Architecture
This page is the top-level map of Minerva Agent internals. Use it to orient yourself in the codebase, then dive into subsystem-specific docs for implementation details.
System Overview
┌─────────────────────────────────────────────────────────────────────┐
│ Entry Points │
│ │
│ CLI (cli.py) Gateway (gateway/run.py) ACP (acp_adapter/) │
│ TUI / Desktop API Server Python Library │
└──────────┬──────────────┬───────────────────────┬───────────────────┘
│ │ │
▼ ▼ ▼
┌─────────────────────────────────────────────────────────────────────┐
│ AIAgent (run_agent.py) │
│ │
│ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │
│ │ Prompt │ │ Provider │ │ Tool │ │
│ │ Builder │ │ Resolution │ │ Dispatch │ │
│ │ (prompt_ │ │ (runtime_ │ │ (model_ │ │
│ │ builder.py) │ │ provider.py)│ │ tools.py) │ │
│ └──────┬───────┘ └──────┬───────┘ └──────┬───────┘ │
│ │ │ │ │
│ ┌──────┴───────┐ ┌──────┴───────┐ ┌──────┴───────┐ │
│ │ Compression │ │ 3 API Modes │ │ Tool Registry│ │
│ │ & Caching │ │ chat_compl. │ │ (registry.py)│ │
│ │ │ │ codex_resp. │ │ 70+ tools │ │
│ │ │ │ anthropic │ │ ~40 toolsets │ │
│ └──────────────┘ └──────────────┘ └──────────────┘ │
└─────────┴─────────────────┴─────────────────┴───────────────────────┘
│ │
▼ ▼
┌───────────────────┐ ┌──────────────────────┐
│ Session Storage │ │ Tool Backends │
│ (SQLite + FTS5) │ │ Terminal (7 backends) │
│ minerva_state.py │ │ Browser (5 backends) │
│ gateway/session.py│ │ Web (10 backends) │
└───────────────────┘ │ MCP (dynamic) │
│ File, Vision, etc. │
└──────────────────────┘
Directory Structure
minerva-agent/
├── run_agent.py # AIAgent facade — loop lives in agent/conversation_loop.py + agent/turn_*.py
├── cli.py # MinervaCLI facade — mixins in minerva_cli/cli_*_mixin.py
├── model_tools.py # Tool discovery, schema collection, dispatch
├── toolsets.py # Tool groupings and platform presets
├── minerva_state.py # SQLite session/state database facade (+ minerva_state_*.py siblings)
├── minerva_constants.py # MINERVA_HOME, profile-aware paths
│
├── agent/ # Agent internals
│ ├── prompt_builder.py # System prompt assembly
│ ├── context_engine.py # ContextEngine ABC (pluggable)
│ ├── context_compressor.py # Default engine — lossy summarization
│ ├── prompt_caching.py # Anthropic prompt caching
│ ├── auxiliary_client.py # Auxiliary LLM for side tasks (vision, summarization)
│ ├── model_metadata.py # Model context lengths, token estimation
│ ├── models_dev.py # models.dev registry integration
│ ├── anthropic_adapter.py # Anthropic Messages API format conversion
│ ├── display.py # KawaiiSpinner, tool preview formatting
│ ├── skill_commands.py # Skill slash commands
│ ├── memory_manager.py # Memory manager orchestration
│ ├── memory_provider.py # Memory provider ABC
│ └── trajectory.py # Trajectory saving helpers
│
├── minerva_cli/ # CLI subcommands and setup
│ ├── main.py # Entry point — `minerva` subcommands (parsers in subcommands/, main_*.py)
│ ├── config.py # DEFAULT_CONFIG, OPTIONAL_ENV_VARS, migration
│ ├── commands.py # COMMAND_REGISTRY — central slash command definitions
│ ├── auth.py # PROVIDER_REGISTRY, credential resolution (+ auth_*.py siblings)
│ ├── runtime_provider.py # Provider → api_mode + credentials
│ ├── models.py # Model catalog, provider model lists
│ ├── model_switch.py # /model command logic (CLI + gateway shared)
│ ├── setup.py # Interactive setup wizard (+ setup_*.py siblings)
│ ├── skin_engine.py # CLI theming engine
│ ├── skills_config.py # minerva skills — enable/disable per platform
│ ├── skills_hub.py # /skills slash command
│ ├── tools_config.py # minerva tools — enable/disable per platform
│ ├── plugins.py # PluginManager — discovery, loading, hooks
