Configuration

Three-layer configuration system for Kremis: env vars, kremis.toml, and compiled defaults.

Kremis loads configuration at startup using a 3-layer priority chain:

env var  >  kremis.toml  >  compiled defaults

Higher-priority layers override lower ones, field by field. You can mix all three — for example, set stable values in kremis.toml and override secrets via env vars in CI.

kremis.toml

Place kremis.toml in the directory where you run kremis server or kremis-mcp. All fields are optional; omit any section you don’t need.

[logging]
format = "text"                          # "text" | "json"
level  = "kremis=info,tower_http=debug"  # tracing filter (same as RUST_LOG)

[api]
rate_limit = 100   # requests per second — 0 disables rate limiting

[security]
# api_key = ""     # Bearer token — prefer env var for secrets (see below)

[cors]
origins = []       # [] = localhost only | ["*"] = all | ["https://app.example.com"]

[mcp]
url = "http://localhost:8080"   # Kremis server URL used by the MCP bridge

Copy the example template to get started:

cp kremis.example.toml kremis.toml

kremis.toml is gitignored — your local configuration stays out of version control.

Environment Variables

Environment variables take precedence over kremis.toml. They are the recommended way to pass secrets and override settings in containerised environments.

Variable	Overrides	Default
KREMIS_LOG_FORMAT	[logging] format	text
RUST_LOG	[logging] level	kremis=info,tower_http=debug
KREMIS_RATE_LIMIT	[api] rate_limit	100
KREMIS_API_KEY	[security] api_key	(none — auth disabled)
KREMIS_CORS_ORIGINS	[cors] origins	(none — localhost only)
KREMIS_URL	[mcp] url	http://localhost:8080

Setting KREMIS_API_KEY to an empty string explicitly disables authentication, even if api_key is set in kremis.toml.

Docker Example

ENV KREMIS_LOG_FORMAT=json
ENV KREMIS_RATE_LIMIT=500
ENV KREMIS_API_KEY=<your-secret>
ENV KREMIS_CORS_ORIGINS=https://app.example.com

Or pass at runtime:

docker run \
  -e KREMIS_API_KEY=secret \
  -e KREMIS_LOG_FORMAT=json \
  kremis server

CI / GitHub Actions

env:
  KREMIS_API_KEY: ${{ secrets.KREMIS_API_KEY }}
  KREMIS_LOG_FORMAT: json

Sections Reference

[logging]

Field	Type	Default	Description
format	string	"text"	"text" for human-readable output, "json" for structured logs (Loki, Datadog, etc.)
level	string	"kremis=info,tower_http=debug"	tracing_subscriber filter — same syntax as RUST_LOG

[api]

Field	Type	Default	Description
rate_limit	u32	100	Global request rate in req/s. 0 disables the limiter entirely.

[security]

Field	Type	Default	Description
api_key	string	(none)	Bearer token. When set, all endpoints except /health require Authorization: Bearer <key>.

Never store api_key in kremis.toml in a shared repository. Use KREMIS_API_KEY or a secrets manager instead.

[cors]

Field	Type	Default	Description
origins	string[]	[]	Allowed CORS origins. Empty list restricts to localhost. ["*"] permits all origins.

[mcp]

Field	Type	Default	Description
url	string	"http://localhost:8080"	URL of the Kremis HTTP server. Used by kremis-mcp when proxying tool calls.

This section is read by both kremis (for the MCP bridge URL reference) and kremis-mcp (to know which server to proxy requests to).