Skip to content

Python API Reference

Python API Reference v1.8.0-rc.26

Functions

detect_language_from_extension()

Detect language name from a file extension (without leading dot).

Returns None for unrecognized extensions. The match is case-insensitive.

Signature:

def detect_language_from_extension(ext: str) -> str | None

Parameters:

Name Type Required Description
ext str Yes The ext

Returns: str | None


detect_language_from_path()

Detect language name from a file path.

Extracts the file extension and looks it up. Returns None if the path has no extension or the extension is not recognized.

Signature:

def detect_language_from_path(path: str) -> str | None

Parameters:

Name Type Required Description
path str Yes Path to the file

Returns: str | None


detect_language_from_content()

Detect language name from file content using the shebang line (#!).

Inspects only the first line of content. If it begins with #!, the interpreter name is extracted and mapped to a language name.

Handles common patterns:

  • #!/usr/bin/env python3"python"
  • #!/bin/bash"bash"
  • #!/usr/bin/env node"javascript"

The -S flag accepted by some env implementations is skipped automatically. Version suffixes (e.g. python3.11, ruby3.2) are stripped before matching.

Returns None when content does not start with #!, the shebang is malformed, or the interpreter is not recognised.

Signature:

def detect_language_from_content(content: str) -> str | None

Parameters:

Name Type Required Description
content str Yes The content to process

Returns: str | None


parse_string()

Parse source code with the named language, returning the syntax tree.

Uses the global registry to look up the language by name. Caches parsers per-thread so repeated calls for the same language avoid re-creating the parser.

Signature:

def parse_string(language: str, source: bytes) -> Tree

Parameters:

Name Type Required Description
language str Yes The language
source bytes Yes The source

Returns: Tree

Errors: Raises Error.


get_highlights_query()

Get the highlights query for a language, if bundled.

Returns the contents of highlights.scm as a static string, or None if no highlights query is bundled for this language.

Signature:

def get_highlights_query(language: str) -> str | None

Parameters:

Name Type Required Description
language str Yes The language

Returns: str | None


get_injections_query()

Get the injections query for a language, if bundled.

Returns the contents of injections.scm as a static string, or None if no injections query is bundled for this language.

Signature:

def get_injections_query(language: str) -> str | None

Parameters:

Name Type Required Description
language str Yes The language

Returns: str | None


get_locals_query()

Get the locals query for a language, if bundled.

Returns the contents of locals.scm as a static string, or None if no locals query is bundled for this language.

Signature:

def get_locals_query(language: str) -> str | None

Parameters:

Name Type Required Description
language str Yes The language

Returns: str | None


get_language()

Get a tree-sitter Language by name using the global registry.

Resolves language aliases (e.g., "shell" maps to "bash"). When the download feature is enabled (default), automatically downloads the parser from GitHub releases if not found locally.

Errors:

Returns Error.LanguageNotFound if the language is not recognized, or Error.Download if auto-download fails.

Signature:

def get_language(name: str) -> Language

Parameters:

Name Type Required Description
name str Yes The name

Returns: Language

Errors: Raises Error.


get_parser()

Get a tree-sitter Parser pre-configured for the given language.

This is a convenience function that calls get_language and configures a new parser in one step.

Errors:

Returns Error.LanguageNotFound if the language is not recognized, or Error.ParserSetup if the language cannot be applied to the parser.

Signature:

def get_parser(name: str) -> Parser

Parameters:

Name Type Required Description
name str Yes The name

Returns: Parser

Errors: Raises Error.


detect_language()

Detect language name from a file path or extension.

This compatibility alias matches the pre-Alef Python binding API.

Signature:

def detect_language(path: str) -> str | None

Parameters:

Name Type Required Description
path str Yes Path to the file

Returns: str | None


available_languages()

List all available language names (sorted, deduplicated, includes aliases).

Returns names of both statically compiled and dynamically loadable languages, plus any configured aliases.

Signature:

def available_languages() -> list[str]

Returns: list[str]


has_language()

Check if a language is available by name or alias.

