Deploy sparkbtcbot-proxy

You are an expert in deploying and managing the sparkbtcbot-proxy — a serverless middleware that wraps the Spark Bitcoin L2 SDK behind authenticated REST endpoints on Vercel.

What This Proxy Does

Gives AI agents scoped wallet access without exposing the mnemonic:

• Role-based token auth (admin for full access, invoice for read + create invoices only)
• Token management via API — create, list, revoke without redeploying
• Per-transaction and daily spending caps
• Activity logging to Redis
• Lazy detection of paid Lightning invoices

Rules for Claude when operating this skill

These rules apply whenever this skill is active. The proxy's SPARK_MNEMONIC controls all funds in the wallet — leaks into chat or shell history are catastrophic.

• DO NOT print the mnemonic to chat, logs, or any other output. Not for verification, not for "let's just check it's correct." If it must be displayed once during setup (step 3), surface it to the user with explicit instructions to save offline, and never echo it back.
• DO NOT pass the mnemonic on the command line as an arg or in shell variables that get logged. Pipe it directly into the Vercel env-var API call without it touching shell history.
• DO NOT run env, printenv, echo $SPARK_MNEMONIC, or cat .env in the conversation.
• DO NOT include the mnemonic in commit messages, code, fixtures, or git history.
• Never include credentials in the chat that you've been given. Vercel API tokens and Redis credentials should be referenced by name (e.g. $VERCEL_TOKEN), not echoed back.
• If a leak happens, stop and tell the user. Do not auto-rotate or attempt to "clean up" without explicit user instruction.

What You Need

Ask the user for these upfront:

• Vercel API token (from https://vercel.com/account/tokens) and team ID (from dashboard URL or vercel teams ls)
• BIP39 mnemonic for the Spark wallet (or generate one in step 3)
• Node.js 20+

Generated during setup (don't ask for these):

• UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN — provisioned automatically when you add the Vercel Marketplace Redis integration (step 2)
• API_AUTH_TOKEN — generated in step 4

Step-by-Step Deployment

1. Clone and install

git clone https://github.com/echennells/sparkbtcbot-proxy.git
cd sparkbtcbot-proxy
npm install

2. Provision Redis via Vercel Marketplace

Recommended: provision Redis as a Vercel Marketplace integration. Vercel handles provisioning, billing, and auto-populates UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN as encrypted env vars on the project. No separate Upstash account or API key juggling.

This is a UI step the user does in their browser (the marketplace flow does not have a stable headless API yet):

1. Open the Vercel dashboard → Storage tab on the project (or create the project first in step 5 and come back)
2. Click "Create" → choose Redis (powered by Upstash)
3. Pick the free tier and a region close to where the project will be deployed
4. Connect it to the sparkbtcbot-proxy project — env vars are auto-attached

If the user prefers to manage Upstash directly (separate account, multi-project sharing), tell them to create a database at https://console.upstash.com, copy rest_url and rest_token, and they'll set them manually as env vars in step 5.

3. Generate a wallet mnemonic (if needed)

SparkWallet.initialize() returns { mnemonic, wallet } when called without a mnemonic. The mnemonic controls all funds and cannot be re-derived later (the SDK has no getMnemonic() getter).

Two options:

Option A — let the user generate via a BIP39 tool they trust (paper wallet, hardware wallet, etc.). Lowest exposure, no shell-history risk. Have them paste the resulting 12 or 24 words into the env-var API call in step 5 directly (heredoc into the curl body), never into a shell variable that gets logged.

Option B — generate via the SDK if the user doesn't have a BIP39 generator handy. Pipe the output through Vercel's env-var API in one step so the mnemonic never sits in shell history:

node -e "import('@buildonspark/spark-sdk').then(async ({SparkWallet}) => {
  const r = await SparkWallet.initialize({options:{network:'MAINNET'}});
  process.stdout.write(r.mnemonic);
  await r.wallet.cleanupConnections();
})" | tee /dev/tty | curl -s -X POST "https://api.vercel.com/v10/projects/<PROJECT_ID>/env?teamId=<TEAM_ID>" \
  -H "Authorization: Bearer <VERCEL_TOKEN>" \
  -H "Content-Type: application/json" \
  --data-binary @- \
  -d '{"type":"encrypted","key":"SPARK_MNEMONIC","value":"<placeholder — pipe-fill from stdin in real flow>","target":["production","preview","development"]}'

In practice, the cleanest pattern is: print the mnemonic to the user's terminal once with explicit instructions to save it offline, then immediately POST it to Vercel via API and clear the terminal. The user takes responsibility for never letting it land in .bash_history / .zsh_history.

