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[FEATURE]: MCP tool calls should carry current session context (session_id) #33035
Description
Feature hasn't been suggested before.
- I have verified this feature I'm about to request hasn't been suggested before.
Feature Request
When OpenCode calls an MCP tool, the current session ID should be injected into the request so that MCP servers can associate operations with the OpenCode session that triggered them.
Use Case
I built an MCP server (mcp-memory) that stores conversation memories. It accepts an optional session_id parameter, but when OpenCode's AI agent calls save_memory, it doesn't know the current session ID, so memories are saved without session context. This makes it impossible to group memories by the OpenCode session they originated from.
Proposed Solution
Inject the current OpenCode session ID into MCP tool call requests via the _meta field of the CallToolRequest (following MCP protocol design). This approach works for both local (stdio) and remote MCP servers, unlike solutions that only cover HTTP transport.
The MCP server would then extract the session ID from the request context.
Why this matters
Without session context, memory/stateful MCP servers have no way to correlate data with the conversations that produced them, limiting their usefulness for cross-session persistence.
Relationship to existing issues
This request differs from related issues:
- [FEATURE]: Expose session context to MCP servers via environment variables #15117 proposes exposing session context via environment variables (
OPENCODE_SESSION_ID). While valuable, env vars are set at process start and cannot change mid-session. Our_metafield approach follows MCP protocol design and works per-request. - [FEATURE]: add mcp.call.before plugin hook for per-call MCP request headers (e.g. sessionID forwarding) #28225 proposes a plugin hook (
mcp.call.before) to inject headers into outbound HTTP MCP calls. This only covers remote MCP over HTTP transport. Our_metafield approach covers both local (stdio) and remote MCP servers uniformly.
Activity
github-actions commentedon Jun 19, 2026
This issue doesn't fully meet our contributing guidelines.
What needs to be fixed:
[FEATURE]:(e.g.[FEATURE]: MCP tool calls should carry current session context (session_id))- [ ] I have verified this feature I'm about to request hasn't been suggested before.)Please edit this issue to address the above within 2 hours, or it will be automatically closed.
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[-]MCP tool calls should carry current session context (session_id)[/-][+][FEATURE]: MCP tool calls should carry current session context (session_id)[/+]github-actions commentedon Jun 19, 2026
Thanks for updating the issue! It now meets our contributing guidelines. Your feature request is clear, well-structured, and includes a solid use case and proposed solution. Appreciate the effort!
m13v commentedon Jun 20, 2026
the _meta vs env-var vs plugin-hook split is really a transport argument, but the thing that actually decides whether memories group correctly is whether the session id is stable across a resume or restart. if it regenerates when the session reattaches, save_memory still lands under a fresh key and the grouping you wanted quietly splits into two. injecting the id per-request is the easy half. durable, restart-surviving session identity is the half that determines if any of the correlation holds, and that part lives in your session store, not the call envelope.
liaosf commentedon Jun 20, 2026
Confirmed — opencode session list returns persistent session IDs stored in OpenCode's SQLite database, which survive restarts and reconnection. The _meta approach would carry this stable ID.
Necmttn commentedon Jun 21, 2026
Since the stable SQLite-backed session id is confirmed, I would make the per-call metadata carry the rest of the provenance too.
Something like:
{ "session_id": "...", "session_run_id": "...", "turn_id": "...", "tool_call_id": "...", "project_id": "...", "parent_agent_id": null }session_run_idcould also be a resume epoch if that is the local concept. The important part is that memory/stateful MCP servers can distinguish "same saved conversation after resume" from "same session id, different tool call." Keep this in MCP_meta, not model-visible tool args, and cover both stdio and HTTP transports in regression tests.Generated with ax.
github-actions commentedon Aug 21, 2026
To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.