Returns True if the language can be loaded (statically compiled, dynamically available, or a known alias for one of these).

Signature:

def has_language(name: str) -> bool

Parameters:

Name Type Required Description
name str Yes The name

Returns: bool


language_count()

Return the number of available languages.

Includes statically compiled languages, dynamically loadable languages, and aliases.

Signature:

def language_count() -> int

Returns: int


process()

Process source code and extract file intelligence using the global registry.

Parses the source with tree-sitter and extracts metrics, structure, imports, exports, comments, docstrings, symbols, diagnostics, and/or chunks based on the flags set in ProcessConfig.

Errors:

Returns an error if the language is not found or parsing fails.

Signature:

def process(source: str, config: ProcessConfig) -> ProcessResult

Parameters:

Name Type Required Description
source str Yes The source
config ProcessConfig Yes The configuration options

Returns: ProcessResult

Errors: Raises Error.


init()

Initialize the language pack with the given configuration.

Applies any custom cache directory, then downloads all languages and groups specified in the config. This is the recommended entry point when you want to pre-warm the cache before use.

Errors:

Returns an error if configuration cannot be applied or if downloads fail.

Signature:

def init(config: PackConfig) -> None

Parameters:

Name Type Required Description
config PackConfig Yes The configuration options

Returns: None

Errors: Raises Error.


configure()

Apply download configuration without downloading anything.

Use this to set a custom cache directory before the first call to get_language or any download function. Changing the cache dir after languages have been registered has no effect on already-loaded languages.

Errors:

Returns an error if the lock cannot be acquired.

Signature:

def configure(config: PackConfig) -> None

Parameters:

Name Type Required Description
config PackConfig Yes The configuration options

Returns: None

Errors: Raises Error.


download()

Download specific languages to the local cache.

Returns the number of newly downloaded languages (languages that were already cached are not counted).

Errors:

Returns an error if any language is not available in the manifest or if the download fails.

Signature:

def download(names: list[str]) -> int

Parameters:

Name Type Required Description
names list[str] Yes The names

Returns: int

Errors: Raises Error.


download_all()

Download all available languages from the remote manifest.

Returns the number of newly downloaded languages.

Errors:

Returns an error if the manifest cannot be fetched or a download fails.

Signature:

def download_all() -> int

Returns: int

Errors: Raises Error.


manifest_languages()

Return all language names available in the remote manifest (305).

Fetches (and caches) the remote manifest to discover the full list of downloadable languages. Use downloaded_languages to list what is already cached locally.

Errors:

Returns an error if the manifest cannot be fetched.

Signature:

def manifest_languages() -> list[str]

Returns: list[str]

Errors: Raises Error.


downloaded_languages()

Return languages that are already downloaded and cached locally.

Does not perform any network requests. Returns an empty list if the cache directory does not exist or cannot be read.

Signature:

def downloaded_languages() -> list[str]

Returns: list[str]


clean_cache()

Delete all cached parser shared libraries.

Resets the cache registration so the next call to get_language or a download function will re-register the (now empty) cache directory.

Errors:

Returns an error if the cache directory cannot be removed.

Signature:

def clean_cache() -> None

Returns: None

Errors: Raises Error.


cache_dir()

Return the effective cache directory path.

This is either the custom path set via configure / init or the default: ~/.cache/tree-sitter-language-pack/v{version}/libs/.

Errors:

Returns an error if the system cache directory cannot be determined.

Signature:

def cache_dir() -> str

Returns: str

Errors: Raises Error.


Types

ChunkContext

Metadata for a single chunk of source code.

Field Type Default Description
language str Language
chunk_index int Chunk index
total_chunks int Total chunks
node_types list[str] [] Node types
context_path list[str] [] Context path
symbols_defined list[str] [] Symbols defined
comments list[CommentInfo] [] Comments
docstrings list[DocstringInfo] [] Docstrings
has_error_nodes bool Whether error nodes

CodeChunk

A chunk of source code with rich metadata.

