Overview of bitcoind

The following diagram gives a brief overview of how some of the major components in bitcoind are related.

This diagram is not exhaustive and includes simplifications.

dashed lines indicate optional components

Figure 1. bitcoind overview

Table 1. Brief description of components in `bitcoind` overview
Component	Simplified description
`AddrMan`	Manage peers' network addresses
`CConnman`	Manage network connections to peers
`Interfaces::Chain`	Give clients access to chain state, fee rate estimates, notifications and allow tx submission
`ChainstateManager`	An interface for interacting with 1 or 2 chainstates (1. IBD-verified, 2. optional snapshot)
`NetGroupManager`	Manage net groups. Ensure we don’t connect to multiple nodes in the same ASN bucket
`CTxMemPool`	Validate and store (valid) transactions which may be included in the next block
`PeerManager`	Manage peer state and interaction e.g. processing messages, fetching blocks & removing for misbehaviour
`BlockManager`	Maintains a tree of blocks on disk (via LevelDB) to determine most-work tip
`ScriptPubKeyMan`	Manages `scriptPubKeys` in a wallet. Can give out new `scriptPubKeys` as well as call into a `SigningProvider` to sign transactions

`bitcoin-cli` overview

The following diagram gives a brief overview of the major components in bitcoin-cli.

This diagram is not exhaustive and includes simplifications.

Figure 2. bitcoin-cli overview

The following diagram gives a brief overview of how the wallet is structured.

This diagram is not exhaustive and includes simplifications.

dashed lines indicate optional components

Figure 3. Wallet structure overview

Table 2. Brief description of components
Component	Simplified description
`WalletDatabase`	Represents a single wallet. Handles reads and writes to disk
`ScriptPubKeyMan`	Base class for the below SPKM classes to override before being used by `CWallet`
`DescriptorScriptPubKeyMan`	A SPKM for descriptor-based wallets
`LegacyScriptPubKeyMan`	A SPKM for legacy wallets
`SigningProvider`	An interface for a `KeyStore` to sign transactions from
`Interfaces::Chain`	Give clients access to chain state, fee rate estimates, notifications and allow tx submission
`cs_wallet`	The primary wallet lock, held for atomic wallet operations