Create events

Records one turn of a session's transcript and answers 201 with it.

POST /v1/agent/sessions/{id}/events

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Address	`https://api.hanzo.ai/v1/agent/sessions/{id}/events`
Method	`POST`
Operation	`post_agent_sessions_by_id_events`
Auth	`Authorization: Bearer $HANZO_API_KEY`

Records one turn of a session's transcript and answers 201 with it.

A progress turn additionally MOVES THE SESSION'S PROGRESS, marked as the run's own word rather than an estimate, and pushes the updated session onto the live stream — so a board's bar follows the run without polling and without a second write path. See progress.go.

THE TURN IS SCANNED BEFORE IT IS STORED. The same engine the code-security surface runs reads the payload at this boundary, and a credential in it refuses the append with 422 rather than redacting it — a redacted transcript is one that still had the secret in it once, and this way the author learns which value to rotate. The refusal carries every finding: the rule, the severity, the line, a MASKED preview and the fingerprint. The secret is never in the answer.

Request

5 fields, body application/json (required).

Field	In	Type	Required	Description
`id`	path	string	yes	ID is the session to append to, from the path.
`actor`	body	string	—	Actor is who produced the turn.
`id`	body	string	—	ID is the session to append to, from the path.
`kind`	body	string	—	Kind is what this turn IS: message, tool-call, spawn, log, status, control or progress.
`payload`	body	any	—	Payload is the turn's own body, any valid JSON up to 64 KiB.

Response

Status	Body	Meaning
`201`	agent.eventView	created
`default`	problem-details	refused

201 body — 7 fields.

Field	In	Type	Always	Description
`actor`	body	string	—	Actor is who produced the turn.
`createdAt`	body	string	—	CreatedAt is when the turn was recorded, RFC 3339 in UTC to the second.
`id`	body	string	—	ID is the event's own handle, minted as "evt_" + 32 hex characters.
`kind`	body	string	—	Kind is what the turn IS, from a closed six: message (a model turn), tool-call, spawn (a subagent started), log, status, control (a steering command the running surface consumes).
`payload`	body	any	—	Payload is the turn's body, embedded as JSON rather than as a string — whatever the writer sent, up to 64 KiB, checked for well-formedness and scanned for credentials before it was stored.
`seq`	body	integer (int64)	—	Seq is the turn's position in this session's log: monotonic from 1, assigned by the store inside the insert, and unique PER SESSION rather than globally.
`sessionId`	body	string	—	SessionID is the session this turn belongs to.

Failure carries the platform error shape — see Errors.

Examples

CLI

SDK

HTTP

MCP

hanzo agent sessions events <id>

.ts

.py

.go

.rs

.java

import { Configuration, AgentApi } from 'hanzoai';

const api = new AgentApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postAgentSessionsByIdEvents({ id: 'id', actor: "<actor>", id: "<id>" });

from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import AgentApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = AgentApi(client).post_agent_sessions_by_id_events(id='id', actor="<actor>", id="<id>")

cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.AgentAPI.PostAgentSessionsByIdEvents(context.Background()).Execute()
if err != nil {
	return err
}

use hanzo_client::apis::{configuration::Configuration, agent_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = agent_api::post_agent_sessions_by_id_events(&cfg, Default::default()).await?;

import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.AgentApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new AgentApi(client).postAgentSessionsByIdEvents();

curl -X POST https://api.hanzo.ai/v1/agent/sessions/<id>/events \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "actor": "<actor>",
       "id": "<id>"
     }'

MCP reaches agent through the agent tool, which names its 38 operations with its own verbs — this one among them, under a name only MCP declares. describe explains any of them:

curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "describe",
         "arguments": {
           "op": "list_agents"
         }
       }
     }'

Agent API · All Hanzo APIs · Interactive reference

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