---
title: "Ingest Runs (Multipart)"
method: POST
path: "/runs/multipart"
tags: ["runs"]
---

# Ingest Runs (Multipart)

`POST /runs/multipart`

Ingests multiple runs, feedback objects, and binary attachments in a single `multipart/form-data` request.
**Part‑name pattern**: `<event>.<run_id>[.<field>]` where `event` ∈ {`post`, `patch`, `feedback`, `attachment`}.
* `post|patch.<run_id>` – JSON run payload.
* `post|patch.<run_id>.<field>` – out‑of‑band run data (`inputs`, `outputs`, `events`, `error`, `extra`, `serialized`).
* `feedback.<run_id>` – JSON feedback payload (must include `trace_id`).
* `attachment.<run_id>.<filename>` – arbitrary binary attachment stored in S3.
**Headers**: every part must set `Content-Type` **and** either a `Content-Length` header or `length` parameter. Per‑part `Content-Encoding` is **not** allowed; the top‑level request may be `Content-Encoding: gzip` or `Content-Encoding: zstd`.
**Best performance** for high‑volume ingestion.

## Response `202`

Accepted

- object

## Other responses

- `400` — Bad Request
- `403` — Forbidden
- `409` — Conflict
- `422` — Unprocessable Entity
- `429` — Too Many Requests

---

[API](https://skmtc.net/langchain-ai/apis/langsmith.md) · [All operations](https://skmtc.net/langchain-ai/apis/langsmith/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/langchain-ai/langsmith/versions/a0acb3a6a101/schema)