t8y2/dbx · error

agentSessionId is required

Error message

agentSessionId is required

What it means

The vastbase-go driver's open_session operation creates a named session keyed by agentSessionId. This identifier is required to route subsequent operations (query, transaction, etc.) to that session, so the driver throws when it is missing or empty.

Source

Thrown at agents/drivers/vastbase-go/main.go:240

		return errorResponse(req.ID, req.Method, stringParam(req.Params, "agentSessionId"), err), false
	}
	return response{JSONRPC: "2.0", ID: req.ID, Result: result}, shutdown
}

func (r *runtimeServer) dispatch(method string, params map[string]json.RawMessage) (any, bool, error) {
	switch method {
	case "handshake":
		return map[string]any{
			"protocolVersion":      protocolVersion,
			"agentProtocolVersion": protocolVersion,
			"capabilities": []string{
				"connect", "test_connection", "metadata", "query", "paged_query", "transaction", "ddl", "multi_session", "structured_error_v1",
			},
		}, false, nil
	case "open_session":
		id := stringParam(params, "agentSessionId")
		if id == "" {
			return nil, false, errors.New("agentSessionId is required")
		}
		var cp connectParams
		if err := decodeParams(params, &cp); err != nil {
			return nil, false, err
		}
		return map[string]bool{"ok": true}, false, r.openSession(id, cp)
	case "close_session":
		return map[string]bool{"ok": true}, false, r.closeSession(stringParam(params, "agentSessionId"))
	case "validate_session":
		session, err := r.session(stringParam(params, "agentSessionId"))
		if err != nil {
			return nil, false, err
		}
		session.mu.Lock()
		defer session.mu.Unlock()
		release, permitErr := session.server.acquireOperationPermit("validate_session")
		if permitErr != nil {
			return nil, false, permitErr

View on GitHub (pinned to c0390bff16)

Solutions

1. Generate and pass a non-empty agentSessionId, e.g. a UUID
2. Reuse the same agentSessionId in later operations targeting the session
3. Validate the id before dispatching open_session

Example fix

// before
{ "op": "open_session", "connect": { "dsn": "vb://localhost/db" } }
// after
{ "op": "open_session", "agentSessionId": "sess-1", "connect": { "dsn": "vb://localhost/db" } }

const id = String(crypto.randomUUID());
if (!id) throw new Error("agentSessionId is required");
await agent.dispatch("open_session", { agentSessionId: id, ...connectParams });

function hasSessionId(p) { return typeof p.agentSessionId === "string" && p.agentSessionId.trim().length > 0; }

try { await agent.dispatch("open_session", params); } catch (e) { if (/agentSessionId is required/.test(e.message)) { params.agentSessionId = crypto.randomUUID(); await agent.dispatch("open_session", params); } else throw e; }

When it happens

Trigger: Dispatching open_session without agentSessionId, or with agentSessionId:""; constructing params programmatically where the id variable was empty.

Common situations: Forgetting the session id when switching from simple query ops to multi-session usage; string interpolation of an unset variable; orchestrators generating session ids that end up empty on first run.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

• agentSessionId is required
• Cassandra connection runtime is closed
• Not connected
• agentSessionId is required
• agentSessionId is required

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/c4539e0e40f6462f. Report an issue: GitHub.