feat(embedded): add GLM tool format adapter for code fence stripping

GLM-4 models wrap tool calls in markdown code fences and inline backticks,
which prevents the streaming parser from detecting them. This adapter:

- Strips ```json and ``` code fence markers during streaming
- Strips inline backticks from tool call JSON
- Handles chunked streaming correctly (buffers potential fence lines)
- Transforms GLM native format (<|assistant|>tool_name) to g3 JSON format

Also refactors embedded provider into module structure:
- embedded/mod.rs - module exports
- embedded/provider.rs - main EmbeddedProvider (moved from embedded.rs)
- embedded/adapters/mod.rs - ToolFormatAdapter trait
- embedded/adapters/glm.rs - GLM-specific adapter

Includes 22 unit tests covering edge cases like nested JSON in strings,
chunk boundary handling, and false pattern detection.

Updates README to show GLM-4 9B now works () for agentic tasks.
This commit is contained in:
Dhanji R. Prasanna
2026-01-29 12:52:09 +11:00
parent 457ba35f80
commit 8191a5e8e6
5 changed files with 871 additions and 4 deletions

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//! GLM/Z-AI tool format adapter
//!
//! GLM models can use two tool calling formats:
//!
//! 1. Native format:
//! ```text
//! <|assistant|>tool_name
//! {"arg": "value"}
//! ```
//!
//! 2. Code-fenced JSON (when following system prompt instructions):
//! ```text
//! ```json
//! {"tool": "shell", "args": {"command": "ls"}}
//! ```
//! ```
//!
//! This adapter handles both formats and strips code fences when present.
use super::{AdapterOutput, ToolFormatAdapter};
/// Safety limits to prevent unbounded buffering
const MAX_PATTERN_BUFFER: usize = 20; // `<|assistant|>` is 13 chars
const MAX_TOOL_NAME: usize = 64;
const MAX_JSON_BUFFER: usize = 65536; // 64KB
const MAX_NEWLINES_BEFORE_JSON: usize = 2;
/// The pattern that indicates a tool call in GLM format
const ASSISTANT_PATTERN: &str = "<|assistant|>";
/// Parser state for the main state machine
#[derive(Debug, Clone, PartialEq)]
enum ParseState {
/// Normal prose, watching for `<|assistant|>`
Prose,
/// Saw start of potential pattern (e.g., "<|"), buffering to confirm
MaybePattern,
/// Confirmed `<|assistant|>`, now reading tool name until newline
InToolName,
/// Got tool name, waiting for `{` to start JSON (allowing whitespace/newlines)
AwaitingJson { tool_name: String, newline_count: usize },
/// Inside JSON body, tracking depth to find end
InToolJson { tool_name: String },
}
/// State for JSON parsing (to handle strings correctly)
#[derive(Debug, Clone, Copy, PartialEq)]
enum JsonState {
/// Normal JSON, counting braces
Normal,
/// Inside a string literal, ignore braces
InString,
/// Just saw backslash in string, next char is escaped
InStringEscape,
}
/// Adapter for GLM/Z-AI model tool calling format
#[derive(Debug)]
pub struct GlmToolAdapter {
/// Buffer for accumulating content
buffer: String,
/// Buffer for current line (to detect code fences)
line_buffer: String,
/// Whether we're currently inside a code fence
in_code_fence: bool,
/// Current parse state
state: ParseState,
/// JSON parsing state (when in InToolJson)
json_state: JsonState,
/// Brace depth for JSON parsing
json_depth: i32,
/// Content to emit that's been confirmed as prose
pending_emit: String,
}
impl GlmToolAdapter {
pub fn new() -> Self {
Self {
buffer: String::new(),
line_buffer: String::new(),
in_code_fence: false,
state: ParseState::Prose,
json_state: JsonState::Normal,
json_depth: 0,
pending_emit: String::new(),
}
}
/// Process a character for code fence detection (streaming-safe)
/// Returns the string to emit (empty if content should be suppressed)
fn process_for_code_fence(&mut self, c: char) -> String {
if c == '\n' {
// End of line - check if it's a code fence
let trimmed = self.line_buffer.trim();
if trimmed.starts_with("```") {
let after_fence = trimmed.trim_start_matches('`').trim();
if after_fence.is_empty() || after_fence.chars().all(|c| c.is_ascii_alphanumeric()) {
// This is a code fence marker line - suppress it
self.line_buffer.clear();
return String::new(); // Don't emit anything for fence lines
}
}
// Not a fence line - just emit the newline
// (buffered content was already emitted char-by-char)
self.line_buffer.clear();
c.to_string()
} else {
self.line_buffer.push(c);
// Only suppress output if the line looks like it could be a code fence
// A code fence line starts with optional whitespace then ```
let trimmed = self.line_buffer.trim_start();
if trimmed.starts_with('`') && trimmed.len() <= 10 {
// Potentially a fence marker - buffer until we see newline
String::new()
} else {
// Not a fence - emit the entire buffer (which includes current char)
// and clear it since we've emitted everything
let result = std::mem::take(&mut self.line_buffer);
result
}
}
}
/// Strip markdown code fence markers from output
///
/// GLM models sometimes wrap tool calls in code fences like:
/// ```json
/// {"tool": "shell", ...}
/// ```
///
/// This strips those markers so the JSON can be parsed as a tool call.
