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Open standard · Character infrastructure

Protagons

Portable character identity for any AI model.

Role
Creator of the standard
Type
Open standard + API
Timeline
2025
Live at
protagons.com
Protagons homepage introducing its open AI character identity standard

The friction

AI personas live as prose system prompts. You can’t diff them, fork them, or move them between models without hand-rewriting — and the reasoning walks out the door when the prompt engineer does. Two products that need one voice means copy-paste-and-pray. Prose has no source of truth.

Where AI helps

A pipeline of 28 extraction agents reads a description or real writing samples and produces a structured, evidence-backed, confidence-scored character file — around 287 fields in about two minutes — that a human would never hand-author. The payoff is portability: compile the same identity to any model and the character holds.

Who it helps — Developers and builders wiring characters into products — agents, NPCs, brand-voice systems, TTS pipelines. Not end-user writers; that’s USAW, built on this standard.

What I built

  • An open schema

    JSON Schema 2020-12: 28 dimensions — linguistic and psychological — across 287 fields, with provenance and safety tiers.

  • A compiler

    One .protagon.json becomes a system prompt, SOUL.md, ElevenLabs voice, or Custom GPT; recompile per model.

  • A public library + free BYOK API

    Generate, chat, validate, and deploy characters others can build on.

Proof

28 dimensions287 fields800+ public profilesFree BYOK API