Configuration

Reference and diagnostic hub for environment variables and on-disk paths: database URLs, ENGINE_URL, LLM credentials, *_ROOT artifact directories, worker tuning, recovery timeouts, and OpenTelemetry. Use it after the demo arc when wiring production-like settings, and when a demo fails because .env, *_ROOT, or host vs container paths do not line up — symptom tables on each demo page and Troubleshooting are the first stop; this page is the full env catalog and path map.

Copy .env.example to .env at the repo root and set the variables in the tables below. Process environment variables override .env values.

Runtime context

Warden splits work across processes that may not share the same filesystem view. Under make up, engine and worker run in containers while you typically run the CLI on the host.

Rule of thumb: The CLI needs access to manifest YAML (paths you pass to warden deploy -f …). The engine and worker need access to prompts, policies, schemas, and compensations via *_ROOT inside their process environment—not your host ./config/... paths unless Compose mounts those files at the container roots below.

Dev stack (make up)

Engine and worker run in containers; you run warden on the host.

Setting	Host (CLI)	Engine / worker (containers)
POSTGRES_DB, POSTGRES_USER, POSTGRES_PASSWORD	.env — read by Compose postgres service	same values bootstrap the DB on first volume init
DB_URL	postgres://...@127.0.0.1:5432/engine_db (host CLI, make migrate)	Built by Compose → ...@postgres:5432/... (engine + worker)
ENGINE_URL	http://127.0.0.1:8000 (CLI only)	not set — engine/worker use Postgres, not HTTP to each other
PROMPTS_ROOT	Leave unset in .env	/app/prompts (set in docker-compose.yml)
POLICIES_ROOT	Leave unset in .env	/app/policies
SCHEMAS_ROOT	Leave unset in .env	/app/schemas
COMPENSATIONS_ROOT	Leave unset in .env	/app/compensations

Compose mounts your repo's ./config/ tree into each container. The host path and container path are different names for the same files:

Repo path (host disk)	Mount inside container	Read by
./config/prompts/	/app/prompts	engine (register + validate), worker (execute)
./config/policies/	/app/policies	engine
./config/schemas/	/app/schemas	engine
./config/compensations/	/app/compensations	engine

Do not mix host paths into .env for Compose

If you set PROMPTS_ROOT=./config/prompts in .env, Compose injects that value into containers via env_file — but ./config/prompts does not exist inside the container filesystem. The compose file already sets PROMPTS_ROOT=/app/prompts and mounts ./config/prompts there. Leave PROMPTS_ROOT, POLICIES_ROOT, SCHEMAS_ROOT, and COMPENSATIONS_ROOT unset in .env for standard make up workflows so containers use those compose-defined paths instead of a host-relative path that does not resolve inside the image.

warden deploy -f config/saga.minimal.yaml reads YAML from your host working tree. After deploy, manifest bodies live in Postgres; prompt, policy, schema, and compensation files stay on disk and must be visible at the container *_ROOT paths above.

Minimal template (docker-compose.example.yml)

Same host DB_URL, in-compose postgres:5432, and container *_ROOT paths as the dev stack. See Installation → Local development stack.

Variable quick reference

Variable	Host CLI	In containers
POSTGRES_DB, POSTGRES_USER, POSTGRES_PASSWORD	.env for Compose substitution	postgres service bootstrap
DB_URL	127.0.0.1:5432	postgres:5432 (engine + worker)
PROMPTS_ROOT	leave unset in .env	/app/prompts
POLICIES_ROOT	leave unset in .env	/app/policies
SCHEMAS_ROOT	leave unset in .env	/app/schemas
COMPENSATIONS_ROOT	leave unset in .env	/app/compensations
ENGINE_URL	http://127.0.0.1:8000 (CLI only)	not set

Database (Compose)

Docker Compose uses two related sets of database variables:

Variables	Read by	Purpose
POSTGRES_DB, POSTGRES_USER, POSTGRES_PASSWORD	postgres service	Bootstrap the database and role on first container start
DB_URL in .env	Host CLI; optional make migrate on the host	Reach Postgres via the published port 127.0.0.1:5432

Compose overrides DB_URL for engine, worker, and migrate — those containers connect to postgres:5432 on the internal network. You do not set their DB_URL in .env.

Both the engine and the worker require DB_URL. The outbox is Postgres-native: the engine writes commands and ingests results; the worker claims work and reports STEP_COMPLETED / STEP_FAILED. Each process must reach the same database—host CLI tools use 127.0.0.1:5432; in Compose, engine and worker use the internal postgres:5432 hostname.

