#Limits

The fixed numbers that bound what Chester does — retries and timeouts, expressions, deployments, nesting, agents, files, lists and the time windows of links and webhooks — each with the page that explains it.

#Where the limits sit

flowchart LR
  M["Modelling"] --> E["Expressions<br/>4096 chars · 10 s · ~1 MB data"]
  M --> N["Nesting<br/>10 levels"]
  D["Deploying"] --> DEV["Development<br/>30 runs or 24 h"]
  R["Running"] --> C["System calls<br/>30 s wait · 3 retries · max 10"]
  R --> T["Timers<br/>under ~24 days"]
  R --> A["Agents<br/>50 steps · 4096 tokens · depth 3"]
  O["Monitoring"] --> EV["1000 events per run"]

#Running a process

Limit	Value	See
Automatic retries of a failed system call	3 by default — 4 attempts — at most 10	Call a system
Wait between retries	5 s by default, doubling, at most 5 minutes	Call a system
Retries of a send task	up to 3, after 1 s, 2 s and 4 s	Send an email
How long Chester waits for a system call	30 s by default, at least 10 s	Connect a REST API
Mail server connection timeout	10 s by default	Email adapter
Timer duration	days, hours, minutes and seconds; ⚠️ less than about 24.8 days	Timer event
Nesting of sub-processes and call activities	10 levels	Sub-process
Duplicate detection of an inbound action	600 s unless set	Inbound actions
Pages of a delta query	10 unless set, at most 100	Inbound actions
Webhook renewal	every 3 hours, for 3 more days	Webhook adapter

#Expressions

Limit	Value	See
Length of one expression	4096 characters	Write an expression
Time for one expression	10 seconds	Write an expression
Data an expression reads	about 1 MB	Write an expression

#Deploying and testing

Limit	Value	See
A development deployment	switches off after 30 runs or 24 hours	Development and production
Active deployments per process	one development and one production	Development and production
Items of a multi-instance step in the workbench	10	Workbench
Real calls by the workbench assistant per request	8	Workbench
An OpenAPI file to import	10 MB, 2000 paths	Connect a REST API

#Agents

Limit	Value	See
Rounds of thinking and tool calls (Max Iter.)	50 by default, 1 to 500	Configure the model
Length of an answer (Max Tokens)	4096 by default	Configure the model
An agent step in a process	5 minutes	Give an agent tools
Tasks calling tasks	3 levels	Let an agent call its own tasks
Messages an agent sees of a chat	the last 60	Start an agent
Files per chat message	5, at most 10 MB each	Chat with an agent

#Lists and screens

Limit	Value	See
Events of a run shown in monitoring	1000	Instance details
Rows per page in monitoring	25	Instance details
Completed tasks loaded at once	100, then Load more	Work on your tasks
Runs per page in My instances	10	Follow your instances

#Accounts

Limit	Value	See
Links in set-password and reset emails	valid for 30 minutes	Users and groups

❌ Chester sets no size limit on files uploaded through a form; the server it runs on may.