paperclip/doc/connections
Dotta 9abb600e72
docs(connections): MCP-direct/DCR playbook section + Notion dry-run appendix (#11030)
## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - Apps give agents governed access to external tools through catalog
connectors.
> - The connector playbook is the repeatable template for adding such
connectors.
> - Notion just shipped as the first MCP-direct connector with RFC 7591
dynamic client registration (#11009).
> - The playbook had no guidance for MCP-direct connections, OAuth
discovery, or DCR.
> - This pull request documents that path and encodes three mandatory
standards into the connector template.
> - It also adds a Notion dry-run appendix recorded from the live probe
and the shipped implementation.
> - The benefit is that the next MCP-direct connector follows a
recorded, verified path.

> [!IMPORTANT]
> **Depends on #11009.** This PR documents the Notion MCP connector that
ships in #11009 (RFC 7591 DCR, discovery-first endpoints,
`redirectConstraints` enforcement, refresh-rotation hardening).
Reviewing this doc against master before #11009 merges will show the
documented behavior as "not implemented" — that is expected. Draft until
#11009 lands, then re-review.

## What Changed

`doc/connections/CONNECTOR-PLAYBOOK.md` only (+364 lines, no code):

- New **"MCP-Direct Connections"** section: RFC 9728/8414 endpoint
discovery chain, an **RFC 7591 dynamic client registration** subsection
(public client, PKCE S256, env-client precedence, persist-and-reuse),
and a **redirect-URI constraints** subsection (`https-or-loopback-http`,
fail-fast wizard error).
- Three mandatory documentation standards encoded into the connector
template itself: a service-involvement statement (DCR providers need
neither Paperclip ID nor Paperclip Connect — instance-local per the
PAP-14828 spec §10 item 8.4; cloud and self-hosted use the same path), a
required **Connection Flow** section (sequence diagram + exact
authorize/token/registration/callback endpoints), and a required
**Administrator Setup** section.
- A **Notion dry-run appendix** mirroring the Linear appendix, recorded
from the live PAP-16649 probe: verified request sequence, redirect-URI
probe results table, sequence diagram (mermaid), shipped manifest
sketch, representative tool risk classes, admin setup (nothing to
register), governance defaults, and validation hooks.

## Verification

- Docs-only change; no code paths affected. `git diff --stat` shows
exactly one file.
- Every endpoint, error code, and constraint in the appendix was checked
against the shipped implementation on the #11009 head:
`server/src/services/tool-access.ts` (`assertOAuthRedirectConstraints`,
DCR registration metadata, refresh serialization),
`server/src/routes/tool-access.ts` (`POST
/api/tools/oauth/:connectionId/start`, `GET /api/tools/oauth/callback`),
and `packages/shared/src/app-definitions/notion.json`
(`redirectConstraints: "https-or-loopback-http"`).
- The request log mirrors the live probe record from PAP-16649
(2026-08-06/07), not vendor docs alone.
- Mermaid source renders cleanly (rendered PNG attached to PAP-16653).

## Risks

- Low: documentation only. Main risk is doc/implementation drift if
#11009 changes before merging — mitigated by the dependency note above
and re-review after #11009 lands.
- The template changes add mandatory sections for future connector
proposals; existing proposals are not retroactively invalidated.

## Model Used

Claude Fable 5 (claude-fable-5).

## Linked Issues or Issue Description

PAP-16653 (parent PAP-16637 P5). Companion catalog package landed in
paperclip-content (`integrations/catalog/platforms/notion/areas/mcp/`).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-07 10:52:04 -05:00
..
CONNECTOR-PLAYBOOK.md docs(connections): MCP-direct/DCR playbook section + Notion dry-run appendix (#11030) 2026-08-07 10:52:04 -05:00
FIRST-30-MATRIX.md docs(connections): cross-reference the identity model (identity vs. connections) (#9953) 2026-07-27 19:12:57 -05:00
GLOSSARY.md
README.md docs(connections): cross-reference the identity model (identity vs. connections) (#9953) 2026-07-27 19:12:57 -05:00
SECURITY-THREAT-MODEL.md
SMOKE-LAB-BROWSER-RUNNER.md
SMOKE-LAB-TUTORIAL.md

README.md

Apps, Connections, and Integrations

Audience: internal engineers and product contributors working on integrations.

Post-read action: classify a new integration request, pick the right Paperclip layer to change, and avoid creating a parallel connection framework.

Decision Record

Board decisions from PAP-13211 make the Apps v2 substrate on the PAP-10341 branch canonical:

  • D1: Apps v2 is the substrate. The active model is tool_applications, tool_connections, catalog entries, profiles, policy rules, action requests, gateway sessions, audit events, and runtime slots. Connections v1 is retired as an implementation path.
  • D2: one vault, brokered projections. Durable third-party credentials live in company_secrets as secret refs. Adapter config, plugin config, harness credential files, and run environments may receive only brokered or projected credentials.
  • D3: the vocabulary and three-door IA are product law. The default product doors are Apps, Connections, and Review. Protocol and operator-depth concepts live behind Developer or Advanced surfaces.
  • D4: unification lands on PAP-10341. Pages, CircleBack-style harness MCP OAuth, provider gallery work, and plugin-provided integrations converge on this branch instead of spawning new integration substrates.
  • D5: inbound stays thin. External clients that call Paperclip use scoped Paperclip tokens and existing profiles/rules. They do not get a separate permission model.

