Open
Conversation
Contributor
anegg0
commented
Feb 10, 2026
anegg0
commented
- Gentle introduction
- Quickstart
- How-to
- Concept
- FAQ
- Troubleshooting
- Reference
- Third-party content
- Not applicable
|
The latest updates on your projects. Learn more about Vercel for GitHub.
|
|
|
||
| 1. A function call doesn't match any existing function signature | ||
| 2. Plain ETH transfer when no `#[receive]` function exists | ||
| 3. The contract receives calldata but no function matches |
Contributor
There was a problem hiding this comment.
Suggested change
| 3. The contract receives calldata but no function matches | |
| 3. The contract receives calldata, but no function matches |
|
|
||
| ### Accessing VM Context | ||
|
|
||
| All public methods can access blockchain context via `self.vm()`: |
Contributor
There was a problem hiding this comment.
Suggested change
| All public methods can access blockchain context via `self.vm()`: | |
| All public methods can access the blockchain context via the `self.vm()` property: |
|
|
||
| ## Delegate calls | ||
|
|
||
| Delegate calls allow a contract to execute code from another contract while maintaining its own context. When Contract A executes a delegate call to Contract B, B's code runs using Contract A's storage, `msg.sender`, and `msg.value`. This means any state changes affect Contract A, and the original sender and value of the transaction are preserved. |
Contributor
There was a problem hiding this comment.
Suggested change
| Delegate calls allow a contract to execute code from another contract while maintaining its own context. When Contract A executes a delegate call to Contract B, B's code runs using Contract A's storage, `msg.sender`, and `msg.value`. This means any state changes affect Contract A, and the original sender and value of the transaction are preserved. | |
| Delegate calls allow a contract to execute code from another contract while maintaining its own context. When Contract A executes a delegate call to Contract B, B's code runs using Contract A's storage, `msg.sender`, and `msg.value`. This means that any state changes affect Contract A, and the original sender and transaction value are preserved. |
|
|
||
| ### Using the low-level `delegate_call` function | ||
|
|
||
| The `delegate_call` function is a low-level operation similar to `call` and `static_call`. It is considered unsafe because it requires trusting the external contract to maintain safety. |
Contributor
There was a problem hiding this comment.
Suggested change
| The `delegate_call` function is a low-level operation similar to `call` and `static_call`. It is considered unsafe because it requires trusting the external contract to maintain safety. | |
| The `delegate_call` function is a low-level operation similar to `call` and `static_call`. It is considered unsafe because it relies on an external contract to ensure safety. |
|
|
||
| ### Using `RawCall` with `new_delegate()` | ||
|
|
||
| For scenarios requiring untyped calls with more configuration options, `RawCall` offers a fluent interface. You can set up a delegate call by chaining optional configuration methods. |
Contributor
There was a problem hiding this comment.
Suggested change
| For scenarios requiring untyped calls with more configuration options, `RawCall` offers a fluent interface. You can set up a delegate call by chaining optional configuration methods. | |
| For scenarios that require untyped calls with additional configuration options, `RawCall` provides a fluent interface. You can set up a delegate call by chaining optional configuration methods. |
| ### Safety considerations | ||
|
|
||
| :::caution | ||
| Delegate calls are inherently unsafe and require careful consideration before use. |
Contributor
There was a problem hiding this comment.
Suggested change
| Delegate calls are inherently unsafe and require careful consideration before use. | |
| Delegate calls are inherently unsafe and should be used with caution. |
|
|
||
| ## Sending ether | ||
|
|
||
| Stylus provides multiple ways to send ether from a contract. Unlike Solidity's `transfer` method which is capped at 2300 gas, Stylus's `transfer_eth` forwards all gas to the recipient. You can cap gas using the low-level `call` method if needed. |
Contributor
There was a problem hiding this comment.
