Environment variables

Client::from_env() reads a small set of environment variables to pick a provider, a key, and a default model. There are also a handful of runtime variables that affect behavior at a lower level. None are required if you build clients explicitly via Client::builder().

Provider selection

Variable	Required	Notes
`COGNIS_PROVIDER`	yes (for `from_env`)	One of `openai`, `anthropic`, `google`, `ollama`, `azure`, `openrouter`.

Per-provider credentials and defaults

Substitute <PROVIDER> with OPENAI, ANTHROPIC, GOOGLE, OLLAMA, AZURE, or OPENROUTER.

Variable	Default	Notes
`COGNIS_<PROVIDER>_API_KEY`	—	Provider key. Not needed for Ollama.
`COGNIS_<PROVIDER>_MODEL`	provider default	Default model name. Override per call via `ChatOptions::model`.
`COGNIS_<PROVIDER>_BASE_URL`	provider default	Override the API base. Useful for self-hosted or proxied backends.

Provider defaults vary; check the provider builder’s source for the exact value if you don’t override.

Azure-specific

Variable	Notes
`COGNIS_AZURE_API_KEY`	Azure OpenAI key.
`COGNIS_AZURE_ENDPOINT`	E.g. `https://your-resource.openai.azure.com`.
`COGNIS_AZURE_DEPLOYMENT`	The deployment name (your custom alias).
`COGNIS_AZURE_API_VERSION`	E.g. `2024-08-06`.
`COGNIS_AZURE_MODEL`	Optional model name (Azure typically uses deployment names).

Langfuse (cognis-trace, feature `langfuse`)

LangfuseExporter::from_env() and LangfuseConfig::from_env() read these. Not prefixed with COGNIS_ to match Langfuse’s conventions.

Variable	Required	Notes
`LANGFUSE_PUBLIC_KEY`	yes	`pk-lf-...`
`LANGFUSE_SECRET_KEY`	yes	`sk-lf-...`
`LANGFUSE_HOST`	optional	Defaults to `https://cloud.langfuse.com`. Override for self-hosted.

Examples

# OpenAI:
export COGNIS_PROVIDER=openai
export COGNIS_OPENAI_API_KEY=sk-...
export COGNIS_OPENAI_MODEL=gpt-4o-mini

# Anthropic:
export COGNIS_PROVIDER=anthropic
export COGNIS_ANTHROPIC_API_KEY=sk-ant-...

# Local Ollama:
export COGNIS_PROVIDER=ollama
export COGNIS_OLLAMA_MODEL=llama3.1
# COGNIS_OLLAMA_BASE_URL defaults to http://localhost:11434

# Azure:
export COGNIS_PROVIDER=azure
export COGNIS_AZURE_API_KEY=...
export COGNIS_AZURE_ENDPOINT=https://your-resource.openai.azure.com
export COGNIS_AZURE_DEPLOYMENT=gpt-4o-prod
export COGNIS_AZURE_API_VERSION=2024-08-06

# OpenRouter:
export COGNIS_PROVIDER=openrouter
export COGNIS_OPENROUTER_API_KEY=...
export COGNIS_OPENROUTER_MODEL=anthropic/claude-sonnet-4

Runtime variables

Cognis honors the standard tracing env vars for log filtering:

export RUST_LOG=cognis=info,cognis_trace=debug

There is no global verbosity flag; control it through tracing-subscriber’s filter directives.

What about `.env` files?

Cognis does not read .env files. Plain .env on disk is a security footgun (they ship to backups, logs, and screen-sharing surfaces). Recommended setup on macOS / Linux: direnv + envchain so the same shell-loaded vars are picked up automatically. See Installation → Set credentials. For CI: set the same variables in your runner’s secret store.

Installation

The full credentials setup.

Models and providers

Builder shapes when env vars aren’t enough.

API per crate

Reference

Environment variables

Provider selection

Per-provider credentials and defaults

Azure-specific

Langfuse (cognis-trace, feature `langfuse`)

Examples

Runtime variables

What about `.env` files?

See also

Installation

Models and providers

​Provider selection

​Per-provider credentials and defaults

​Azure-specific

​Langfuse (cognis-trace, feature langfuse)

​Examples

​Runtime variables

​What about .env files?

​See also

Installation

Models and providers

Provider selection

Per-provider credentials and defaults

Azure-specific

Langfuse (cognis-trace, feature `langfuse`)

Examples

Runtime variables

What about `.env` files?

See also