---
title: ANARCI outputs and interpretation
description: Numbered positions, CDR and framework regions, and germline genes from ANARCI.
tags:
  - anarci
  - outputs
---

ANARCI returns, per sequence, the chain type, a map of canonical position numbers to residues, the six CDR loops and four framework regions split out as sequences, and the assigned germline genes. Read the CDR regions first — they are what you target in humanization and paratope work, and they are what distinguishes one antibody from another.

## Per-sequence result

Each successfully numbered sequence carries these fields:

| Field | Type | What it tells you |
|---|---|---|
| `sequence_name` | string | The name you gave the sequence (or an auto label). |
| `chain_type` | `VH` \| `VL` \| `VK` | Whether ANARCI numbered it as a heavy, lambda-light, or kappa-light chain. |
| `numbered_positions` | map position→residue | The canonical numbering — each position label mapped to its amino acid. |
| `cdr_sequences` | map region→sequence | The six CDRs, keyed by region (e.g. `CDR-H1`, `CDR-L3`). |
| `framework_sequences` | map region→sequence | The four framework regions, keyed by region (e.g. `FR-H1`, `FR-L4`). |
| `germline_vh` | string \| null | Closest germline V gene for the heavy chain, when germline assignment is on. |
| `germline_vl` | string \| null | Closest germline V gene for the light chain. |

## Job-level summary

Alongside the per-sequence results, the job reports which sequences failed and how many succeeded:

| Field | Type | Meaning |
|---|---|---|
| `failed_sequences` | string[] | Names of sequences ANARCI could not number. |
| `success_count` | int | How many sequences numbered successfully. |
| `fail_count` | int | How many failed. |
| `scheme_used` | string | The numbering scheme that was applied. |

## Reading the result card

The ANARCI result renders on the canvas as an antibody annotation card. It surfaces the numbered sequence and region breakdown so you can see CDRs and framework regions at a glance before deciding what to run next.

## What to do next

- The CDR boundaries feed [paratope prediction](/docs/paragraph) and CDR-focused engineering.
- The numbered sequence feeds [humanness scoring](/docs/humatch) and [humanization](/docs/biophi).
- The germline assignment tells you how far the sequence has drifted from its nearest human (or murine) germline.

## Read next