One exception: AI steps and MCP Tasks send prompt content, which can include record data, to an LLM provider and remote tools — so workflows aren’t fully air-gapped. See AI provider.
Do I need Forest Runtime?
Yes — Forest Runtime is what executes your workflow steps. Webhook-triggered workflows especially: a webhook can fire at any time, with no guarantee anyone has Forest open in a browser, so they can only run server-side. Running on infrastructure you control also keeps the records handled by data steps out of Forest’s infrastructure — decisive for compliance or data-residency requirements, or when a step needs access to systems reachable only from within your network.How it works
- A workflow is triggered — by a user or a webhook. The Forest orchestrator queues the pending steps.
- Forest Runtime polls the orchestrator and pulls the steps assigned to it.
- Each step runs locally, reaching your data and actions through your Forest agent.
- It reports the step outcome back to the orchestrator, which advances the workflow.
Prerequisites
- A recent Forest Admin agent — the minimum version depends on how you run Forest Runtime (below).
- A PostgreSQL database for production: Forest Runtime persists its run state there. A database-free mode exists for testing only.
Running Forest Runtime
Run Forest Runtime one of two ways:- Embedded in your Node.js agent — one line in your agent, nothing separate to deploy. The simplest option.
- Standalone — a separate process (Docker or CLI), to scale it independently of your agent or to use it with a Ruby agent.
Embedded in the Node.js agent
Requirements:@forestadmin/agent— embedded mode arrived in 1.84.0, but the options shown below (schema,ai,encryptionKey, the tuning knobs) landed in later releases, so use a recent version.- Node.js ≥ 22.12.0 — required by the executor package.
- The executor package, installed at the exact version your agent pins. It’s an optional peer dependency the agent loads dynamically at runtime, so
tscwon’t flag it when it’s missing — butagent.start()throws “The embedded workflow executor requires the@forestadmin/workflow-executorpackage”. The pin is exact (a^range conflicts), so install that specific version — find it in your lockfile or withnpm info @forestadmin/agent@<your-agent-version> peerDependencies(pin the version you actually run — without it, npm answers forlatest, whose pin may differ): - TypeScript 5.5+ — the package ships zod 4, which is only tested against TypeScript 5.5 and later. On TypeScript 4.x its typings can’t even be parsed, and
skipLibCheckwon’t help (it suppresses type errors, not the syntax errors these typings trigger).
Safe to reuse the database your agent already reads: the executor keeps its tables in a dedicated
forest Postgres schema, so they stay out of the public schema your datasource introspects and never show up as collections in your panel. Pass a schema if you’d rather name it differently.Creating that schema needs the CREATE privilege on the database. If your role doesn’t have it, have an administrator create the schema and grant the role access to it — the executor checks whether the schema already exists before trying to create one, so a pre-created schema boots fine with schema-level privileges only.Embedded has full configuration parity with standalone: your own AI provider (
ai), the encryption key, and every tuning knob are all settable here. It only inherits your agent’s secrets and Forest connection; set nothing and AI steps use Forest’s AI server.Standalone (Docker or CLI)
Run Forest Runtime as its own service — the way to run it with any agent other than the v2 Node.js one (which can also embed it), and to scale or deploy it separately. 1. Point your agent at it with the workflow executor URL, so the agent mounts the route that forwards workflow requests to Forest Runtime (relaying the JWT). It’s supported across both agent generations:The route itself lives in
forest-express, which both wrappers pin to an exact version. The minimums above pull in forest-express 10.7.0, so that’s the number to look for in a lockfile. You never install or configure it yourself.The Python agents (
agent-python, django-forestadmin) don’t support the workflow executor yet.404 on those routes and Forest Runtime never receives any work. When the agent and Forest Runtime run on separate hosts, use an internal address the agent can reach on Forest Runtime’s HTTP port (default 3400).
2. Run the executor as a Docker image or via the CLI:
When Forest Runtime runs in Docker and your agent runs on the host machine, use
host.docker.internal instead of localhost in AGENT_URL and DATABASE_URL. On Linux Docker Engine that hostname doesn’t exist by default, so the --add-host=host.docker.internal:host-gateway flag above is required to resolve it (on Docker Desktop it’s already provided and the flag is harmless).Network requirements
A standalone Forest Runtime opens these connections (an embedded executor makes the same outbound calls from the agent process, with no extra inbound port):
On first boot Forest Runtime auto-creates its
workflow_step_executions table, then polls the orchestrator every 30 seconds (POLLING_INTERVAL_S) for work.
Forest Runtime is stateless apart from its Postgres database: you can run several instances against the same database for high availability — each pending step is claimed by exactly one instance. If you use OAuth-protected MCP connectors, give every instance the same encryption key.
Health check
GET /health is public (no auth) and returns the runtime’s current state:
For liveness probes, treat any
200 as healthy. For readiness probes, route traffic only on {"state":"running"} so a draining instance stops receiving new work while it finishes in-flight steps.
AI provider
Several step types rely on an LLM: guidance, decisions, MCP Tasks, and AI-assisted data steps. By default Forest Runtime uses Forest’s AI server — no configuration required, AI steps work out of the box. To keep AI calls off Forest’s server and use your own provider instead, set these variables:AI_PROVIDER and AI_MODEL always go together. Add AI_API_KEY for openai and anthropic; leave it out for bedrock — setting it there stops Forest Runtime at startup instead of being ignored. Set none of them to keep using Forest’s AI server.Amazon Bedrock
WithAI_PROVIDER=bedrock, Forest Runtime reaches the model through Amazon Bedrock, so the calls stay inside your AWS account. Set AI_MODEL to a Bedrock model id, a cross-region inference profile id, or an inference profile ARN — and AWS_REGION to the region the model is enabled in.
