# Rename a symbol across the repo in Axum with Atlas in 2026

> Atlas enables Axum developers to rename symbols across their codebase, leveraging `lsp` for precise references and `grep` for comprehensive coverage, all verified by `cargo nextest`.

In 2026, Axum developers can rename a function, class, or constant across their entire repository with Atlas, ensuring all references are updated and verified using `cargo nextest` and `rustfmt` for a robust refactoring experience.

## Key takeaways

- Atlas uses `lsp` to find true Axum symbol references, avoiding false positives.
- `grep` catches Axum-specific strings and comments outside the type system.
- The `edit` tool prevents ambiguous replacements in Axum code.
- `cargo nextest` verifies Axum refactors by running your test suite.
- `rustfmt` ensures consistent formatting after Axum symbol renames.
- Atlas provides unified diffs and git patches for safe Axum refactoring review and rollback.

## How Atlas renames Axum functions and constants across a repository

Atlas renames Axum symbols by combining precise language server protocol (LSP) data with robust keyword search, ensuring 100% accuracy. In 2026, this hybrid approach prevents the common pitfalls of naive find-and-replace, especially for complex `Router` configurations or `State` types.

Atlas orchestrates a sophisticated symbol renaming workflow for Axum projects. It begins by utilizing the `lsp` tool's `findReferences` operation, which queries the language server to obtain the authoritative set of references for the target symbol. This is crucial for Axum, where handler functions, `State` types, and `tower` layers can have complex interdependencies that a simple text search would miss or incorrectly match. Following this, Atlas runs `grep` for the old symbol name to catch occurrences outside the type system, such as string literals, comments, or documentation within `src/` files or `Cargo.toml`. Finally, the `edit` tool applies the mechanical renames using `replaceAll`. A key safety feature is that `edit` refuses ambiguous single replacements, meaning an unintended match results in an error rather than silent corruption of your Axum codebase.

## What are the concrete Atlas commands for renaming Axum symbols?

To rename an Axum symbol, Atlas orchestrates a sequence of 3 core tools: `lsp`, `grep`, and `edit`. This process begins by identifying the symbol's true references, often within a `src/main.rs` or `src/lib.rs` file, before applying changes and verifying them.

The concrete commands for renaming an Axum symbol with Atlas are straightforward and leverage the agent's integrated toolset. First, you would instruct Atlas to find all references to your old symbol, for example, an Axum handler function named `old_handler_name`:
`atlas lsp findReferences old_handler_name`
Next, to ensure comprehensive coverage beyond compiler-visible code, you'd use `grep`:
`atlas grep old_handler_name`
Once the references are identified and reviewed, Atlas applies the mechanical changes. If you're renaming `old_handler_name` to `new_handler_name`:
`atlas edit replaceAll old_handler_name new_handler_name`
Atlas will then present a unified diff for your approval before writing any changes to files within your Axum crate, such as `src/main.rs`, `src/lib.rs`, or even `Cargo.toml` if the symbol is a package name or feature.

## How does Atlas ensure safety and review for Axum symbol renames?

Atlas ensures safety in Axum symbol renames through a multi-stage approval process, including a read-only plan agent and a unified diff for every file edit. This prevents unintended changes, offering 2 distinct points of review before any code is written to disk.

Safety and review are paramount when refactoring an Axum codebase, and Atlas incorporates several mechanisms to protect your code. Every Atlas tool call is permission-gated, allowing you to set `allow`, `ask`, or `deny` rules before execution. Atlas drafts a plan in a read-only plan agent, asking for your approval before switching to a build agent that can modify files. For every proposed file edit, Atlas computes a unified diff and surfaces it for your explicit approval, giving you granular control over changes to your Axum handlers, `Router` definitions, or `State` types. Furthermore, Atlas snapshots file changes as git patches, meaning any edits can be easily diffed and rolled back if an issue is discovered, providing a robust safety net for complex refactors.

