交易生命周期
从签名到挖矿
交易生命周期 是 CoddyKit 上的免费 Web3 & DApp Development Fundamentals 课时。 这是第 2 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Web3 & DApp Development Fundamentals 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Web3 & DApp Development Fundamentals 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
From Click to Confirmation
When you send a transaction, a lot happens behind the scenes before it becomes permanent.
This lesson walks through the full transaction lifecycle, from signing to inclusion in a block.
Step 1: Building the Transaction
Your wallet assembles a transaction object containing the recipient, value, data, gas settings, and a nonce.
tx = {
to: 0xRecipient...,
value: 1000000000000000000, // 1 ETH
nonce: 7,
gasLimit: 21000,
maxFeePerGas: 30 gwei
}Step 2: Signing
The wallet signs the transaction with your private key, producing a digital signature.
The signature proves you authorized it without ever revealing your private key. Anyone can verify it using your public address.
Step 3: Broadcasting
The signed transaction is broadcast to a node, which validates it and gossips it to peers across the network.
Within seconds, nodes everywhere know about your pending transaction.
Step 4: The Mempool
Pending transactions wait in the mempool (memory pool) — a holding area for transactions not yet included in a block.
Validators pick from the mempool when building the next block.
mempool (pending):
tx A (tip: 5 gwei)
tx B (tip: 2 gwei)
tx C (tip: 8 gwei) <- picked firstStep 5: Selection by a Validator
A validator building a block selects transactions, usually favoring higher fee tips for more revenue.
Paying a higher tip can speed up inclusion, especially when the network is congested.
Step 6: Execution
The validator executes the transaction on the EVM, updating account balances and contract state, consuming gas as it goes.
If it runs out of gas or hits an error, it reverts — but the gas spent is still consumed.
Step 7: Inclusion in a Block
The executed transaction is packed into a new block along with others. The block is proposed and attested to by validators.
At this point your transaction has one confirmation.
Step 8: Confirmations and Finality
As more blocks build on top, your transaction gains confirmations. On Ethereum PoS, it eventually becomes finalized and irreversible.
Now the transfer or contract call is permanently settled.
Receipts
After execution, the network produces a transaction receipt recording status (success or revert), gas used, and any emitted events (logs).
Apps read receipts to confirm what actually happened on-chain.
receipt = {
status: 1, // 1 = success, 0 = revert
gasUsed: 21000,
blockNumber: 18250431,
logs: [ ... ]
}Putting It Together
A transaction is built, signed, broadcast, queued in the mempool, selected and executed by a validator, included in a block, and finally confirmed and finalized.
A receipt records the outcome.
Quick Check
Test your understanding of the lifecycle.
Recap: Transaction Lifecycle
You learned the stages:
- Build and sign with the private key
- Broadcast to the network
- Wait in the mempool
- Selected, executed, and included in a block
- Confirmed and finalized, with a receipt
Next: gas limits and fees.
常见问题解答
「交易生命周期」课时是免费的吗？
是的 — 「交易生命周期」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Web3 & DApp Development Fundamentals 课程的其余内容，请升级到 CoddyKit PRO。 Web3 & DApp Development Fundamentals 课程共包含 4 节课。
「交易生命周期」这节课中我会学到什么？
从签名到挖矿 你通过在浏览器中直接运行的动手代码来练习 Web3 & DApp Development Fundamentals，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Web3 & DApp Development Fundamentals 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Web3 & DApp Development Fundamentals 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 2 节课，共 4 节。
「交易生命周期」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Web3 & DApp Development Fundamentals 课中编写并运行代码吗？
能。每节 Web3 & DApp Development Fundamentals 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。