To find the id, open AWS’s Models at a glance and pick your Claude model: its page carries the model id, and an Inference profile IDs section with the eu. and us. ones. Either can be copied straight into AI_MODEL.
Supported models: Anthropic Claude Sonnet, Haiku and Opus. Any other Bedrock model is refused at startup, with a message naming what is accepted. AI steps ask the model to answer in a strict, structured format, and the rest of the Bedrock catalogue either can’t do that reliably or hasn’t been tested on our side — so a model we can’t vouch for is rejected immediately, rather than breaking halfway through a workflow.
A cross-region inference profile id works and is the usual choice, since it keeps your data in one geography: eu. stays in the EU, us. in the US. Avoid the global. prefix if data residency is the reason you are on Bedrock, as it routes worldwide.
Bedrock takes no AI_API_KEY. Forest Runtime signs in to AWS exactly the way the AWS CLI does, so whatever already works for your other AWS tools works here too — you don’t configure anything specific to Forest. Whichever method you use, it needs permission to call bedrock:InvokeModel on the models you picked.
That includes assuming a role, so you never have to hand long-lived keys to the container:
Mounting an AWS profile into Docker: the image runs as the To mount somewhere else, point
node user, so mount your AWS directory to /home/node/.aws, not /root/.aws. Mounting it to /root/.aws fails quietly — the container starts, and the first AI step reports that no credentials could be loaded.AWS_CONFIG_FILE and AWS_SHARED_CREDENTIALS_FILE at the files directly.Automated inboxes
An inbox backed by a segment can start a workflow on its own, on every record that enters it, with no one clicking anything. Forest Runtime is what sweeps the segment. It decides nothing. It reads your data and reports what it saw; Forest starts the runs, applies the limit of concurrent runs, and refuses a record a workflow is already handling. A runtime that cannot reach Forest, or that you turn off, stops the automation — it never starts work twice.How a sweep works
EveryAUTOMATION_POLL_INTERVAL_S, for each automated inbox:
- It asks Forest which automated inboxes to sweep, and which records are already being handled.
- It asks your agent whether the records whose workflow has finished are still in the segment.
- It asks your agent for the first page of the segment, to find records nobody has handled yet.
- It reports both answers back. Forest starts a workflow per new record.
Requirements
- Forest Runtime on the version that ships automated inboxes or above. An older one is not served the configuration, and the inbox shows as configured but inactive in its settings.
- A segment-backed inbox, with automation enabled on it. It is configured on the inbox, not in the workflow’s Process section.
Running several instances
Nothing to configure. Each instance identifies itself and Forest hands the sweep to one of them, so several instances do not sweep the same segment in parallel. Two consequences worth knowing:- If Forest cannot run that election, every instance sweeps. That costs duplicate reads on your database, and it is deliberate — the alternative would stop every automation silently. No record is ever run twice.
- After you restart or redeploy your runtime, the new process waits for the previous one’s turn to lapse before it starts sweeping. Expect up to ten minutes with no sweep.
What the sweep can read
- The service account’s permissions apply. The runtime reads the segment as the account the automation runs as, so a restrictive scope on that account’s role hides records from the sweep.
- Relative dates in a segment filter (
previous 30 days,today…) are evaluated in your project’s timezone, or UTC when it has none. - SQL segments need a connection name on agents that support several connections. On
forest-railsandforest-express-sequelize, which run the query against their single database, none is needed.
In your logs
OAuth-protected MCP connectors
If your workflows include MCP Tasks backed by OAuth-protected connectors, Forest Runtime stores each user’s OAuth credentials in its database, encrypted at rest. Provide the encryption key:- Required only for OAuth-protected MCP connectors, and read lazily — an instance that stores no such credentials runs fine without it.
- Use the same value on every instance that shares a database, or an instance won’t decrypt credentials written by another.
- Treat it as permanent: there is no managed rotation. Changing it forces every affected user to reconnect their connectors.
Observability
The Docker image ships with OpenTelemetry APM built in, compatible with any OTLP backend (Datadog, Grafana Tempo, Jaeger, Honeycomb…). It is off by default and turns on as soon as you setOTEL_EXPORTER_OTLP_ENDPOINT. OpenTelemetry is bundled only in the Docker image, not the npm package.
When an MCP Task can’t load its tools
Forest Runtime logs the reason atError, so it is in your logs without changing LOG_LEVEL. This is the JSON the Docker image writes to stdout; running in a terminal you get the same fields in the pretty single-line format instead.
kind tells you where to look:
auth— the server rejected the credential (HTTP 401). For an OAuth connector the runtime refreshes the token and retries once on its own, so act only if the failure repeats without a follow-upMCP tools loaded after refreshing the credentialline. For a static credential, renew it in the connector’s configuration.connection— unreachable, refused, or slower than the 15-second per-server load timeout.unknown— the server answered but the load failed anyway, including HTTP 403 permission or scope errors that no token refresh can fix;errorcarries the reason.
If your logs show a
failedConfigNames list instead of failures, your runtime predates this change: it names which server failed but not why, and reports a healthy server exposing no tools as a failure. Upgrade to get the cause.Tuning
Beyond the required variables, these optional knobs have sensible defaults and rarely need changing:For the remaining variables (individual database parts,
DATABASE_SSL, in-memory testing mode, full OTel configuration), see the package README on npm.Learn more
Workflows overview
Build and manage workflows in the no-code editor
MCP Servers
Configure the connectors used by MCP Tasks