.com https://hooks.stripe.com

Stripe Link must be disabled in the Dashboard. Left on, it needs link.com in the CSP above and reintroduces an email prompt of its own, which this design otherwise avoids.

Enable card only; do not enable redirect-based methods (iDEAL, Bancontact, PayPal, and the rest) in the Dashboard. The embedded checkout sends no return_url, which Stripe requires the moment a redirect-based method is offered, so enabling one makes every checkout fail to create. The service pins the Stripe API version it was built against, so the account's default version does not affect the card lane.

The checkout endpoints

The browser in web/ is the only client of the /api routes; the two webhooks below are the providers', one each for BTCPay and Stripe. The invoice id is the only credential for reading or cancelling an order: it is 16 random bytes, it travels in the path, and anything that logs request paths logs it. It is also what the buyer is shown as their reference and asked to quote, so support sees it: losing it lets someone cancel an invoice, which is why the code, which lets them take the badge, is never printed until the service says the invoice is paid. The service keeps it out of its own logs, which name the provider's reference instead.

Route	Answers
POST /api/invoice	{invoiceId, badgeType, months, amount, currency, expiresAt} plus a destination: clientSecret for a card, or address, cryptoAmount, cryptoCurrency. Refuses with code_conflict, catalog_changed, bad_request, provider_unavailable or rate_limited.
GET /api/invoice/:id	{status, badgeType, months, amount, currency, expiresAt} and the same destination — no invoiceId, since the caller already has it — plus amountPaid, cryptoAmountPaid, cryptoAmountDue, paidInFull, settledAt and requiredConfirmations once each has a value. Never the code, which this service has never seen.
GET /api/invoice/:id?wait=<status>&seenPaid=<figure>&seenFull=<0|1>	The same, held for up to 30 seconds while the invoice's status is still <status> and its payment is the one the caller says it has rendered. wait=paid and any value that is not a status answer at once, since neither can change. A status the caller has not seen, or a payment it has not seen, answers at once — the provider's verdict counts as much as the figure, because Monero reports an invoice as confirming while its figures are still zero. A request that omits seenPaid holds on the status alone.
POST /api/invoice/:id/cancel	Invalidates an open invoice at the provider and expires it here. Refuses a settled or expired one with not_open, and one that already holds a payment with funded. The provider is told first, and a payment landing in between does not keep the invoice open: nothing can reach that address any more, so the row is expired either way and the poller settles or reports what arrived.
POST /webhooks/btcpay	Verifies BTCPay-Sig over the bytes as received and queues a read. A hint only: the poller is what carries authority, so an unverified or unreadable delivery costs nothing but a log line.
POST /webhooks/stripe	Verifies Stripe-Signature over the bytes as received and queues a read. The card lane's equivalent of the row above, and a hint just the same: the poller carries authority, so an unverified or unreadable delivery costs nothing but a log line.

Every /api refusal is {"error": "<code>"}. Besides the codes above, any of them can answer internal, an unknown id answers not_found, and a wrong verb answers method_not_allowed — ten codes in all, which is what the browser's WIRE_ERROR_CODES lists. The two webhook routes are the exception: each answers 200, 400 or 413 with an empty body, because its provider is the only caller and nothing it could read would change what the route does. A wrong verb on any route, those two included, answers method_not_allowed.

Redeeming over chat, for local testing

[dev]
chat_redeem = on

With this on, the service accepts contact requests and answers /redeem <code> from a contact with the credential as one-line JSON, ready to paste into a client as /badge add <json>. Off by default, and only on/off parse, so a typo cannot silently arm it. It applies to the service mode only; --run-cli ignores it.

Keep it off anywhere real. The service RPC signs over a master key only the client holds; here there is no client key, so the service generates one and hands it over with the credential, which means it can link every badge it issues this way. simplex-chat badge sign has the same property and is the offline equivalent.

Issuing codes

Issuing a code is an operator command sent to the running service in --run-cli mode, not a way to start it — so codes are issued without a second process touching the service's database:

//issue <badge_type> [months] [paid|unpaid|free]
//issue supporter 12

months defaults to 1 and must be between 1 and 255; the status defaults to free and records whether the code was sold (paid), is awaiting payment (unpaid), or was issued by an operator (free). Redemption refuses an unpaid code with payment_pending: the web checkout writes the code row when the invoice is created, and settlement is what marks it paid.

The code is printed once and only its SHA-256 is stored, so a code that is not copied when it is shown cannot be recovered.

A code that leaked, or that was refunded, is withdrawn the same way:

//revoke <code>

A revoked code answers redemption with code_invalid, as if it had never existed, so its holder learns nothing from trying. Revoking is not repeatable: the second attempt says so. A code that was already redeemed cannot be revoked: its badge was issued, and the command answers with an error.

Core parses //... into CustomChatCommand and leaves it to the service's preCmdHook, which is why issuing codes lives in the service rather than in core.