Logs & Debugging

Q: Does solana logs work on devnet?

Yes - pass --url devnet or set config URL first. Public endpoints may rate-limit subscriptions.

Q: What is a common Program failed to complete error?

Custom program error codes map to anchor_lang::error or your ProgramError variants - decode against your program's error enum.

Q: Can I save logs to a file?

Pipe solana logs > session.log or capture logMessages from JSON transaction output.

Q: How do I see compute units used?

solana confirm -v and transaction meta include computeUnitsConsumed on supporting RPC versions.

Q: Do logs include CPI calls?

Yes - inner instruction logs appear indented in logMessages order.

Q: Can I debug mainnet transactions?

Use solana transaction against mainnet RPC - no need for solana logs unless streaming live.

Q: How is this different from local validator output?

anchor test prints validator stdout directly; solana logs uses RPC subscriptions - same content, different transport.

Q: Can I watch a specific account?

Use RPC logsSubscribe with mentions filter in client code; CLI solana logs supports mention filters per solana logs --help.

Stream program logs in real time and inspect failed transactions with solana logs, solana confirm, and solana transaction.

Recipe

Quick-reference recipe card - copy-paste ready.

solana logs
solana logs --url devnet
solana confirm -v <SIGNATURE>
solana transaction <SIGNATURE>

When to reach for this:

msg! / println! output from your program during local dev.
Diagnosing custom program errors after a failed client send.
Watching live traffic on devnet while testing integrations.
Correlating instruction logs with compute unit consumption.

Working Example

# Terminal 1: stream logs (localnet example)
solana config set --url http://127.0.0.1:8899
solana logs
 
# Terminal 2: invoke your program or transfer
solana transfer <RECIPIENT> 0.01 --allow-unfunded-recipient
# or: anchor test / curl RPC sendTransaction
 
# After a failed tx, inspect signature
SIG="<FAILED_SIGNATURE>"
solana confirm -v "$SIG"
solana transaction "$SIG" --output json-compact | jq '.meta.logMessages, .meta.err'

What this demonstrates:

solana logs subscribes to logsSubscribe over WebSocket RPC.
Verbose confirm prints program logs and error codes inline.
JSON transaction output preserves ordered logMessages for tickets.

Deep Dive

How It Works

Programs emit logs via solana_program::log macros captured in transaction meta.
solana logs filters by mentions or shows all program output depending on flags.
Failed transactions still return meta with logs up to the failure point.
Compute budget consumption appears in meta fields on RPC responses.

Log Workflow

Step	Command	Output
Stream	`solana logs`	Live program lines
Submit	app / CLI tx	Signature
Verify	`solana confirm -v`	Status + logs
Archive	`solana transaction --output json`	Full meta blob

bash Notes

# Filter logs mentioning your program ID
solana logs | grep "<YOUR_PROGRAM_ID>"
 
# Include vote logs (noisy)
solana logs --include-votes

Gotchas

No logs without invocation - only executed programs log. Fix: confirm your instruction actually ran (check account locks and signers).
Log truncation - excessive msg! hits CU and size limits. Fix: log summaries, not full account data.
Wrong RPC WebSocket URL - HTTP port ≠ WS port on some providers. Fix: use provider-documented WSS endpoint; CLI maps from config URL on standard nodes.
Reading logs before confirm - race if you query too early. Fix: wait for confirmed or use confirm -v in scripts.
Vote log noise - default streams hide votes; enabling them floods output. Fix: omit --include-votes unless debugging validators.

Alternatives

Alternative	Use When	Don't Use When
`solana-test-validator` stdout	Local Anchor tests	Remote devnet debugging
Explorer transaction tab	Sharing links with teammates	Automated CI capture
`simulateTransaction` RPC	Pre-flight without landing	Post-mortem of landed failures
Surfpool / LiteSVM tests	Deterministic unit tests	Watching live mainnet traffic

FAQs

Does solana logs work on devnet?

Yes - pass --url devnet or set config URL first. Public endpoints may rate-limit subscriptions.

Why are my msg! lines missing?

Program may not have executed (failed prior instruction), logs were truncated, or you filtered the wrong program ID.

What is a common Program failed to complete error?

Custom program error codes map to anchor_lang::error or your ProgramError variants - decode against your program's error enum.

Can I save logs to a file?

Pipe solana logs > session.log or capture logMessages from JSON transaction output.

How do I see compute units used?

solana confirm -v and transaction meta include computeUnitsConsumed on supporting RPC versions.

Do logs include CPI calls?

Yes - inner instruction logs appear indented in logMessages order.

Can I debug mainnet transactions?

Use solana transaction <SIG> against mainnet RPC - no need for solana logs unless streaming live.

How is this different from local validator output?

anchor test prints validator stdout directly; solana logs uses RPC subscriptions - same content, different transport.

Why does confirm hang?

RPC not advancing, wrong signature, or network partition. Ctrl+C and retry with a healthier endpoint.

Can I watch a specific account?

