post_v1_pubsub_publish
Publish puts one message on the org's bus.
Publish puts one message on the org's bus. When a stream captures the subject the write is DURABLE — the receipt names the stream and sequence only after JetStream has it on storage, and a repeated Nats-Msg-Id header within the dedup window answers duplicate instead of storing twice. When nothing captures it, the message goes out core NATS: delivered to current subscribers, receipt {ok}, nothing retained.
| Tool | post_v1_pubsub_publish |
| Door | https://api.hanzo.ai/v1/mcp |
| Method | tools/call (JSON-RPC 2.0) |
| Arguments | 3 |
| Operation | POST /v1/pubsub/publish |
| Product | pubsub |
Arguments
| Field | Type | Required | Default | Values | Description |
|---|---|---|---|---|---|
data | string | — | — | — | Data is the payload, carried verbatim as UTF-8 text (typically JSON). Binary payloads belong on the NATS port. |
headers | object | — | — | — | Headers are optional message headers, one value per name. A Nats-Msg-Id header is JetStream's deduplication key: a repeat within the stream's dedup window is acknowledged as duplicate rather than stored twice. |
subject | string | — | — | — | Subject is the subject to publish to, in the org's own namespace — e.g. orders.created. No wildcards. |
tools/list declares a type and a description for each field and nothing further. A — means neither the door nor that operation constrains the field.
Call it
A tools/call carries every argument in one flat object — nothing binds to a path or a query string. Nothing above is required, so every declared argument is shown rather than a guess at which matter.
curl -X POST https://api.hanzo.ai/v1/mcp \
-H "Authorization: Bearer $HANZO_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "post_v1_pubsub_publish",
"arguments": {
"data": "<data>",
"headers": {},
"subject": "<subject>"
}
}
}'Values are the operation's own defaults and enumerated values where it declares them, and a <placeholder> where neither source declares one. tools/list needs no credential; tools/call does — called without one the door answers HTTP 200 with a JSON-RPC result whose isError is set and whose text says what was missing. How to get a key →
The operation behind it
| Operation | Route | Product | Summary |
|---|---|---|---|
post_v1_pubsub_publish | POST /v1/pubsub/publish | pubsub | Publish puts one message on the org's bus. |
The same capability over plain HTTP is in the pubsub API reference, on https://api.hanzo.ai.
All 755 tools · The door · API reference
Generated from tools/list on https://api.hanzo.ai/v1/mcp — 833 tools captured 2026-08-01, of which 755 are documented here (the operator surface is not published) (this build read the vendored copy; the door was unreachable).
How is this guide?