Python API Reference

Python API Reference v1.9.1¶

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

Example:

result = detect_language_from_extension("value")

Parameters:

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

Example:

result = detect_language_from_path("value")

Parameters:

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

Example:

result = detect_language_from_content("value")

Parameters:

Returns: str | None

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

Example:

result = get_highlights_query("value")

Parameters:

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

Example:

result = get_injections_query("value")

Parameters:

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

Example:

result = get_locals_query("value")

Parameters:

Returns: str | None

get_tags_query()¶

Get the tags query for a language, if bundled.

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

Signature:

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

Example:

result = get_tags_query("value")

Parameters:

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

Example:

result = get_language("value")

Parameters:

Returns: Language

Errors: Raises Error.

get_parser()¶

Get a 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

Example:

result = get_parser("value")

Parameters:

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

Example:

result = detect_language("value")

Parameters:

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]

Example:

result = available_languages()

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

Example:

result = has_language("value")

Parameters:

Returns: bool

language_count()¶

Return the number of available languages.

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

Signature:

def language_count() -> int

Example:

result = language_count()

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

Example:

result = process("value", ProcessConfig())

Parameters:

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

Example:

init(PackConfig())

Parameters:

Returns: No return value.

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

Example:

configure(PackConfig())

Parameters:

Returns: No return value.

Errors: Raises Error.

download()¶

Download specific languages to the local cache.

Returns the number of requested languages available after the call. Already compiled or cached languages are included in the count.

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

Example:

result = download([])

Parameters:

Returns: int

Errors: Raises Error.

download_all()¶

Download all available languages from the remote manifest.

Downloads the platform bundle and extracts every library it contains. Languages that appear in the manifest but are absent from the bundle (e.g. grammars that failed to compile at release time) are silently skipped — they are not treated as an error.

Returns the total number of languages now available (statically compiled plus downloaded and cached).

Errors:

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

Signature:

def download_all() -> int

Example:

result = download_all()

Returns: int

Errors: Raises Error.

download_group()¶

Download every language in a named group (e.g. "web", "data").

Groups are defined in the remote manifest and let you ensure a curated set of related grammars in one call instead of listing each name to download(). Already-cached languages are skipped.

Returns the total number of languages now available (statically compiled plus downloaded and cached).

Errors:

Returns an error if the manifest cannot be fetched, the group is unknown, or any constituent language fails to download.

Signature:

def download_group(name: str) -> int

Example:

result = download_group("value")

Parameters:

Returns: int

Errors: Raises Error.

manifest_languages()¶

Return all language names available in the remote manifest (306).

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]

Example:

result = manifest_languages()

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]

Example:

result = downloaded_languages()

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

Example:

clean_cache()

Returns: No return value.

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

Example:

result = cache_dir()

Returns: str

Errors: Raises Error.

Types¶

ByteRange¶

A byte range — start (inclusive) to end (exclusive).

ChunkContext¶

Metadata for a single chunk of source code.

CodeChunk¶

A chunk of source code with rich metadata.

CommentInfo¶

A comment extracted from source code.

DataAttribute¶

An XML-style attribute attached to an Element node.

Populated only for DataNodeKind.Element; always empty for KeyValue and Sequence nodes.

DataNode¶

A node in the hierarchical data tree produced by data-format extraction.

When ProcessConfig.data_extraction is True, ProcessResult.data is populated with a root DataNode whose children mirror the structure of the parsed file.

The kind field determines which other fields are meaningful:

Diagnostic¶

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

DocSection¶

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

DocstringInfo¶

A docstring extracted from source code.

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

Example:

result = DownloadManager.new("value")

Parameters:

Returns: DownloadManager

Errors: Raises Error.

installed_languages()¶

List languages that are already downloaded and cached.

Signature:

def installed_languages(self) -> list[str]

Example:

result = instance.installed_languages()

Returns: list[str]

download_all_best_effort()¶

Download the platform bundle and extract every library file it contains.

Unlike Self.ensure_languages, this does not check the manifest language list against archive contents — it simply extracts all .so/.dylib/.dll files from the bundle. Languages in the manifest that are missing from the archive are silently ignored rather than returning an error.