## How to verify Axum symbol renames with `cargo nextest` and `rustfmt`

After Atlas performs a symbol rename in an Axum project, verification is crucial and involves running `cargo nextest run` to catch any runtime regressions. Additionally, `rustfmt` ensures the updated code adheres to 1 consistent style, preventing formatting changes from obscuring the refactor.

Post-refactoring verification is a critical step in the Axum symbol rename workflow. Atlas allows you to execute your existing Axum toolchain commands directly. First, to ensure the renamed symbol hasn't broken any functionality, you'll run your test suite:
`atlas bash "cargo nextest run"`
This command leverages `cargo nextest`, the standard test runner for Rust projects, to thoroughly check your Axum application's behavior. Next, to confirm no lingering instances of the old symbol remain, a final `grep` is performed:
`atlas bash "grep -r <OldFunctionName> ."`
Finally, to maintain code consistency and prevent formatting changes from being mixed with the refactor, you'll run the Rust formatter:
`atlas bash "rustfmt src/"`
This ensures your Axum codebase remains clean and adheres to `rustfmt` standards after the rename.

## Steps

1. Run `atlas lsp findReferences <OldFunctionName>` to get the authoritative callsite list for your Axum symbol from the language server, understanding its usage in `Router` and `State`.
2. Execute `atlas grep <OldFunctionName>` to catch occurrences outside the type system, such as strings, comments, or documentation within your Axum project files.
3. Apply the mechanical renames with `atlas edit replaceAll <OldFunctionName> <NewFunctionName>`, ensuring Atlas's `edit` tool handles the replacement precisely and refuses ambiguous matches.
4. Compile and test your Axum application by running `atlas bash "cargo nextest run"` to immediately catch any functional regressions introduced by the symbol rename.
5. Format your Axum codebase with `atlas bash "rustfmt src/"` to ensure all modified files adhere to the standard Rust formatting, maintaining code consistency.
6. Perform a final verification with `atlas bash "grep -r <OldFunctionName> ."` across the entire repository to confirm that zero instances of the old symbol name remain.

## FAQ

### How does Atlas handle renaming Axum handler functions?

Atlas uses the `lsp` tool's `findReferences` to precisely locate all callsites and declarations of your Axum handler function, including those within `Router` definitions, before applying the rename.

### Can Atlas rename an Axum `State` type safely?

Yes, Atlas can safely rename an Axum `State` type. It leverages AST declarations via tree-sitter and LSP data to ensure all references, including those in `Router` layers and handler signatures, are correctly updated.

### What if my Axum project uses custom `tower` layers? Will Atlas rename symbols there?

Atlas's `lsp` tool integrates with the language server to understand your entire Axum project, including custom `tower` layers. It will identify and rename symbols within these layers as part of the refactoring process.

### How does Atlas prevent accidental renames in Axum comments or strings?

Atlas uses `lsp` for code references and `grep` for non-code occurrences. The `edit` tool refuses ambiguous single replacements, requiring explicit `replaceAll` or context to prevent unintended changes in comments or string literals.

### Does Atlas integrate with `cargo nextest` for Axum test verification?

Yes, Atlas integrates with `cargo nextest`. After a rename, you can use `atlas bash "cargo nextest run"` to execute your Axum test suite, ensuring the refactor hasn't introduced any regressions.

### Is it possible to roll back an Axum symbol rename done by Atlas?

Yes, Atlas snapshots file changes as git patches. This allows you to easily diff and roll back any edits made during an Axum symbol rename, providing a safety net for complex refactors.

### Can Atlas rename a constant used in an Axum `Router` configuration?

Absolutely. Atlas's hybrid semantic and keyword retrieval, combined with LSP data, ensures that constants used in Axum `Router` configurations, `Extractor` implementations, or anywhere else, are accurately identified and renamed.

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Canonical HTML: https://runatlas.sh/resources/stacks/rename-a-symbol-across-the-repo-in-axum
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Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.
