SpeechMarkdown Rust

High-performance SpeechMarkdown parser written in Rust. Converts SpeechMarkdown syntax to platform-specific SSML for Amazon Alexa, Google Assistant, Microsoft Azure, and more.

Repository Structure

This repository contains the core Rust SpeechMarkdown parser with bindings for multiple languages:

speechmarkdown-rust/
├── src/                      # Core Rust library (language-agnostic)
├── bindings/                 # Language-specific bindings
│   ├── python/               # Python bindings via PyO3
│   ├── nodejs/               # Node.js bindings via napi-rs
│   ├── dotnet/               # .NET bindings via rust-cpp
│   └── swift/                # Swift bindings via C API + SPM
├── Package.swift             # Swift Package Manager configuration (Swift-only)
├── build-swift-package.sh    # Swift package build script (Swift-only)
└── Cargo.toml                # Rust package configuration

Important Notes for Non-Swift Users:

• Swift-specific files are ignored by other build systems: Package.swift, build-swift-package.sh, and swift-package-dist/ are only used by Swift Package Manager. They do not affect Rust, Python, Node.js, or .NET builds.
• Core Rust library unchanged: The src/ directory and Cargo.toml remain the single source of truth for the SpeechMarkdown parser across all languages.
• Isolated language bindings: Each language in bindings/ has its own build configuration and doesn't interfere with others.

For Rust/.NET/Python/Node.js Developers: You can safely ignore Swift-specific files. Your respective package managers (Cargo, NuGet, PyPI, npm) only use the core library and your language's binding directory.

Install

| Language | Package | Install | |----------|---------|---------| | Rust | speechmarkdown-rust | cargo add speechmarkdown-rust | | Python | speechmarkdown-rust | pip install speechmarkdown-rust | | Node.js | speechmarkdown | npm install speechmarkdown | | .NET | SpeechMarkdown | dotnet add package SpeechMarkdown | | Swift | Release asset | See Swift section below |

Supported Platforms

| Platform | String ID | |----------|-----------| | Amazon Alexa | "amazon-alexa" or "alexa" | | Google Assistant | "google-assistant" or "google" | | Microsoft Azure | "microsoft-azure" or "azure" | | Apple | "apple" | | W3C | "w3c" | | Samsung Bixby | "samsung-bixby" or "bixby" | | ElevenLabs (pre-v3) | "elevenlabs" | | ElevenLabs v3 | "elevenlabs-v3" | | IBM Watson | "ibm-watson" or "watson" |

ElevenLabs note

ElevenLabs does not parse SSML documents, so both ElevenLabs platforms emit prompt markup rather than SSML, and the correct dialect depends on the model:

• "elevenlabs" — pre-v3 models (eleven_multilingual_v2, eleven_flash_v2_5, eleven_flash_v2, eleven_turbo_v2): <break time="x.xs"/> pauses (max 3s) and <phoneme> for IPA (flash/turbo, English only). No <speak> wrapper.
• "elevenlabs-v3" — eleven_v3 / eleven_v3_conversational: bracketed natural-language audio tags ([whispers], [excited], [pause], [long pause], [laughs]), punctuation pauses, and native "/IPA/". Audio tags are model-interpreted direction — best-effort, voice-dependent — and are not understood by pre-v3 models.

API

All bindings expose the same core methods:

| Method | Returns | Description | |--------|---------|-------------| | to_ssml(input, platform) | string | Convert SpeechMarkdown to SSML for the given platform | | to_text(input) | string | Convert SpeechMarkdown to plain text (strips all markup) | | to_smd(ssml) | string | Convert SSML to SpeechMarkdown (best-effort, lossy for unsupported elements) | | parse(input) | string (JSON) | Parse SpeechMarkdown and return the AST as JSON | | is_speech_markdown(input) | bool | Check if a string contains SpeechMarkdown syntax | | validate(input) | bool | Validate that SpeechMarkdown parses without errors | | supported_ssml(platform) | string (JSON) | Get supported SSML elements for a platform |

Usage

Rust

use speechmarkdown_rust::{SpeechMarkdownParser, Platform};

// Convert to SSML
let ssml = SpeechMarkdownParser::to_ssml(
    "Hello (world)[emphasis:\"strong\"]",
    Platform::AmazonAlexa,
)?;

// Convert to plain text
let text = SpeechMarkdownParser::to_text("Hello (world)[emphasis:\"strong\"]")?;

// Parse to AST (JSON string)
let ast = SpeechMarkdownParser::parse("Hello world")?;

// Check if input contains SpeechMarkdown syntax
if SpeechMarkdownParser::is_speech_markdown(&input) {
    // ...
}

// Validate input
SpeechMarkdownParser::validate(&input)?;

// Convert SSML back to SpeechMarkdown (best-effort)
let smd = SpeechMarkdownParser::to_smd(r#"<speak><emphasis level="strong">word</emphasis></speak>"#)?;
// Returns: ++word++

Python

from speechmarkdown_rust import to_ssml, to_text, parse, is_speech_markdown, validate

ssml = to_ssml('Hello (world)[emphasis:"strong"]', 'amazon-alexa')
text = to_text('Hello (world)[emphasis:"strong"]')
ast = parse('Hello world')

is_smd = is_speech_markdown('Hello (world)[emphasis:"strong"]')  # True
is_smd = is_speech_markdown('Hello world')                       # False

validate('Hello (world)[emphasis:"strong"]')  # raises ValueError if invalid

# Convert SSML to SpeechMarkdown (best-effort)
smd = to_smd('<speak><emphasis level="strong">word</emphasis></speak>')
# Returns: ++word++

