Flow limits

This page collects the limits of flows in one place. Plan limits depend on your IoT tier; fixed limits are the same for everyone. The pages linked in each section explain them.

Plan limits

Limit	Starter	Growth	Scale	Counted
Flows	6	12	58	Every flow you create, of every host. Deleted flows do not count; a restored one counts again.
Script blocks	3	6	29	Script blocks in deployed flows

• The seeded Default root flow does not count toward flows. Its script blocks, if you add any, count.
• Flows built by modules (Rules-card rules) do not count until you detach one into an ordinary flow.
• A deploy, create or restore over a limit is refused: “Your plan allows n flows: m in use, and this deploy adds k.”
• The usage card on Automation shows Flows and Script blocks against the plan, plus Runs, Steps, Script CPU and Limit hits this month (UTC).

See Plans and the IoT add-on.

Flow protections

Defaults; a plan may set other values within the bounds shown.

Protection	Default	Bounds
Runs of one flow a minute before it pauses	6,000	60 to 600,000
Failed runs in a row before it pauses	100	5 to 100,000
Runs of one flow at once	16	1 to 1,024
Messages one block sends for one input	100	1 to 10,000
Repeated device message window	60 s	1 to 3,600 s
Message time-to-live	5 min	10 s to 24 h
Commands and settings from flows to one device	30 a minute	1 to 600
Same notification to the same person	once per 10 min	1 min to 24 h
Shortest Inject repeat	60 s	1 to 3,600 s
Failed messages kept	10,000	100 to 100,000

Root flows are exempt from the automatic pause and from the runs-at-once limit. See Protections and failed messages.

Fixed limits

Item	Limit
Blocks in one flow	500
Message size	256 KiB
Steps in one run	512
Chain of events and Run flow between flows	4 hops
Link call nesting	16 calls deep
Flow context (flow.*)	1 MiB per flow
Global context (global.*)	4 MiB per organisation
A block’s memory	10,000 keys per block; the oldest is forgotten beyond that
Messages a block holds (delays, joins, queues)	16 MiB per block
Named timers	64 timers of 60 s or less at once, and 10,000 longer ones, per organisation
Longest wait (Delay, Trigger, Timer, Watchdog)	7 days
Comparison patterns (regular expressions)	64 characters; text tested at most 64 KiB
Expressions	512 characters; 10,000 evaluation steps
Enabling or disabling flows from flows	6 a minute per organisation

Script blocks

Item	Limit
CPU time per message	50 ms by default (a plan can raise it to at most 200 ms)
Memory	32 MiB
Code size	64 KiB
Messages a script returns	64
Context sent into a script	64 KiB
Kills before a pause	3 timeouts or memory kills in a row block the block for 60 seconds
Outputs	1 to 4

See The script block.

Webhooks

Item	Limit
Calls per webhook	60 a minute
Calls per organisation, all webhooks	50 per 5 seconds
Body	16 KiB by default, at most 256 KiB
Synchronous callers waiting	20 per organisation; each waits at most 10 s
Signed requests	The timestamp must be within 300 s
Repeated Idempotency-Key	A no-op within 24 hours

Outbound calls

Block	Timeout	Retries	Size
HTTP request	10 s default, 1 to 30 s	3 attempts by default, at most 5	Answer 64 KiB default, at most 256 KiB
MQTT out	10 s default, 1 to 30 s	3 attempts by default, at most 5	Message 256 KiB
Notify			20 recipients; attachments 10 files, 1 MiB together

Private and internal addresses are always refused. See Connections and secrets.

Messages

Item	Limit
Automation messages (General host)	Only when your plan sets a monthly quota; over it, new entries are refused and webhooks answer 429
Device messages (IoT host)	Counted as IoT messages; never refused for the allowance. See Message quota and usage.

How long records are kept

Record	Kept
Run records	24 hours
Debug block messages	24 hours
Log lines (System log block)	24 hours
Error log	7 days
Lifecycle events	30 days (the last 100)
Recording Every run	5 minutes, then the level goes back
An armed trace	5 minutes
Deleted flows	7 days
Unsaved drafts	30 days by default
Versions	The newest 100 and those younger than 90 days, by default

See Versions, testing and rollback.