---
title: "Best-Execution Evidence Pack"
method: POST
path: "/v1/tools/compute_best_execution_evidence_pack"
tags: ["best execution", "price improvement", "execution policy", "monitoring MI", "MiFIR", "RTS 27", "RTS 28", "zero network", "zero-PII"]
---

# Best-Execution Evidence Pack

`POST /v1/tools/compute_best_execution_evidence_pack`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/compute_best_execution_evidence_pack`
- Auth: none declared

Compiles a caller-declared best-execution monitoring evidence pack: the fill-weighted average price improvement in basis points across declared per-venue fills (2dp half-up), the declared negative-improvement venues in declared order, and a REVIEW_ITEM_FLAGGED / WITHIN_POLICY verdict. Declared fills only: per-venue fill counts and improvements are your declarations, never observations this page makes; it reads no order store, venue connection, or fill observer. Absent or invalid venue records fail closed and are named. Basis: Commission Delegated Regulation (EU) 2026/825 (order execution policies), applying from 12 February 2028. No network, no storage, no clock.

**Tool URL:** https://ainumbers.co/tools/681-best-execution-evidence-pack.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `venues` object[], required: Declared per-venue records: venue (non-empty string), fills (integer > 0), avg_improvement_bps (finite number).
    - `venue` string, required
    - `fills` number, required
    - `avg_improvement_bps` number, required

## Response `200`

Successful tool execution result

- object
  - `weighted_improvement_bps` number, nullable
  - `negative_venues` unknown
  - `overall` string, nullable
  - `trace` string
  - `domain_errors` unknown[]
    - unknown

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)