erst export

Export data from the current session

Export debugging data, such as state snapshots and memory dumps, from the currently active session.

Usage

erst export [flags]
erst export decode-memory [flags]

Description

The export command allows you to extract and save debugging data from an active session for:

• Offline analysis
• Sharing with team members
• Integration with other tools
• Creating reproducible test fixtures
• Memory forensics

You must run erst debug <tx-hash> first to create an active session before using this command.

Subcommands

• export - Export state snapshot
• decode-memory - Decode and print linear memory dump

export

Export the current session’s ledger state and optionally WASM linear memory to a JSON snapshot file.

Flags

--snapshot · string · required

Output file for JSON snapshot

The snapshot will contain all ledger entries accessed during the transaction.

--include-memory · boolean · default: "false"

Include WASM linear memory dump from simulation response

Only available if the simulator was configured to capture memory.

Examples

Export ledger state

erst debug abc123...def
erst export --snapshot state.json

Output

Snapshot exported to state.json (127 entries)

With --include-memory:

Snapshot exported to state.json (127 entries)
Included linear memory dump: 65536 bytes (base64)

Snapshot format

The exported JSON file contains:

{
  "ledger_entries": {
    "<key1>": "<xdr-value1>",
    "<key2>": "<xdr-value2>",
    ...
  },
  "linear_memory": "<base64-encoded-memory>"
}

• ledger_entries: Map of ledger keys to XDR-encoded values
• linear_memory: Base64-encoded WASM memory dump (if --include-memory)

decode-memory

Decode and display a hexdump of the linear memory from a snapshot file.

Flags

--snapshot · string · required

Snapshot file that contains linear memory

--offset · int · default: "0"

Start offset in bytes

Must be >= 0 and within memory bounds.

--length · int · default: "256"

Number of bytes to print

Must be > 0.

Examples

Decode first 256 bytes

erst export decode-memory --snapshot state.json

Output format

Displays a hexdump with ASCII representation:

Linear memory segment [0:256] (256 bytes)
0x00000000  00 00 00 00 01 00 00 00  48 65 6c 6c 6f 00 00 00  |........Hello...|
0x00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
0x00000020  57 6f 72 6c 64 00 00 00  00 00 00 00 03 00 00 00  |World...........|
0x00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
...

Format:

• Address: Hexadecimal offset
• Hex bytes: Up to 16 bytes per line
• ASCII: Printable characters (. for non-printable)

Use cases

Create test fixtures

Export ledger state for unit tests:

# Debug a transaction
erst debug abc123...def

# Export state
erst export --snapshot fixtures/test_state.json

# Use in tests
const state = require('./fixtures/test_state.json');

Offline debugging

Export data for analysis without network:

# Online: export session data
erst debug abc123...def --network mainnet
erst export --snapshot mainnet_state.json --include-memory

# Offline: analyze locally
erst export decode-memory --snapshot mainnet_state.json

Share debugging context

Share exact ledger state with team:

# Export state
erst debug abc123...def
erst export --snapshot bug_reproduction.json

# Team member loads it
erst debug --snapshot bug_reproduction.json

Memory forensics

Analyze WASM memory for debugging:

# Export with memory
erst debug abc123...def
erst export --snapshot crash.json --include-memory

# Examine stack region
erst export decode-memory --snapshot crash.json --offset 65536 --length 1024

# Check heap
erst export decode-memory --snapshot crash.json --offset 1048576 --length 4096

Compare states

Export before/after snapshots:

# Before
erst debug tx_before --snapshot before.json

# After
erst debug tx_after --snapshot after.json

# Diff the snapshots
diff <(jq -S . before.json) <(jq -S . after.json)

Snapshot files

Size

Snapshot file sizes vary based on:

• Ledger entries: Typically 10-500 KB
• Linear memory: Adds 64 KB - 4 MB (if included)

Compression

For large snapshots, consider compression:

# Export
erst export --snapshot state.json --include-memory

# Compress
gzip state.json

# Later: decompress and use
gunzip state.json.gz
erst export decode-memory --snapshot state.json

Portability

Snapshots are portable across:

• Different machines
• Different OS platforms
• Different Erst versions (same schema)

Snapshots use XDR encoding for ledger entries, making them network-agnostic and version-stable.

Error handling

No active session

Error: no active session. Run 'erst debug <tx-hash>' first

Solution: Debug a transaction first:

erst debug abc123...def
erst export --snapshot state.json

No memory dump available

Warning: Simulator response does not include a linear memory dump.
Snapshot exported to state.json (127 entries)

Cause: Simulator wasn’t configured to capture memory.

Solution: This is expected - memory dumps are optional. The snapshot still contains all ledger state.

Invalid offset

Error: offset 100000 out of bounds for memory size 65536

Solution: Use a valid offset:

# Check memory size first
erst export decode-memory --snapshot state.json --offset 0 --length 16

Related commands

• debug - Create sessions for export
• session - Manage saved sessions
• trace - Analyze execution traces