Suggested change
| Stylus provides multiple ways to send ether from a contract. Unlike Solidity's `transfer` method which is capped at 2300 gas, Stylus's `transfer_eth` forwards all gas to the recipient. You can cap gas using the low-level `call` method if needed. | |
| Stylus provides multiple ways to send ether from a contract. Unlike Solidity's `transfer` method, which is capped at 2300 gas, Stylus's `transfer_eth` forwards all gas to the recipient. You can cap gas using the low-level `call` method if needed. |
| } | ||
| ``` | ||
|
|
||
| ### Using low-level `call()` with value |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Using low-level `call()` with value | |
| ### Using a low-level `call()` with a value |
| } | ||
| ``` | ||
|
|
||
| ### Where you can send ether |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Where you can send ether | |
| ### Where can you send `ETH` |
| ### Where you can send ether | ||
|
|
||
| 1. **Externally owned account (EOA) addresses**: Directly send ether to any EOA address | ||
| 2. **Solidity contracts with `receive()` function**: Send ether without calldata to contracts implementing `receive()` |
Contributor
There was a problem hiding this comment.
Suggested change
| 2. **Solidity contracts with `receive()` function**: Send ether without calldata to contracts implementing `receive()` | |
| 2. **Solidity contracts with the `receive()` function**: Send ether without calldata to contracts implementing `receive()` |
|
|
||
| 1. **Externally owned account (EOA) addresses**: Directly send ether to any EOA address | ||
| 2. **Solidity contracts with `receive()` function**: Send ether without calldata to contracts implementing `receive()` | ||
| 3. **Solidity contracts with `fallback()` function**: Send ether with calldata to contracts implementing `fallback()` |
Contributor
There was a problem hiding this comment.
Suggested change
| 3. **Solidity contracts with `fallback()` function**: Send ether with calldata to contracts implementing `fallback()` | |
| 3. **Solidity contracts with the `fallback()` function**: Send ether with calldata to contracts implementing `fallback()` |
|
|
||
| ## Factory contract deployment (coming soon) | ||
|
|
||
| The factory pattern allows a contract to deploy other contracts programmatically. This is useful for creating contract instances on-demand, such as deploying new token contracts or creating user-specific vaults. |
Contributor
There was a problem hiding this comment.
Suggested change
| The factory pattern allows a contract to deploy other contracts programmatically. This is useful for creating contract instances on-demand, such as deploying new token contracts or creating user-specific vaults. | |
| The factory pattern allows a contract to deploy other contracts programmatically. This is useful for creating contract instances on demand, such as deploying new token contracts or creating user-specific vaults. |
| 2. **Entrypoint**: Marks the main contract struct that handles incoming calls | ||
| 3. **Public Methods**: Functions exposed to external callers via the `#[public]` macro | ||
|
|
||
| ### Minimal Contract |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Minimal Contract | |
| ### Minimal contract |
| - Uses `#[public]` to expose the `user_main` function | ||
| - Returns `ArbResult`, which is `Result<Vec<u8>, Vec<u8>>` | ||
|
|
||
| ## Storage Definition |
Contributor
There was a problem hiding this comment.
Suggested change
| ## Storage Definition | |
| ## Storage definition |
|
|
||
| Both approaches produce identical storage layouts and are fully interoperable with Solidity contracts using the same storage structure. | ||
|
|
||
| ## The `#[entrypoint]` Macro |
Contributor
There was a problem hiding this comment.
Suggested change
| ## The `#[entrypoint]` Macro | |
| ## The `#[entrypoint]` macro |
| 2. A `user_entrypoint` function that Stylus calls when the contract receives a transaction | ||
| 3. Method routing logic to dispatch calls to `#[public]` methods | ||
|
|
||
| ## Public Methods with `#[public]` |
Contributor
There was a problem hiding this comment.
Suggested change
| ## Public Methods with `#[public]` | |
| ## Public methods with `#[public]` |
|
|
||
| The `#[public]` macro exposes Rust methods as external contract functions callable from Solidity, other Stylus contracts, or external callers. | ||
|
|
||
| ### Basic Public Methods |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Basic Public Methods | |
| ### Basic public methods |
| } | ||
| ``` | ||
|
|
||
| ### State Mutability |
Contributor
There was a problem hiding this comment.
