What causes "Failed to create JetStream context" in micro/go-micro?

Enable JetStream on the NATS server (start with -js or set jetstream.enabled=true) and restart it

Failed to create JetStream context

Error message

Failed to create JetStream context

What it means

Returned by Init when creating a JetStream context on an established NATS connection fails via conn.JetStream(). The library needs a JetStreamContext to manage KV buckets, so without it the store cannot operate. Usually indicates the NATS server has JetStream disabled or a supplied JS option is invalid.

Source

Thrown at store/nats-js-kv/nats.go:85

	return n
}

// Init initializes the store. It must perform any required setup on the
// backing storage implementation and check that it is ready for use,
// returning any errors.
func (n *natsStore) Init(opts ...store.Option) error {
	n.setOption(opts...)

	// Connect to NATS servers
	conn, err := n.nopts.Connect()
	if err != nil {
		return errors.Wrap(err, "Failed to connect to NATS Server")
	}

	// Create JetStream context
	js, err := conn.JetStream(n.jsopts...)
	if err != nil {
		return errors.Wrap(err, "Failed to create JetStream context")
	}

	n.conn = conn
	n.js = js

	// Create default config if no configs present
	if len(n.kvConfigs) == 0 {
		if _, err := n.mustGetBucketByName(n.opts.Database); err != nil {
			return err
		}
	}

	// Create kv store buckets
	for _, cfg := range n.kvConfigs {
		if _, err := n.mustGetBucket(cfg); err != nil {
			return err
		}
	}

View on GitHub (pinned to 24529f1404)

Solutions

Enable JetStream on the NATS server (start with -js or set jetstream.enabled=true) and restart it
Verify the server version is >= 2.2 with jetstream enabled: run 'nats --server <url> server info' and check the jetstream block
Review any []nats.JSOpt supplied via natsjskv.WithJSOptions/context for invalid settings and remove or correct them
Upgrade github.com/nats-io/nats.go and the nats-server to compatible versions

Example fix

// before
nats-server -p 4222
// after
nats-server -p 4222 -js

Defensive patterns

Strategy: validation

Validate before calling

nc, err := nats.Connect(url)
if err != nil { return err }
js, err := nc.JetStream()
if err != nil {
    return fmt.Errorf("jetstream not available: %w", err)
}
info, err := js.AccountInfo()
if err != nil { return err }

Try / catch

if err := st.Init(); err != nil {
    if strings.Contains(err.Error(), "Failed to create JetStream context") {
        return fmt.Errorf("NATS server lacks JetStream: %w", err)
    }
    return err
}

Prevention

Always start nats-server with -js or jetstream.enabled=true in production configs
Probe JetStream availability with a lightweight conn.JetStream()/AccountInfo check at startup before depending on the store
Pin compatible nats-server and nats.go versions in CI
Fail fast at deploy time with a health check that calls store.Init

When it happens

Trigger: Calling store.Init() (or any operation that lazily calls initConn) against a NATS server where JetStream is not enabled (jetstream disabled in nats-server config), or with invalid nats.JSOpt options passed via the jsOptionsKey context value.

Common situations: Connecting to a NATS server started without the -js flag or without 'jetstream { enabled: true }' in its config; pointing at an old NATS server (<2.2) that lacks JetStream; passing a malformed nats.JSOpt (e.g. bad api prefix or prepend/append option) through context options.

Related errors

AI-assisted analysis of micro/go-micro@24529f1404 (2026-09-01). Data as JSON: /api/errors/94047d6d1a7cabde. Report an issue: GitHub.