Node.js

const { to_ssml, to_text, parse, is_speech_markdown, validate } = require('speechmarkdown')

const ssml = to_ssml('Hello (world)[emphasis:"strong"]', 'amazon-alexa')
const text = to_text('Hello (world)[emphasis:"strong"]')
const ast = parse('Hello world')

is_speech_markdown('Hello (world)[emphasis:"strong"]')  // true
is_speech_markdown('Hello world')                       // false

validate('Hello (world)[emphasis:"strong"]')  // throws if invalid

// Convert SSML to SpeechMarkdown (best-effort)
const smd = to_smd('<speak><emphasis level="strong">word</emphasis></speak>')
// Returns: ++word++

.NET (C#)

using SpeechMarkdown;

var parser = new SpeechMarkdownParser();

string ssml = parser.ToSsml("Hello (world)[emphasis:\"strong\"]", Platform.AmazonAlexa);
string text = parser.ToText("Hello (world)[emphasis:\"strong\"]");
string json = parser.ParseToJson("Hello world");

bool isSmd = parser.IsSpeechMarkdown("Hello (world)[emphasis:\"strong\"]"); // true
parser.Validate("Hello (world)[emphasis:\"strong\"]"); // throws on invalid

// Convert SSML to SpeechMarkdown (best-effort)
string smd = parser.ToSmd("<speak><emphasis level=\"strong\">word</emphasis></speak>");
// Returns: ++word++

Swift

The repo root contains a Package.swift with a binary target pointing to a pre-built XCFramework. This enables both local development and Swift Package Index integration.

Option 1 — SPM (recommended):

// In your Package.swift:
.package(url: "https://github.com/AACTools/speechmarkdown-rust", branch: "spm")

Option 2 — Local package: Download speechmarkdown-swift-package.zip from the latest release, unzip, and add as a local package in Xcode (File > Add Packages > Add Local).

Includes macOS (arm64 + x86_64), iOS device (arm64), and iOS simulator (arm64) slices.

To build from source: ./build-swift-package.sh

import SpeechMarkdown

let parser = SpeechMarkdownParser()

let ssml = try parser.toSsml(input: "Hello (world)[emphasis:\"strong\"]", platform: "amazon-alexa")
let text = try parser.toText(input: "Hello (world)[emphasis:\"strong\"]")
let json = try parser.parseToJson(input: "Hello world")

let isSmd = parser.isSpeechMarkdown(input: "Hello (world)[emphasis:\"strong\"]") // true
try parser.validate(input: "Hello (world)[emphasis:\"strong\"]") // throws on invalid

// Convert SSML to SpeechMarkdown (best-effort)
let smd = try parser.toSmd(ssml: "<speak><emphasis level=\"strong\">word</emphasis></speak>")
// Returns: ++word++

C API

#include "speechmarkdown.h"

// Convert to SSML
const char* ssml = speechmarkdown_to_ssml("Hello (world)[emphasis:\"strong\"]", "amazon-alexa");
speechmarkdown_free((char*)ssml);

// Convert to plain text
const char* text = speechmarkdown_to_text("Hello (world)[emphasis:\"strong\"]");
speechmarkdown_free((char*)text);

// Parse to JSON
const char* json = speechmarkdown_parse("Hello world");
speechmarkdown_free((char*)json);

// Check for SpeechMarkdown syntax
bool is_smd = speechmarkdown_is_speech_markdown("Hello (world)[emphasis:\"strong\"]");

// Validate
bool valid = speechmarkdown_validate("Hello (world)[emphasis:\"strong\"]");

// Convert SSML to SpeechMarkdown (best-effort)
const char* smd = speechmarkdown_to_smd("<speak><emphasis level=\"strong\">word</emphasis></speak>");
speechmarkdown_free((char*)smd);

// Get last error (thread-local)
const char* err = speechmarkdown_get_error();

Building from Source

Core Rust Library

The core Rust parser is built with:

cargo build --release

This produces:

• Windows: target/release/speechmarkdown_rust.dll
• macOS: target/release/libspeechmarkdown_rust.dylib
• Linux: target/release/libspeechmarkdown_rust.so

Language-Specific Builds

Each language binding has its own build process:

Python:

cd bindings/python
maturin develop
# or for release: maturin build --release

Node.js:

cd bindings/nodejs
npm install
npm run build

.NET:

cd bindings/dotnet
dotnet build

Swift:

# Uses pre-built XCFramework from releases
# Or build from source:
./build-swift-package.sh

Development Workflow

The repository follows a unified development model where all language bindings share the same core Rust parser:

1. Core changes: Modify src/ for parser logic changes
2. Language changes: Modify bindings/<language>/ for binding-specific changes
3. Testing: Each language has its own test suite
4. Releases: All packages are released together with version synchronization

For Contributors:

• Rust developers: Work in src/ and test with cargo test
• Python developers: Work in bindings/python/ and test with pytest
• Node.js developers: Work in bindings/nodejs/ and test with npm test
• .NET developers: Work in bindings/dotnet/ and test with dotnet test
• Swift developers: Work in bindings/swift/ and use SPM for testing

License

MIT