Keep POSTGRES_* and host DB_URL aligned (same user, password, and database name). You can use any values — admin / password / engine_db are the repo defaults, not a hard requirement:

POSTGRES_DB=engine_db
POSTGRES_USER=admin
POSTGRES_PASSWORD=password
DB_URL=postgres://admin:password@127.0.0.1:5432/engine_db

POSTGRES_* is applied only when the Postgres data volume is created. Changing credentials in .env later does not update an existing volume — run make reset or alter the role manually.

Use 127.0.0.1 in host DB_URL, not postgres — the service hostname resolves only inside Compose.

Dev stack (Makefile and ports)

When you use make up, Postgres data persists in the Docker named volume engine_db_data. Stopping containers keeps that volume; deleting it gives you an empty database on the next start.

Make targets

Target	Effect
make up	Start dev compose (db, migrate, engine, worker, jaeger, adminer)
make up-db	Postgres only
make stop / make down	Stop containers; keep engine_db_data
make clean	Stop and delete engine_db_data
make reset	make clean then make up
make migrate	Apply migrations from the host (DB_URL → 127.0.0.1:5432)
make doctor	Service status + recent migrate, engine, and worker logs

You normally do not run make migrate for a first boot — the one-shot migrate service runs before engine and worker start. Use host-side make migrate when Postgres is up but you are not using the full compose migrate container. If the engine or worker exits with Database schema is not initialized, migrations did not complete — see Troubleshooting.

Default ports (dev stack)

Service	URL
Engine	http://127.0.0.1:8000
Postgres (from host)	127.0.0.1:5432
Adminer	http://127.0.0.1:8080
Jaeger	http://127.0.0.1:16686

Environment variables

Variable	Consumer	Notes
DB_URL	engine, worker, migrations	Both engine and worker need Postgres for the outbox loop. Host: 127.0.0.1:5432. Compose containers: built from POSTGRES_* → postgres:5432
POSTGRES_DB, POSTGRES_USER, POSTGRES_PASSWORD	postgres service (Compose)	Must match credentials in host DB_URL
ENGINE_URL	host CLI only	http://127.0.0.1:8000 from your machine (published port). Engine and worker containers do not use this variable—they coordinate through Postgres. If you run the CLI inside the Compose network, use http://engine:8000 instead of loopback
OPENAI_API_KEY	worker	when provider: openai — not required for provider: local or provider: mock. Checked at step runtime, not at deploy
WARDEN_LOCAL_LLM_BASE_URL	worker	OpenAI-compatible local endpoint (optional; defaults to http://localhost:11434/v1)
GITHUB_PERSONAL_ACCESS_TOKEN	worker	GitHub MCP demo only (stdio env_inherit)
${ENV:…} in worker manifest	worker	SSE MCP auth — names like COMPANY_MCP_TOKEN referenced in tool_sources[].headers; set on worker, not in YAML

Under Compose, .env is injected when a container starts. After you add or change worker-scoped variables (OPENAI_API_KEY, WARDEN_LOCAL_LLM_BASE_URL, MCP tokens), restart the worker — not the engine: docker compose up -d worker. A step that already failed with missing credentials stays failed until you retry it or start a new saga instance.

For hosted SSE MCP, declare headers in the worker manifest with ${ENV:VAR} placeholders and set VAR on the worker process. Example worker manifest:

headers:
  Authorization: "Bearer ${ENV:COMPANY_MCP_TOKEN}"

# .env (worker container via env_file)
COMPANY_MCP_TOKEN=your-bearer-token

See MCP and tools → Hosted MCP authentication and Worker manifests.

A minimal .env for Compose + host CLI:

POSTGRES_DB=engine_db
POSTGRES_USER=admin
POSTGRES_PASSWORD=password
DB_URL=postgres://admin:password@127.0.0.1:5432/engine_db
ENGINE_URL=http://127.0.0.1:8000
OPENAI_API_KEY=sk-...

For the local Quickstart path, set WARDEN_LOCAL_LLM_BASE_URL and deploy config/worker.local-minimal.yaml:

WARDEN_LOCAL_LLM_BASE_URL=http://host.docker.internal:11434/v1

For the mock demo, omit both — use provider: mock manifests.

Local LLM under Docker (Ollama)

Warden does not run Ollama in Compose. You install and start Ollama on the host (systemctl start ollama or the desktop app), pull the model named in your worker manifest (ollama pull llama3.2), then point the worker container at that HTTP API.