Field Type Default Description
content str The extracted text content
start_byte int Start byte
end_byte int End byte
start_line int Start line
end_line int End line
metadata ChunkContext Document metadata

CommentInfo

A comment extracted from source code.

Field Type Default Description
text str Text
kind CommentKind CommentKind.LINE Kind (comment kind)
span Span Span (span)
associated_node str | None None Associated node

Diagnostic

A diagnostic (syntax error, missing node, etc.) from parsing.

Field Type Default Description
message str Message
severity DiagnosticSeverity DiagnosticSeverity.ERROR Severity (diagnostic severity)
span Span Span (span)

DocSection

A section within a docstring (e.g., Args, Returns, Raises).

Field Type Default Description
kind str Kind
name str | None None The name
description str Human-readable description

DocstringInfo

A docstring extracted from source code.

Field Type Default Description
text str Text
format DocstringFormat DocstringFormat.PYTHON_TRIPLE_QUOTE Format (docstring format)
span Span Span (span)
associated_item str | None None Associated item
parsed_sections list[DocSection] [] Parsed sections

DownloadManager

Manages downloading and caching of pre-built parser shared libraries.

Methods
new()

Create a new download manager for the given version.

Signature:

@staticmethod
def new(version: str) -> DownloadManager
with_cache_dir()

Create a download manager with a custom cache directory.

Signature:

@staticmethod
def with_cache_dir(version: str, cache_dir: str) -> DownloadManager
default_cache_dir()

Default cache directory: ~/.cache/tree-sitter-language-pack/v{version}/libs/

Signature:

@staticmethod
def default_cache_dir(version: str) -> str
cache_dir()

Return the path to the libs cache directory.

Signature:

def cache_dir(self) -> str
installed_languages()

List languages that are already downloaded and cached.

Signature:

def installed_languages(self) -> list[str]
ensure_languages()

Ensure the specified languages are available in the cache. Downloads the platform bundle if any requested languages are missing.

Signature:

def ensure_languages(self, names: list[str]) -> None
ensure_group()

Ensure all languages in a named group are available.

Signature:

def ensure_group(self, group: str) -> None
lib_path()

Get the expected path for a language's shared library in the cache.

Signature:

def lib_path(self, name: str) -> str
fetch_manifest()

Fetch the parser manifest from GitHub Releases.

Signature:

def fetch_manifest(self) -> ParserManifest
clean_cache()

Remove all cached parser libraries.

Signature:

def clean_cache(self) -> None

ExportInfo

An export statement extracted from source code.

Field Type Default Description
name str The name
kind ExportKind ExportKind.NAMED Kind (export kind)
span Span Span (span)

FileMetrics

Aggregate metrics for a source file.

Field Type Default Description
total_lines int Total lines
code_lines int Code lines
comment_lines int Comment lines
blank_lines int Blank lines
total_bytes int Total bytes
node_count int Number of nodes
error_count int Number of errors
max_depth int Maximum depth

ImportInfo

An import statement extracted from source code.

Field Type Default Description
source str Source
items list[str] [] Items
alias str | None None Alias
is_wildcard bool Whether wildcard
span Span Span (span)

Language


LanguageInfo

Field Type Default Description
group str Group
size int Size in bytes

LanguageRegistry

Thread-safe registry of tree-sitter language parsers.

Manages both statically compiled and dynamically loaded language grammars. Use LanguageRegistry.new() for the default registry, or access the global instance via the module-level convenience functions (crate.get_language, crate.available_languages, etc.).

Methods
with_libs_dir()

Create a registry with a custom directory for dynamic libraries.

Overrides the default build-time library directory. Useful when dynamic grammar shared libraries are stored in a non-standard location.

Signature:

@staticmethod
def with_libs_dir(libs_dir: str) -> LanguageRegistry
add_extra_libs_dir()

Add an additional directory to search for dynamic libraries.

When get_language cannot find a grammar in the primary library directory, it searches these extra directories in order. Typically used by the download system to register its cache directory.

Takes &self (not &mut self) because extra_lib_dirs uses interior mutability via an Arc<RwLock<...>>, so the outer registry can remain immutable while the directory list is updated.