│ ├── callbacks.py # Terminal callbacks (clarify, sudo, approval)
│ └── gateway.py # minerva gateway start/stop
│
├── tools/ # Tool implementations (one file per tool)
│ ├── registry.py # Central tool registry
│ ├── approval.py # Dangerous command detection
│ ├── terminal_tool.py # Terminal orchestration
│ ├── process_registry.py # Background process management
│ ├── file_tools.py # read_file, write_file, patch, search_files
│ ├── web_tools.py # web_search, web_extract
│ ├── browser_tool.py # Browser automation tools facade (+ browser_tool_*.py siblings)
│ ├── code_execution_tool.py # execute_code sandbox
│ ├── delegate_tool.py # Subagent delegation
│ ├── mcp_tool.py # MCP client facade (+ mcp_tool_*.py siblings)
│ ├── credential_files.py # File-based credential passthrough
│ ├── env_passthrough.py # Env var passthrough for sandboxes
│ ├── ansi_strip.py # ANSI escape stripping
│ └── environments/ # Terminal backends (local, docker, ssh, modal, daytona, singularity, vercel_sandbox)
│
├── gateway/ # Messaging platform gateway
│ ├── run.py # GatewayRunner facade — message dispatch (+ run_*.py siblings)
│ ├── session.py # SessionStore — conversation persistence
│ ├── delivery.py # Outbound message delivery
│ ├── pairing.py # DM pairing authorization
│ ├── hooks.py # Hook discovery and lifecycle events
│ ├── mirror.py # Cross-session message mirroring
│ ├── status.py # Token locks, profile-scoped process tracking
│ └── platforms/ # Built-in adapters: webhook, api_server
│
├── plugins/platforms/ # Bundled platform plugins: telegram, discord, slack
│
├── acp_adapter/ # ACP server (VS Code / Zed / JetBrains)
├── cron/ # Scheduler (jobs.py, scheduler.py)
├── plugins/memory/ # Memory provider plugins
├── plugins/context_engine/ # Context engine plugins
├── skills/ # Bundled skills, by category (all active)
├── website/ # Docusaurus documentation site
└── tests/ # Pytest suite (~40,000 tests across ~3,500 files)
Data Flow
CLI Session
User input → MinervaCLI.chat()
→ AIAgent.run_conversation()
→ system_prompt.build_system_prompt()
→ runtime_provider.resolve_runtime_provider()
→ API call (chat_completions / codex_responses / anthropic_messages)
→ tool_calls? → model_tools.handle_function_call() → loop
→ final response → display → save to SessionDB
Gateway Message
Platform event → Adapter.on_message() → MessageEvent
→ GatewayRunner._handle_message()
→ authorize user
→ resolve session key
→ create AIAgent with session history
→ AIAgent.run_conversation()
→ deliver response back through adapter
Cron Job
Scheduler tick → load due jobs from jobs.json
→ create fresh AIAgent (no history)
→ inject attached skills as context
→ run job prompt
→ deliver response to target platform
→ update job state and next_run
Recommended Reading Order
If you are new to the codebase:
- This page — orient yourself
- Agent Loop Internals — how AIAgent works
- Prompt Assembly — system prompt construction
- Provider Runtime Resolution — how providers are selected
- Adding Providers — practical guide to adding a new provider
- Tools Runtime — tool registry, dispatch, environments
- Session Storage — SQLite schema, FTS5, session lineage
- Gateway Internals — messaging platform gateway
- Context Compression & Prompt Caching — compression and caching
- ACP Internals — IDE integration
Major Subsystems
Agent Loop
The synchronous orchestration engine (AIAgent, exposed by the run_agent.py facade; the loop lives in agent/conversation_loop.py and agent/turn_*.py). Handles provider selection, prompt construction, tool execution, retries, fallback, callbacks, compression, and persistence. Supports three API modes for different provider backends.