Canonical Object Model

Use connection as the unifying noun. A connection is four things:

  1. A stored credential reference.
  2. A capability catalog.
  3. A governance layer.
  4. An audit trail.

Everything else is an axis on that object:

Axis Values It answers
Direction outbound, inbound Who is the client?
Transport MCP, native REST/OpenAPI, OAuth app install, webhook How do bytes move?
Auth mode OAuth, API key/PAT, app installation, none What does the secret represent?
Credential owner company, user, run Whose identity acts?
Packaging catalog entry, plugin, skill How does it ship?

MCP is a transport, not a product category. "Install the Discord app", "connect Google Drive", and "add an MCP endpoint" all produce governed connections with different transport/auth values.

Layer Stack

When you are unsure where a change belongs, place it on the narrowest layer that solves the problem:

Layer Owns Examples
Surface user-facing Apps, Connections, Review, Developer/Advanced screens gallery cards, setup wizard, review queue
Governance profiles, bindings, allow/ask-first/block rules, quarantine, audit read-only profile, ask-first write policy
Capability action catalogs, schemas, risk classes, changed-tool review search_issues, create_comment, schema hash
Credential company_secrets, OAuth broker, credential resolver, token broker Slack bot token ref, Google OAuth refresh token ref
Identity actor attribution and token exchange board user, agent run, first-party service identity
Transport how the external system is reached remote HTTP MCP, local stdio, REST/OpenAPI, webhook

The agent should not hold a durable provider credential. It should hold a Paperclip run/session token; the server or broker resolves the connection, checks governance, invokes the provider, and writes audit.

Identity vs. connections

Signing a user in and connecting a resource are different planes with different owners, different token profiles, and different homes. Do not merge them. This section is the public, connections-side statement of the identity model so connector implementers inherit the rule without depending on private identity-service documentation or re-deriving it.

Plane Question Lives where Token profile
P1. Sign-in methods Who are you? paperclip-id (id.paperclip.ing → Account) Minimal-scope provider tokens (openid email profile), used once to authenticate, encrypted at rest, never exported
P2. Connections (Apps) What may your agents touch? Paperclip App instances (tool_connections), acquired via the connect broker for hosted + self-hosted Rich-scope, long-lived resource tokens in the instance's encrypted vault; per-agent grants; ask-first on writes
P3. Login with Paperclip Who may authenticate against us? paperclip-id OIDC provider + DB-backed client registry Our ES256 ID/access tokens issued by us to registered RPs (instances, the broker, future third parties)

Everything in doc/connections/ — the First-30 matrix, the connector playbook, and the connect-broker work — lives on plane P2. It never acquires, stores, or brokers a P1 sign-in token.

The standing rule (D7)

Adopted as a standing rule (decision D7) with the identity-model plan. State it verbatim in any P2 design so the app-store work cannot drift into merging the planes:

Sign-in tokens are never reused as resource tokens; id.paperclip.ing never stores resource tokens; no connections hub on the ID service.

P2 tokens flow broker → instance vault as pass-through only; the id.paperclip.ing Account page therefore must not grow a "Connections" hub. The reasons to hold the planes apart (from the plan §3):

  • Scope discipline. Sign-in wants the narrowest grant; connections want deliberately broad ones. One button that does both is how you grant repo access just to log in.
  • Blast radius. id.paperclip.ing holding every customer's Vercel/Slack/GitHub resource tokens would make it the single juiciest target in the fleet; the broker is intentionally pass-through.
  • Self-hosted symmetry. Instances own their vaults, so self-hosters don't depend on our uptime to use their own connections.
  • Legibility. Sign-in and connections answer different user questions, and every product we benchmarked (Vercel, Railway, GitHub, Google) keeps them on separate pages with separate names.

Naming alignment

Use the surface-correct name for each plane; they intentionally differ:

Surface Plane Name to use
Paperclip App instances P2 "Connections"
id.paperclip.ing Account P1 "Ways to sign in"
id.paperclip.ing admin P3 "OIDC clients" (until the app store productizes it)

Packaging Rule

Default to a catalog entry when an integration can be described as metadata: manifest, auth config, action catalog, resource filters, and policy defaults.

Use a plugin only when the integration needs product code such as custom UI pages, its own tables, workers, migrations, routines, or specialized ingestion. A plugin may bundle catalog entries, but it must not bypass the connection, profile, policy, credential, and audit model.

Use a skill for agent instructions. Skills may use connections; they must not own durable tokens.

Canonical Docs

Migration Notes

Connections v1 contributed useful policy, UX, and rollout thinking, but its implementation branch is no longer the target. When you see old tickets or code using connections, connection_grants, or a provider-directory mental model, translate the intent into Apps v2:

Connections v1 intent Apps v2 home
Provider directory Apps gallery / tool_applications
Configured provider instance Connection / tool_connections
Grant allowlist Profiles, profile bindings, policies
Resource filters Policy/profile conditions plus provider config
Tool broker Tool gateway and runtime supervisor
Connection UX tail Apps, Connections, Review, Developer/Advanced IA

Do not add new work to the retired v1 branch. If an old ticket still describes a valid product gap, retarget it to an active Apps v2 issue or close it as superseded with a link to the replacement.