Signature:

def add_extra_libs_dir(self, dir: str) -> None
get_language()

Get a tree-sitter Language by name.

Resolves aliases (e.g., "shell" -> "bash", "makefile" -> "make"), then looks up the language in the static table. When the dynamic-loading feature is enabled, falls back to loading a shared library on demand.

Errors:

Returns Error.LanguageNotFound if the name (after alias resolution) does not match any known grammar.

Signature:

def get_language(self, name: str) -> Language
available_languages()

List all available language names, sorted and deduplicated.

Includes statically compiled languages, dynamically loadable languages (if the dynamic-loading feature is enabled), and all configured aliases.

Signature:

def available_languages(self) -> list[str]
has_language()

Check whether a language is available by name or alias.

Returns True if the language can be loaded, either from the static table or from a dynamic library on disk.

Signature:

def has_language(self, name: str) -> bool
language_count()

Return the total number of available languages (including aliases).

Signature:

def language_count(self) -> int
process()

Parse source code and extract file intelligence based on config in a single pass.

Signature:

def process(self, source: str, config: ProcessConfig) -> ProcessResult
default()

Signature:

@staticmethod
def default() -> LanguageRegistry

PackConfig

Configuration for the tree-sitter language pack.

Controls cache directory and which languages to pre-download. Can be loaded from a TOML file, constructed programmatically, or passed as a dict/object from language bindings.

Field Type Default Description
cache_dir str | None None Override default cache directory. Default: ~/.cache/tree-sitter-language-pack/v{version}/libs/
languages list[str] | None [] Languages to pre-download on init. Each entry is a language name (e.g. "python", "rust").
groups list[str] | None [] Language groups to pre-download (e.g. "web", "systems", "scripting").
Methods
from_toml_file()

Load configuration from a TOML file.

Errors:

Returns an error if the file cannot be read or the TOML is invalid.

Signature:

@staticmethod
def from_toml_file(path: str) -> PackConfig
discover()

Discover configuration by searching for language-pack.toml in:

  1. Current directory and up to 10 parent directories
  2. $XDG_CONFIG_HOME/tree-sitter-language-pack/config.toml
  3. ~/.config/tree-sitter-language-pack/config.toml

Returns None if no configuration file is found.

Signature:

@staticmethod
def discover() -> PackConfig | None

Parser


ParserManifest

Manifest describing available parser downloads for a specific version.

Field Type Default Description
version str Version string
platforms dict[str, PlatformBundle] Platforms
languages dict[str, LanguageInfo] Languages
groups dict[str, list[str]] Groups

PlatformBundle

Field Type Default Description
url str Url
sha256 str Sha256
size int Size in bytes

ProcessConfig

Configuration for the process() function.

Controls which analysis features are enabled and whether chunking is performed.

Field Type Default Description
language str Language name (required).
structure bool True Extract structural items (functions, classes, etc.). Default: true.
imports bool True Extract import statements. Default: true.
exports bool True Extract export statements. Default: true.
comments bool False Extract comments. Default: false.
docstrings bool False Extract docstrings. Default: false.
symbols bool False Extract symbol definitions. Default: false.
diagnostics bool False Include parse diagnostics. Default: false.
chunk_max_size int | None None Maximum chunk size in bytes. None disables chunking.
Methods
default()

Signature:

@staticmethod
def default() -> ProcessConfig
with_chunking()

Enable chunking with the given maximum chunk size in bytes.

Signature:

def with_chunking(self, max_size: int) -> ProcessConfig
all()

Enable all analysis features.

Signature:

def all(self) -> ProcessConfig
minimal()

Disable all analysis features (only metrics computed).

Signature:

def minimal(self) -> ProcessConfig

ProcessResult

Complete analysis result from processing a source file.

Contains metrics, structural analysis, imports/exports, comments, docstrings, symbols, diagnostics, and optionally chunked code segments. Fields are populated based on the crate.ProcessConfig flags.

