## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - Apps give agents governed access to external tools.
> - The Apps gallery lists Notion, but the server required manually
configured OAuth credentials.
> - Notion's hosted MCP server supports OAuth discovery and dynamic
client registration.
> - Notion also requires HTTPS or a loopback HTTP redirect URI.
> - This pull request adds a direct Notion MCP OAuth path with PKCE and
reusable dynamic clients.
> - It also adds the current Apps UI states for connect and
reauthorization.
> - The benefit is a secure Notion connection with no manual client
credential setup.
## Linked Issues or Issue Description
**What existing behavior does this improve?**
The Apps gallery, Apps connect route, OAuth token lifecycle, and managed
MCP gateway.
**Subsystem affected**
`server/`, `packages/shared/`, `scripts/`, and `ui/`.
**Current behavior**
The Notion gallery cards are disabled. The server uses the classic
Notion OAuth endpoints and requires operator-supplied client
credentials. It does not register an OAuth client from provider
metadata. Concurrent refreshes can also replay a rotating refresh token.
**Proposed behavior**
Enable the Notion Apps flow. Discover OAuth metadata from
`https://mcp.notion.com/mcp`. Register and reuse a public RFC 7591
client with PKCE. Require HTTPS or loopback HTTP callbacks. Serialize
refreshes, store each rotated refresh token before the new access token
can be used, and show a reconnect state for `invalid_grant`.
**Reason and benefit**
Operators can connect the built-in Notion MCP app without creating or
copying OAuth credentials. Paperclip keeps dynamic clients and rotating
tokens in the company secret store.
**Breaking changes**
None. Explicit environment client credentials still take priority.
Existing Slack and Linear OAuth endpoint hints remain unchanged. Other
OAuth apps remain disabled unless they are allowlisted.
**Additional context**
PR #10910 is a related, broader Connections v3 wizard replacement. This
PR is the focused current Apps flow. The MCP Tool Gateway and Connected
Apps items in `ROADMAP.md` cover this planned capability.
## What Changed
- Classify all 20 reviewed Notion MCP tools with provider-scoped read
and write defaults.
- Require approval for selected Notion mutations, including move,
duplicate, and convert actions that generic verb matching missed.
- Preserve company-scoped connection and catalog resolution for Notion
profiles and policies.
- Add RFC 7591 dynamic client registration with
`token_endpoint_auth_method=none` and mandatory PKCE.
- Store the dynamic client ID on the connection and store any returned
client secret in the company secret store.
- Reuse the registered client for later connects and keep explicit
environment credentials as the first choice.
- Discover protected-resource and authorization-server metadata from the
Notion MCP endpoint.
- Add `redirectConstraints: "https-or-loopback-http"` to the generated
Notion app definition and shared contract.
- Reject non-loopback plain HTTP callbacks before network access with a
TLS setup error.
- Serialize client registration and token refresh operations within the
server process.
- Store a rotated refresh token before publishing the refreshed access
token.
- Treat `invalid_grant` as terminal and move the connection to a clear
reauthorization state.
- Add focused coverage for registration reuse, callback constraints,
refresh rotation, and terminal grants.
- Enable the Notion Apps route and add connect, redirect, success,
error, and reconnect UI states.
- Keep non-allowlisted OAuth apps blocked and cover the UI policy with
regression tests.
## Verification
- The focused Notion policy integration test passed with embedded
PostgreSQL.
- The focused 20-tool classification test passed.
- The server typecheck passed on the governance head.
- `pnpm -r typecheck` passed on the rebased head.
- `pnpm --filter @paperclipai/server typecheck` passed after the
security follow-up.
- `pnpm exec vitest run server/src/__tests__/tool-access-service.test.ts
-t \u0027DCR|refresh tokens|invalid_grant|abandoned lease\u0027` passed
10 focused security tests.
- `pnpm build` passed on the rebased head.
- `pnpm exec vitest run server/src/__tests__/tool-access-service.test.ts
-t 'OAuth|oauth'` passed 14 tests.
- `pnpm exec vitest run packages/shared/src/app-definitions.test.ts`
passed 5 tests.
- The complete server group passed 3,686 tests with 4 skipped.
- The complete UI group passed 3,656 tests.
- The full local runner found one environment-only CLI failure because
this agent runtime injects static AWS credentials into a test that
expects `AWS_PROFILE` only. `env -u AWS_ACCESS_KEY_ID -u
AWS_SECRET_ACCESS_KEY pnpm exec vitest run
cli/src/__tests__/secrets.test.ts` passed all 8 tests.
- The prior UI verification passed 55 focused tests, `pnpm
check:token-gates`, the Storybook build, and review of six 1440 x 1000
screenshots.
- OAuth request sequence: protected-resource metadata `GET
https://mcp.notion.com/.well-known/oauth-protected-resource/mcp`;
authorization metadata `GET
https://mcp.notion.com/.well-known/oauth-authorization-server`; dynamic
registration `POST https://mcp.notion.com/register`; authorization `GET
https://mcp.notion.com/authorize`; token exchange and refresh `POST
https://mcp.notion.com/token`; MCP traffic `POST
https://mcp.notion.com/mcp`.
- The live metadata and registration probe confirmed that Notion accepts
HTTPS and loopback HTTP redirects. It rejects a plain HTTP private
hostname.
- A later QA task owns the full browser consent and managed gateway
tool-list dry run against a configured HTTPS deployment.
## Risks
- Notion can add tools. Unrecognized names use the generic classifier,
and new or changed risky tools stay quarantined after connection
activation.
- A deployment that uses a private non-loopback hostname must configure
HTTPS before it can connect Notion.
- Dynamic registration creates a provider-side client. Paperclip reuses
it because registration does not provide a standard delete operation.
- Refresh coordination uses a database CAS lease across service
instances. An unclean crash leaves an uncertain lease and requires
reconnect instead of risking refresh-token replay.
- The current Apps surface overlaps with PR #10910. Merge order can
require a small conflict resolution if that PR lands first.
> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.
## Model Used
- OpenAI Codex on a GPT-5 runtime. The exact deployment ID and context
window are not exposed. The runtime used reasoning, repository tools,
code execution, and network tools.
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
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