Configuration

Everything Xynthis persists lives under one directory, ~/.xynthis by default. XYNTHIS_HOME relocates most of it: config, sessions, skills and the daemon’s PID file all resolve through it. It does not move the brain’s stores. bmc/, and with it identity.ed25519 and witness.log, stays at ~/.xynthis/bmc whatever XYNTHIS_HOME is set to; only the brain socket follows the override. persona.txt likewise resolves against your real home directory. If you are relocating to move your memory onto another volume, that is the part it will not move.

Directory layout

~/.xynthis/
├── bin/                   installed binaries + skill scripts
├── bmc/                   binary memory stores (the brain's persistent state)
├── sessions/              per-session JSON + working-memory ledgers
├── skills/                skill library (one SKILL.md per directory)
├── skill/                 per-user skill model checkpoint
├── llm/                   on-device model state (state.json, train_config.json, checkpoints)
├── extensions/            external MCP/webhook extension manifests
├── recipes/               task templates (<name>.yaml)
├── archive/               archived sessions (xynthis sessions archive)
├── serve_<port>.pid       daemon PID file, one per serve port
├── logs/                  daemon stdout/stderr
├── brain.sock             unix socket — the brain's only API
├── config.toml            model + provider config
├── auth.json              API keys (mode 0600)
├── lessons.json           the agent's failure-to-correction store
├── learned_actions.json   cached successful tool patterns
├── tool_policy.json       per-tool allow / deny / ask-always policy
├── cortex.json            situation bulletin (when built)
└── persona.txt            condensed user persona (when built)

Inside bmc/, alongside the memory store itself, the brain also keeps identity.ed25519 (the local signing identity for witnessed memory, mode 0600) and witness.log (the append-only Merkle log of confirmed facts). The brain is the only process that writes bmc/. Everything else (the CLI, the daemon, the app, MCP clients) goes through brain.sock.

config.toml

Two sections: [models] selects what runs, [providers.<name>] defines how to reach each backend. Missing files are replaced by defaults, so a brand-new machine works without any config.

[models]
active = "anthropic/claude-sonnet-4-5"
fast = "anthropic/claude-haiku-4-5"      # optional

[providers.anthropic]
kind = "anthropic-messages"
base_url = "https://api.anthropic.com/v1/messages"
default_model = "claude-sonnet-4-5"

[providers.ollama]
kind = "openai-chat"
base_url = "http://localhost:11434/v1"
default_model = "llama3.3"

[models]

Field	Type	Default	Meaning
`active`	string	`"echo"`	Active target: `"<provider>/<model>"`, or `"<provider>"` to use its `default_model`. Also accepts `"auto"` / `"auto:fast"` / `"auto:deep"` / `"auto:private"` to route per call — see Smart Auto
`fast`	string	unset	Optional cheaper target the agent uses for easy turns (post-tool summaries, short acknowledgements). Same format as `active`. Unset means every turn goes to `active`

[providers.<name>]

Field	Type	Default	Meaning
`kind`	string	required	One of `anthropic-messages`, `openai-chat`, `subprocess`, `codex-oauth`, `claude-oauth`, `xynthis-llm`, `echo`
`base_url`	string	unset	HTTP backends: for `openai-chat`, the root without `/chat/completions`; for `anthropic-messages`, the full `/messages` endpoint
`default_model`	string	unset	Model id used when the target doesn’t name one
`command`	string	unset	`subprocess` only: the CLI to spawn (e.g. `"claude"`)
`args`	string array	`[]`	`subprocess` only: fixed arguments
`model_arg`	string	unset	`subprocess` only: flag used to pass the model name (e.g. `"--model"`)
`lite`	bool	`false`	Lite mode for small local models: plain chat with no tool schemas, a short system prompt, and no pre-turn memory injection. Set this for models that can’t tool-call
`launch_command`	string	unset	Local providers only: shell command that starts the provider’s server when it isn’t running

The kind values map to how xynthis reaches the backend: openai-chat covers OpenAI, Ollama, llama.cpp, Groq, DeepSeek, Gemini, xAI, LM Studio, and anything else implementing the standard. subprocess pipes through an external CLI like claude or codex using that CLI’s own auth. codex-oauth and claude-oauth call the respective backends directly with tokens from an existing Codex or Claude Code login. xynthis-llm targets the local model server on http://127.0.0.1:8080/v1. echo is a deterministic network-free fallback. Twenty-one providers are pre-registered on first save: echo, anthropic, openai, ollama, xynthis-llm, llamacpp, groq, deepseek, gemini, xai, claude-code, codex, codex-oauth, claude-oauth, claude-fable, codex-5-6, apfel, minicpm, llama-1b, qwen-05b, and qwen-3b. xynthis models list --all shows them.

API keys

Keys never live in config.toml. Lookup order per provider: the macOS Keychain (service com.xynthis.app, account <provider>-api-key; this is where the app’s Settings writes), then ~/.xynthis/auth.json (written by xynthis login and xynthis auth apply, mode 0600).

Environment variables

Variable	Default	Effect
`XYNTHIS_HOME`	`~/.xynthis`	Relocate the entire data directory. Blank values are treated as unset
`XYNTHIS_BRAIN_SOCKET`	`$XYNTHIS_HOME/brain.sock`	Override the brain socket path
`XYNTHIS_LLM_OVERRIDE`	unset	Force an LLM target for one invocation (same as the global `--llm` flag); does not write config
`XYNTHIS_NO_APP`	unset	`1` stops `xynthis chat` from launching the macOS app
`XYNTHIS_API_KEY`	unset	Non-interactive key for `xynthis models add`
`XYNTHIS_SKILLS_DIR`	`~/.xynthis/skills`	Override the skill library root
`XYNTHIS_CORTEX`	off	`on` injects the cortex bulletin into the system prompt
`XYNTHIS_CORTEX_REFRESH_SECS`	`900`	Bulletin staleness threshold in seconds
`XYNTHIS_LEXICAL_FLOOR`	on	`0` disables the lexical floor in memory retrieval (re-scoring stage that guarantees strong keyword matches rank)
`XYNTHIS_LLM_PORT`	`8080`	Model server listen port
`XYNTHIS_LLM_BIND`	`127.0.0.1`	Model server bind address. `0.0.0.0` listens on all interfaces; only do that behind a tunnel or VPN
`XYNTHIS_LLM_SMALL`	unset	Set to serve the smaller backbone preset
`XYNTHIS_LLM_MODEL_ID`	`xynthis-local`	Model id advertised on `/v1/models`
`XYNTHIS_LLM_TRAIN`	unset	First-run seed only: if set (any value) when `~/.xynthis/llm/train_config.json` does not exist, the model server creates that file with training enabled. Once the file exists, it governs and this variable is ignored; toggle training with the MCP `llm_train_set` tool or the app
`XYNTHIS_JSPACE`	off	Set to capture workspace readouts; responses carry `xynthis_jspace`
`XYNTHIS_JSPACE_TOPK`	`5`	Concepts captured per generated token (minimum 1)
`XYNTHIS_JSPACE_TO_BRAIN`	off	Also submit each reply’s readout summary to the brain as short-lived working-memory context. Requires `XYNTHIS_JSPACE`; inert without it

Getting started

Core concepts

Guides

On-device model

Reference

Directory layout

config.toml

[models]

[providers.<name>]

API keys

Environment variables

​Directory layout

​config.toml

​[models]

​[providers.<name>]

​API keys

​Environment variables

Directory layout

config.toml

[models]

[providers.<name>]

API keys

Environment variables