Log in Sign up
First-party app
PostBin

PostBin

Create disposable bins that collect any HTTP request sent to them, for testing API clients and webhooks.

stable Developer Tools

About

PostBin ships in the w6w first-party pack. It declares 5 actions, 2 health checks, and the host runs its code in a sandbox that never sees the credential.

App id
io.w6w.postbin
Version
0.1.2
Author
w6w
Licence
MIT
Categories
Developer Tools

Overview

PostBin gives a workflow a disposable HTTP inbox: create a bin, get back a throwaway URL, point any API client or webhook sender at it, then read back exactly what arrived. Bins expire around 30 minutes after creation, which makes this genuinely useful for testing a webhook integration or inspecting what a client actually sends, without standing up a real endpoint.

There is no bulk “list requests” call — a workflow reads everything a bin collected by repeatedly popping the oldest uncollected request off the queue until none remain, or fetches one already-known request directly if it already has the id. Popping a request is a mutating operation even though it happens to use GET on the wire, so it is not safe to retry blindly.

PostBin has no account, no API key and no OAuth flow — every call, including creating and deleting a bin, is unauthenticated by design, and deleting an already-gone bin still succeeds cleanly rather than erroring.

Build with PostBin

Three routes to the same 5 actions. The Workflow tab is generated from PostBin's own manifest and carries its real ids, so it is copy-pasteable; the Code and CLI examples are the same call for any action on any app, so every app-specific value in them is a blank you fill in.

Create Bin

create-bin

Create a new PostBin bin that collects any request sent to it for ~30 minutes.

Delete Bin

delete-bin

Delete a bin and everything collected in it. Succeeds even if the bin is already gone.

Get Bin

get-bin

Look up a bin's creation and expiry time by its ID.

Get Request

get-request

Fetch one request a bin collected, by its request ID. Leaves it in the bin.

Shift Next Request

shift-request

Pop and return the oldest request a bin collected. Removes it from the bin, so the next call returns the one after it.

A workflow step names the app and the action, and the editor fills in the connection when you pick one. This is the Step shape from the workflow spec, carrying PostBin's real ids. 

{
  "manifestVersion": "2",
  "name": "postbin-example",
  "steps": [
    {
      "id": "get-bin",
      "uses": {
        "app": "io.w6w.postbin",
        "action": "get-bin",
        "connection": null
      },
      "with": {
        "binId": "<binId>"
      }
    }
  ]
}

Here are some of the things you can do

  • Get Bin

    read
    get-bin

  • Create Bin

    perform
    create-bin

  • Get Request

    read
    get-request

  • Shift Next Request

    perform
    shift-request

+1 more action available

Every app-specific value here is a blank you have to fill in. An app action is reached through the connection that authenticates it, so the address is a connection id, not the app id — and connections belong to your account, so a public page cannot know yours. Create one for PostBin, then fill in the three blanks: conn_YOUR_CONNECTION_ID, the action key, and the parameters that action declares. The call itself is real — the shape is transcribed from the studio's own snippet builder, which prints the same kind of blanks — but nothing in it is specific to PostBin. The Workflow tab is where this app's real ids are.

Install 
npm install @w6w/sdk
yarn add @w6w/sdk
pnpm add @w6w/sdk
deno add npm:@w6w/sdk
Code 
import { W6wClient, isActionRun } from "@w6w/sdk";

// Reads W6W_BASE_URL and W6W_TOKEN from the environment when omitted.
const client = new W6wClient();

const envelope = await client.run({
  urn: "conn_YOUR_CONNECTION_ID",
  action: "create-bin",
  payload: {},
});

if (isActionRun(envelope)) console.log(envelope.value);
Install the CLI 
npm install -g @w6w/cli
CLI 
w6w run conn_YOUR_CONNECTION_ID --action create-bin --payload '{}'

Give an AI agent PostBin — without giving it PostBin's credentials. One MCP endpoint exposes every app, function and workflow the caller is entitled to, as tools it can discover and run. Access is granted per team while we onboard.

One tool call 
{
  "name": "w6w_invoke",
  "arguments": {
    "ref": "app:io.w6w.postbin#get-bin",
    "input": {
      "binId": "<binId>"
    }
  }
}

Every tool names its target with a single ref. The app: form above doesn't name a connection at all — the host resolves which of the caller's PostBin connections to sign with, and refuses rather than guesses when the answer is ambiguous.

What the agent gets

Credentials it can't read

The token is attached host-side, at the moment of the call. It is never a tool argument, never in the model's context, and never in a transcript — so a prompt injection has nothing to exfiltrate.

A tool surface scoped to the caller

Tools are derived per end user from what that person has actually connected and is entitled to — not one shared bot identity carrying the union of everyone's access.

A durable workflow in one call

Multi-step work runs on the workflow engine and returns a run handle the agent can poll — retries, branching and state survive the conversation that started them.

Health-aware discovery

PostBin's declared health checks are on the surface too, so an agent can tell "the vendor is down" from "your credential expired" before it burns a retry on either.

The MCP surface is part of the hosted platform. PostBin itself is MIT, and the runtime that executes it is source-available (FSL).

Request MCP access

Health checks

PostBin declares its own checks, so its health is a property of the app rather than something the host guesses at.

service

PostBin reachable

GETs the PostBin homepage. PostBin publishes no status page/feed, and every API endpoint either needs an existing bin or creates one, so this is the narrowest available side-effect-free probe.

quota

API quota headroom