Document system-prompt template variables#104
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JakeSCahill merged 1 commit intoJun 18, 2026
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Add a Template variables section to the system prompts page covering the .Now date fields (.Date/.Weekday/.Month/.Year), the raw .Now.Time, and .User.Email. Notes that times are UTC, that day-granular fields keep the upstream prompt cache warm while sub-day .Now.Time formatting does not, and that a malformed template fails at agent startup. Documents the feature added in the ai-agent system prompt provider.
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Opened from a fork, so I couldn't request reviewers directly. @JakeSCahill @kbatuigas - could one of you take this, or assign the docs team? Documents the system-prompt template variables shipped in redpanda-data/cloudv2#27240. |
JakeSCahill
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Jun 18, 2026
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Lovely. Thank you. |
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What
Add a Template variables section to the agent system prompts page (
modules/connect/pages/system-prompts.adoc) documenting the variables an agent injects into its system prompt at render time: the.Nowdate fields (.Date,.Weekday,.Month,.Year), the raw.Now.Time, and.User.Email.Why
The agent system prompt supports Go-template interpolation, but the feature was undocumented. Agents commonly need the current date for temporal grounding and the caller's email for per-user scoping. Without docs, builders can't discover the variables or the behavior that bites: times are UTC, sub-day formatting hurts prompt caching, and a malformed template fails the agent at startup.
Implementation details
One new
== Template variablessection: a variable reference table with example output, a worked example prompt, a cache-stability note, and a validation note. It states that all times are UTC, that the day-granular date fields keep the upstream model prompt cache warm while sub-day formatting of.Now.Timedefeats it, and that a broken template stops the agent from starting rather than failing per request. The same variables apply to agent and subagent prompts.Grounded in the ai-agent system prompt provider and verified against the shipped behavior.
References
Implements docs for redpanda-data/cloudv2#27240.