[Feature]: MCP get_context cannot produce an audit trail - no receipt requested, no receipt id and no provenance returned #450

Feature Area

Backend API / Server

Problem Statement

Statewave's audit story works over the HTTP API and not over MCP, which is how most people first use it.

In statewave-connectors, packages/mcp-server/src/client.ts:

• getContext() sends only subject_id, task and max_tokens. It never sends emit_receipt, and the server default is on_request, so no receipt is written for a call made through the MCP tool.
• RawContextBundle declares neither receipt_id nor receipt_emitted, so both fields are discarded at parse time even when a receipt was written (for example under tenant config receipts: always).
• RawMemory does not declare source_episode_ids, and toMemorySearchResult() keeps only id, subject, kind, text and score. Provenance never reaches the agent.
• toMemorySearchResult() is shared with searchMemories(), so statewave_search_memories drops provenance the same way.

Observed: after recording a demo through Claude Code, GET /v1/receipts?subject_id=… held exactly one receipt, written by a manual curl call — none from the agent's statewave_get_context calls.

The server side is complete: /v1/context accepts emit_receipt and returns receipt_id plus receipt_emitted.

Proposed Solution

1. Add an optional emit_receipt boolean to the statewave_get_context input schema and pass it through. The tool's schema sets additionalProperties: false, so it has to be declared, not only forwarded.
2. Widen RawContextBundle with receipt_id and receipt_emitted, and return both in the tool result. Both are needed: without receipt_emitted, an agent cannot tell "no receipt was requested" from "a receipt was requested and emission failed".
3. Add source_episode_ids to RawMemory and carry it through toMemorySearchResult(), so both statewave_get_context and statewave_search_memories return provenance per memory.
4. Keep the default off. Tenants that want a receipt for every call set receipts: always; this change makes that setting visible to the agent. Revisit the default once receipt erasure ([Bug]: Receipts keep the subject's task text after subject deletion and after retention expiry #423, [Feature]: Record key destruction as its own receipt, and restrict who can read a subject key #425) has shipped — until then, a receipt keeps the caller's task text and cannot be erased.
5. The types to widen (MemorySearchResult, ContextBundle, RawContextBundle, RawMemory) are all declared inside packages/mcp-server/src/client.ts, so the change stays inside that package.

Checked against statewave-connectors@a120673 (mcp-server 0.4.8) and statewave main.

API Design (if applicable)

Alternatives Considered

• Tenant config receipts: always alone: makes the receipt exist, but the agent still never sees its id, so nothing can cite it.
• Defaulting emit_receipt to true in the MCP server: produces an audit trail nobody asked for, and writes the caller's task text into records that currently cannot be erased.

Priority to You

High - Major improvement needed

Additional Context

No response

Contribution

• I would be interested in contributing this feature
• I would be interested in testing this feature