Sui Networks and Gas

MCP tool: When available in your environment, also query the Sui documentation MCP server (https://sui.mcp.kapa.ai) for up-to-date answers. Use it for verification and for details not covered by these reference files.

Source constraint: All information in this skill is sourced exclusively from docs.sui.io. When extending or updating this skill, only pull from this source. Do not use third-party blogs, tutorials, or unofficial documentation.

Related skills

Sui networks

Sui operates four network environments:

• Mainnet: Production network. SUI tokens have real monetary value. Use for final deployments.
• Testnet: Mirrors Mainnet features. Free SUI tokens from faucets. Use for integration testing and staging.
• Devnet: Development network. Free SUI tokens. Use for early-stage development and experimentation.
• Localnet: Runs locally on your machine. Use for offline development and unit testing.

Gas cost model

Every transaction on Sui requires SUI tokens to pay gas. The total gas cost is:

gas cost = computation cost + storage cost - storage rebate

• Computation cost: Proportional to the computational effort of executing the transaction.
• Storage cost: The cost of storing new or expanded objects onchain. You pay for the bytes your objects occupy.
• Storage rebate: When a transaction deletes objects or reduces their size, you receive a rebate for the storage freed. This incentivizes cleaning up unused state.

The gas budget (--gas-budget) sets the maximum you are willing to pay. If the transaction exceeds the budget, it aborts. On Testnet and Devnet, tokens are free through faucets (see the sui-client skill for faucet methods). Gas prices can vary per epoch; query the current gas price through the RPC.

Epochs

An epoch is a fixed time period during which the validator set and gas price remain constant. On Mainnet, one epoch is approximately 24 hours. At the epoch boundary, the network processes staking rewards, rotates validators, and updates the gas price. Use ctx.epoch() to read the current epoch number in Move and ctx.epoch_timestamp_ms() for the epoch start time.

Rules

• Always specify --gas-budget when submitting transactions from the CLI.
• Use sui client switch --env <ENV> to change networks. Do not edit client.yaml manually.

Common mistakes

• Forgetting to switch networks. Publishing to Mainnet when you meant Testnet. Always verify with sui client active-env.
• Running out of gas on Testnet/Devnet. Use the faucet (see sui-client skill) to get free tokens.