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COTLang in workflows

COTLang is the small expression language Cotalker uses to interpolate runtime values into a bot's configuration. When a bot fires inside a workflow, the strings in its data block are parsed as COTLang expressions and resolved against the live context — so {{task._id}} becomes the current task's ID, {{user.company}} becomes the company, and so on.

You'll meet COTLang mainly in the data values of the bots you attach to transitions, StartForms, and survey triggers. Most of the time it just works. This page is about the one way it surprises people.

Reserved characters​

COTLang parses data values as expressions, and a few characters are reserved by the grammar. The two you'll actually hit are:

  • = (equals)
  • # (hash)

Put either one inside a plain string value and the parser fails with Unexpected end of input. There is no escape syntax and no raw-string literal — you can't write \= or wrap the value in quotes to opt out. The grammar also reserves |, (, ), [, and ], but those rarely surface by accident; = and # are the usual culprits.

The classic break: a URL with a query string​

data:
  # This FAILS to parse — the `=` in the query string is reserved.
  url: "https://example.com/api?company={{user.company}}&token=abc"

Note that ? and & are fine — it's the = that breaks it.

Working around it​

Since you can't escape the character, you assemble the offending string inside a script bot (CCJS / ESMCode) and pass the finished value along, or use a bot's structured fields when it offers them.

You needDo this
A URL with ?foo=barBuild the URL inside a CCJS/ESMCode stage using String.fromCharCode(61) for =, and return the assembled string
A literal #tagAssemble it in a script and pass it via data
A header like Bearer token=...Pass the pieces separately in data and concatenate them inside the script before the request

When a bot exposes structured query or headers fields, prefer those over hand-building a URL — they sidestep the parser entirely.

Debugging tip​

If a bot mysteriously stops before a stage, suspect a reserved character. Temporarily replace the suspect value with a hardcoded "ok"; if the bot then reaches the next stage, the parser was rejecting your original string — move its construction into a script.

See also​