Returns the number of library files extracted (including those already cached).

Signature:

def download_all_best_effort(self) -> int

Example:

result = instance.download_all_best_effort()

Returns: int

Errors: Raises Error.

clean_cache()¶

Remove all cached parser libraries.

Acquires the cross-process lock so clean_cache cannot race a concurrent downloader (avoids Windows sharing-violation errors against an in-flight bundle write). The .download.lock file itself is not removed — it is permanent infrastructure; deleting it could allow a concurrent process that already opened the file to continue holding a stale lock handle while a new process opens a fresh inode, breaking the mutual-exclusion guarantee.

Signature:

def clean_cache(self) -> None

Example:

instance.clean_cache()

Returns: No return value.

Errors: Raises Error.

ExportInfo¶

An export statement extracted from source code.

FileMetrics¶

Aggregate metrics for a source file.

ImportInfo¶

An import statement extracted from source code.

Language¶

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 (get_language, available_languages, etc.).

Methods¶

new()¶

Create a new registry populated with all statically compiled languages.

When the dynamic-loading feature is enabled, the registry also knows about dynamically loadable grammars and will load them on demand.

Signature:

@staticmethod
def new() -> LanguageRegistry

Example:

result = LanguageRegistry.new()

Returns: LanguageRegistry

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

Example:

result = instance.get_language("value")

Parameters:

Returns: Language

Errors: Raises Error.

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]

Example:

result = instance.available_languages()

Returns: list[str]

has_parser()¶

Check whether a parser is statically compiled into this build.

Returns True only when the grammar was compiled in at build time (i.e. it appears in the STATIC_LANGUAGES table). This is independent of the extension-to-language mapping: detect_language_from_extension consults the static ext table for all 306 grammars regardless of which parsers are compiled in.

Use this when you need to distinguish "we know the language name" from "we can actually parse files in that language right now".

use tree_sitter_language_pack::{detect_language_from_extension, LanguageRegistry};

let registry = LanguageRegistry::new();
// Extension detection uses the static table — independent of compiled parsers.
let lang = detect_language_from_extension("feature"); // always returns Some("gherkin")
// Parser availability depends on which grammars were compiled in.
let can_parse = lang.map(|name| registry.has_parser(name)).unwrap_or(false);

Signature:

def has_parser(self, name: str) -> bool

Example:

result = instance.has_parser("value")

Parameters:

Returns: bool

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

Example:

result = instance.has_language("value")

Parameters:

Returns: bool

language_count()¶

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

Signature:

def language_count(self) -> int

Example:

result = instance.language_count()

Returns: 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

Example:

result = instance.process("value", ProcessConfig())

Parameters:

Returns: ProcessResult

Errors: Raises Error.

default()¶

Signature:

@staticmethod
def default() -> LanguageRegistry

Example:

result = LanguageRegistry.default()

Returns: LanguageRegistry

Node¶

A single syntax node within a Tree.

Nodes hold a strong reference to their parent tree so they remain valid regardless of how the tree is moved or stored at the FFI boundary.

Methods¶

clone()¶

Signature:

def clone(self) -> Node

Example:

result = instance.clone()

Returns: Node

kind()¶

Return the node's kind name (e.g. "function_definition").

Signature:

def kind(self) -> str

Example:

result = instance.kind()

Returns: str

kind_id()¶

Return the node's numeric kind ID.

Tree-sitter assigns a stable u16 ID to every node kind in a grammar (e.g. "function_definition" → 42). Comparing kind_id() is cheaper than comparing the string kind() in tight AST loops.

Signature:

def kind_id(self) -> int

Example:

result = instance.kind_id()

Returns: int

start_byte()¶

Return the inclusive start byte offset of this node.

Signature:

def start_byte(self) -> int

Example:

result = instance.start_byte()

Returns: int

end_byte()¶

Return the exclusive end byte offset of this node.

Signature:

def end_byte(self) -> int

Example:

result = instance.end_byte()

Returns: int

byte_range()¶

Return the node's byte range as a ByteRange.

Callers should slice their own source bytes — this is a zero-copy text accessor.

