---
title: "Recover an accepted Hub `chai1` request. New launches return HTTP 410 `hub_execution_retired`; use `/v2/zencloud`."
method: POST
path: "/v2/hub/chai1/start"
tags: ["Hub"]
---

# Recover an accepted Hub \`chai1\` request. New launches return HTTP 410 \`hub_execution_retired\`; use \`/v2/zencloud\`.

`POST /v2/hub/chai1/start`

## Request

- Base URL: `https://api.omtx.ai` (the document declares no server; this is the origin it was published from)
- URL: `https://api.omtx.ai/v2/hub/chai1/start`
- Auth: one of:
  - API key in header `x-api-key`
  - HTTP bearer

## Headers

- `Idempotency-Key` string, required

## Request body

- object: Chai-1 canonical primitive-only launch schema.
  - `job_name` string: Human-readable Chai-1 job name
  - `protein_sequence` string, required: Primary protein sequence; hosted input is capped at 600 total protein residues.
  - `ligand_name` string, nullable: Optional ligand name/identifier.
  - `ligand_smiles` string, nullable: Ligand partner SMILES (exactly one partner is required).
  - `dna_sequence` string, nullable: DNA partner sequence (exactly one partner is required).
  - `rna_sequence` string, nullable: RNA partner sequence (exactly one partner is required).

## Response `200`

Successful Response

- unknown

## Other responses

- `202`: Job accepted. Poll /v2/jobs/{job_id} for status/result.

---

[API](https://skmtc.dev/omtx/apis/gateway.md) - [All operations](https://skmtc.dev/omtx/apis/gateway/llms.txt) - [OpenAPI document](https://skmtc.dev/omtx/apis/gateway/revisions/232715a75205?raw)