sandbox-agent/research/acp/missing-features-spec/feature-index.md

Missing Features Index

Features selected for implementation from the v1-to-v2 gap analysis.

Completely UNIMPLEMENTED in v2

#	Feature	Implementation notes
1	Questions	Deferred to agent process side (#156)
2	Event history/polling	Not selected
3	Turn stream	Not selected
4	Filesystem API -- all 8 endpoints (list, read, write, delete, mkdir, move, stat, upload-batch). ACP only has text-only fs/read_text_file + fs/write_text_file (agent->client direction).
5	Health endpoint -- typed HealthResponse with status.
6	Server status -- ServerStatus (Running/Stopped/Error), ServerStatusInfo (baseUrl, lastError, restartCount, uptimeMs).
7	Session termination -- v1 had full terminate. v2 only has session/cancel (turn cancellation, not session kill). No explicit close/delete.	See existing ACP RFD
8	Model variants -- deferred for now.	Out of scope
9	Agent capability flags	Not selected
10	include_raw -- deferred for now.	Out of scope

Downgraded / Partial in v2

#	Feature	Implementation notes
11	Permission reply granularity	Not selected
12	Agent listing -- v1 GET /v1/agents returned typed AgentListResponse with installed, credentialsAvailable, path, capabilities, serverStatus. v2 returns generic JSON.
13	Models/modes listing -- expose as optional models/modes fields on agent response payloads (installed agents only), lazily populated.	No separate /models or /modes endpoints
14	Message attachments -- v1 MessageRequest.attachments (path, mime, filename). v2 ACP embeddedContext is only partial.
15	Session creation richness -- v1 CreateSessionRequest had mcp (full MCP server config with OAuth, env headers, bearer tokens), skills (sources with git refs), agent_version, directory. Most have no ACP equivalent.	Check with our extensions, do not implement if already done
16	Session info -- v1 SessionInfo tracked event_count, created_at, updated_at, full mcp config. Mostly lost.	Add as sessions HTTP endpoint
17	Error termination metadata -- v1 captured exit_code, structured StderrOutput (head/tail/truncated). Gone.