v0.17.0

[0.17.0] — 2026-07-29

Migrates to mcp 2.x, which closes the OBS-001 criterion 0.16.0 had to
leave open. Protocol version moves from 2025-11-25 to 2026-07-28.

The pinned tests did their job

0.16.0 shipped two tests asserting that protocol errors carry code 0, whose
stated purpose was to fail the day the SDK emitted a real one. They fail now.

Under 2.0, resources/read on a missing resource answers -32602
(INVALID_PARAMS) and prompts/get answers -32603. The spec made the same
correction independently: 2026-07-28 moved resource-not-found from -32002 to
-32602 to align with JSON-RPC and reserved -32020…-32099 for MCP. Both
tests became assertions, plus a range check so a regression to 0 cannot pass
unnoticed. OBS-001 criterion 3 is met.

Unchanged and still pinned: an unknown tool arrives as a tool result with
is_error rather than as a protocol error. mask_error_details does not exist
in 2.0 either, so OBS-002 stays test-enforced. One detail improved —
prompts/get used to echo the raw ValueError and now answers "Internal server
error", keeping the detail server-side.

A gap the migration exposed

Mutation-testing the migrated code found something that predates it: deleting
lifespan=_lifespan from the server construction left all 214 tests passing.
The pooled HTTP client's shutdown hook (SDK-001) had no guard here, though the
sister server has had one since its 0.10.0. test_the_pooled_client_has_a_shutdown_hook
closes that, asserted against the user-supplied lifespan specifically — 2.0
installs a default one, so the weaker "some lifespan is set" check would have
passed with ours removed.

API changes

Two imports: FastMCP → MCPServer, same constructor kwargs; the tool
decorator, run() and sse_app() are unchanged. mcp.settings.host / .port
are gone, so bind_host() / bind_port() read the environment and hand the
values to uvicorn directly — which is where they were always going.

Tests needed McpError → MCPError,
create_connected_server_and_client_session → mcp.Client(server), and
camelCase → snake_case (isError → is_error).

What the new spec means for the accepted risks

2026-07-28 removes protocol-level sessions — no initialize handshake, no
Mcp-Session-Id, no SSE stream resumability — and reclassifies HTTP+SSE as
Deprecated with a twelve-month removal window.

That lands harder here than on the sister server, because SSE is this server's
only HTTP transport. Nothing breaks today: the SDK still ships sse_app(), and
_cors.py was re-verified against the starlette 1.3.1 that mcp 2.0 pulls in
(preflight 200, Mcp-Session-Id allowed and exposed, bearer gate intact).

SEC-009, SCALE-002 and SCALE-003 change character — from controls this
server has not implemented toward controls the protocol no longer defines — but
stay recorded as fail until the audit catalogue catches up. Reclassifying a
finding on our own authority is the drift these documents exist to prevent.
ROADMAP.md now carries migrating off SSE as dated work.

215 tests pass, ruff check clean.