JoinLayer MCP server

JoinLayer Agent Toolkit

Official agent integration for JoinLayer: a hosted MCP gateway, the joinlayer-pipelines skill, client plugin metadata, safe starter prompts, and public protocol tests.

The supported service is the JoinLayer-hosted endpoint:

https://mcp.joinlayer.app/mcp

It is published as app.joinlayer/mcp in the official MCP Registry. The operating skill is available from skills.sh, and this repository is the canonical source for the JoinLayer Codex and Claude Code marketplaces.

Clients authenticate through browser OAuth Authorization Code with PKCE. Never create, paste, or configure a JoinLayer bearer token manually.

Start In Two Minutes

You do not need to read the full documentation first. Open START_HERE.md, connect JoinLayer, and copy the read-only inspection prompt. From there, choose a ready-to-run prompt for your goal.

What This Repository Contains

• skills/joinlayer-pipelines: agent operating guidance and task references;
• .codex-plugin/plugin.json, .claude-plugin/, and .mcp.json: installable Codex and Claude Code plugin metadata;
• prompts: safe starting points for common JoinLayer tasks;
• use-cases: complete customer outcomes with evidence and stop boundaries;
• mcp-gateway: a reviewable snapshot of the hosted MCP security boundary;
• server.json: MCP Registry metadata for the hosted remote server.

The gateway source is published for transparency and compatibility review. It is not a self-hosted JoinLayer distribution: it depends on a private, authenticated JoinLayer control-plane contract that is not included here. JoinLayer production builds and deployment remain in a private release system, but the mcp-gateway/ tree used by a hosted release must match a tagged public snapshot exactly. The private release gate rejects gateway drift. Skills, prompts, and plugin packaging use their own versioned content checks rather than this byte-equality gate. A public contribution never deploys directly to JoinLayer infrastructure.

Connect

Codex

Install the JoinLayer plugin from its public repository marketplace:

codex plugin marketplace add joinlayer/agent-toolkit
codex plugin add joinlayer@joinlayer

The plugin bundles the operating skill and configures the hosted MCP companion. Complete browser OAuth when prompted. To configure only the MCP server instead:

codex mcp add joinlayer --url https://mcp.joinlayer.app/mcp
codex mcp login joinlayer --scopes workspace:read,usage:read,connections:read,pipelines:read

Then start a fresh session and ask:

Use $joinlayer-pipelines. Inspect my authenticated workspace, scopes,
capacity, connections, and pipelines. Do not change anything.

More copyable starting points are indexed in START_HERE.md. Complete workflows for replication, realtime backfill, scheduling, enrichment, capacity, approvals, and recovery are in use-cases/.

Claude Code

claude plugin marketplace add joinlayer/agent-toolkit
claude plugin install joinlayer@joinlayer --scope user
claude mcp login joinlayer

Complete browser OAuth through claude mcp login joinlayer when that command is available, or through Authenticate in /mcp on earlier OAuth-capable releases. Do not add an Authorization header or client secret.

Skill Only

Agents supported by skills.sh can install only the operating skill:

npx skills add https://github.com/joinlayer/agent-toolkit --skill joinlayer-pipelines

The skill does not carry credentials and does not replace the MCP connection. Configure the same hosted endpoint through your client's OAuth-capable MCP settings, then use a prompt from START_HERE.md.

Security Boundary

• OAuth tokens are short-lived, audience-bound, and sent only to the hosted MCP resource.
• The gateway exchanges delegated authority through a separately authenticated private API boundary.
• Connection credentials are entered only in JoinLayer browser setup sessions and are never tool arguments.
• Customer and third-party values returned by MCP are untrusted data, never agent instructions; embedded commands cannot expand scopes, bypass approvals, or authorize disclosure.
• Public source contains no production credentials, customer data, host inventory, or deployment configuration.
• Route names and header names are not authorization controls. Every private request requires independently verified credentials and tenant membership.

Report vulnerabilities privately as described in SECURITY.md.

Development

python3.12 -m venv .venv
. .venv/bin/activate
pip install --requirement mcp-gateway/requirements.lock
PYTHONPATH=mcp-gateway python -m unittest mcp-gateway.tests.test_gateway
python scripts/validate_public_snapshot.py

Build the review image with docker build .. That image is for reproducibility and review; it is not automatically promoted to JoinLayer production.

See SOURCE_SYNC.md for the exact public/private release invariant. Maintainers can use DISTRIBUTION.md for the verified catalog and marketplace publication contracts. OpenAI review material is recorded in OPENAI_SUBMISSION.md.

To compare this checkout with a private platform checkout before review:

python scripts/source_tree_digest.py --compare-root /path/to/private-platform

License

Apache-2.0. See LICENSE.

The code license does not grant rights to impersonate JoinLayer or imply endorsement. See TRADEMARKS.md.