Getting Started

Syncro Sender by P2P.ORG offers two access modes: a public endpoint that requires no API key (just include a tip in your transaction) and a private endpoint authenticated with an API key.

Endpoint	URL	Auth Method	Notes
Public	`https://sfls.l2.p2p.org/public`, `https://sfls-geo-fra.l2.p2p.org/public`, `https://sfls-geo-nyc.l2.p2p.org/public`, `https://sfls-geo-lon.l2.p2p.org/public`, `https://sfls-geo-tky.l2.p2p.org/public`, `https://sfls-geo-sgp.l2.p2p.org/public`	Tip in transaction	`sendTransaction` only
Private	`https://sfls.l2.p2p.org`, `https://sfls-geo-fra.l2.p2p.org`, `https://sfls-geo-nyc.l2.p2p.org`, `https://sfls-geo-lon.l2.p2p.org`, `https://sfls-geo-tky.l2.p2p.org`, `https://sfls-geo-sgp.l2.p2p.org`	API key	Still requires tip in transaction

Sending a transaction via public endpoint

The public endpoint requires no API key. Instead, include a System Program transfer to one of the tip accounts in your transaction.

Tip accounts:

BPZrtYhdoAhiHWV5EgGLoV7bZFbMamBZurGDq4DmST8v

Minimum tip: 100,000 lamports

If the tip is missing or insufficient, an error is returned:

Missing tip: "Missing tip: no transfer to tip accounts found" (code -32602)
Insufficient tip: "Insufficient tip: provided X lamports, required Y lamports" (code -32602)

Example request (cURL):

curl -X POST https://sfls.l2.p2p.org/public \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "sendTransaction",
    "params": ["<BASE64_ENCODED_TX_WITH_TIP>", {"encoding": "base64"}]
  }'

Note: The transaction itself must contain a tip instruction to a tip account. No Authorization header is needed.

Example response:

{
  "jsonrpc": "2.0",
  "result": "<TRANSACTION_SIGNATURE>",
  "id": 1
}

Sending a transaction via private endpoint

Getting an API key

Contact the P2P.org team to get your API key and client profile: t.me/P2Pstaking.

Authentication

Syncro Sender supports two authentication headers via private endpoint. If both are present, Authorization: Bearer takes priority.

Header	Format	Priority
`Authorization`	`Bearer <API_KEY>`	1 (preferred)
`X-Api-Key`	`<API_KEY>`	2 (fallback)

Example request:

curl -X POST https://sfls.l2.p2p.org \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "sendTransaction",
    "params": ["<BASE64_ENCODED_TX>", {"encoding": "base64"}]
  }'

Example response:

{
  "jsonrpc": "2.0",
  "result": "<TRANSACTION_SIGNATURE>",
  "id": 1
}

Error codes

Code	Name	HTTP Status	Description
`-32700`	PARSE_ERROR	400	Malformed JSON-RPC request body
`-32600`	INVALID_REQUEST	400 / 403	Invalid request structure or authentication failure
`-32601`	METHOD_NOT_FOUND	200	Unsupported method (e.g., non-`sendTransaction` on public endpoint)
`-32602`	INVALID_PARAMS	200 / 400	Invalid parameters, missing tip, or insufficient tip amount
`-32603`	INTERNAL_ERROR	500	Server-side processing error
`-32000`	SERVER_ERROR	500	General server error
`-32005`	RATE_LIMIT	429	Rate limit exceeded

Error response format:

{
  "jsonrpc": "2.0",
  "result": null,
  "error": {
    "code": -32005,
    "message": "Rate limit exceeded"
  },
  "id": 1
}

Rate limit headers

If the rate limit is hit (HTTP 429), the response includes these headers:

Header	Description
`X-RateLimit-Limit`	Maximum requests per second for your client
`X-RateLimit-Remaining`	Remaining requests in the current 1-second window
`Retry-After`	Seconds until the rate limit window resets (minimum 1)