Tcx Calculation

Reproducible Financial Calculation

Use the smallest governed input and leave an auditable Calculation Run whenever the result can affect a conclusion. Keep quick arithmetic that does not support a conclusion explicitly exploratory.

Follow the calculation workflow

1. Search Dataset and Calculation cards before fetching data or computing.
2. Inspect only the relevant manifest or run summary. Confirm source lineage, units, currency, timezone, adjustment policy, and knowledge_cutoff.
3. Reuse a prior result only when prepare_calculation reports an exact fingerprint match. Treat similar runs as references, not cached answers.
4. Materialize only the needed columns, instruments, and time range. Keep private portfolio or ledger inputs run-scoped; never register them as a Dataset or copy them into scripts, logs, or artifacts.
5. Create one direct basename-only .py file under $TRADINGCODEX_SCRATCH with native apply_patch. For a conclusion-relevant calculation, call prepare_calculation before execution and use only its declared inputs and outputs.
6. Run exactly ./tcx-calc <filename.py> from the workspace root on POSIX or .\\tcx-calc.cmd <filename.py> on Windows. Do not invoke system Python, install packages, use heredocs, or pass -c, -m, paths, or extra args.
7. Call the runner-injected tcx_emit_result global exactly once with one positional object. Never import it, pass keyword arguments, invent wrapper fields, or emit a metrics mapping. Copy the exact typed shape from references/data-runtime.md.
8. Record success or failure with record_calculation_run. On failure, read its safe error_code and error_message, make one concrete correction, stage a new script basename, prepare a new immutable spec, and retry. Never overwrite a prepared script/result, repeat the same failed code unchanged, install packages, or reuse a failed Run. Stop and hand off as waiting if the same error code recurs after its targeted correction.
9. Bind accepted calculation_run_ids, Dataset lineage, assumptions, diagnostics, and warnings into the role artifact. Do not cite an exploratory sidecar-free execution as decision evidence.

Use search_datasets, get_dataset_manifest, profile_dataset, and materialize_dataset_slice progressively. Avoid loading complete payloads or long calculation logs into context.

Apply the quality floor

• Separate observed inputs, derived values, assumptions, and judgment.
• Preserve point-in-time posture; never substitute revised or current data for the requested vintage without disclosure.
• Make units, sign conventions, compounding, annualization, timing, missing values, and sample definitions explicit.
• Set deterministic seeds for stochastic work and report solver convergence, statistical diagnostics, and sensitivity where relevant.
• Reject NaN, Infinity, silent coercion, executable serialization, and results whose inputs or method cannot be reconstructed.
• Lower readiness when data quality, method assumptions, sample size, convergence, or sensitivity does not support the claim.

Read references/finance-methods.md before DCF, IRR, return/risk, regression, optimization, or portfolio calculations. Read references/data-runtime.md before registering, materializing, reusing, or recording Dataset and Calculation objects.