Signature:

def byte_range(self) -> ByteRange

Example:

result = instance.byte_range()

Returns: ByteRange

start_position()¶

Return the start Point (row, column).

Signature:

def start_position(self) -> Point

Example:

result = instance.start_position()

Returns: Point

end_position()¶

Return the end Point (row, column).

Signature:

def end_position(self) -> Point

Example:

result = instance.end_position()

Returns: Point

is_named()¶

True when this node is named (not punctuation/whitespace).

Signature:

def is_named(self) -> bool

Example:

result = instance.is_named()

Returns: bool

is_error()¶

True when this is an error node.

Signature:

def is_error(self) -> bool

Example:

result = instance.is_error()

Returns: bool

is_missing()¶

True when this is a missing-token node.

Signature:

def is_missing(self) -> bool

Example:

result = instance.is_missing()

Returns: bool

is_extra()¶

True when this is an "extra" node (e.g. a comment).

Signature:

def is_extra(self) -> bool

Example:

result = instance.is_extra()

Returns: bool

has_error()¶

True when this node or any descendant is an error.

Signature:

def has_error(self) -> bool

Example:

result = instance.has_error()

Returns: bool

parent()¶

Return this node's parent, if any.

Signature:

def parent(self) -> Node | None

Example:

result = instance.parent()

Returns: Node | None

child()¶

Return the i-th child of this node, if any.

Signature:

def child(self, index: int) -> Node | None

Example:

result = instance.child(42)

Parameters:

Returns: Node | None

child_count()¶

Total number of children (including unnamed).

Signature:

def child_count(self) -> int

Example:

result = instance.child_count()

Returns: int

named_child()¶

Return the i-th named child of this node, if any.

Signature:

def named_child(self, index: int) -> Node | None

Example:

result = instance.named_child(42)

Parameters:

Returns: Node | None

named_child_count()¶

Number of named children of this node.

Signature:

def named_child_count(self) -> int

Example:

result = instance.named_child_count()

Returns: int

child_by_field_name()¶

Look up a child by its grammar-defined field name.

Signature:

def child_by_field_name(self, name: str) -> Node | None

Example:

result = instance.child_by_field_name("value")

Parameters:

Returns: Node | None

to_sexp()¶

Return the S-expression form of this node's subtree.

Signature:

def to_sexp(self) -> str

Example:

result = instance.to_sexp()

Returns: str

walk()¶

Return a TreeCursor positioned at this node.

Signature:

def walk(self) -> TreeCursor

Example:

result = instance.walk()

Returns: TreeCursor

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.

Parser¶

A tree-sitter parser configured for one language at a time.

Methods¶

new()¶

Construct a new parser with no language set.

Call Parser.set_language before parsing.

Signature:

@staticmethod
def new() -> Parser

Example:

result = Parser.new()

Returns: Parser

set_language()¶

Configure the parser to use the language identified by name (e.g. "python").

Resolves the language through the global registry — auto-downloading if necessary, when the download feature is enabled.

Errors:

Returns Error.LanguageNotFound if the language is not recognized, or Error.ParserSetup if the language ABI is incompatible.

Signature:

def set_language(self, name: str) -> None

Example:

instance.set_language("value")

Parameters:

Returns: No return value.

Errors: Raises Error.

parse()¶

Parse a UTF-8 source string. Returns None if parsing was cancelled or no language is set.

Signature:

def parse(self, source: str) -> Tree | None

Example:

result = instance.parse("value")

Parameters:

Returns: Tree | None

parse_bytes()¶

Parse a raw byte slice. Returns None if parsing was cancelled or no language is set.

Signature:

def parse_bytes(self, source: bytes) -> Tree | None

Example:

result = instance.parse_bytes(b"data")

Parameters:

Returns: Tree | None

reset()¶

Reset internal state. The next call to parse will not be incremental.

Signature:

def reset(self) -> None

Example:

instance.reset()

Returns: No return value.

default()¶

Signature:

@staticmethod
def default() -> Parser

Example:

result = Parser.default()

Returns: Parser

Point¶

A source position — row + column, zero-indexed.

