debug

The debug namespace provides debugging and diagnostic methods for Erigon node operators and developers. These methods offer deep introspection into blockchain state, transaction execution, and node performance.

The debug namespace must be explicitly enabled using the --http.api=debug flag when starting the RPC daemon.

The debug namespace is intended for debugging and development purposes, not for production use.

Security and Access Control

• Debug methods are considered private and should not be exposed on public RPC endpoints;

• These methods can consume significant resources and should be used carefully in production environments;

• Access should be restricted to trusted operators and developers only.

Performance Considerations

• Tracing methods (debug_traceBlockByHash, debug_traceBlockByNumber, debug_traceTransaction, debug_traceCall, debug_traceCallMany) support streaming for large results to reduce memory usage

• The AccountRangeMaxResults constant limits account range queries to 8192 results, or 256 when storage is included;

• Memory and GC control methods allow fine-tuning of node performance.

• Some methods like debug_accountRange have compatibility layers for both Geth and legacy Erigon parameter formats debug_api

Integration with Erigon Architecture

• Debug methods leverage Erigon's temporal database for historical state access;

• The implementation uses kv.TemporalRoDB for efficient historical queries;

• Tracing functionality integrates with Erigon's execution engine and EVM implementation.

Usage in Development and Testing

• These methods are essential for debugging transaction execution issues;

• Storage range methods help analyze contract state changes;

• Memory management methods assist in performance optimization and resource monitoring.

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JSON-RPC Specification

debug_getRawReceipts

Returns an array of EIP-2718 binary-encoded receipts from a single block.

Parameters

Parameter	Type	Description
blockNrOrHash	QUANTITY | TAG | DATA	Block number, tag ("earliest", "latest", "pending"), or block hash

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_getRawReceipts","params":["0x123456"],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Array of DATA	Array of binary-encoded transaction receipts

debug_accountRange

Returns a range of accounts involved in the given block range.

Parameters

Parameter	Type	Description
blockNrOrHash	QUANTITY | TAG	Block number or tag
start	DATAARRAY	Array of prefixes to match account addresses
maxResults	QUANTITY	Maximum number of accounts to retrieve
excludeCode	BOOLEAN	If true, exclude byte code from results
excludeStorage	BOOLEAN	If true, exclude storage from results
incompletes	BOOLEAN	If true, return missing preimages (not supported when true)

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_accountRange","params":["0xaaaaa",[1],1,true,true,true],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	IteratorDump object containing account information

debug_accountAt

Returns account information at a specific block and transaction index.

Parameters

Parameter	Type	Description
blockHash	DATA, 32 Bytes	Hash of the block
txIndex	QUANTITY	Transaction index within the block
address	DATA, 20 Bytes	Account address

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_accountAt","params":["0x123456...",1,"0x123456..."],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	AccountResult with balance, nonce, code, and codeHash

debug_getModifiedAccountsByNumber

Returns a list of accounts modified in the given block range by number.

Parameters

Parameter	Type	Description
startNumber	QUANTITY | TAG	Start block number or tag
endNumber	QUANTITY | TAG	End block number or tag (optional)

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_getModifiedAccountsByNumber","params":["0xccccd","0xcccce"],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Array of DATA, 20 Bytes	Array of modified account addresses

debug_getModifiedAccountsByHash

Returns a list of accounts modified in the given block range by hash.

Parameters

Parameter	Type	Description
startHash	DATA, 32 Bytes	Hash of the start block
endHash	DATA, 32 Bytes	Hash of the end block (optional)

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_getModifiedAccountsByHash","params":["0x2a1af0...","0x4e3d3e..."],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Array of DATA, 20 Bytes	Array of modified account addresses

debug_storageRangeAt

Returns information about a range of storage locations for a contract address.

Parameters

Parameter	Type	Description
blockHash	DATA, 32 Bytes	Hash of block at which to retrieve data
txIndex	QUANTITY, 8 Bytes	Transaction index in the block
contractAddress	DATA, 20 Bytes	Contract address
keyStart	DATA, 32 Bytes	Storage key to start from
maxResult	QUANTITY, 8 Bytes	Maximum number of values to retrieve

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_storageRangeAt","params":["0xd3f185...",1,"0xb734c7...","0x00",2],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	StorageRangeResult with key/value pairs and nextKey

debug_traceBlockByHash

Returns Geth style transaction traces for a block by hash.

Parameters

Parameter	Type	Description
hash	DATA, 32 Bytes	Hash of block to trace
config	Object (optional)	Trace configuration options

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_traceBlockByHash","params":["0x123456...",{}],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Array	Array of transaction trace objects

debug_traceBlockByNumber

Returns Geth style transaction traces for a block by number.

Parameters

Parameter	Type	Description
blockNumber	QUANTITY | TAG	Block number or tag
config	Object (optional)	Trace configuration options

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_traceBlockByNumber","params":["0x123456",{}],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Array	Array of transaction trace objects

debug_traceTransaction

Returns Geth style transaction trace.

Parameters

Parameter	Type	Description
hash	DATA, 32 Bytes	Hash of transaction to trace
config	Object (optional)	Trace configuration options

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_traceTransaction","params":["0x123456...",{}],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	Transaction trace object

debug_traceCall

Returns Geth style call trace.

Parameters

Parameter	Type	Description
args	Object	Call arguments (to, from, gas, gasPrice, value, data)
blockNrOrHash	QUANTITY | TAG | DATA	Block number, tag, or hash
config	Object (optional)	Trace configuration options

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_traceCall","params":[{"to":"0x123456..."},"latest",{}],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	Call trace object

debug_traceCallMany

Returns Geth style traces for multiple call bundles.

Parameters

Parameter	Type	Description
bundles	Array	Array of transaction bundles to trace
simulateContext	Object	Simulation context (blockNumber, transactionIndex)
config	Object (optional)	Trace configuration options

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_traceCallMany","params":[[{"transactions":[...]}],{"blockNumber":"latest"},{}],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Array	Array of trace results for each bundle

debug_setMemoryLimit

Sets the GOMEMLIMIT for the process.

Parameters

Parameter	Type	Description
limit	QUANTITY	Memory limit in bytes

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_setMemoryLimit","params":[8589934592],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
QUANTITY	Previous memory limit

debug_setGCPercent

Sets the garbage collection target percentage.

Parameters

Parameter	Type	Description
v	QUANTITY	GC percentage (negative value disables GC)

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_setGCPercent","params":[100],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
QUANTITY	Previous GC percentage setting

debug_freeOSMemory

Forces a garbage collection to free OS memory.

Parameters

None

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_freeOSMemory","params":[],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
null	No return value

debug_gcStats

Returns garbage collection statistics.

Parameters

None

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_gcStats","params":[],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	GC statistics object

debug_memStats

Returns detailed runtime memory statistics.

Parameters

None

Example

curl -s --data '{"jsonrpc":"2.0","method":"debug_memStats","params":[],"id":"1"}' -H "Content-Type: application/json" -X POST http://localhost:8545

Returns

Type	Description
Object	Runtime memory statistics object