Prompt System
Prompt construction and maintenance across the conversation lifecycle:
system_prompt.py+prompt_builder.py— assembles the ordered system-prompt tiers (stable→context→volatile): identity/tool guidance/skills, context files, then memory/profile/timestamp blocksprompt_caching.py— Applies Anthropic cache breakpoints for prefix cachingcontext_compressor.py— Summarizes middle conversation turns when context exceeds thresholds
→ Prompt Assembly, Context Compression & Prompt Caching
Provider Resolution
A shared runtime resolver used by CLI, gateway, cron, ACP, and auxiliary calls. Maps (provider, model) tuples to (api_mode, api_key, base_url). Handles 18+ providers, OAuth flows, credential pools, and alias resolution.
Tool System
Central tool registry (tools/registry.py) with 70+ registered tools across ~40 toolsets. Each tool file self-registers at import time. The registry handles schema collection, dispatch, availability checking, and error wrapping. Terminal tools support 7 backends (local, Docker, SSH, Daytona, Modal, Singularity, Vercel Sandbox).
Session Persistence
SQLite-based session storage with FTS5 full-text search. Sessions have lineage tracking (parent/child across compressions), per-platform isolation, and atomic writes with contention handling.
Messaging Gateway
Long-running process with platform adapters (Telegram, Discord, Slack, webhooks, API server), unified session routing, user authorization (allowlists + DM pairing), slash command dispatch, hook system, cron ticking, and background maintenance.
Plugin System
Three discovery sources: ~/.minerva/plugins/ (user), .minerva/plugins/ (project), and pip entry points. Plugins register tools, hooks, and CLI commands through a context API. Two specialized plugin types exist: memory providers (plugins/memory/) and context engines (plugins/context_engine/). Both are single-select — only one of each can be active at a time, configured via minerva plugins or config.yaml.
→ Plugin Guide, Memory Provider Plugin
Cron
First-class agent tasks (not shell tasks). Jobs store in JSON, support multiple schedule formats, can attach skills and scripts, and deliver to any platform.
ACP Integration
Exposes Minerva as an editor-native agent over stdio/JSON-RPC for VS Code, Zed, and JetBrains.
Trajectories
Saves agent sessions as ShareGPT-format trajectories (save_trajectories) for training data or debugging.
→ Trajectories & Training Format
Design Principles
| Principle | What it means in practice |
|---|---|
| Prompt stability | System prompt doesn't change mid-conversation. No cache-breaking mutations except explicit user actions (/model). |
| Observable execution | Every tool call is visible to the user via callbacks. Progress updates in CLI (spinner) and gateway (chat messages). |
| Interruptible | API calls and tool execution can be cancelled mid-flight by user input or signals. |
| Platform-agnostic core | One AIAgent class serves CLI, TUI/desktop, gateway, ACP, and API server. Platform differences live in the entry point, not the agent. |
| Loose coupling | Optional subsystems (MCP, plugins, memory providers) use registry patterns and check_fn gating, not hard dependencies. |
| Profile isolation | Each profile (minerva -p <name>) gets its own MINERVA_HOME, config, memory, sessions, and gateway PID. Multiple profiles run concurrently. |
File Dependency Chain
tools/registry.py (no deps — imported by all tool files)
↑
tools/*.py (each calls registry.register() at import time)
↑
model_tools.py (imports tools/registry + triggers tool discovery)
↑
run_agent.py, cli.py
This chain means tool registration happens at import time, before any agent instance is created. Any tools/*.py file with a top-level registry.register() call is auto-discovered — no manual import list needed.