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flue dev starts a long-running dev server that watches your project root for changes, rebuilds on every edit, and reloads the running server automatically. It is the primary command for iterative local development.

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Usage

flue dev [--target <node|cloudflare>] [--root <path>] [--output <path>] [--config <path>] [--port <number>] [--env <path>]...

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Flags

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--target
string
Build and serve target. Accepted values: node or cloudflare. Required if not set in flue.config.*.
  • node — Builds a single bundled .mjs and spawns a Node.js child process. Every file change triggers a full rebuild and child respawn.
  • cloudflare — Builds an unbundled TypeScript entry and hands it to Wrangler (unstable_startWorker). Wrangler watches the source graph itself and hot-reloads workerd on agent body edits; Flue only rebuilds when something structural changes (new or removed agent, changed triggers, wrangler.jsonc edit).
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--root
string
default:"cwd"
Project root directory. Source files (agents/, roles/) live at <root>/.flue/ if that directory exists, otherwise at <root>/ directly. Defaults to the current working directory.
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--output
string
default:"<root>/dist"
Where build artifacts are written. Defaults to <root>/dist.
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--config
string
Explicit path to a flue.config.{ts,mts,mjs,js,cjs,cts} file (relative to cwd). Defaults to auto-discovery from the root directory. CLI flags always override values set in the config file.
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--port
number
default:"3583"
Port for the dev server. Default is 3583 — “FLUE” on a phone keypad.
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--env
string
Path to a .env-format file to load before starting the server. Repeatable; later files override earlier ones on key collision. Shell-set environment variables win over file values.Edits to a watched env file trigger a reload (Node: child respawn; Cloudflare: worker restart).Works for both node and cloudflare targets.
flue dev --target node --env .env --env .env.local

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Cloudflare target

The cloudflare target requires wrangler as a peer dependency in your project.
npm install --save-dev wrangler
When --target cloudflare is set, flue dev delegates bundling and hot-reloading to Wrangler. Flue manages the structural rebuild cycle (new agents, changed triggers, wrangler.jsonc edits) while Wrangler handles source-level hot-reload for agent body changes — so plain edits to an agent’s logic appear instantly without a full restart.

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Dev vs. production

flue devflue run
LifecycleLong-running; blocks until Ctrl+COne-shot; exits after the run
RebuildsOn every file changeOnce, before invocation
Targetnode or cloudflarenode only
Use caseInteractive developmentCI, scripts, automation

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Examples

# Start a Node.js dev server
flue dev --target node

# Start a Cloudflare dev server on a custom port
flue dev --target cloudflare --port 8787

# Load environment variables from a file
flue dev --target node --env .env

# Use a non-default project root
flue dev --target node --root ./my-app
After the server starts, invoke any agent with a curl POST: 
curl http://localhost:3583/agents/<agent-name>/<instance-id> \
  -H 'Content-Type: application/json' \
  -d '{}'

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