Two common gotchas when the worker runs in Docker but Ollama runs on the host:

1. Ollama binds to loopback only — default is 127.0.0.1:11434, which containers cannot reach. Set OLLAMA_HOST on the Ollama service so it accepts traffic from the Docker bridge, then restart Ollama:

   sudo mkdir -p /etc/systemd/system/ollama.service.d
   sudo tee /etc/systemd/system/ollama.service.d/override.conf <<'EOF'
   [Service]
   Environment="OLLAMA_HOST=0.0.0.0:11434"
   EOF
   sudo systemctl daemon-reload
   sudo systemctl restart ollama

   Confirm with ss -tlnp | grep 11434 — you want 0.0.0.0:11434, not only 127.0.0.1. Binding to all interfaces is fine for local dev; restrict port 11434 with a firewall if the machine is on an untrusted network.

2. host.docker.internal on Linux — Docker Desktop defines this hostname automatically; native Linux Docker often does not. The repo's docker-compose.yml (and docker-compose.example.yml) add extra_hosts on the worker service:

   extra_hosts:
     - "host.docker.internal:host-gateway"

   Recreate the worker after adding it: docker compose up -d worker. If you use a custom Compose file without extra_hosts, set WARDEN_LOCAL_LLM_BASE_URL to your Docker bridge gateway instead (for example http://172.18.0.1:11434/v1 — inspect with docker inspect <worker-container> --format '{{range .NetworkSettings.Networks}}{{.Gateway}}{{end}}').

Worker manifest: provider: local and model_name matching ollama list — see config/worker.local-minimal.yaml.

Smoke tests:

# Host — Ollama API up
curl http://127.0.0.1:11434/v1/models

# Worker container — DNS + HTTP to host Ollama
docker compose exec worker python -c "
import socket, urllib.request
print(socket.gethostbyname('host.docker.internal'))
print(urllib.request.urlopen('http://host.docker.internal:11434/v1/models', timeout=5).read()[:200])
"

After changing .env or Compose networking, restart the worker (docker compose up -d worker). Failed saga steps stay FAILED until you retry or start a new instance — see Demo: Quickstart → When a step shows FAILED.

Disk artifact roots

Worker and saga manifest YAML is stored in Postgres when you warden deploy. Prompts, policies, output schemas, and compensation files stay on disk and are resolved at runtime using these variables:

Variable	Resolves	Consumer
PROMPTS_ROOT	prompt: foo.j2 → {root}/foo.j2	engine (register), worker (execute)
POLICIES_ROOT	policy: gate.yaml → {root}/gate.yaml (legacy stem gate → {root}/gate.yaml)	engine
SCHEMAS_ROOT	output_schema: triage.json → {root}/triage.json	engine (register + saga start)
COMPENSATIONS_ROOT	compensation: disburse_undo.yaml → {root}/disburse_undo.yaml	engine (register + saga start)

Each value is a path relative to the root — subdirectories are allowed (e.g. policy: teams/marketing/gate.yaml). For policy, prefer an explicit path with extension; stem-only refs without an extension still resolve via {ref}.yaml when the exact path is missing (one deploy-time warning per unique legacy ref).

Repo defaults are ./config/prompts, ./config/policies, ./config/schemas, and ./config/compensations.

Worker tuning

These default to conservative values. Adjust as needed for your workload.

ReAct tool responses can be large. WARDEN_REACT_TOOL_MESSAGE_LIMIT trades token economy against context visibility in the LLM transcript: a lower limit saves context window but clips the tail of tool payloads—the agent may miss data and reason from incomplete context. Set 0 to disable clipping entirely for deep debugging passes. Facts extraction always uses the full tool payload regardless of this limit.

Variable	Default	Purpose
WORKER_MAX_IN_FLIGHT	1	Max concurrent step commands handled by one worker process (outbox consumer semaphore)
WARDEN_REACT_TOOL_MESSAGE_LIMIT	8000	Max characters for tool-role messages in the ReAct LLM transcript; 0 disables clipping

Throughput and parallelism

Parallelism happens at the worker level, not inside a single saga. The engine still schedules one forward step at a time per saga instance—steps in the same workflow do not run concurrently. Throughput across many saga instances comes from how many worker commands your fleet can execute at once.

Each worker process (typically one workers/main.py per container) polls the worker-commands outbox and runs handlers behind an asyncio semaphore sized by WORKER_MAX_IN_FLIGHT:

Scale lever	Effect
Raise WORKER_MAX_IN_FLIGHT on one process	That process may execute multiple step commands concurrently (different sagas, or different steps that are already queued)
Run more worker replicas	More processes compete for outbox rows—each replica usually keeps WORKER_MAX_IN_FLIGHT=1 unless you have a reason to combine both

Example: four worker containers with default WORKER_MAX_IN_FLIGHT=1 can execute up to four step commands at once, usually for four different saga instances. One container with WORKER_MAX_IN_FLIGHT=4 can do the same from a single process, at the cost of more concurrent LLM/MCP load and DB connections in that process.