Suggested change
| ### State Mutability | |
| ### State mutability |
|
|
||
| The `#[constructor]` attribute marks a function that runs once during contract deployment. | ||
|
|
||
| ### Basic Constructor |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Basic Constructor | |
| ### Basic constructor |
| } | ||
| ``` | ||
|
|
||
| ### Constructor Features |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Constructor Features | |
| ### Constructor features |
| - Constructor runs exactly once when the contract is deployed | ||
| - Use `tx_origin()` instead of `msg_sender()` when deploying via a factory contract | ||
|
|
||
| ## Method Attributes |
Contributor
There was a problem hiding this comment.
Suggested change
| ## Method Attributes | |
| ## Method attributes |
| - Easy to test components independently | ||
| - Compatible with Solidity interface standards | ||
|
|
||
| ### Accessing VM Context |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Accessing VM Context | |
| ### Accessing VM context |
| - Limited to 3 indexed parameters per event | ||
| - Indexed parameters are stored in log topics, not data | ||
|
|
||
| ### Emitting Events |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Emitting Events | |
| ### Emitting events |
| } | ||
| ``` | ||
|
|
||
| ### Raw Log Emission |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Raw Log Emission | |
| ### Raw log emission |
| } | ||
| ``` | ||
|
|
||
| ## External Contract Calls |
Contributor
There was a problem hiding this comment.
Suggested change
| ## External Contract Calls | |
| ## External contract calls |
|
|
||
| Stylus contracts can call other contracts (Solidity or Stylus) using typed interfaces or raw calls. | ||
|
|
||
| ### Defining Contract Interfaces |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Defining Contract Interfaces | |
| ### Defining contract interfaces |
| } | ||
| ``` | ||
|
|
||
| ### Calling External Contracts |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Calling External Contracts | |
| ### Calling external contracts |
|
|
||
| ### Calling External Contracts | ||
|
|
||
| #### View Calls (Read-Only) |
Contributor
There was a problem hiding this comment.
Suggested change
| #### View Calls (Read-Only) | |
| #### View calls (read-only) |
| } | ||
| ``` | ||
|
|
||
| #### Mutating Calls |
Contributor
There was a problem hiding this comment.
Suggested change
| #### Mutating Calls | |
| #### Mutating calls |
| } | ||
| ``` | ||
|
|
||
| #### Payable Calls |
Contributor
There was a problem hiding this comment.
Suggested change
| #### Payable Calls | |
| #### Payable calls |
| } | ||
| ``` | ||
|
|
||
| #### Configuring Gas |
Contributor
There was a problem hiding this comment.
Suggested change
| #### Configuring Gas | |
| #### Configuring gas |
| } | ||
| ``` | ||
|
|
||
| ### Low-Level Calls |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Low-Level Calls | |
| ### Low-Level calls |
| - `static_call()`: Read-only call (equivalent to Solidity `staticcall`) | ||
| - `RawCall`: Low-level unsafe calls with fine-grained control | ||
|
|
||
| ## Error Handling |
Contributor
There was a problem hiding this comment.
Suggested change
| ## Error Handling | |
| ## Error handling |
|
|
||
| Stylus contracts can define and return custom errors using Solidity-compatible error types. | ||
|
|
||
| ### Defining Errors |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Defining Errors | |
| ### Defining errors |
| } | ||
| ``` | ||
|
|
||
| ### Using Errors in Methods |
Contributor
There was a problem hiding this comment.
Suggested change
| ### Using Errors in Methods | |
| ### Using errors in methods |
| - Error data includes the error signature and parameters | ||
| - Compatible with Solidity `try/catch` blocks | ||
|
|
||
| ## Complete Example |
Contributor
There was a problem hiding this comment.
Suggested change
| ## Complete Example | |
| ## Complete example |
|
|
||
| ## Complete Example | ||
|
|
||
| Here's a complete ERC-20-style token contract demonstrating all major features: |
Contributor
There was a problem hiding this comment.
Suggested change
| Here's a complete ERC-20-style token contract demonstrating all major features: | |
| Here's a complete `ERC-20`-style token contract demonstrating all major features: |
| } | ||
| ``` | ||
|
|
||
| ## Best Practices |
Contributor
There was a problem hiding this comment.