fn strip_code_fences(text: &str) -> String {
text.lines()
.filter_map(|line| {
let trimmed = line.trim();
// Filter out lines that are just code fence markers (with optional language)
if trimmed.starts_with("```") {
// Check if there's content after the fence marker on the same line
let after_fence = trimmed.trim_start_matches('`').trim();
if after_fence.is_empty() || after_fence.chars().all(|c| c.is_ascii_alphanumeric()) {
// Just a fence marker (possibly with language like "json"), skip it
return None;
}
}
Some(line)
})
.collect::<Vec<_>>()
.join("\n")
}
/// Strip inline code backticks from text
///
/// GLM models sometimes wrap tool calls in inline backticks like:
/// `{"tool": "shell", ...}`
fn strip_inline_backticks(text: &str) -> String {
let trimmed = text.trim();
if trimmed.starts_with('`') && trimmed.ends_with('`') && !trimmed.starts_with("```") {
trimmed[1..trimmed.len()-1].to_string()
} else {
text.to_string()
}
}
/// Check if a string is a valid tool name
/// Pattern: starts with letter or underscore, followed by alphanumeric or underscore
fn is_valid_tool_name(name: &str) -> bool {
if name.is_empty() || name.len() > MAX_TOOL_NAME {
return false;
}
let mut chars = name.chars();
match chars.next() {
Some(c) if c.is_ascii_alphabetic() || c == '_' => {}
_ => return false,
}
chars.all(|c| c.is_ascii_alphanumeric() || c == '_')
}
/// Process a single character in Prose state
fn process_prose_char(&mut self, c: char) {
// First, filter through code fence detection
let filtered = self.process_for_code_fence(c);
for filtered_c in filtered.chars() {
if filtered_c == '<' {
// Potential start of pattern
self.buffer.push(filtered_c);
self.state = ParseState::MaybePattern;
} else {
self.pending_emit.push(filtered_c);
}
}
// If empty string, the character is being buffered for code fence detection
}
/// Process a single character in MaybePattern state
fn process_maybe_pattern_char(&mut self, c: char) {
self.buffer.push(c);
// Check if buffer matches start of pattern
if ASSISTANT_PATTERN.starts_with(&self.buffer) {
// Still could be the pattern
if self.buffer == ASSISTANT_PATTERN {
// Complete pattern match!
self.buffer.clear();
self.state = ParseState::InToolName;
}
// else: keep buffering
} else {
// Not the pattern, emit buffer as prose
self.pending_emit.push_str(&self.buffer);
self.buffer.clear();
self.state = ParseState::Prose;
}
// Safety: if buffer gets too long, it's not our pattern
if self.buffer.len() > MAX_PATTERN_BUFFER {
self.pending_emit.push_str(&self.buffer);
self.buffer.clear();
self.state = ParseState::Prose;
}
}
/// Process a single character in InToolName state
fn process_tool_name_char(&mut self, c: char) {
if c == '\n' {
// End of tool name
let tool_name = self.buffer.trim().to_string();
self.buffer.clear();
if Self::is_valid_tool_name(&tool_name) {
self.state = ParseState::AwaitingJson {
tool_name,
newline_count: 1,
};
} else {
// Invalid tool name, emit as prose
self.pending_emit.push_str(ASSISTANT_PATTERN);
self.pending_emit.push_str(&tool_name);
self.pending_emit.push(c);
self.state = ParseState::Prose;
}
} else if c.is_whitespace() && self.buffer.is_empty() {
// Skip leading whitespace after <|assistant|>
} else {
self.buffer.push(c);
// Safety: tool name too long
if self.buffer.len() > MAX_TOOL_NAME {
self.pending_emit.push_str(ASSISTANT_PATTERN);
self.pending_emit.push_str(&self.buffer);
self.buffer.clear();
self.state = ParseState::Prose;
}
}
}
/// Process a single character in AwaitingJson state
fn process_awaiting_json_char(&mut self, c: char, tool_name: String, newline_count: usize) {
if c == '{' {
// Start of JSON!
self.buffer.push(c);
self.json_depth = 1;
self.json_state = JsonState::Normal;
self.state = ParseState::InToolJson { tool_name };
} else if c == '\n' {
let new_count = newline_count + 1;
if new_count > MAX_NEWLINES_BEFORE_JSON {
// Too many newlines, not a tool call
self.pending_emit.push_str(ASSISTANT_PATTERN);
self.pending_emit.push_str(&tool_name);
for _ in 0..new_count {
self.pending_emit.push('\n');
}
self.state = ParseState::Prose;
} else {
self.state = ParseState::AwaitingJson {
tool_name,
newline_count: new_count,
};
}
} else if c.is_whitespace() {
// Skip whitespace while waiting for JSON
self.state = ParseState::AwaitingJson {
tool_name,
newline_count,
};
} else {
// Non-JSON character, not a tool call
self.pending_emit.push_str(ASSISTANT_PATTERN);
self.pending_emit.push_str(&tool_name);
self.pending_emit.push('\n');
self.pending_emit.push(c);
self.state = ParseState::Prose;
}
}
/// Process a single character in InToolJson state
fn process_json_char(&mut self, c: char, tool_name: String) -> Option<String> {
self.buffer.push(c);
// Update JSON state machine
match self.json_state {
JsonState::Normal => {
match c {
'{' => self.json_depth += 1,
'}' => {
self.json_depth -= 1;
if self.json_depth == 0 {
// JSON complete!
