# Wellfound Send Message API

> Send one message in an existing Wellfound conversation as the signed-in account. Takes the bare conversation modelId from wellfound-list-conversations and the session blob from wellfound-login. Returns the new message id, or Wellfound's rejection messages. A sent message cannot be unsent.

Category: [Social Media APIs](https://upapi.io/apis/social-media) · Last updated 2026-11-07

## How to call it

- Endpoint: `POST https://api.upapi.io/wellfound-send-message.post`, key in the `X-Api-Key` header, JSON body.
- Cost: 4 weighted units per call.
- Timeout: 30 seconds.
- Cache: none; every call runs the operation.
- Try it without writing code: https://app.upapi.io/try/wellfound-send-message.post

```bash
curl -X POST https://api.upapi.io/wellfound-send-message.post \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -d '{ "body": "example", "session": "example", "messageType": "JOBPAIRING", "conversationId": "982616801" }'
```

## Request parameters

- `body` (string, required) — Message text to send.
- `session` (string, required) — Session blob from wellfound-login.
- `proxyUrl` (string) — Same exit the session was minted on. Omit to send directly.
- `messageType` (string) — Wellfound ConversationTypeEnum value.
- `conversationId` (string, required) — The BARE modelId from wellfound-list-conversations, for example 982616801. Not the prefixed node id.

## Response fields

- `errors` (array) — Rejection messages Wellfound returned.
- `session` (string) — Refreshed blob carrying rotated cookies. Persist THIS one, not the input.
- `success` (boolean, required) — True when Wellfound accepted the message with no errors.
- `messageId` (string)

## Example request and response

The example response is generated from the published output schema: it shows the shape and field names, not values from a recorded call.

```json
{
  "body": "example",
  "session": "example",
  "messageType": "JOBPAIRING",
  "conversationId": "982616801"
}
```

```json
{
  "errors": [
    "example"
  ],
  "session": "",
  "success": false,
  "messageId": ""
}
```

## Frequently asked questions

### How much does the Wellfound Send Message API cost per call?

Each call spends 4 weighted units of your plan's monthly quota. Full pricing is at https://upapi.io/pricing.

### How do I authenticate to the Wellfound Send Message API?

Send your key in the X-Api-Key header. A free guest key is available without creating an account.

### Are Wellfound Send Message API responses cached?

No — every call runs the operation live; responses are not cached.

## More Social Media APIs

- [Wellfound Apply To Job](https://upapi.io/apis/social-media/wellfound-apply)
- [Wellfound Conversation Detail](https://upapi.io/apis/social-media/wellfound-conversation-detail)
- [Wellfound List Conversations](https://upapi.io/apis/social-media/wellfound-list-conversations)
- [Wellfound Viewer](https://upapi.io/apis/social-media/wellfound-viewer)
- [Wellfound Application Modal](https://upapi.io/apis/social-media/wellfound-application-modal)
- [Wellfound Browse Jobs](https://upapi.io/apis/social-media/wellfound-browse-jobs)
- [Wellfound Company Overview](https://upapi.io/apis/social-media/wellfound-company-overview)
- [Wellfound Job Detail](https://upapi.io/apis/social-media/wellfound-job-detail)