If you raise WORKER_MAX_IN_FLIGHT materially (for example above 8), size the worker Postgres pool accordingly.

Recovery timeouts

Background loops in the worker and engine processes recover from worker crashes and outbox consumer stalls. Set these timeouts above worst-case step latency (LLM + MCP) for your manifests.

Variable	Default	Consumer	Purpose
WORKER_STALE_CLAIM_SECONDS	1800	worker	Reap unfinished processed_commands claims
WORKER_CLAIM_REAP_INTERVAL_SECONDS	60	worker	Claim reap tick interval
OUTBOX_STALE_IN_PROGRESS_SECONDS	1800	engine, worker	Reap outbox rows stuck IN_PROGRESS
OUTBOX_REAP_INTERVAL_SECONDS	60	engine, worker	Outbox reap tick interval
OUTBOX_REAP_BATCH_SIZE	20	engine, worker	Max rows reaped per tick per topic

Workers use claim_token fencing: superseded handlers log claim_superseded with execution_duration_s instead of emitting duplicate results. Frequent supersession within a few seconds means these timeouts are too low.

Operator recovery (after automation): warden saga retry-step / warden saga retry-compensation. --force on commit steps requires --allow-destructive (duplicate side-effect risk). See Saga recovery.

Observability (OpenTelemetry)

Engine and worker export traces over OTLP gRPC at startup. Warden reads these settings from the environment:

Variable	Default	Consumer	Purpose
OTLP_ENDPOINT	unset	engine, worker	Collector URL (for example http://127.0.0.1:4317 or http://jaeger:4317 in Compose)
OTLP_INSECURE	true	engine, worker	Plaintext gRPC when true; set false for TLS

When OTLP_ENDPOINT is unset, the OpenTelemetry SDK may still honor OTEL_EXPORTER_OTLP_ENDPOINT and other standard OTEL_EXPORTER_OTLP_* variables on the process.

With make up, Compose already points engine and worker at Jaeger (OTLP_ENDPOINT=http://jaeger:4317). Open the UI at http://127.0.0.1:16686 and filter traces on attribute saga.id (your Warden trace_id from warden start saga).

For correlation fields, TLS, vendor headers, and debugging workflows, see Observability.

Enterprise tier

The open-core kernel ships engine, workers, CEL policies, HITL gates, compensation, and Postgres-backed saga state—enough to build and run governed workflows in your own infrastructure.

For compliance-grade capabilities—forensic audit history, extended operational enforcement, and related enterprise features—see Open Core vs Enterprise.

LLM retries (automated backoff)

WARDEN_LLM_RETRY_* variables configure transient LLM API resilience inside the worker — network blips, rate limits, and short provider outages on each ainvoke call (ReAct turns on react steps, the single call on simple steps). The worker retries with exponential backoff and jitter; it does not restart a failed saga step, re-run compensation, or replace operator actions.

Variable	Default	Purpose
WARDEN_LLM_RETRY_ENABLED	true	Toggle backoff wrapper around LLM calls
WARDEN_LLM_RETRY_MAX_ATTEMPTS	3	Max attempts per LLM call (including the first)
WARDEN_LLM_RETRY_BASE_DELAY_S	1.0	Initial backoff delay (seconds)
WARDEN_LLM_RETRY_MAX_DELAY_S	60.0	Cap on backoff delay before jitter

If you need…	Use…
Backoff on a transient provider error during execution	WARDEN_LLM_RETRY_* (above)
An operator to re-run a paused human-gated step	warden review retry — see HITL review
Recovery after a forward step is stuck IN_PROGRESS	warden saga retry-step — see Saga recovery
Recovery after compensation failed or stalled	warden saga retry-compensation
Recovery after the step has already failed (normal path)	Saga FSM and compensation — no env var auto-restarts the step

What's next

Path mismatches between host and container are the most common deploy failure—start with Runtime context when ./config/... works on the host but registration or execution fails inside Docker. For active errors, see Troubleshooting.

For saga authoring, MCP wiring, and policy design, continue to Guides → Manifests and artifacts. For a lean deployment layout without dev-only services, start from docker-compose.example.yml in the repo root.

Related

• Installation
• Troubleshooting
• Observability