Python SDK — Tier 1 Assessment

SDK: modelcontextprotocol/python-sdk
Version: 2.0.0 (GA 2026-07-28) · assessed on main @ 9057285 (2.0.0 plus documentation and policy files; no API changes)
Assessed: 2026-08-17
Requested tier: Tier 1 (unchanged — previous assessment #2304, v1.26.0, 2026-02-23)
Tool: @modelcontextprotocol/conformance tier-check 0.2.0-alpha.11 (conformance main @ 74edef3), --requirements 2025-11-25,2026-07-28, plus the mcp-sdk-tier-audit skill's documentation and policy evaluations

Result

All Tier 1 requirements are met. tier-check: "implied_tier": {"tier": 1, "tier1_blockers": [], "tier2_met": true}.

Requirements Detail

1–2. Conformance — ✅ server 67/67, client 50/50

Scored against the frozen 2025-11-25 and 2026-07-28 requirement sets, each run at its own wire, with examples/servers/everything-server as the server under test and .github/actions/conformance/client.py as the client. The SDK's CI runs the same suites on every push to main (workflow; green run at the assessed commit).

Not scored (informational, all extension-tagged and listed in the SDK's expected-failures baseline): server tasks-* (SEP-2663 Tasks extension, not yet implemented — python-sdk#2806); client auth/dpop, auth/dpop-nonce, auth/wif-jwt-bearer (DPoP / jwt-bearer grant not yet implemented). Every dated scenario passes; the per-revision baselines (expected-failures.2025-11-25.yml, .2026-07-28.yml) are empty.

3. Issue Triage — ✅ 99.5%

196 of 197 open issues carry a label (tier-check method); the one exception, #3309, was opened Fri 2026-08-14 21:34Z and was inside two business days at assessment time. All 12 taxonomy labels exist (labels); the triage commitment is published in CONTRIBUTING.md § Issue Triage.

4. P0 Resolution — ✅ 0 open

No open P0s. P0 history: #1442, closed in 3 days (all P0 issues).

5–6. Stable Release and Spec Tracking — ✅ 2.0.0

2.0.0 (PyPI) implements the 2026-07-28 revision and negotiates every earlier one; it was published 2026-07-28T13:41Z, the same day as the spec release (16:47Z). tier-check reports a 0-day gap on conformance main (which includes conformance#458, counting a release in the 24h before the spec tag); under the published 0.2.0-alpha.11 rule the same facts read as "20 days since spec, no release after it" and pass until day 30. The v1.x maintenance line released 1.29.0 the same day.

7. Documentation — ✅ 48/48

Documentation site: https://py.sdk.modelcontextprotocol.io/ (sources: docs/, runnable examples in docs_src/ included into the pages, plus examples/). All 48 non-experimental features from the audit's feature list have prose and an example; the five experimental Tasks features are not implemented (SEP-2663) and not required.

8–10. Policies — ✅

• Dependency policy: DEPENDENCY_POLICY.md (floors-only requirements, when a floor moves, automated updates) + .github/dependabot.yml (monthly grouped uv and Actions updates).
• Roadmap: ROADMAP.md — organized by spec revision; links the 2026-07-28 project boards and the open items (capabilities API #2896, Tasks extension #2806, DPoP, jwt-bearer).
• Versioning policy: VERSIONING.md — SemVer in PEP 440 syntax, the public-API boundary, what is and is not a breaking change, the two deprecation channels, supported release lines; breaking changes between majors are recorded in the Migration Guide.
• Also: SECURITY.md (supported versions, reporting), CONTRIBUTING.md.

Reproduce This Assessment

git clone https://github.com/modelcontextprotocol/conformance.git && cd conformance
git checkout 74edef3 && npm install && npm run build      # 0.2.0-alpha.11 + #458
export GITHUB_TOKEN=$(gh auth token)

# Known-SDK mode: clones python-sdk main, starts the everything-server and
# drives .github/actions/conformance/client.py for each revision
node dist/index.js tier-check --sdk-path /path/to/python-sdk \
  --requirements 2025-11-25,2026-07-28 --output markdown

# or URL mode from a python-sdk checkout:
#   uv sync --frozen && uv run --frozen mcp-everything-server --port 3001 &
#   node dist/index.js tier-check --repo modelcontextprotocol/python-sdk --branch main \
#     --conformance-server-url http://localhost:3001/mcp \
#     --client-cmd 'uv run --frozen python .github/actions/conformance/client.py' \
#     --requirements 2025-11-25,2026-07-28 --timeout 60000 --output markdown

gh release view v2.0.0 --repo modelcontextprotocol/python-sdk

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