# swqos.com > swqos.com is a prepaid Solana transaction relay. You submit an already-signed transaction over HTTPS or QUIC and it forwards those exact bytes to the leader over stake-weighted QoS connections that are held open and kept warm. There is no RPC hop, no simulation, no blockhash fetch and no tip instruction in the forwarding path. ## Facts - Site: https://swqos.com - HTTPS endpoint: https://send.swqos.com - QUIC endpoint: send.swqos.com:11000 (ALPN ultrasend/1) - Network: Solana mainnet-beta - Price: 0.0002 SOL per accepted submission, prepaid in native SOL - Billing rule: You are charged once a submission is accepted and forwarded. Refused submissions are free. - Guarantee: A receipt means we forwarded your bytes and the upstream acknowledged the stream. Landing on chain is the network's decision, not ours. - Measured relay overhead: 6.29 ms p50, 20.92 ms p90, 32.3 ms p99 on production QUIC traffic - Max transaction size: 1232 bytes serialized - Deduplication window: 90 seconds per account per signature - API key prefix: usq_live_ - Auth: Authorization: Bearer over HTTPS; key-derived client certificate over QUIC - Languages documented: TypeScript, Python, Rust, Go, curl ## Submit a transaction POST https://send.swqos.com/v1/transactions Authorization: Bearer usq_live_... Content-Type: application/json {"transaction":""} Returns: {"signature","accepted","duplicate","charged_lamports","balance_remaining_lamports"} ## Documentation - [Overview](https://swqos.com/docs): What swqos.com is, what it guarantees, and what it does not. - [Quickstart](https://swqos.com/docs/quickstart): Key, fund, send, verify. Ten minutes, four languages. - [Authentication](https://swqos.com/docs/authentication): How API keys work over HTTPS and QUIC, and how to look after them. - [Send over HTTPS](https://swqos.com/docs/send-http): POST /v1/transactions, every field of the request and the receipt. - [Send over QUIC](https://swqos.com/docs/send-quic): The low latency path: one connection, one stream per submission. - [Limits and behaviour](https://swqos.com/docs/limits): Payload size, deduplication, timeouts and retry guidance. - [Billing](https://swqos.com/docs/billing): The exact charge boundary, refunds, and what accepted means. - [Deposits](https://swqos.com/docs/deposits): Funding a balance with SOL, and how a deposit becomes credit. - [Errors](https://swqos.com/docs/errors): Every error code, what caused it, and how to fix it. - [FAQ](https://swqos.com/docs/faq): The questions that come up most, answered at length. ## Engineering writing Long-form technical guides on getting Solana transactions to land. Each one answers a specific question and carries runnable code. - [Why your Solana transactions are not landing](https://swqos.com/blog/why-solana-transactions-dont-land): A transaction that never lands failed at one of six specific points: blockhash expiry, an underpriced fee, compute budget, RPC forwarding, leader connection limits, or account contention. This walks through each one, how to tell them apart from the outside, and what actually fixes each. - [Stake-weighted QoS, explained properly](https://swqos.com/blog/stake-weighted-qos-explained): Stake-weighted QoS is how a Solana leader decides whose packets to accept when more arrive than it can process. Connection capacity is allocated in proportion to stake, so a transaction sent through a staked connection competes in a much smaller queue than one sent through a public RPC. - [Priority fees on Solana: a practical guide](https://swqos.com/blog/solana-priority-fees-guide): A Solana priority fee is a per-compute-unit bid that decides where your transaction sits in the leader's scheduling queue. This covers how the fee is actually computed, how to price it from live network data instead of guessing, and the mistakes that make a fee do nothing. - [The blockhash lifecycle, and why it killed your transaction](https://swqos.com/blog/blockhash-lifecycle): A Solana blockhash is valid for 150 slots, roughly 60 to 90 seconds, and a transaction referencing an older one is rejected outright. This explains the full lifecycle, why the window is shorter in practice than the arithmetic suggests, and how to structure a sender so it never fights the clock. - [Compute units: the limit that silently fails your transaction](https://swqos.com/blog/compute-units-explained): Every Solana transaction gets a compute budget, and exceeding it fails the transaction on chain after you have already paid for it. This covers how compute units are metered, how to measure what your instruction actually consumes, and why requesting the maximum is the wrong default. - [Writing a Solana QUIC TPU client from scratch](https://swqos.com/blog/solana-quic-tpu-client): A TPU client authenticates with a self-signed certificate carrying an Ed25519 keypair, negotiates the solana-tpu ALPN, and writes one serialized transaction per unidirectional stream. This builds one in Rust, explains every step of the handshake, and covers the connection management that decides whether it is fast. - [Landing transactions on pump.fun](https://swqos.com/blog/landing-pumpfun-transactions): pump.fun buys compete against every other bot watching the same mint, and the winner is usually decided by who reaches the leader first rather than who paid most. This covers bonding curve mechanics, the compute profile of a buy, slippage under contention, and how to structure a sniper that lands. - [Landing Raydium and Jupiter swaps](https://swqos.com/blog/landing-raydium-jupiter-swaps): A swap that arrives late does not just miss, it can execute at a price you would not have accepted. This covers the compute profile of Raydium AMM and CLMM swaps, how Jupiter routing changes the risk, how to set slippage that protects you without causing needless failures, and why address lookup tables matter more than people think. - [Jito bundles versus staked connections](https://swqos.com/blog/jito-bundles-vs-staked-connections): Jito bundles buy atomic, ordered execution and a shot at the top of a block. Staked connections buy fast, reliable delivery to the leader. They solve different problems, they are not mutually exclusive, and picking the wrong one costs you either money or fills. - [Measuring your real landing rate](https://swqos.com/blog/measuring-landing-rate): Landing rate is the share of submitted transactions that reach a finalized block, and almost nobody measures it correctly. This covers how to instrument a sender end to end, which RPC calls give a truthful answer, how to separate delivery failures from on-chain failures, and how to turn the result into a number you can act on. ## Important distinction An accepted receipt means the transaction was forwarded and the upstream acknowledged the stream. It is not a guarantee that the transaction landed on chain. Confirm landing with getSignatureStatuses or getTransaction using the signature from the receipt. The per-send price is a relay fee, not a Solana validator tip. swqos.com does not attach tip instructions or modify priority fees.