let json_args = self.buffer.clone();
self.buffer.clear();
self.state = ParseState::Prose;
// Transform to g3 format
let transformed = format!(
"{{\"tool\": \"{}\", \"args\": {}}}",
tool_name, json_args
);
return Some(transformed);
}
}
'"' => self.json_state = JsonState::InString,
_ => {}
}
}
JsonState::InString => {
match c {
'\\' => self.json_state = JsonState::InStringEscape,
'"' => self.json_state = JsonState::Normal,
_ => {}
}
}
JsonState::InStringEscape => {
// Any character after backslash, return to InString
self.json_state = JsonState::InString;
}
}
// Safety: JSON buffer too large
if self.buffer.len() > MAX_JSON_BUFFER {
// Emit as malformed - let downstream handle it
self.pending_emit.push_str(ASSISTANT_PATTERN);
self.pending_emit.push_str(&tool_name);
self.pending_emit.push('\n');
self.pending_emit.push_str(&self.buffer);
self.buffer.clear();
self.state = ParseState::Prose;
self.json_state = JsonState::Normal;
self.json_depth = 0;
}
// Keep state for next iteration
self.state = ParseState::InToolJson { tool_name };
None
}
}
impl Default for GlmToolAdapter {
fn default() -> Self {
Self::new()
}
}
impl ToolFormatAdapter for GlmToolAdapter {
fn handles(&self, model_type: &str) -> bool {
model_type.contains("glm")
}
fn process_chunk(&mut self, chunk: &str) -> AdapterOutput {
let mut has_tool_call = false;
for c in chunk.chars() {
match self.state.clone() {
ParseState::Prose => {
self.process_prose_char(c);
}
ParseState::MaybePattern => {
self.process_maybe_pattern_char(c);
}
ParseState::InToolName => {
self.process_tool_name_char(c);
}
ParseState::AwaitingJson { tool_name, newline_count } => {
self.process_awaiting_json_char(c, tool_name, newline_count);
}
ParseState::InToolJson { tool_name } => {
if let Some(transformed) = self.process_json_char(c, tool_name) {
self.pending_emit.push('\n');
self.pending_emit.push_str(&transformed);
has_tool_call = true;
}
}
}
}
// Return accumulated emit content, stripping any code fence markers
let raw_emit = std::mem::take(&mut self.pending_emit);
let stripped_fences = Self::strip_code_fences(&raw_emit);
let emit = Self::strip_inline_backticks(&stripped_fences);
AdapterOutput {
emit: emit.to_string(),
has_tool_call,
}
}
fn flush(&mut self) -> AdapterOutput {
let mut emit = std::mem::take(&mut self.pending_emit);
// Emit any buffered content as-is
match &self.state {
ParseState::Prose => {
// Nothing extra to emit
}
ParseState::MaybePattern => {
emit.push_str(&self.buffer);
}
ParseState::InToolName => {
emit.push_str(ASSISTANT_PATTERN);
emit.push_str(&self.buffer);
}
ParseState::AwaitingJson { tool_name, newline_count } => {
emit.push_str(ASSISTANT_PATTERN);
emit.push_str(tool_name);
for _ in 0..*newline_count {
emit.push('\n');
}
}
ParseState::InToolJson { tool_name } => {
emit.push_str(ASSISTANT_PATTERN);
emit.push_str(tool_name);
emit.push('\n');
emit.push_str(&self.buffer);
}
}
// Flush any remaining line buffer content (if not a code fence)
if !self.line_buffer.is_empty() {
let trimmed = self.line_buffer.trim();
let is_fence = trimmed.starts_with("```") &&
(trimmed.trim_start_matches('`').trim().is_empty() ||
trimmed.trim_start_matches('`').trim().chars().all(|c| c.is_ascii_alphanumeric()));
if !is_fence {
emit.push_str(&self.line_buffer);
}
}
self.reset();
// Strip code fences and inline backticks from final output
let stripped_fences = Self::strip_code_fences(&emit);
let stripped = Self::strip_inline_backticks(&stripped_fences);
AdapterOutput {
emit: stripped,
has_tool_call: false,
}
}
fn reset(&mut self) {
self.buffer.clear();
self.line_buffer.clear();
self.in_code_fence = false;
self.state = ParseState::Prose;
self.json_state = JsonState::Normal;
self.json_depth = 0;
self.pending_emit.clear();
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_handles_glm_models() {
let adapter = GlmToolAdapter::new();
assert!(adapter.handles("glm4"));
assert!(adapter.handles("glm"));
assert!(adapter.handles("some-glm-variant"));
assert!(!adapter.handles("qwen"));
assert!(!adapter.handles("llama"));
}
#[test]
fn test_valid_tool_names() {
assert!(GlmToolAdapter::is_valid_tool_name("shell"));
assert!(GlmToolAdapter::is_valid_tool_name("read_file"));
assert!(GlmToolAdapter::is_valid_tool_name("_private"));
assert!(GlmToolAdapter::is_valid_tool_name("tool123"));
assert!(!GlmToolAdapter::is_valid_tool_name(""));
assert!(!GlmToolAdapter::is_valid_tool_name("123tool"));
assert!(!GlmToolAdapter::is_valid_tool_name("tool-name"));
assert!(!GlmToolAdapter::is_valid_tool_name("tool name"));
}
#[test]
fn test_basic_tool_call() {
let mut adapter = GlmToolAdapter::new();
let input = "Let me list files.<|assistant|>shell\n{\"command\": \"ls\"}";
let output = adapter.process_chunk(input);
assert!(output.has_tool_call);
assert!(output.emit.contains("Let me list files."));
assert!(output.emit.contains(r#"{"tool": "shell", "args": {"command": "ls"}}"#));
}
#[test]
fn test_tool_call_chunked() {
let mut adapter = GlmToolAdapter::new();
// Simulate chunked input
let chunks = vec![
"Let me ",
"list.<|assis",
"tant|>shell\n{\"co",
"mmand\": \"ls\"}",
];
let mut full_output = String::new();
let mut found_tool = false;
for chunk in chunks {
let output = adapter.process_chunk(chunk);
full_output.push_str(&output.emit);
if output.has_tool_call {
found_tool = true;
}
}
let final_output = adapter.flush();
full_output.push_str(&final_output.emit);
assert!(found_tool);
assert!(full_output.contains("Let me list."));
assert!(full_output.contains(r#"{"tool": "shell", "args": {"command": "ls"}}"#));
}
#[test]
fn test_nested_json_in_string() {
let mut adapter = GlmToolAdapter::new();
let input = r#"<|assistant|>shell
{"command": "echo '{\"nested\": true}'"}
Done."#;
let output = adapter.process_chunk(input);
let final_output = adapter.flush();
assert!(output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
assert!(full.contains(r#""args": {"command": "echo '{\"nested\": true}'"}}"#));
}
#[test]
fn test_escaped_quotes_in_string() {
let mut adapter = GlmToolAdapter::new();
let input = r#"<|assistant|>shell
{"command": "echo \"hello\""}
Done."#;
let output = adapter.process_chunk(input);
assert!(output.has_tool_call);
assert!(output.emit.contains(r#""args": {"command": "echo \"hello\""}"#));
}
#[test]
fn test_false_pattern_in_prose() {
let mut adapter = GlmToolAdapter::new();
let input = "The format is <|assistant|>tool_name for GLM models.";
let output = adapter.process_chunk(input);
let final_output = adapter.flush();
// Should not detect as tool call since no JSON follows
assert!(!output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
assert!(full.contains("<|assistant|>"));
}
#[test]
fn test_multiple_tool_calls() {
let mut adapter = GlmToolAdapter::new();
let input = r#"First:<|assistant|>shell
{"command": "ls"}
Second:<|assistant|>read_file
{"path": "test.txt"}"#;
let output = adapter.process_chunk(input);
assert!(output.has_tool_call);
assert!(output.emit.contains(r#"{"tool": "shell"#));
assert!(output.emit.contains(r#"{"tool": "read_file"#));
}
#[test]
fn test_whitespace_before_json() {
let mut adapter = GlmToolAdapter::new();
let input = "<|assistant|>shell\n {\"command\": \"ls\"}";
let output = adapter.process_chunk(input);
assert!(output.has_tool_call);
}
#[test]
fn test_extra_newline_before_json() {
let mut adapter = GlmToolAdapter::new();
let input = "<|assistant|>shell\n\n{\"command\": \"ls\"}";
let output = adapter.process_chunk(input);
assert!(output.has_tool_call);
}
#[test]
fn test_too_many_newlines_before_json() {
let mut adapter = GlmToolAdapter::new();
let input = "<|assistant|>shell\n\n\n{\"command\": \"ls\"}";
let output = adapter.process_chunk(input);
let final_output = adapter.flush();
// Should not detect as tool call - too many newlines
assert!(!output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
assert!(full.contains("<|assistant|>shell"));
}
#[test]
fn test_invalid_tool_name() {
let mut adapter = GlmToolAdapter::new();
let input = "<|assistant|>123invalid\n{\"command\": \"ls\"}";
let output = adapter.process_chunk(input);
let final_output = adapter.flush();
// Should not detect as tool call - invalid name
assert!(!output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
assert!(full.contains("<|assistant|>123invalid"));
}
#[test]
fn test_stream_ends_mid_pattern() {
let mut adapter = GlmToolAdapter::new();
let output = adapter.process_chunk("text<|assis");
let final_output = adapter.flush();
assert!(!output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
assert_eq!(full, "text<|assis");
}
#[test]
fn test_stream_ends_mid_json() {
let mut adapter = GlmToolAdapter::new();
let output = adapter.process_chunk("<|assistant|>shell\n{\"command\": \"ls");
let final_output = adapter.flush();
assert!(!output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
// Should emit the incomplete content
assert!(full.contains("<|assistant|>shell"));
assert!(full.contains("{\"command\": \"ls"));
}
#[test]
fn test_prose_with_angle_brackets() {
let mut adapter = GlmToolAdapter::new();
let input = "Use <html> tags and <|other|> patterns.";
let output = adapter.process_chunk(input);
let final_output = adapter.flush();
assert!(!output.has_tool_call);
let full = format!("{}{}", output.emit, final_output.emit);
assert_eq!(full, input);
}
#[test]
fn test_reset() {
let mut adapter = GlmToolAdapter::new();
// Start processing but don't finish
adapter.process_chunk("<|assistant|>shell\n{\"cmd");
// Reset
adapter.reset();
// Should be back to clean state
let output = adapter.process_chunk("Normal text");
assert_eq!(output.emit, "Normal text");
assert!(!output.has_tool_call);
}
}
#[test]
fn test_strip_code_fences() {
assert_eq!(
GlmToolAdapter::strip_code_fences("```json\n{\"tool\": \"shell\"}\n```"),
"{\"tool\": \"shell\"}"
);
assert_eq!(
GlmToolAdapter::strip_code_fences("```\n{\"tool\": \"shell\"}\n```"),
"{\"tool\": \"shell\"}"
);
assert_eq!(
GlmToolAdapter::strip_code_fences("normal text"),
"normal text"
);
assert_eq!(
GlmToolAdapter::strip_code_fences("```json\ncode\n```\nmore text"),
"code\nmore text"
);
}
#[test]
fn test_code_fenced_tool_call() {
let mut adapter = GlmToolAdapter::new();
let input = "```json\n{\"tool\": \"shell\", \"args\": {\"command\": \"ls\"}}\n```";
let output = adapter.process_chunk(input);
let final_output = adapter.flush();
let full = format!("{}{}", output.emit, final_output.emit);
// Should strip the code fences
assert!(!full.contains("```"));
assert!(full.contains("{\"tool\": \"shell\""));
}

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//! Tool format adapters for embedded models
//!
//! Different model families use different formats for tool calling.
//! Adapters transform model-specific formats to g3's standard JSON format:
//! `{"tool": "name", "args": {...}}`
//!
//! This module provides:
//! - `ToolFormatAdapter` trait for implementing format transformations
//! - `GlmToolAdapter` for GLM/Z-AI models that use `<|assistant|>tool_name` format
mod glm;
pub use glm::GlmToolAdapter;
/// Output from processing a chunk through an adapter
#[derive(Debug, Clone, Default)]
pub struct AdapterOutput {
/// Text safe to emit downstream (prose and/or complete tool calls)
pub emit: String,
/// True if a complete tool call was detected and transformed
pub has_tool_call: bool,
}
impl AdapterOutput {
pub fn new() -> Self {
Self::default()
}
pub fn with_emit(emit: String) -> Self {
Self {
emit,
has_tool_call: false,
}
}
pub fn with_tool_call(emit: String) -> Self {
Self {
emit,
has_tool_call: true,
}
}
}
/// Trait for adapting model-specific tool call formats to g3's standard format
///
/// Adapters are stateful to handle streaming - they buffer incomplete patterns
/// and emit complete chunks as soon as they're ready.
pub trait ToolFormatAdapter: Send + Sync {
/// Check if this adapter handles the given model type
fn handles(&self, model_type: &str) -> bool;
/// Process a chunk of model output
///
/// The adapter may buffer content if it's in the middle of a potential pattern.
/// Returns content that's safe to emit downstream.
fn process_chunk(&mut self, chunk: &str) -> AdapterOutput;
/// Flush any remaining buffered content (call at end of stream)
///
/// This should emit any buffered content, even if incomplete.
fn flush(&mut self) -> AdapterOutput;
/// Reset the adapter state (call between conversations)
fn reset(&mut self);
}
/// Create an adapter for the given model type, if one exists
pub fn create_adapter_for_model(model_type: &str) -> Option<Box<dyn ToolFormatAdapter>> {
let glm_adapter = GlmToolAdapter::new();
if glm_adapter.handles(model_type) {
return Some(Box::new(glm_adapter));
}
// Add other adapters here as needed:
// let mistral_adapter = MistralToolAdapter::new();
// if mistral_adapter.handles(model_type) { ... }
None
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_create_adapter_for_glm() {
assert!(create_adapter_for_model("glm4").is_some());
assert!(create_adapter_for_model("glm").is_some());
assert!(create_adapter_for_model("some-glm-variant").is_some());
}
#[test]
fn test_no_adapter_for_unknown() {
assert!(create_adapter_for_model("qwen").is_none());
assert!(create_adapter_for_model("llama").is_none());
assert!(create_adapter_for_model("mistral").is_none());
}
}

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@@ -0,0 +1,12 @@
//! Embedded LLM provider using llama.cpp
//!
//! This module provides local model inference via llama.cpp with Metal acceleration.
pub mod adapters;
mod provider;
// Re-export adapter types
pub use adapters::{create_adapter_for_model, AdapterOutput, ToolFormatAdapter};
// Re-export the main provider
pub use provider::EmbeddedProvider;

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@@ -0,0 +1,813 @@
//! Embedded LLM provider using llama.cpp with Metal acceleration on macOS.
//!
//! Supports multiple model families with their native chat templates:
//! - Qwen (ChatML format)
//! - GLM-4 (ChatGLM4 format)
//! - Mistral (Instruct format)
//! - Llama/CodeLlama (Llama2 format)
use crate::{
CompletionRequest, CompletionResponse, CompletionStream, LLMProvider, Message, MessageRole,
Usage,
streaming::{make_final_chunk_with_reason, make_text_chunk},
};
use anyhow::Result;
use llama_cpp_2::{
context::LlamaContext,
context::params::LlamaContextParams,
llama_backend::LlamaBackend,
llama_batch::LlamaBatch,
model::{AddBos, LlamaModel, Special, params::LlamaModelParams},
sampling::LlamaSampler,
};
use std::num::NonZeroU32;
use std::path::PathBuf;
use std::sync::Arc;
use std::sync::OnceLock;
use tokio::sync::mpsc;
use tokio_stream::wrappers::ReceiverStream;
use tracing::{debug, error};
// ============================================================================
// Global Backend
// ============================================================================
/// Global llama.cpp backend - can only be initialized once per process
static LLAMA_BACKEND: OnceLock<Arc<LlamaBackend>> = OnceLock::new();
/// Get or initialize the global llama.cpp backend
fn get_or_init_backend() -> Result<Arc<LlamaBackend>> {
if let Some(backend) = LLAMA_BACKEND.get() {
return Ok(Arc::clone(backend));
}
// Suppress llama.cpp's verbose logging to stderr
suppress_llama_logging();
debug!("Initializing llama.cpp backend...");
let backend = LlamaBackend::init()
.map_err(|e| anyhow::anyhow!("Failed to initialize llama.cpp backend: {:?}", e))?;
// Store it (ignore if another thread beat us to it)
let _ = LLAMA_BACKEND.set(Arc::new(backend));
Ok(Arc::clone(LLAMA_BACKEND.get().expect("backend was just set")))
}
fn suppress_llama_logging() {
unsafe {
unsafe extern "C" fn void_log(
_level: std::ffi::c_int,
_text: *const std::os::raw::c_char,
_user_data: *mut std::os::raw::c_void,
) {
// Intentionally empty
}
extern "C" {
fn llama_log_set(
log_callback: Option<
unsafe extern "C" fn(
std::ffi::c_int,
*const std::os::raw::c_char,
*mut std::os::raw::c_void,
),
>,
user_data: *mut std::os::raw::c_void,
);
}
llama_log_set(Some(void_log), std::ptr::null_mut());
}
}
// ============================================================================
// Provider Struct
// ============================================================================
use super::adapters::create_adapter_for_model;
pub struct EmbeddedProvider {
name: String,
model: Arc<LlamaModel>,
backend: Arc<LlamaBackend>,
model_type: String,
model_name: String,
max_tokens: Option<u32>,
temperature: f32,
context_length: u32,
threads: Option<u32>,
}
impl EmbeddedProvider {
/// Create a new embedded provider with default naming ("embedded").
pub fn new(
model_path: String,
model_type: String,
context_length: Option<u32>,
max_tokens: Option<u32>,
temperature: Option<f32>,
gpu_layers: Option<u32>,
threads: Option<u32>,
) -> Result<Self> {
Self::new_with_name(
"embedded".to_string(),
model_path,
model_type,
context_length,
max_tokens,
temperature,
gpu_layers,
threads,
)
}
/// Create a new embedded provider with a custom name.
pub fn new_with_name(
name: String,
model_path: String,
model_type: String,
context_length: Option<u32>,
max_tokens: Option<u32>,
temperature: Option<f32>,
gpu_layers: Option<u32>,
threads: Option<u32>,
) -> Result<Self> {
debug!("Loading embedded model from: {}", model_path);
let expanded_path = shellexpand::tilde(&model_path);
let model_path_buf = PathBuf::from(expanded_path.as_ref());
if !model_path_buf.exists() {
anyhow::bail!("Model file not found: {}", model_path_buf.display());
}
let backend = get_or_init_backend()?;
let n_gpu_layers = gpu_layers.unwrap_or(99);
let model_params = LlamaModelParams::default().with_n_gpu_layers(n_gpu_layers);
debug!("Using {} GPU layers", n_gpu_layers);
debug!("Loading model...");
let model = LlamaModel::load_from_file(&backend, &model_path_buf, &model_params)
.map_err(|e| anyhow::anyhow!("Failed to load model: {:?}", e))?;
let model_ctx_train = model.n_ctx_train();
let context_size = context_length.unwrap_or(model_ctx_train);
debug!(
"Context length: {} (model trained: {}, configured: {:?})",
context_size, model_ctx_train, context_length
);
debug!("Successfully loaded {} model as '{}'", model_type, name);
Ok(Self {
name,
model: Arc::new(model),
backend,
model_type: model_type.to_lowercase(),
model_name: format!("embedded-{}", model_type),
max_tokens,
temperature: temperature.unwrap_or(0.1),
context_length: context_size,
threads,
})
}
fn effective_max_tokens(&self) -> u32 {
self.max_tokens
.unwrap_or_else(|| std::cmp::min(4096, self.context_length / 4))
}
/// Estimate token count from text (~4 chars per token)
fn estimate_tokens(&self, text: &str) -> u32 {
(text.len() as f32 / 4.0).ceil() as u32
}
}
// ============================================================================
// Chat Template Formatting
// ============================================================================
impl EmbeddedProvider {
/// Format messages according to the model's native chat template.
fn format_messages(&self, messages: &[Message]) -> String {
match self.model_type.as_str() {
t if t.contains("glm") => format_glm4(messages),
t if t.contains("qwen") => format_qwen(messages),
t if t.contains("mistral") => format_mistral(messages),
_ => format_llama(messages),
}
}
/// Get stop sequences based on model type.
fn get_stop_sequences(&self) -> &'static [&'static str] {
get_stop_sequences_for_model(&self.model_type)
}
}
/// GLM-4 ChatGLM4 format: [gMASK]<sop><|role|>\ncontent
fn format_glm4(messages: &[Message]) -> String {
let mut out = String::from("[gMASK]<sop>");
for msg in messages {
let role = match msg.role {
MessageRole::System => "<|system|>",
MessageRole::User => "<|user|>",
MessageRole::Assistant => "<|assistant|>",
};
out.push_str(&format!("{}\n{}", role, msg.content));
}
out.push_str("<|assistant|>\n");
out
}
/// Qwen ChatML format: <|im_start|>role\ncontent<|im_end|>
fn format_qwen(messages: &[Message]) -> String {
let mut out = String::new();
for msg in messages {
let role = match msg.role {
MessageRole::System => "system",
MessageRole::User => "user",
MessageRole::Assistant => "assistant",
};
out.push_str(&format!("<|im_start|>{}\n{}<|im_end|>\n", role, msg.content));
}
out.push_str("<|im_start|>assistant\n");
out
}
/// Mistral Instruct format: <s>[INST] ... [/INST] response</s>
fn format_mistral(messages: &[Message]) -> String {
let mut out = String::new();
let mut in_inst = false;
for (i, msg) in messages.iter().enumerate() {
match msg.role {
MessageRole::System if i == 0 => {
out.push_str("<s>[INST] ");
out.push_str(&msg.content);
out.push_str("\n\n");
in_inst = true;
}
MessageRole::System => {} // Ignore non-first system messages
MessageRole::User => {
if !in_inst {
out.push_str("<s>[INST] ");
}
out.push_str(&msg.content);
out.push_str(" [/INST]");
in_inst = false;
}
MessageRole::Assistant => {
out.push(' ');
out.push_str(&msg.content);
out.push_str("</s> ");
in_inst = false;
}
}
}
if messages.last().is_some_and(|m| matches!(m.role, MessageRole::User)) {
out.push(' ');
}
out
}
/// Llama/CodeLlama format: [INST] <<SYS>>\nsystem<</SYS>>\n\nuser [/INST]
fn format_llama(messages: &[Message]) -> String {
let mut out = String::new();
for msg in messages {
match msg.role {
MessageRole::System => {
out.push_str(&format!("[INST] <<SYS>>\n{}\n<</SYS>>\n\n", msg.content));
}
MessageRole::User => {
out.push_str(&format!("{} [/INST] ", msg.content));
}
MessageRole::Assistant => {
out.push_str(&format!("{} </s><s>[INST] ", msg.content));
}
}
}
out
}
/// Get stop sequences for a model type.
fn get_stop_sequences_for_model(model_type: &str) -> &'static [&'static str] {
if model_type.contains("glm") {
&["<|endoftext|>", "<|user|>", "<|observation|>", "<|system|>"]
} else if model_type.contains("qwen") {
&["<|im_end|>", "<|endoftext|>", "</s>", "<|im_start|>"]
} else if model_type.contains("code-llama") || model_type.contains("codellama") {
&["</s>", "[/INST]", "<</SYS>>", "[INST]", "<<SYS>>"]
} else if model_type.contains("llama") {
&[
"</s>",
"[/INST]",
"<</SYS>>",
"### Human:",
"### Assistant:",
"[INST]",
]
} else if model_type.contains("mistral") {
&["</s>", "[/INST]", "<|im_end|>"]
} else if model_type.contains("vicuna") || model_type.contains("wizard") {
&[
"### Human:",
"### Assistant:",
"USER:",
"ASSISTANT:",
"</s>",
]
} else if model_type.contains("alpaca") {
&["### Instruction:", "### Response:", "### Input:", "</s>"]
} else {
// Generic fallback
&[
"</s>",
"<|endoftext|>",
"<|im_end|>",
"### Human:",
"### Assistant:",
"[/INST]",
"<</SYS>>",
]
}
}
// ============================================================================
// Inference Helpers
// ============================================================================
/// Parameters for inference, extracted from request and provider defaults.
struct InferenceParams {
prompt: String,
max_tokens: u32,
temperature: f32,
stop_sequences: Vec<String>,
}
/// Prepared inference context with tokenized prompt ready for generation.
struct PreparedContext<'a> {
ctx: LlamaContext<'a>,
batch: LlamaBatch,
sampler: LlamaSampler,
token_count: i32,
}
impl EmbeddedProvider {
/// Extract inference parameters from a completion request.
fn extract_params(&self, request: &CompletionRequest) -> InferenceParams {
InferenceParams {
prompt: self.format_messages(&request.messages),
max_tokens: request.max_tokens.unwrap_or_else(|| self.effective_max_tokens()),
temperature: request.temperature.unwrap_or(self.temperature),
stop_sequences: self
.get_stop_sequences()
.iter()
.map(|s| s.to_string())
.collect(),
}
}
}
/// Prepare the inference context: create context, tokenize prompt, decode initial batch.
fn prepare_context<'a>(
model: &'a LlamaModel,
backend: &'a LlamaBackend,
prompt: &str,
temperature: f32,
context_length: u32,
threads: Option<u32>,
) -> Result<PreparedContext<'a>> {
let n_ctx = NonZeroU32::new(context_length).unwrap_or(NonZeroU32::new(4096).unwrap());
let mut ctx_params = LlamaContextParams::default()
.with_n_ctx(Some(n_ctx))
.with_n_batch(context_length);
if let Some(n_threads) = threads {
ctx_params = ctx_params.with_n_threads(n_threads as i32);
}
let mut ctx = model
.new_context(backend, ctx_params)
.map_err(|e| anyhow::anyhow!("Failed to create context: {:?}", e))?;
let tokens = model
.str_to_token(prompt, AddBos::Always)
.map_err(|e| anyhow::anyhow!("Failed to tokenize: {:?}", e))?;
debug!("Tokenized prompt: {} tokens", tokens.len());
let batch_size = std::cmp::max(512, tokens.len());
let mut batch = LlamaBatch::new(batch_size, 1);
for (i, token) in tokens.iter().enumerate() {
batch
.add(*token, i as i32, &[0], i == tokens.len() - 1)
.map_err(|e| anyhow::anyhow!("Failed to add token to batch: {:?}", e))?;
}
ctx.decode(&mut batch)
.map_err(|e| anyhow::anyhow!("Failed to decode prompt: {:?}", e))?;
let sampler = LlamaSampler::chain_simple([
LlamaSampler::temp(temperature),
LlamaSampler::dist(1234),
]);
Ok(PreparedContext {
ctx,
batch,
sampler,
token_count: tokens.len() as i32,
})
}
/// Check if text contains any stop sequence. Returns the truncation position if found.
fn find_stop_sequence(text: &str, stop_sequences: &[String]) -> Option<usize> {
for stop_seq in stop_sequences {
if let Some(pos) = text.find(stop_seq) {
return Some(pos);
}
}
None
}
/// Truncate text at the first stop sequence, if any.
fn truncate_at_stop_sequence(text: &mut String, stop_sequences: &[String]) {
if let Some(pos) = find_stop_sequence(text, stop_sequences) {
text.truncate(pos);
}
}
// ============================================================================
// LLMProvider Implementation
// ============================================================================
#[async_trait::async_trait]
impl LLMProvider for EmbeddedProvider {
async fn complete(&self, request: CompletionRequest) -> Result<CompletionResponse> {
debug!(
"Processing completion request with {} messages",
request.messages.len()
);
let params = self.extract_params(&request);
let prompt_tokens = self.estimate_tokens(&params.prompt);
debug!("Formatted prompt length: {} chars", params.prompt.len());
// Clone what we need for the blocking task
let model = self.model.clone();
let backend = self.backend.clone();
let context_length = self.context_length;
let threads = self.threads;
let model_name = self.model_name.clone();
let (content, completion_tokens) = tokio::task::spawn_blocking(move || {
let mut prepared = prepare_context(
&model,
&backend,
&params.prompt,
params.temperature,
context_length,
threads,
)?;
let mut generated_text = String::new();
let mut token_count = 0u32;
for _ in 0..params.max_tokens {
let new_token = prepared.sampler.sample(&prepared.ctx, prepared.batch.n_tokens() - 1);
prepared.sampler.accept(new_token);
if model.is_eog_token(new_token) {
debug!("Hit end-of-generation token at {} tokens", token_count);
break;
}
let token_str = model
.token_to_str(new_token, Special::Tokenize)
.unwrap_or_default();
generated_text.push_str(&token_str);
token_count += 1;
if find_stop_sequence(&generated_text, &params.stop_sequences).is_some() {
debug!("Hit stop sequence at {} tokens", token_count);
break;
}
// Prepare next batch
prepared.batch.clear();
prepared
.batch
.add(new_token, prepared.token_count, &[0], true)
.map_err(|e| anyhow::anyhow!("Failed to add token to batch: {:?}", e))?;
prepared.token_count += 1;
prepared
.ctx
.decode(&mut prepared.batch)
.map_err(|e| anyhow::anyhow!("Failed to decode: {:?}", e))?;
}
truncate_at_stop_sequence(&mut generated_text, &params.stop_sequences);
Ok::<_, anyhow::Error>((generated_text.trim().to_string(), token_count))
})
.await
.map_err(|e| anyhow::anyhow!("Task join error: {}", e))??;
Ok(CompletionResponse {
content,
usage: Usage {
prompt_tokens,
completion_tokens,
total_tokens: prompt_tokens + completion_tokens,
cache_creation_tokens: 0,
cache_read_tokens: 0,
},
model: model_name,
})
}
async fn stream(&self, request: CompletionRequest) -> Result<CompletionStream> {
debug!(
"Processing streaming request with {} messages",
request.messages.len()
);
let params = self.extract_params(&request);
let prompt_tokens = self.estimate_tokens(&params.prompt);
let (tx, rx) = mpsc::channel(100);
let model = self.model.clone();
let backend = self.backend.clone();
let context_length = self.context_length;
let threads = self.threads;
let model_type = self.model_type.clone();
tokio::task::spawn_blocking(move || {
// Create adapter for model-specific tool format transformation (e.g., GLM)
let mut adapter = create_adapter_for_model(&model_type);
let mut prepared = match prepare_context(
&model,
&backend,
&params.prompt,
params.temperature,
context_length,
threads,
) {
Ok(p) => p,
Err(e) => {
let _ = tx.blocking_send(Err(e));
return;
}
};
let mut accumulated_text = String::new();
let mut token_count = 0u32;
let mut stop_reason: Option<String> = None;
for _ in 0..params.max_tokens {
let new_token = prepared.sampler.sample(&prepared.ctx, prepared.batch.n_tokens() - 1);
prepared.sampler.accept(new_token);
if model.is_eog_token(new_token) {
debug!("Hit end-of-generation token at {} tokens", token_count);
stop_reason = Some("end_turn".to_string());
break;
}
let token_str = model
.token_to_str(new_token, Special::Tokenize)
.unwrap_or_default();
accumulated_text.push_str(&token_str);
token_count += 1;
if find_stop_sequence(&accumulated_text, &params.stop_sequences).is_some() {
debug!("Hit stop sequence at {} tokens", token_count);
stop_reason = Some("stop_sequence".to_string());
break;
}
// Stream the token (through adapter if present)
let output_text = if let Some(ref mut adapt) = adapter {
let output = adapt.process_chunk(&token_str);
output.emit
} else {
token_str
};
if !output_text.is_empty() {
if tx.blocking_send(Ok(make_text_chunk(output_text))).is_err() {
return; // Receiver dropped
}
}
if token_count >= params.max_tokens {
debug!("Reached max token limit: {}", params.max_tokens);
stop_reason = Some("max_tokens".to_string());
break;
}
// Prepare next batch
prepared.batch.clear();
if let Err(e) = prepared.batch.add(new_token, prepared.token_count, &[0], true) {
error!("Failed to add token to batch: {:?}", e);
break;
}
prepared.token_count += 1;
if let Err(e) = prepared.ctx.decode(&mut prepared.batch) {
error!("Failed to decode: {:?}", e);
break;
}
}
// Flush any remaining content from the adapter
if let Some(ref mut adapt) = adapter {
let final_output = adapt.flush();
if !final_output.emit.is_empty() {
if tx.blocking_send(Ok(make_text_chunk(final_output.emit))).is_err() {
return;
}
}
}
let usage = Usage {
prompt_tokens,
completion_tokens: token_count,
total_tokens: prompt_tokens + token_count,
cache_creation_tokens: 0,
cache_read_tokens: 0,
};
let final_chunk =
make_final_chunk_with_reason(vec![], Some(usage), stop_reason.or(Some("end_turn".to_string())));
let _ = tx.blocking_send(Ok(final_chunk));
});
Ok(ReceiverStream::new(rx))
}
fn name(&self) -> &str {
&self.name
}
fn model(&self) -> &str {
&self.model_name
}
fn max_tokens(&self) -> u32 {
self.effective_max_tokens()
}
fn temperature(&self) -> f32 {
self.temperature
}
fn context_window_size(&self) -> Option<u32> {
Some(self.context_length)
}
}
// ============================================================================
// Tests
// ============================================================================
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_format_glm4_messages() {
let messages = vec![
Message::new(MessageRole::System, "You are a helpful assistant.".to_string()),
Message::new(MessageRole::User, "Hello!".to_string()),
];
let formatted = format_glm4(&messages);
assert!(formatted.starts_with("[gMASK]<sop>"));
assert!(formatted.contains("<|system|>\nYou are a helpful assistant."));
assert!(formatted.contains("<|user|>\nHello!"));
assert!(formatted.ends_with("<|assistant|>\n"));
}
#[test]
fn test_format_qwen_messages() {
let messages = vec![
Message::new(MessageRole::System, "You are a helpful assistant.".to_string()),
Message::new(MessageRole::User, "Hello!".to_string()),
];
let formatted = format_qwen(&messages);
assert!(formatted.contains("<|im_start|>system\nYou are a helpful assistant.<|im_end|>"));
assert!(formatted.contains("<|im_start|>user\nHello!<|im_end|>"));
assert!(formatted.ends_with("<|im_start|>assistant\n"));
}
#[test]
fn test_format_mistral_messages() {
let messages = vec![
Message::new(MessageRole::System, "You are a helpful assistant.".to_string()),
Message::new(MessageRole::User, "Hello!".to_string()),
];
let formatted = format_mistral(&messages);
assert!(formatted.starts_with("<s>[INST] "));
assert!(formatted.contains("You are a helpful assistant."));
assert!(formatted.contains("Hello!"));
assert!(formatted.contains("[/INST]"));
}
#[test]
fn test_format_llama_messages() {
let messages = vec![
Message::new(MessageRole::System, "You are a helpful assistant.".to_string()),
Message::new(MessageRole::User, "Hello!".to_string()),
];
let formatted = format_llama(&messages);
assert!(formatted.contains("<<SYS>>"));
assert!(formatted.contains("You are a helpful assistant."));
assert!(formatted.contains("<</SYS>>"));
assert!(formatted.contains("Hello!"));
assert!(formatted.contains("[/INST]"));
}
#[test]
fn test_glm4_stop_sequences() {
let stop_seqs = get_stop_sequences_for_model("glm4");
assert!(stop_seqs.contains(&"<|endoftext|>"));
assert!(stop_seqs.contains(&"<|user|>"));
assert!(stop_seqs.contains(&"<|observation|>"));
assert!(stop_seqs.contains(&"<|system|>"));
}
#[test]
fn test_qwen_stop_sequences() {
let stop_seqs = get_stop_sequences_for_model("qwen");
assert!(stop_seqs.contains(&"<|im_end|>"));
assert!(stop_seqs.contains(&"<|endoftext|>"));
assert!(stop_seqs.contains(&"<|im_start|>"));
}
#[test]
fn test_glm4_multi_turn_conversation() {
let messages = vec![
Message::new(MessageRole::System, "You are a coding assistant.".to_string()),
Message::new(
MessageRole::User,
"Write a hello world in Python.".to_string(),
),
Message::new(
MessageRole::Assistant,
"print('Hello, World!')".to_string(),
),
Message::new(MessageRole::User, "Now in Rust.".to_string()),
];
let formatted = format_glm4(&messages);
// Verify all parts are present in order
let system_pos = formatted.find("<|system|>").unwrap();
let user1_pos = formatted.find("<|user|>\nWrite a hello world").unwrap();
let assistant_pos = formatted.find("<|assistant|>\nprint").unwrap();
let user2_pos = formatted.find("<|user|>\nNow in Rust").unwrap();
let final_assistant_pos = formatted.rfind("<|assistant|>\n").unwrap();
assert!(system_pos < user1_pos);
assert!(user1_pos < assistant_pos);
assert!(assistant_pos < user2_pos);
assert!(user2_pos < final_assistant_pos);
}
#[test]
fn test_find_stop_sequence() {
let stop_seqs = vec!["</s>".to_string(), "<|im_end|>".to_string()];
assert_eq!(find_stop_sequence("hello world", &stop_seqs), None);
assert_eq!(find_stop_sequence("hello</s>world", &stop_seqs), Some(5));
assert_eq!(
find_stop_sequence("hello<|im_end|>world", &stop_seqs),
Some(5)
);
}
#[test]
fn test_truncate_at_stop_sequence() {
let stop_seqs = vec!["</s>".to_string()];
let mut text = "hello</s>world".to_string();
truncate_at_stop_sequence(&mut text, &stop_seqs);
assert_eq!(text, "hello");
let mut text2 = "no stop here".to_string();
truncate_at_stop_sequence(&mut text2, &stop_seqs);
assert_eq!(text2, "no stop here");
}
}