Suggested change
| ## Best Practices | |
| ## Best practices |
|
|
||
| ## Best Practices | ||
|
|
||
| ### 1. Use Appropriate State Mutability |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 1. Use Appropriate State Mutability | |
| ### 1. Use appropriate state mutability |
| } | ||
| ``` | ||
|
|
||
| ### 2. Validate Inputs Early |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 2. Validate Inputs Early | |
| ### 2. Validate inputs early |
| } | ||
| ``` | ||
|
|
||
| ### 3. Use Custom Errors |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 3. Use Custom Errors | |
| ### 3. Use custom errors |
| } | ||
| ``` | ||
|
|
||
| ### 4. Emit Events for State Changes |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 4. Emit Events for State Changes | |
| ### 4. Emit events for state changes |
| } | ||
| ``` | ||
|
|
||
| ### 5. Access Control Patterns |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 5. Access Control Patterns | |
| ### 5. Access control patterns |
| } | ||
| ``` | ||
|
|
||
| ### 6. Gas-Efficient Storage Access |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 6. Gas-Efficient Storage Access | |
| ### 6. Gas-efficient storage access |
| } | ||
| ``` | ||
|
|
||
| ### 7. Check Effects Interactions Pattern |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 7. Check Effects Interactions Pattern | |
| ### 7. Check effects interactions pattern |
| } | ||
| ``` | ||
|
|
||
| ### 8. Use Type-Safe Interfaces for External Calls |
Contributor
There was a problem hiding this comment.
Suggested change
| ### 8. Use Type-Safe Interfaces for External Calls | |
| ### 8. Use type-safe interfaces for external calls |
| } | ||
| ``` | ||
|
|
||
| ## See Also |
Contributor
There was a problem hiding this comment.
Suggested change
| ## See Also | |
| ## See also |
| - [Primitives](./data-types/primitives.mdx) - Basic data types | ||
| - [Compound Types](./data-types/compound-types.mdx) - Arrays, structs, tuples | ||
| - [Storage Types](./data-types/storage.mdx) - Persistent storage | ||
| - [Global Variables and Functions](./global-variables-and-functions.mdx) - VM context methods |
Contributor
There was a problem hiding this comment.
Suggested change
| - [Global Variables and Functions](./global-variables-and-functions.mdx) - VM context methods | |
| - [Global Variables and Functions](./global-variables-and-functions.mdx): VM context methods |
|
|
||
| - [Primitives](./data-types/primitives.mdx) - Basic data types | ||
| - [Compound Types](./data-types/compound-types.mdx) - Arrays, structs, tuples | ||
| - [Storage Types](./data-types/storage.mdx) - Persistent storage |
Contributor
There was a problem hiding this comment.
Suggested change
| - [Storage Types](./data-types/storage.mdx) - Persistent storage | |
| - [Storage Types](./data-types/storage.mdx): Persistent storage |
| ## See Also | ||
|
|
||
| - [Primitives](./data-types/primitives.mdx) - Basic data types | ||
| - [Compound Types](./data-types/compound-types.mdx) - Arrays, structs, tuples |
Contributor
There was a problem hiding this comment.
Suggested change
| - [Compound Types](./data-types/compound-types.mdx) - Arrays, structs, tuples | |
| - [Compound Types](./data-types/compound-types.mdx): Arrays, structs, tuples |
|
|
||
| ## See Also | ||
|
|
||
| - [Primitives](./data-types/primitives.mdx) - Basic data types |
Contributor
There was a problem hiding this comment.
Suggested change
| - [Primitives](./data-types/primitives.mdx) - Basic data types | |
| - [Primitives](./data-types/primitives.mdx): Basic data types |
pete-vielhaber
approved these changes
Feb 17, 2026
Contributor
pete-vielhaber
left a comment
pete-vielhaber
left a comment
There was a problem hiding this comment.
Minor nits; should we use ETH or ether across the board? IIRC we do use both, just a thought we should make it consistent across a page.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.