An open specification for reading a person and using that read across any AI surface. Patent-protected, reference-implemented, freely consumable.
Version 1.0 . 2026-05-19 . Status: draft for public review
This specification describes a behavioral identity primitive for AI systems. The primitive is a compressed read of a single person, derived from how their body behaves during a short structured prompt, expressed as five claims: word, rhythm, force, half_truth, compliance_lever. Any AI surface, agent, or model can consume the primitive at conversation start to personalize its outputs to the body's read of the person, not the language they perform.
Every conversation a person has with an AI begins cold. The model has no read on the person. It defaults to a generic helpful tone. Memory features paper over this by replaying chat history, which captures what the person said but never what the person is.
The behavioral identity primitive solves this by reading the body, not the language. Keystroke rhythm, pause distribution, backspace pattern, completion latency, and structured response shape are the inputs. The output is a compressed identity that can be carried across surfaces.
The body has rehearsed nothing. The body cannot lie. The read of the body is the most honest input a model can be given.
The primitive is a JSON object with five required claims and a small number of optional metadata fields.
{
"word": "anchor", // the spine word, 1 token
"rhythm": "Mirror", // one of 8: Builder, Mirror, Keeper, Flame,
// Ghost, Storm, Fool, Saint
"force": "Fidelity", // one of N: Fidelity, Fear, Deception,
// Hatred, Yearning, ...
"half_truth": "I'm fine until I'm not.",
"compliance_lever": "recognition",
"mark": "abc123def", // stable user identifier
"issued_at": 1730000000,
"issuer": "noctara"
}
The compressed read is produced by a structured prompt protocol. Implementations may vary, but to be Noctara-compatible the capture must:
The capture inputs feed a compression engine that returns the five claims. The engine is not specified in detail because the patent (US Prov. #64/048,624) covers the most reliable production method. The specification only requires that:
word is one token, returned in the subject's native language.rhythm is one of eight named patterns. (Builder, Mirror, Keeper, Flame, Ghost, Storm, Fool, Saint.)force describes the orientation the subject brings under pressure.half_truth is one sentence the subject is telling themselves that the body's read disagrees with.compliance_lever names the single thing that gets this subject to act when they otherwise would not.A single token that describes the subject's compressed identity. Returned in the subject's native language. Not a label. An image. The word becomes the artifact the subject carries.
One of eight named patterns describing how the subject holds under pressure. The eight rhythms are: Builder, Mirror, Keeper, Flame, Ghost, Storm, Fool, Saint. These are not personality types. They are behavioral postures, derived from the time-series of the capture.
The orientation the subject brings under load. Whether they pull toward Fidelity, Fear, Deception, Hatred, Yearning, or another named force. Forces are not moral judgments. They describe direction, not virtue.
One sentence the subject is telling themselves that the body's read disagrees with. Useful as a calibration check: when the model speaks to the subject, the half-truth marks the place where flattery would fail.
The single thing that gets this subject to act when they otherwise would not. Examples: recognition, urgency, entrustment, scarcity, witness. The lever is what a coach, therapist, or friend would use to move them. The model uses it sparingly and never out loud.
An AI surface consumes the primitive in one of three modes:
The simplest path. Call POST /api/mcp/system_prompt with the subject's email or mark. Receive a Claude-ready system addendum that prepends to the model's existing system prompt.
For multi-service deployments. Call POST /api/mcp/identity_token to mint a signed JWT (HS256) carrying word, rhy, frc. Pass between services. Verify at POST /api/identity-verify.
For MCP-aware clients (Claude Desktop, Claude Code, Cursor, Cline, OpenClaw). Install the noctara-mcp-server npm package. The model calls modes as tools.
The identity token is a standard JWT with the following claims:
{
"iss": "noctara",
"sub": "<mark>",
"aud": "<consuming-app>",
"iat": <unix-seconds>,
"exp": <unix-seconds>,
"word": "anchor",
"rhy": "Mirror",
"frc": "Fidelity"
}
Signing algorithm: HS256. Default TTL: 24 hours. Maximum TTL: 30 days. Tokens are minted by the issuer and verified by any service holding the shared signing secret or via the public verifier at /api/identity-verify.
An AI surface consuming this primitive must respect the voice rules carried in the system prompt. These rules are the difference between a model that uses the read and a model that announces the read.
The primitive is the subject's property. Implementations must:
The behavioral identity primitive described in this specification is covered by US provisional patent application #64/048,624, "Systems and Methods for Behavioral Biometric Identity Assessment and Authentication," filed April 24, 2026.
Licensing:
The canonical implementation is at noctaracorp.com. The MCP server source is at github.com/noctara/sdk. Live endpoints:
POST https://noctaracorp.com/api/mcp/system_promptPOST https://noctaracorp.com/api/mcp/identity_tokenPOST https://noctaracorp.com/api/mcp/scrubPOST https://noctaracorp.com/api/identity-verifynpx noctara-mcp-server (MCP stdio transport)