# Syntactic Code Navigation

<TierCallout>
	Supported on [Enterprise](/pricing/plans/enterprise) plans.
	<user>
		This feature is currently in Beta and enabled by default for Cloud
		customers
	</user>
</TierCallout>

Syntactic code navigation is a zero configuration feature that improves code navigation for certain languages in the absence of
[Precise code navigation](./precise-code-navigation) set up. It works by periodically indexing repositories for which it is [enabled](#enabling-syntactic-code-navigation), using high level syntax analysis heuristics.

This mechanism is more robust than search-based navigation, but less powerful than Precise code navigation.
When syntactic indexing data is available for a given file and repository, it will be selected over search-based navigation automatically,
but only if Precise data is not available. To summarize, the order of priorities is as follows:

-   Precise data
-   Syntactic, if no precise data available
-   Search-based, if no syntactic available

## Enabling Syntactic code navigation

First, enable the experimental feature flag in Site config:

```json
  "experimentalFeatures.codeintelSyntacticIndexing.enabled": true
```

Next, you need to ensure that syntactic indexing is enabled in a code graph configuration policy. Note that for cloud customers this feature is enabled by default for all repositories, as part of
automatically managed policy called `[Sourcegraph Managed] Head of default branch policy`.

For all other deployments, you will need to create a HEAD policy with "Syntactic indexing" enabled:

![Screenshot of sourcegraph interface demonstrating Syntactic indexing toggle enabled for a code graph policy](https://storage.googleapis.com/sourcegraph-assets/Docs/syntactic-indexing-policy.png)

Syntactic indexing can only be enabled if the policy type is set to HEAD – only indexing the tip of default branch on each repository. You may choose to apply this policy only to selected repositories, although the recommendation is to enable it instance-wide.

## Supported languages

Syntactic code navigation requires language-specific implementations, and we currently support the following languages:

-   [Java](https://www.java.com/en/)
-   [Go](https://go.dev/)
-   [Scala](https://scala-lang.org)
-   [C#](https://learn.microsoft.com/en-us/dotnet/csharp/)
-   [C++](https://isocpp.org/)

We are constantly looking to expand the list of supported languages, with Python, Typescript/Javascript, and C planned.
If you are interested in syntactic indexing for these or any other languages, please contact your Sourcegraph account representative.

## Comparison with Precise and Search-based

Syntactic code navigation falls between Precise and Search-based code navigation both in terms of quality of navigation,
and in terms of effort to maintain for different languages:

![Comparison chart showing where different navigation modes are located in terms of effort to maintain and quality of results](https://storage.googleapis.com/sourcegraph-assets/Docs/code-navigation-levels-comparison.png)

As the indexing does not involve build tools or actual compilers, it can be performed in isolated environment, with no network access
and no configuration, unlike Precise.