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Agent: configuration reference

See also: Environment variable reference — shared env vars; agent-specific vars are listed below. Regenerate the generated table with pnpm docs:env. Unknown KICI_* env vars cause the agent to refuse to start (typo catcher); set KICI_DEV=true for warn-only behaviour during local development.

All agent configuration is provided via environment variables.

These environment variables are specific to the agent. Variables shared across KiCI services (log level, OpenTelemetry endpoint, heartbeat/concurrency timeouts) and the rotated-file logger live in the environment variable reference.

Env varRequiredDefaultTypeAliasesDescription
KICI_AGENT_COMMANDnostring
KICI_AGENT_IDnostring
KICI_AGENT_IS_ORCHESTRATOR_HOSTnostring
KICI_AGENT_PAYLOAD_DIRnostring
KICI_AGENT_TOKENnostring
KICI_BACKPRESSURE_MODEno”pause”enum:pause|drop
KICI_DEFAULT_STEP_TIMEOUT_MSno1800000number
KICI_DOCKER_KEEP_FAILEDno”false”string
KICI_EXECUTION_MODEnoenum:container|bare-metal|firecracker
KICI_GITHUB_TOKENnostring
KICI_IN_PLACEno”false”string
KICI_LABELSnostring
KICI_MAX_LOG_SIZE_BYTESno10485760number
KICI_ORCHESTRATOR_URLyesstring
KICI_PORTno8080number
KICI_PROPERTIESnostring
KICI_ROLESnostring
KICI_SANDBOXno”false”string
KICI_SANDBOX_HARDENEDno”true”string
KICI_SANDBOX_MEMORY_BYTESno2147483648number
KICI_SANDBOX_NANO_CPUSno2000000000number
KICI_SANDBOX_NETWORKno”isolated”enum:isolated|host
KICI_SANDBOX_PIDS_LIMITno512number
KICI_SANDBOX_READONLY_ROOTFSno”false”string
KICI_SANDBOX_USERnostring
KICI_SCALER_IDLE_TIMEOUTno5000number
KICI_SCALER_MANAGEDnostring
KICI_SCALER_PENDING_DISPATCH_TIMEOUTno60000number
KICI_TRUSTED_ENVno”false”string

The agent exposes three HTTP endpoints on the configured KICI_PORT:

EndpointPurposeResponse
/healthLiveness probeAlways 200. Body includes agentId, activeJobs, connected status, and the build identity (version, buildCommit, plus the SDK / shared / engine versions and bundle hashes) so operators can correlate deployed builds across services.
/readyReadiness probe200 when connected to orchestrator, 503 when disconnected.
/metricsPrometheus metricsPrometheus text format with kici_agent_ prefixed metrics.

Labels allow the orchestrator to route jobs to specific agents. When a workflow specifies runsOn: 'linux', the orchestrator dispatches the job only to agents that have the linux label.

Terminal window
# Agent with Linux and Docker capabilities
KICI_LABELS=linux,docker
# Agent with GPU support
KICI_LABELS=linux,gpu,cuda
# Agent with macOS for Apple-specific builds
KICI_LABELS=macos,arm64

Multiple agents can share labels. The orchestrator selects from available agents with matching labels.

Roles control which types of special jobs an agent can handle. The two built-in roles are builder (dependency cache build jobs) and init-runner (dynamic init jobs). Roles manifest as reserved kici:role:* auto-labels used internally for routing.

Terminal window
# Accept all roles (default when KICI_ROLES is unset)
# Equivalent to KICI_ROLES=all
unset KICI_ROLES
# Only handle builder jobs (no init-runner)
KICI_ROLES=builder
# Both roles explicitly
KICI_ROLES=builder,init-runner
# Execution only — no special role jobs, only regular workflow jobs
KICI_ROLES=

The kici:* label prefix is reserved for internal use. User-provided labels in KICI_LABELS must not use this prefix.

Each agent executes one job at a time. When a job is already running, the agent rejects additional dispatches, and the orchestrator routes them to another available agent or queues them.

Two agent-launch profiles change how a dispatched job is prepared. Both are set only by the operator at agent (or scaler) launch — neither is derivable from a dispatch payload or from workflow code, so a Platform-connected agent can never be pushed onto them.

VariableDefaultEffect
KICI_TRUSTED_ENVfalseTrusted fleet-agent profile: step sandboxes receive the ambient host environment (minus the agent’s own KiCI identity and operational secrets) instead of the system-variable allowlist. See Agent security.
KICI_IN_PLACEfalseIn-place no-clone profile: when the dispatched source is a file:// local source, the agent uses that source’s real repository path as the job work directory and skips the git clone. Any other source is unaffected and still clones into a throwaway directory.

KICI_IN_PLACE exists for running an operator’s own already-built working tree directly — module-relative paths, installed dependencies, and build output are all present because nothing is copied. See Local development plane.

Set KICI_AGENT_IS_ORCHESTRATOR_HOST=true when the agent shares a host with the orchestrator. A workflow’s restartHost() step is then refused locally (refusing to reboot the orchestrator host), so a fleet-wide reboot workflow cannot take the control plane down with it. Defaults to false; the orchestrator refuses the same request independently.

