zeph-core
Core agent loop, configuration, context builder, metrics, vault, and sub-agent orchestration for Zeph.
Overview
Core orchestration crate for the Zeph agent. Manages the main agent loop, bootstraps the application from TOML configuration with environment variable overrides, and assembles the LLM context from conversation history, skills, and memory. Includes sub-agent orchestration with zero-trust permission grants, background execution, filtered tool/skill access, A2A-based in-process communication channels, and /agent CLI commands for runtime management. All other workspace crates are coordinated through zeph-core.
Key modules
| Module | Description |
|---|---|
agent |
Agent<C> — main loop driving inference and tool execution; ToolExecutor erased via Box<dyn ErasedToolExecutor>; supports external cancellation via with_cancel_signal() |
agent::tool_execution |
Tool call handling, redaction, result processing; call_llm_with_retry() / call_chat_with_tools_retry() — auto-detect ContextLengthExceeded, compact context, and retry (max 2 attempts) |
agent::message_queue |
Message queue management |
agent::builder |
Agent builder API |
agent::commands |
Chat command dispatch (skills, feedback, skill management via /skill install and /skill remove, sub-agent management via /agent, etc.) |
agent::utils |
Shared agent utilities |
bootstrap |
AppBuilder — fluent builder for application startup |
channel |
Channel trait defining I/O adapters; LoopbackChannel / LoopbackHandle for headless daemon I/O (LoopbackHandle exposes cancel_signal: Arc<Notify> for session cancellation); Attachment / AttachmentKind for multimodal inputs |
config |
TOML config with ZEPH_* env overrides; typed ConfigError (Io, Parse, Validation, Vault) |
context |
LLM context assembly from history, skills, memory; resilient compaction with reactive context-overflow retry (max 2 attempts), middle-out progressive tool response removal (10/20/50/100% tiers), 9-section structured compaction prompt, LLM-free metadata fallback via build_metadata_summary() with safe UTF-8 truncation; parallel chunked summarization; tool-pair summarization via maybe_summarize_tool_pair() — when visible pairs exceed tool_call_cutoff, oldest pair is LLM-summarized with XML-delimited prompt and originals hidden via agent_visible=false; visibility-aware history loading (agent-only vs user-visible messages); durable compaction via replace_conversation(); uses shared Arc<TokenCounter> for accurate tiktoken-based budget tracking |
cost |
Token cost tracking and budgeting |
daemon |
Background daemon mode with PID file lifecycle (optional feature) |
metrics |
Runtime metrics collection |
project |
Project-level context detection |
redact |
Regex-based secret redaction (AWS, OpenAI, Anthropic, Google, GitLab, HuggingFace, npm, Docker) |
vault |
Secret storage and resolution via vault providers (age-encrypted read/write); scans ZEPH_SECRET_* keys to build the custom-secrets map used by skill env injection |
diff |
Diff rendering utilities |
pipeline |
Composable, type-safe step chains for multi-stage workflows |
subagent |
Sub-agent orchestration: SubAgentManager lifecycle with background execution, SubAgentDef TOML definitions, PermissionGrants zero-trust delegation, FilteredToolExecutor scoped tool access, A2A in-process channels, real-time status tracking |
Re-exports: Agent
Configuration
Key AgentConfig fields (TOML section [agent]):
| Field | Type | Default | Env override | Description |
|---|---|---|---|---|
name |
string | "zeph" |
— | Agent display name |
max_tool_iterations |
usize | 10 |
— | Max tool calls per turn |
summary_model |
string? | null |
— | Model used for context summarization |
auto_update_check |
bool | true |
ZEPH_AUTO_UPDATE_CHECK |
Check GitHub releases for a newer version on startup / via scheduler |
Key MemoryConfig fields (TOML section [memory]):
| Field | Type | Default | Description |
|---|---|---|---|
vector_backend |
"qdrant" / "sqlite" |
"qdrant" |
Vector search backend |
token_safety_margin |
f32 | 1.0 |
Safety multiplier for tiktoken-based token budget (validated: must be >= 1.0) |
redact_credentials |
bool | true |
Scrub secrets and paths before LLM context injection |
autosave_assistant |
bool | false |
Persist assistant responses to semantic memory automatically |
autosave_min_length |
usize | 20 |
Minimum response length (chars) to trigger autosave |
tool_call_cutoff |
usize | 6 |
Max visible tool call/response pairs before oldest is summarized via LLM |
[]
= true # set to false to disable update notifications
Set ZEPH_AUTO_UPDATE_CHECK=false to disable without changing the config file.
Sub-agent Commands
In-session commands for managing sub-agents:
| Command | Description |
|---|---|
/agent list |
List available sub-agent definitions |
/agent spawn <name> <prompt> |
Spawn a sub-agent with a task prompt |
/agent bg <name> <prompt> |
Spawn a background sub-agent |
/agent status |
Show active sub-agents with state, turns, and elapsed time |
/agent cancel <id> |
Cancel a running sub-agent by ID prefix |
@agent_name <prompt> |
Mention shorthand for /agent spawn (disambiguated from file references) |
Sub-agents run as independent tokio tasks with their own LLM provider and filtered tool executor. Each sub-agent receives only explicitly granted tools, skills, and secrets via PermissionGrants.
Installation
License
MIT