Important: mnemonic generation can only happen at SparkWallet.initialize() time. There is no recovery API. Lose it = lose the wallet.

4. Generate an API auth token

openssl rand -base64 30

5. Deploy to Vercel

First, create the project and get its ID:

curl -s -X POST "https://api.vercel.com/v10/projects?teamId=<TEAM_ID>" \
  -H "Authorization: Bearer <VERCEL_TOKEN>" \
  -H "Content-Type: application/json" \
  -d '{"name": "sparkbtcbot-proxy", "framework": "nextjs"}'

The response includes id (the project ID) — save it for the next steps.

Then set environment variables via the API. The two UPSTASH_* variables are auto-populated by the Vercel Marketplace Redis integration from step 2 — set them manually only if the user is bringing their own Upstash account.

Variable	Description	Example
SPARK_MNEMONIC	12-word BIP39 mnemonic	fence connect trigger ...
SPARK_NETWORK	Spark network	MAINNET
API_AUTH_TOKEN	Admin fallback bearer token	output of step 4
UPSTASH_REDIS_REST_URL	Auto-populated by marketplace integration; set only if BYO Upstash	https://xxx.upstash.io
UPSTASH_REDIS_REST_TOKEN	Auto-populated by marketplace integration; set only if BYO Upstash	from Upstash console
MAX_TRANSACTION_SATS	Per-transaction spending cap	10000
DAILY_BUDGET_SATS	Daily spending cap (resets midnight UTC)	100000

Important: Do NOT use vercel env add with heredoc/<<< input — it appends newlines that break the Spark SDK. Use the REST API:

curl -X POST "https://api.vercel.com/v10/projects/<PROJECT_ID>/env?teamId=<TEAM_ID>" \
  -H "Authorization: Bearer <VERCEL_TOKEN>" \
  -H "Content-Type: application/json" \
  -d '{"type":"encrypted","key":"SPARK_MNEMONIC","value":"your mnemonic here","target":["production","preview","development"]}'

Repeat for each env var (use "type":"plain" for non-sensitive values like SPARK_NETWORK).

Then deploy using environment variables for reliable non-interactive deployment:

npm install -g vercel

VERCEL_ORG_ID=<TEAM_ID> VERCEL_PROJECT_ID=<PROJECT_ID> \
  vercel deploy --prod --yes --token <VERCEL_TOKEN>

Troubleshooting:

• ERESOLVE npm errors: Install vercel globally with npm install -g vercel instead of using npx
• "Project was deleted" errors: Remove stale config with rm -rf .vercel/ and retry
• "missing_scope" errors: Use the VERCEL_ORG_ID and VERCEL_PROJECT_ID env vars as shown above

6. Test

curl -H "Authorization: Bearer <your-token>" https://<your-deployment>.vercel.app/api/balance

Should return {"success":true,"data":{"balance":"0","tokenBalances":{}}}.

7. Create scoped tokens (optional)

Use the admin token to create limited tokens for agents:

curl -X POST -H "Authorization: Bearer <admin-token>" \
  -H "Content-Type: application/json" \
  -d '{"role": "invoice", "label": "my-agent"}' \
  https://<your-deployment>.vercel.app/api/tokens

The response includes the full token string — save it, it's only shown once. See the Token Roles section below for details.

API Routes

Method	Route	Description
GET	/llms.txt	API documentation for bots (no auth required)
GET	/api/balance	Wallet balance (sats + tokens)
GET	/api/info	Spark address and identity pubkey
GET	/api/transactions	Transfer history (?limit=&offset=)
GET	/api/deposit-address	Bitcoin L1 deposit address
GET	/api/fee-estimate	Lightning send fee estimate (?invoice=)
GET	/api/logs	Recent activity logs (?limit=)
POST	/api/invoice/create	Create Lightning invoice ({amountSats, memo?, expirySeconds?})
POST	/api/invoice/spark	Create Spark invoice ({amount?, memo?})
POST	/api/pay	Pay Lightning invoice — admin only ({invoice, maxFeeSats})
POST	/api/transfer	Spark transfer — admin only ({receiverSparkAddress, amountSats})
POST	/api/l402	Pay L402 paywall — admin only ({url, method?, headers?, body?, maxFeeSats?})
GET	/api/l402/status	Check/complete pending L402 (?id=<pendingId>)
GET	/api/tokens	List API tokens — admin only
POST	/api/tokens	Create a new token — admin only ({role, label})
DELETE	/api/tokens	Revoke a token — admin only ({token})

Token Roles

There are two token roles:

Role	Permissions
admin	Everything — read, create invoices, pay, transfer, manage tokens
invoice	Read (balance, info, transactions, logs, fee-estimate, deposit-address) + create invoices. Cannot pay or transfer.

