regextool

Overview ¶

Package regextool provides regular expression tools for agents. LLMs are notoriously unreliable at generating and reasoning about regex patterns — this tool lets them test, match, extract, and replace using Go's regexp engine for precise results.

Problem: Agents need to parse structured text (log files, configs, code) and LLMs cannot reliably execute regex operations mentally. This package provides a deterministic regex engine the agent can call.

Safety guards:

• Input capped at 1 MB to prevent excessive processing
• Pattern length capped at 10,000 chars
• Output truncated at 32 KB to limit LLM context consumption
• Go's RE2 engine guarantees linear-time matching (no catastrophic backtracking)

Dependencies:

• Go stdlib only (regexp uses RE2 — guaranteed linear-time, no backtracking)
• No external system dependencies