Field Type Default Description
language str Language
metrics FileMetrics Metrics (file metrics)
structure list[StructureItem] [] Structure
imports list[ImportInfo] [] Imports
exports list[ExportInfo] [] Exports
comments list[CommentInfo] [] Comments
docstrings list[DocstringInfo] [] Docstrings
symbols list[SymbolInfo] [] Symbols
diagnostics list[Diagnostic] [] Diagnostics
chunks list[CodeChunk] [] Text chunks for chunking/embedding

Span

Byte and line/column range in source code.

Represents both byte offsets (for slicing) and human-readable line/column positions (for display and diagnostics).

Field Type Default Description
start_byte int Start byte
end_byte int End byte
start_line int Start line
start_column int Start column
end_line int End line
end_column int End column

StructureItem

A structural item (function, class, struct, etc.) in source code.

Field Type Default Description
kind StructureKind StructureKind.FUNCTION Kind (structure kind)
name str | None None The name
visibility str | None None Visibility
span Span Span (span)
children list[StructureItem] [] Children
decorators list[str] [] Decorators
doc_comment str | None None Doc comment
signature str | None None Signature
body_span Span | None None Body span (span)

SymbolInfo

A symbol (variable, function, type, etc.) extracted from source code.

Field Type Default Description
name str The name
kind SymbolKind SymbolKind.VARIABLE Kind (symbol kind)
span Span Span (span)
type_annotation str | None None Type annotation
doc str | None None Doc

Tree


Enums

StructureKind

The kind of structural item found in source code.

Categorizes top-level and nested declarations such as functions, classes, structs, enums, traits, and more. Use Other for language-specific constructs that do not fit a standard category.

Value Description
FUNCTION Function
METHOD Method
CLASS Class
STRUCT Struct
INTERFACE Interface
ENUM Enum
MODULE Module
TRAIT Trait
IMPL Impl
NAMESPACE Namespace
OTHER Other — Fields: 0: str

CommentKind

The kind of a comment found in source code.

Distinguishes between single-line comments, block (multi-line) comments, and documentation comments.

Value Description
LINE Line
BLOCK Block
DOC Doc

DocstringFormat

The format of a docstring extracted from source code.

Identifies the docstring convention used, which varies by language (e.g., Python triple-quoted strings, JSDoc, Rustdoc /// comments).

Value Description
PYTHON_TRIPLE_QUOTE Python triple quote
JS_DOC J s doc
RUSTDOC Rustdoc
GO_DOC Go doc
JAVA_DOC Java doc
OTHER Other — Fields: 0: str

ExportKind

The kind of an export statement found in source code.

Covers named exports, default exports, and re-exports from other modules.

Value Description
NAMED Named
DEFAULT Default
RE_EXPORT Re export

SymbolKind

The kind of a symbol definition found in source code.

Categorizes symbol definitions such as variables, constants, functions, classes, types, interfaces, enums, and modules.

Value Description
VARIABLE Variable
CONSTANT Constant
FUNCTION Function
CLASS Class
TYPE Type
INTERFACE Interface
ENUM Enum
MODULE Module
OTHER Other — Fields: 0: str

DiagnosticSeverity

Severity level of a diagnostic produced during parsing.

Used to classify parse errors, warnings, and informational messages found in the syntax tree.

Value Description
ERROR Error
WARNING Warning
INFO Info

Errors

Error

Errors that can occur when using the tree-sitter language pack.

Covers language lookup failures, parse errors, query errors, and I/O issues. Feature-gated variants are included when config, download, or related features are enabled.

Base class: Error(Exception)

Exception Description
LanguageNotFound(Error) Language '{0}' not found
DynamicLoad(Error) Dynamic library load error:
NullLanguagePointer(Error) Language function returned null pointer for '{0}'
ParserSetup(Error) Failed to set parser language:
LockPoisoned(Error) Registry lock poisoned:
Config(Error) Configuration error:
ParseFailed(Error) Parse failed: parsing returned no tree
QueryError(Error) Query error:
InvalidRange(Error) Invalid byte range:
Io(Error) IO error: