use std::fs;
use std::path::{Path, PathBuf};
use engram_storage::Database;
use crate::config::home_directory;
use crate::error::CoreError;
const ENGRAM_DIRECTORY: &str = ".engram";
const CONFIG_FILENAME: &str = "engram.toml";
const AGENT_MD_FILENAME: &str = "AGENT.md";
const DATABASE_FILENAME: &str = "engram.db";
const SOCKET_FILENAME: &str = "engram.sock";
const MCP_JSON_FILENAME: &str = ".mcp.json";
const GITIGNORE_FILENAME: &str = ".gitignore";
const GITIGNORE_MARKER: &str = ".engram/";
const AGENT_MD_CONTENT: &str = include_str!("../AGENT.md");
const UNIX_SOCKET_PATH_MAX_BYTES: usize = 104;
const MCP_NPX_PACKAGE: &str = "@engramm/engram-mcp-server";
const DEFAULT_ENGRAM_BIN_NAME: &str = "engram";
const DEFAULT_CONFIG_TEMPLATE: &str = r#"# Global engram config. Runtime always prefers per-project state under
# <project>/.engram/{engram.db, engram.sock} (discovered by walking up from cwd
# like .git). No database.path setting is needed for normal use; the runtime
# resolves it from the project marker, and ENGRAM_DB_PATH env var overrides
# both.
[embedding]
provider = "voyage" # voyage | ollama | deterministic
model = "voyage-4"
dimension = 1024
# host: only for provider = "ollama". Defaults to http://localhost:11434 (ENGRAM_OLLAMA_HOST overrides).
# hyde_threshold: opt-in HyDE. 0 = disabled (default). N>0 = enable HyDE
# when the query has fewer than N words. HyDE adds ~1.5s latency on cache
# miss but improves recall on terse queries; cache is keyed by the
# original query so repeated calls are instant.
hyde_threshold = 0
[llm]
provider = "openai" # openai | ollama | local
model = "gpt-4o-mini"
# host: only for provider = "ollama". Defaults to http://localhost:11434 (ENGRAM_OLLAMA_HOST overrides).
[server]
# socket_path is optional and only used as a last-resort fallback when no
# project .engram/ marker is found and ENGRAM_SOCKET_PATH is not set.
# Uncomment to provide an explicit fallback location:
# socket_path = "~/.engram/engram.sock"
reindex_interval_secs = 3600
[hnsw]
max_connections = 16
ef_construction = 200
ef_search = 40
dimension = 1024
[consolidation]
stale_days = 90
min_score = 0.3
"#;
const PROJECT_LOCAL_CONFIG_TEMPLATE: &str = r#"# Project-local engram config. Every value here is deep-merged over the
# global ~/.engram/engram.toml — uncomment only the fields this project
# needs to override; anything left commented is inherited from global.
# Effective priority: ENGRAM_* env vars > this file > global config.
#
# Provider API keys are intentionally absent here — they are always taken
# from the global config and can never be set or overridden per project.
# [embedding]
# model = "voyage-4"
# dimension = 1024
# output_dimension = 1024
# hyde_threshold = 0
# host = "http://localhost:11434" # only for provider = "ollama"
# [llm]
# model = "gpt-4o-mini"
# host = "http://localhost:11434" # only for provider = "ollama"
# [server]
# reindex_interval_secs = 3600
# [hnsw]
# max_connections = 16
# ef_construction = 200
# ef_search = 40
# dimension = 1024
# [consolidation]
# stale_days = 90
# min_score = 0.3
"#;
#[derive(Debug)]
pub enum McpCommand {
Node { script_path: PathBuf },
Npx,
}
pub fn execute() -> Result<(), CoreError> {
let cwd = std::env::current_dir()
.map_err(|error| CoreError::InitFailed(format!("cwd unavailable: {error}")))?;
let home = home_directory()
.ok_or_else(|| CoreError::InitFailed("HOME environment variable not set".into()))?;
try_interactive_wizard();
execute_with_dirs(&cwd, Path::new(&home))
}
pub fn execute_with_dirs(project_dir: &Path, home_dir: &Path) -> Result<(), CoreError> {
validate_socket_path(project_dir)?;
let home_config_path = home_dir.join(ENGRAM_DIRECTORY).join(CONFIG_FILENAME);
let mcp_command = resolve_mcp_server_command();
if home_config_path.exists() {
create_engram_directory(project_dir)?;
write_project_local_config(project_dir)?;
initialize_database(project_dir)?;
write_agent_instructions(project_dir)?;
write_mcp_json(project_dir, &mcp_command)?;
write_gitignore(project_dir)?;
return Ok(());
}
create_engram_directory(project_dir)?;
write_project_local_config(project_dir)?;
write_default_config_to_home(home_dir)?;
write_mcp_json(project_dir, &mcp_command)?;
initialize_database(project_dir)?;
write_agent_instructions(project_dir)?;
write_gitignore(project_dir)?;
print_completion_info(project_dir);
Ok(())
}
fn try_interactive_wizard() {
if !std::io::IsTerminal::is_terminal(&std::io::stdin()) {
return;
}
let _ = std::process::Command::new("engram-tui")
.arg("init")
.status();
}
fn validate_socket_path(project_dir: &Path) -> Result<(), CoreError> {
let socket_path = project_dir.join(ENGRAM_DIRECTORY).join(SOCKET_FILENAME);
let length = socket_path.as_os_str().as_encoded_bytes().len();
if length >= UNIX_SOCKET_PATH_MAX_BYTES {
return Err(CoreError::InitFailed(format!(
"project path too deep: socket path '{}' is {length} bytes, max {} (UNIX limit)",
socket_path.display(),
UNIX_SOCKET_PATH_MAX_BYTES - 1
)));
}
Ok(())
}
fn create_engram_directory(project_dir: &Path) -> Result<(), CoreError> {
let target = project_dir.join(ENGRAM_DIRECTORY);
fs::create_dir_all(&target).map_err(|error| {
CoreError::InitFailed(format!("failed to create {}: {error}", target.display()))
})
}
fn write_project_local_config(project_dir: &Path) -> Result<(), CoreError> {
let config_path = project_dir.join(ENGRAM_DIRECTORY).join(CONFIG_FILENAME);
if config_path.exists() {
return Ok(());
}
fs::write(&config_path, PROJECT_LOCAL_CONFIG_TEMPLATE).map_err(|error| {
CoreError::InitFailed(format!(
"failed to write {}: {error}",
config_path.display()
))
})
}
fn write_default_config_to_home(home_dir: &Path) -> Result<(), CoreError> {
let home_engram = home_dir.join(ENGRAM_DIRECTORY);
fs::create_dir_all(&home_engram).map_err(|error| {
CoreError::InitFailed(format!(
"failed to create {}: {error}",
home_engram.display()
))
})?;
let config_path = home_engram.join(CONFIG_FILENAME);
if config_path.exists() {
return Ok(());
}
fs::write(&config_path, DEFAULT_CONFIG_TEMPLATE)
.map_err(|error| CoreError::InitFailed(format!("failed to write config: {error}")))
}
fn initialize_database(project_dir: &Path) -> Result<(), CoreError> {
let engram_dir = project_dir.join(ENGRAM_DIRECTORY);
fs::create_dir_all(&engram_dir).map_err(|error| {
CoreError::InitFailed(format!("failed to create database directory: {error}"))
})?;
let database_path = engram_dir.join(DATABASE_FILENAME);
let database_path_str = database_path
.to_str()
.ok_or_else(|| CoreError::InitFailed("database path is not valid utf-8".into()))?;
let _database = Database::open(database_path_str)?;
println!("Database initialized at {database_path_str}");
Ok(())
}
fn write_agent_instructions(project_dir: &Path) -> Result<(), CoreError> {
let agent_md_path = project_dir.join(ENGRAM_DIRECTORY).join(AGENT_MD_FILENAME);
fs::write(&agent_md_path, AGENT_MD_CONTENT)
.map_err(|error| CoreError::InitFailed(format!("failed to write AGENT.md: {error}")))?;
println!("Agent instructions written to {}", agent_md_path.display());
Ok(())
}
fn resolve_mcp_server_command() -> McpCommand {
if let Ok(env_path) = std::env::var("ENGRAM_MCP_SERVER_PATH") {
let path = PathBuf::from(&env_path);
if path.exists() {
return McpCommand::Node { script_path: path };
}
}
if let Some(bin_path) = resolve_engram_bin()
&& let Some(bin_dir) = bin_path.parent()
{
let candidate = bin_dir
.join("..")
.join("mcp-server")
.join("dist")
.join("index.js");
if candidate.exists() {
if let Ok(canonical) = candidate.canonicalize() {
return McpCommand::Node {
script_path: canonical,
};
}
return McpCommand::Node {
script_path: candidate,
};
}
}
eprintln!(
"warning: could not locate bundled engram mcp-server script; falling back to 'npx {MCP_NPX_PACKAGE}'. \
Set ENGRAM_MCP_SERVER_PATH to an absolute path of mcp-server/dist/index.js to silence this warning."
);
McpCommand::Npx
}
fn resolve_engram_bin() -> Option<PathBuf> {
if let Ok(value) = std::env::var("ENGRAM_BIN") {
let candidate = PathBuf::from(value);
if candidate.exists() {
return Some(candidate);
}
}
let output = std::process::Command::new("which")
.arg(DEFAULT_ENGRAM_BIN_NAME)
.output()
.ok()?;
if !output.status.success() {
return None;
}
let stdout = String::from_utf8(output.stdout).ok()?;
let trimmed = stdout.trim();
if trimmed.is_empty() {
return None;
}
Some(PathBuf::from(trimmed))
}
fn write_mcp_json(project_dir: &Path, command: &McpCommand) -> Result<(), CoreError> {
let (command_name, args): (&str, Vec<String>) = match command {
McpCommand::Node { script_path } => {
let path_str = script_path
.to_str()
.ok_or_else(|| CoreError::InitFailed("mcp script path is not valid utf-8".into()))?
.to_string();
("node", vec![path_str])
}
McpCommand::Npx => ("npx", vec![MCP_NPX_PACKAGE.to_string()]),
};
let engram_bin = resolve_engram_bin();
let engram_bin_string = engram_bin.as_ref().and_then(|path| {
let canonical = path.canonicalize().unwrap_or_else(|_| path.clone());
canonical.to_str().map(|value| value.to_string())
});
let mut server_entry = serde_json::json!({
"command": command_name,
"args": args,
});
if let Some(bin_string) = engram_bin_string.as_ref() {
server_entry["env"] = serde_json::json!({ "ENGRAM_BIN": bin_string });
} else {
eprintln!(
"warning: could not resolve engram binary; MCP config has no ENGRAM_BIN env — set it manually before starting Claude Code"
);
}
let document = serde_json::json!({
"mcpServers": {
"engram": server_entry,
}
});
let serialized = serde_json::to_string_pretty(&document)
.map_err(|error| CoreError::InitFailed(format!("failed to serialize mcp json: {error}")))?;
let mcp_path = project_dir.join(MCP_JSON_FILENAME);
fs::write(&mcp_path, serialized)
.map_err(|error| CoreError::InitFailed(format!("failed to write .mcp.json: {error}")))?;
println!("MCP config written to {}", mcp_path.display());
Ok(())
}
fn write_gitignore(project_dir: &Path) -> Result<(), CoreError> {
let gitignore_path = project_dir.join(GITIGNORE_FILENAME);
let existing = match fs::read_to_string(&gitignore_path) {
Ok(content) => content,
Err(error) if error.kind() == std::io::ErrorKind::NotFound => String::new(),
Err(error) => {
return Err(CoreError::InitFailed(format!(
"failed to read .gitignore: {error}"
)));
}
};
if gitignore_contains_marker(&existing) {
return Ok(());
}
let mut updated = existing;
if !updated.is_empty() && !updated.ends_with('\n') {
updated.push('\n');
}
updated.push_str(GITIGNORE_MARKER);
updated.push('\n');
fs::write(&gitignore_path, updated)
.map_err(|error| CoreError::InitFailed(format!("failed to write .gitignore: {error}")))
}
fn gitignore_contains_marker(content: &str) -> bool {
content.lines().any(|line| {
line.trim() == GITIGNORE_MARKER.trim_end_matches('/') || line.trim() == GITIGNORE_MARKER
})
}
fn print_completion_info(project_dir: &Path) {
println!();
println!("Engram initialized at {}", project_dir.display());
println!();
println!("Set API keys via environment variables:");
println!(" export ENGRAM_VOYAGE_API_KEY=your-voyage-key");
println!(" export ENGRAM_OPENAI_API_KEY=your-openai-key");
println!();
println!("MCP config written to .mcp.json; Claude Code will pick it up automatically.");
println!("Add to your project's CLAUDE.md:");
println!(" Engram memory system: .engram/AGENT.md");
}
#[cfg(test)]
mod docs_invariant_tests {
use super::DEFAULT_CONFIG_TEMPLATE;
const README: &str = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/../../README.md"));
const EMBEDDING_PROVIDERS: [&str; 3] = ["voyage", "ollama", "deterministic"];
const LLM_PROVIDERS: [&str; 3] = ["openai", "ollama", "local"];
#[test]
fn every_provider_enum_appears_in_template_and_readme() {
for provider in EMBEDDING_PROVIDERS.iter().chain(LLM_PROVIDERS.iter()) {
assert!(
DEFAULT_CONFIG_TEMPLATE.contains(provider),
"config template must document provider `{provider}`"
);
assert!(
README.contains(provider),
"README must document provider `{provider}`"
);
}
}
}