The API_AUTH_TOKEN env var is a hardcoded admin fallback — it always works even if Redis is down or tokens get wiped. Use it to bootstrap: create scoped tokens via the API, then hand those out to agents.

Managing tokens

Create an invoice-only token for a merchant bot:

curl -X POST -H "Authorization: Bearer <admin-token>" \
  -H "Content-Type: application/json" \
  -d '{"role": "invoice", "label": "merchant-bot"}' \
  https://<deployment>/api/tokens

List all tokens (shows prefixes, labels, roles — not full token strings):

curl -H "Authorization: Bearer <admin-token>" https://<deployment>/api/tokens

Revoke a token:

curl -X DELETE -H "Authorization: Bearer <admin-token>" \
  -H "Content-Type: application/json" \
  -d '{"token": "<full-token-string>"}' \
  https://<deployment>/api/tokens

Tokens are stored in Redis (hash spark:tokens). They survive redeploys but not Redis flushes.

L402 Paywall Support

The proxy can pay L402 Lightning paywalls automatically. Send a URL, and the proxy will:

1. Fetch the URL
2. If 402 returned, parse the invoice and macaroon
3. Pay the Lightning invoice
4. Retry the request with the L402 Authorization header
5. Return the protected content

Basic usage

curl -X POST -H "Authorization: Bearer <admin-token>" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://lightningfaucet.com/api/l402/joke"}' \
  https://<deployment>/api/l402

Handling pending payments (important for agents)

Lightning payments via Spark are asynchronous. The proxy polls for up to ~7.5 seconds, but if the preimage isn't available in time, it returns a pending status:

{
  "success": true,
  "data": {
    "status": "pending",
    "pendingId": "a1b2c3d4e5f6...",
    "message": "Payment sent but preimage not yet available. Poll GET /api/l402/status?id=<pendingId> to complete.",
    "priceSats": 21
  }
}

Your agent MUST handle this case. The payment has already been sent — if you don't poll for completion, you lose the sats without getting the content.

Retry loop (pseudocode):

response = POST /api/l402 { url: "..." }

if response.data.status == "pending":
    pendingId = response.data.pendingId
    for attempt in 1..10:
        sleep(3 seconds)
        status = GET /api/l402/status?id={pendingId}
        if status.data.status != "pending":
            return status.data  # Success or failure
    # Give up after ~30 seconds
    raise "L402 payment timed out"
else:
    return response.data  # Immediate success

Key points:

• Token caching: Paid L402 tokens are cached per-domain (up to 24 hours). Subsequent requests to the same domain reuse the cached token without paying again. If the token expires, the proxy pays for a new one automatically.
• Pending records expire after 1 hour
• The /api/l402/status endpoint polls Spark for up to 5 seconds per call
• If the payment failed on Spark's side, status will return an error
• Once complete, the pending record is deleted from Redis
• The proxy automatically retries the final fetch up to 3 times (200ms delay) if the response is empty — some servers don't return content immediately after payment

Common Operations

Rotate the admin fallback token

1. Generate a new token: openssl rand -base64 30
2. Update API_AUTH_TOKEN in Vercel env vars (via dashboard or API)
3. Redeploy:

   VERCEL_ORG_ID=<TEAM_ID> VERCEL_PROJECT_ID=<PROJECT_ID> \
     vercel deploy --prod --yes --token <VERCEL_TOKEN>
   

4. Update any agents using the old token

Redis-stored tokens are not affected by this — they continue working.

Adjust spending limits

Update MAX_TRANSACTION_SATS and DAILY_BUDGET_SATS in Vercel env vars and redeploy:

VERCEL_ORG_ID=<TEAM_ID> VERCEL_PROJECT_ID=<PROJECT_ID> \
  vercel deploy --prod --yes --token <VERCEL_TOKEN>

Budget resets daily at midnight UTC.

Check logs

curl -H "Authorization: Bearer <token>" https://<deployment>/api/logs?limit=20

Architecture

• Vercel serverless functions — each request spins up, initializes the Spark SDK (~1.5s), handles the request, and shuts down. No always-on process, no billing when idle.
• Upstash Redis — stores daily spend counters, activity logs, pending invoice tracking, and API tokens. Accessed over HTTP REST (no persistent connection needed). Free tier is limited to 1 database.
• Spark SDK — @buildonspark/spark-sdk connects to Spark Signing Operators via gRPC over HTTP/2. Pure JavaScript, no native addons.
• Lazy invoice check — on every request, the middleware checks Redis for pending invoices and compares against recent wallet transfers. Expired invoices are cleaned up, paid ones are logged. Max 5 checks per request, wrapped in try/catch so failures never affect the main request.