An ops agent holding the kici:capability:ssh-transport capability stages a self-contained agent plus vendored Node runtime onto a fresh box during init-runner bring-up. By default that payload comes from the orchestrator’s own object storage. Two variables, read only by the agent performing the bring-up, override that:

VariableEffect
KICI_AGENT_PAYLOAD_DIRLocal directory holding version-keyed payloads (<dir>/<version>/kici-agent-<platform>.tar.gz) as produced by kici-admin agent package. When set, the payload is read from disk instead of pulled from object storage — the air-gapped path.
KICI_AGENT_COMMANDGolden-image escape hatch: a fixed command that starts the init-runner on a target that already ships kici-agent and a Node runtime at a known path. When set, payload staging is skipped entirely.

For workflows that specify container in their job configuration, the agent executes the job inside a disposable Docker or Podman container.

Requirements:

  • A container runtime (Docker or Podman) must be installed and accessible on the agent host
  • When the agent itself runs in a container, the runtime socket must be mounted into it:
volumes:
- /var/run/docker.sock:/var/run/docker.sock

Podman exposes its socket at a different path (/run/podman/podman.sock rootful, or /run/user/<uid>/podman/podman.sock rootless). Mount that path instead and point DOCKER_HOST at it; the agent talks to whichever socket that variable resolves to, falling back to /var/run/docker.sock.

The agent:

  1. Creates a job container from the specified image (already-present images are used as-is; a missing image is pulled on demand first) with /workspace as a container-owned volume
  2. Starts the workflow runner inside the container via a single exec — the repository clone, dependency install, and every step all run inside the container
  3. Removes the container (and its workspace volume) after job completion

Job containers are hardened by default: all Linux capabilities dropped, no-new-privileges, cgroup PID/memory/CPU caps, and a private tmpfs /tmp, tunable via the KICI_SANDBOX_* variables above. See Agent security for the full isolation model and the per-job sandbox: escape hatch.

Set KICI_DOCKER_KEEP_FAILED=true to preserve failed containers for debugging. The container name follows the pattern kici-sandbox-{jobId}-{timestamp}.

The agent authenticates with the orchestrator using a pre-shared key (PSK) token. When the orchestrator has KICI_AGENT_AUTH=token (the default), the agent must provide a valid token via the KICI_AGENT_TOKEN environment variable.

Obtaining a token:

Terminal window
# On the orchestrator host (or via the admin CLI)
kici-admin agent register --labels linux,x64
# Save the displayed token -- it cannot be recovered

Configuring the agent:

Terminal window
KICI_AGENT_TOKEN=kat_<64 hex chars>

Authentication flow:

  1. Agent connects to the orchestrator’s WebSocket endpoint
  2. Agent sends auth.request with the token before registration
  3. Orchestrator validates the token against its SHA-256 hash database
  4. On success, orchestrator responds with auth.success and the agent proceeds to send agent.register
  5. On failure, the orchestrator responds with auth.failure and closes the connection

Auth failure behavior: If authentication fails, the agent logs an error and permanently stops reconnection. A bad token cannot self-heal, so retrying wastes resources. Fix the token and restart the agent.

Scaler-managed agents: Agents spawned by the orchestrator’s auto-scaler receive automatically generated ephemeral tokens. No manual token configuration is needed for scaler-managed agents.

Unauthenticated mode: When the orchestrator is configured with KICI_AGENT_AUTH=none, agents connect without tokens. The KICI_AGENT_TOKEN variable is ignored. This is only safe on trusted networks.

Set KICI_GITHUB_TOKEN for cloning private repositories. The token is passed via git’s http.extraHeader configuration (not embedded in the URL) to prevent exposure in logs.

If the orchestrator provides a short-lived installation token in the job dispatch, it takes precedence over the agent-local token.

SignalBehavior
SIGTERMStart graceful shutdown. Wait up to 10s for running jobs to complete, then force-kill child processes and exit.
SIGINTSame as SIGTERM.
SIGUSR1Enter drain mode. Stop accepting new jobs. Once all active jobs complete, exit cleanly. Use for rolling deployments.
  1. Send SIGUSR1 to the running agent
  2. Agent stops accepting new job dispatches
  3. Currently running jobs continue to completion
  4. Once all jobs finish, agent exits with code 0
  5. Start the new agent version
Terminal window
# In a deployment script
kill -USR1 $(pidof node)
# Wait for exit, then start new version

If the WebSocket connection to the orchestrator drops, the agent automatically reconnects with exponential backoff:

  • Initial delay: 1 second
  • Multiplier: 1.5x per attempt
  • Jitter: 0-50% randomness
  • Maximum delay: 60 seconds

Messages generated during disconnection are buffered and flushed on reconnection: up to 10,000 log lines and up to 5,000 other events (job status, heartbeats). This preserves job status and log data even during brief network interruptions.

Terminal window
KICI_ORCHESTRATOR_URL=ws://localhost:4000/ws
Terminal window
KICI_ORCHESTRATOR_URL=ws://orchestrator.internal:4000/ws
KICI_AGENT_ID=agent-prod-01
KICI_LABELS=linux,docker,x86_64
KICI_PORT=8080
KICI_LOG_LEVEL=info
KICI_GITHUB_TOKEN=ghp_xxxx
KICI_MAX_LOG_SIZE_BYTES=10485760
KICI_DEFAULT_STEP_TIMEOUT_MS=3600000