Use RPC logsSubscribe with mentions filter in client code; CLI solana logs supports mention filters per solana logs --help.

Sending SOL & Transactions - generate signatures to inspect
Local Logs & Debugging - validator-side debugging
WebSocket Subscriptions - underlying subscription API
Inspecting Accounts & Programs - account state checks

Stack versions: This page was written for Agave 4.1.1, Solana CLI 3.0.10, Anchor 0.32.1, anchor-lang 0.32.1, Rust 1.91.1, @solana/kit 7.0.0, Surfpool 0.12.0, and LiteSVM 0.6.x.

Recipe

Quick-reference recipe card - copy-paste ready.

solana logs
solana logs --url devnet
solana confirm -v <SIGNATURE>
solana transaction <SIGNATURE>

When to reach for this:

msg! / println! output from your program during local dev.
Diagnosing custom program errors after a failed client send.
Watching live traffic on devnet while testing integrations.
Correlating instruction logs with compute unit consumption.

Working Example

# Terminal 1: stream logs (localnet example)
solana config set --url http://127.0.0.1:8899
solana logs
 
# Terminal 2: invoke your program or transfer
solana transfer <RECIPIENT> 0.01 --allow-unfunded-recipient
# or: anchor test / curl RPC sendTransaction
 
# After a failed tx, inspect signature
SIG="<FAILED_SIGNATURE>"
solana confirm -v "$SIG"
solana transaction "$SIG" --output json-compact | jq '.meta.logMessages, .meta.err'

What this demonstrates:

solana logs subscribes to logsSubscribe over WebSocket RPC.
Verbose confirm prints program logs and error codes inline.
JSON transaction output preserves ordered logMessages for tickets.

Deep Dive

How It Works

Programs emit logs via solana_program::log macros captured in transaction meta.
solana logs filters by mentions or shows all program output depending on flags.
Failed transactions still return meta with logs up to the failure point.
Compute budget consumption appears in meta fields on RPC responses.

Log Workflow

Step	Command	Output
Stream	`solana logs`	Live program lines
Submit	app / CLI tx	Signature
Verify	`solana confirm -v`	Status + logs
Archive	`solana transaction --output json`	Full meta blob

bash Notes

# Filter logs mentioning your program ID
solana logs | grep "<YOUR_PROGRAM_ID>"
 
# Include vote logs (noisy)
solana logs --include-votes

Gotchas

No logs without invocation - only executed programs log. Fix: confirm your instruction actually ran (check account locks and signers).
Log truncation - excessive msg! hits CU and size limits. Fix: log summaries, not full account data.
Wrong RPC WebSocket URL - HTTP port ≠ WS port on some providers. Fix: use provider-documented WSS endpoint; CLI maps from config URL on standard nodes.
Reading logs before confirm - race if you query too early. Fix: wait for confirmed or use confirm -v in scripts.
Vote log noise - default streams hide votes; enabling them floods output. Fix: omit --include-votes unless debugging validators.

Alternatives

Alternative	Use When	Don't Use When
`solana-test-validator` stdout	Local Anchor tests	Remote devnet debugging
Explorer transaction tab	Sharing links with teammates	Automated CI capture
`simulateTransaction` RPC	Pre-flight without landing	Post-mortem of landed failures
Surfpool / LiteSVM tests	Deterministic unit tests	Watching live mainnet traffic

FAQs

Does solana logs work on devnet?

Yes - pass --url devnet or set config URL first. Public endpoints may rate-limit subscriptions.

Why are my msg! lines missing?

Program may not have executed (failed prior instruction), logs were truncated, or you filtered the wrong program ID.

What is a common Program failed to complete error?

Custom program error codes map to anchor_lang::error or your ProgramError variants - decode against your program's error enum.

Can I save logs to a file?

Pipe solana logs > session.log or capture logMessages from JSON transaction output.

How do I see compute units used?

solana confirm -v and transaction meta include computeUnitsConsumed on supporting RPC versions.

Do logs include CPI calls?

Yes - inner instruction logs appear indented in logMessages order.

Can I debug mainnet transactions?

Use solana transaction <SIG> against mainnet RPC - no need for solana logs unless streaming live.

How is this different from local validator output?

anchor test prints validator stdout directly; solana logs uses RPC subscriptions - same content, different transport.

Why does confirm hang?

RPC not advancing, wrong signature, or network partition. Ctrl+C and retry with a healthier endpoint.

Can I watch a specific account?

Use RPC logsSubscribe with mentions filter in client code; CLI solana logs supports mention filters per solana logs --help.

Sending SOL & Transactions - generate signatures to inspect
Local Logs & Debugging - validator-side debugging
WebSocket Subscriptions - underlying subscription API
Inspecting Accounts & Programs - account state checks

Stack versions: This page was written for Agave 4.1.1, Solana CLI 3.0.10, Anchor 0.32.1, anchor-lang 0.32.1, Rust 1.91.1, @solana/kit 7.0.0, Surfpool 0.12.0, and LiteSVM 0.6.x.

Logs & Debugging

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Logs & Debugging