Error code reference

Each FloxError carries a stable code (e.g. E_SYM_001), a human message, and a help URL pointing to the per-code page in this section. AI agents reading FLOX errors can resolve the code to a documented fix without parsing free-text messages.

Code format

E_<DOMAIN>_<NUMBER> — DOMAIN is a short uppercase tag identifying the subsystem; NUMBER is a zero-padded 3-digit counter within that domain. Codes never change meaning once published; if the cause shifts, a new code is allocated.

Domain	Subsystem
SYM	Symbol registry / lookups
DATA	Input data loading and parsing
INPUT	Tape loading and input validation
KEY	Event field lookups and required keys
TIME	Calendar, intervals, timestamps
LEN	Array length mismatches
VAL	Binding argument validation
GRAPH	Indicator graph construction
ADF	ADF stationarity test
RUN	Backtest / runner lifecycle
BACKTEST	Backtest configuration and execution
IO	Filesystem and binary log I/O

Catalog

Every code has its own page in this directory (E_<DOMAIN>_<NNN>.md); a few representative entries:

Code	Message
E_SYM_001	Symbol is not registered
E_RUN_003	Invalid factory return value (GridSearch)
E_ADF_001	ADF — invalid regression mode

Browse the full set by opening any E_*.md in this folder.

How to add a new code

1. Decide on a domain. If a new domain is needed, add it to the table above.
2. Pick the next number in that domain.
3. Write a Markdown page docs/errors/<code>.md with the frontmatter shown below.

4. Use the code at the throw site:

   throw flox::FloxError(
       "E_SYM_001",
       "Symbol '" + name + "' is not registered. ...");
   

5. Run python3 scripts/check_error_codes.py (it also runs in CI). It verifies every code referenced from source has a Markdown page and vice-versa.

Frontmatter convention

---
code: E_SYM_001
title: Symbol is not registered
severity: error
since: 0.1.0
---