Resource Limits & Fees
Resource Limits
Resource limitations and fees only apply to smart contract transactions. Read more about the inner workings of fees on Stellar in the Fees section.
Per-transaction limits
These define the maximum amount of work a single Smart contract transaction can do.
| Network Setting | Value |
|---|---|
| Max CPU instructions | 100 million |
| Max memory (RAM) | 40 MB |
| Max number of keys in the footprint | 100 |
| Disk reads* | 100 entries/200 KB |
| Disk writes | 50 entries/132 KB |
| Transaction size | 132 KB |
| Events+return value size bytes | 16 KB |
| Individual ledger key size (contract storage key) | 250 bytes |
| Individual ledger entry size (including Wasm entries) | 128 KiB |
* Most transactions don't perform any disk reads, as only archived entries and 'classic' entries (G-accounts, trustlines) are considered to be disk reads. Live smart contract state is in-memory and is not counted towards this limit.
TTL extension parameters
These define TTL extension parameters.
| Network Setting | Value |
|---|---|
| Persistent entry TTL on creation | 120 days |
| Temporary entry TTL on creation | 1 day |
| Max ledger entry TTL extension | 6 months |
Ledger-wide limits
These define the maximum amount of work done by all the transactions in a single ledger (single block).
| Network Setting | Value |
|---|---|
| Max CPU instructions | 600 million |
| Max memory (RAM) | no explicit limit |
| Max number of keys in the footprint | no explicit limit |
| Disk reads | 1000 entries/7 MB |
| Disk writes | 500 entries/143 KB |
| Transactions size | 133 KB |
| Events+return value size bytes | no explicit limit |
Resource Fees
| Network Setting | Cost (stroops) |
|---|---|
| 10,000 CPU instructions | 25 (250,000/max tx) |
| Read 1 ledger entry from disk | 6,250 (625,000/max tx) |
| Read 1KB from disk | 1,786 (357,200/max tx) |
| Write 1 ledger entry | 10,000 (500,000/max tx) |
| Write 1KB to disk | 3,500 (462'000/max tx) |
| 1KB of transaction size (bandwidth) | 1,624 (214,368/max tx) |
| 1KB of transaction size (history) | 16,235 (2,143,020/max tx) |
| 1KB of Events/return value | 10,000 (160,000/max tx) |
| 30 days of rent for 1 KB of persistent storage | ~427,000 |
| 30 days of rent for 1 KB of temporary storage | ~213,500 |
Note, that the rent fees provided here may go up in case if a lot of contract data is written to the ledger within a short time period. This happens because the rent fees are designed in such a way that the closer the state size to some validator-defined threshold, the more expensive it gets to write new data or extend the TTLs.