What's broken

Starting in v1.14.44, POST /session/{id}/prompt_async accepts the request (returns 204) but never fires the model. No SSE events are emitted, no inference runs. The session just sits there.

The sync POST /session/{id}/message endpoint works perfectly on the same session, same model, same everything.

Two separate issues

1. prompt_async silently discards requests

Fire prompt_async, get a clean 204 back, and then... nothing. The SSE stream only ever receives server.connected. No message.part.delta, no session.status, no error. The model is never invoked. Token counts are 0/0.

This isn't a rate limit or auth problem. Health endpoint returns healthy, session creation works, and the sync /message endpoint on the same session responds with a full model output (tokens, reasoning, text, the whole thing).

2. session.idle sent on SSE connect before any prompt

v1.14.44 sends a session.status: idle event as soon as you connect to /event. If your client opens the SSE stream before firing prompt_async (which is the right pattern to avoid missing early delta events), the idle event looks like a completion signal and kills the stream before the prompt even fires.

Previous versions didn't do this.

Bonus: opencode version is also broken

$ opencode version
Error: Failed to change directory to /Users/.../version

Looks like it's trying to cd into a directory called "version" instead of printing the version string.

How to reproduce

# Start the server
opencode serve --port 4096

# Create a session
SESSION=$(curl -s -X POST http://127.0.0.1:4096/session \
  -H "Content-Type: application/json" -d '{}' | jq -r '.id')

# Open SSE in one terminal
curl -N http://127.0.0.1:4096/event

# Fire prompt_async in another terminal
curl -X POST "http://127.0.0.1:4096/session/$SESSION/prompt_async" \
  -H "Content-Type: application/json" \
  -d '{"parts":[{"type":"text","text":"Say hello"}]}'
# Returns 204, but SSE only shows server.connected. Nothing else.

# Compare with sync endpoint (this works fine):
SESSION2=$(curl -s -X POST http://127.0.0.1:4096/session \
  -H "Content-Type: application/json" -d '{}' | jq -r '.id')
curl -s -X POST "http://127.0.0.1:4096/session/$SESSION2/message" \
  -H "Content-Type: application/json" \
  -d '{"parts":[{"type":"text","text":"Say hello"}]}' | jq .info.tokens
# Returns full response with tokens

Environment

• macOS (Intel)
• opencode v1.14.44 (binary at ~/.opencode/bin/opencode)
• Provider: opencode-go (deepseek-v4-flash), also tested with default model (big-pickle). Same result.
• Health endpoint reports {"healthy":true,"version":"1.14.44"}

Workaround

Fall back to the sync /message endpoint. Works fine but you lose streaming and real-time tool call visibility.

Impact

Anyone using prompt_async + SSE for streaming responses (which is the whole point of the async API) is broken on v1.14.44. The sync endpoint works, so it's not a total outage, but it's a significant regression for API consumers that depend on streaming.

Checked v1.14.45 and v1.14.46 release notes, doesn't look like this was addressed yet.