ProcessConfig¶

Configuration for the process() function.

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

Methods¶

default()¶

Signature:

@staticmethod
def default() -> ProcessConfig

Example:

result = ProcessConfig.default()

Returns: ProcessConfig

with_chunking()¶

Enable chunking with the given maximum chunk size in bytes.

Signature:

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

Example:

result = instance.with_chunking(42)

Parameters:

Returns: ProcessConfig

all()¶

Enable all analysis features.

Signature:

def all(self) -> ProcessConfig

Example:

result = instance.all()

Returns: ProcessConfig

minimal()¶

Disable all analysis features (only metrics computed).

Signature:

def minimal(self) -> ProcessConfig

Example:

result = instance.minimal()

Returns: ProcessConfig

with_data_extraction()¶

Enable or disable hierarchical data extraction for data-format files.

When True, ProcessResult.data is populated with a key/value tree for supported data-format languages.

Signature:

def with_data_extraction(self, enabled: bool) -> ProcessConfig

Example:

result = instance.with_data_extraction(True)

Parameters:

Returns: 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 ProcessConfig flags.

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).

StructureItem¶

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

SymbolInfo¶

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

Tree¶

A parsed syntax tree. Cheap to clone (refcount bump).

Methods¶

root_node()¶

Return the root Node of this tree.

Signature:

def root_node(self) -> Node

Example:

result = instance.root_node()

Returns: Node

walk()¶

Return a TreeCursor positioned at the root.

Signature:

def walk(self) -> TreeCursor

Example:

result = instance.walk()

Returns: TreeCursor

TreeCursor¶

A cursor for traversing a Tree.

Methods¶

node()¶

Return the Node at the cursor's current position.

Signature:

def node(self) -> Node

Example:

result = instance.node()

Returns: Node

goto_first_child()¶

Move the cursor to the first child of the current node. Returns True if a child existed.

Signature:

def goto_first_child(self) -> bool

Example:

result = instance.goto_first_child()

Returns: bool

goto_parent()¶

Move the cursor to the parent of the current node. Returns True if a parent existed.

Signature:

def goto_parent(self) -> bool

Example:

result = instance.goto_parent()

Returns: bool

goto_next_sibling()¶

Move the cursor to the next sibling of the current node. Returns True if a sibling existed.

Signature:

def goto_next_sibling(self) -> bool

Example:

result = instance.goto_next_sibling()

Returns: bool

field_name()¶

Return the field name for the current node, if any.

Signature:

def field_name(self) -> str | None

Example:

result = instance.field_name()

Returns: str | None

Enums¶

DataNodeKind¶

The kind of a data node extracted from a data-format file.

Classifies each node in the hierarchical DataNode tree returned when data_extraction is enabled on ProcessConfig.

Wire format (public JSON contract)¶

Unit variants serialize as a bare string ("KeyValue"). DO NOT add #[serde(tag = "...")] or rename variants — every language binding has a hand-written deserializer matching this exact shape, and any change breaks all bindings' process() tests simultaneously. Covered by tests/wire_format.rs.

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.

Wire format (public JSON contract)¶

Unit variants serialize as a bare string ("Function"); the Other variant serializes as a single-keyed object ({"Other": "macro"}). DO NOT add #[serde(tag = "...")] or rename variants — every language binding has a hand-written deserializer matching this exact shape, and any change breaks all bindings' process() tests simultaneously. Covered by tests/wire_format.rs.

CommentKind¶

The kind of a comment found in source code.

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

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).

Wire format (public JSON contract)¶

Unit variants serialize as a bare string ("JSDoc"); the Other variant serializes as a single-keyed object ({"Other": "rst"}). DO NOT add #[serde(tag = "...")]. Covered by tests/wire_format.rs.

ExportKind¶

The kind of an export statement found in source code.

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

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.

Wire format (public JSON contract)¶

Unit variants serialize as a bare string ("Function"); the Other variant serializes as a single-keyed object ({"Other": "macro"}). DO NOT add #[serde(tag = "...")]. Covered by tests/wire_format.rs.

DiagnosticSeverity¶

Severity level of a diagnostic produced during parsing.

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

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)

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