Expression Number
asterwise_get_expression_number
Calculates the Expression (Destiny) number from the full name using Pythagorean letter values. Reduces each name part separately before summing (Decoz per-part method), keeping master numbers 11, 22, 33 at every step.
Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
name | string | yes | Full legal name as used at birth, all parts; its letters are converted to numerology values. |
response_format | enum: markdown, json | no | Output format: 'markdown' (default) for a readable report, or 'json' for the raw structured payload. |
What it covers
The Expression number describes the natural talents, abilities, and shortcomings a person brought into this life — what they are capable of becoming. It differs from the Soul Urge (inner motivation) and Personality (outer mask). Uses all letters A–Z mapped to Pythagorean values 1–9. Not Chaldean (asterwise_get_chaldean_numerology).
Workflow
BEFORE: None — this tool is standalone.
AFTER: asterwise_get_soul_urge_number — complete the core trinity (Expression, Soul Urge, Personality).
Input
name — Full legal name as used at birth. Include all name parts separated by spaces.
Example: 'Arjun Mehta', 'Sofia Rossi', 'James Carter'
Format: string, any case (uppercase/lowercase both accepted)
Constraint: at least one alphabetic character required
Output contract
data.number (int — Expression number; may be 11, 22, or 33 for master numbers)
data.is_master_number (bool — true when number is 11, 22, or 33)
data.karmic_debt_number (int or null — 13, 14, 16 or 19 when it appears anywhere in the reduction of the name total, e.g. 58 → 13 → 4 gives 13; a one-word name uses its letter total; null otherwise)
Response format
response_format=json serialises the complete response as indented JSON — use this for programmatic parsing, typed clients, and downstream tool chaining.
response_format=markdown renders the same data as a human-readable report.
Both modes return identical underlying data — no fields are added, removed, or filtered by either mode.
Compute class
FAST_LOOKUP
Errors
INVALID_PARAMS (local — caught before upstream call):
None — validation is upstream.
INVALID_PARAMS (upstream):
— 422 validation_error with details[].issue = no_letters when the name has no letters A-Z (e.g. '123', '!!!', or a name written only in a non-Latin script) — ask the user for the name spelled in Latin letters; this is not a server fault.
INTERNAL_ERROR:
— Any upstream API failure or timeout → MCP INTERNAL_ERROR
Do not confuse with
asterwise_get_soul_urge_number — vowels only, not all letters.
asterwise_get_personality_number — consonants only, not all letters.
asterwise_get_numerology_profile — returns Expression plus all other core numbers, pinnacles, challenges, and lucky numbers in one call.
asterwise_get_chaldean_numerology — different letter-value system (Chaldean 1–8).
Connect
Remote MCP endpoint: https://mcp.asterwise.com/mcp. Authenticate with Authorization: Bearer <API key> or OAuth. See the MCP setup guide.