knowledge-gateway

A single MCP server that gives agents (Claude Code, Codex, Cursor, Gemini, Copilot, Antigravity) three capabilities over one connection:

• Vault - read, search, and edit a git-backed Markdown/Obsidian vault (no Obsidian GUI), git as the source of truth.
• Code graph (optional [graph] / [graph-all]) - build and query a code/Ansible knowledge graph of a repo (functions, calls, roles, tasks, handlers, task -> filter edges); AST-only, local, no LLM.
• Convert (optional [convert]) - turn PDF / Office / image / HTML files into Markdown.

The vault layer exists because the Obsidian Local REST API plugin serves only the one vault open in a running desktop instance, writes without a lock (silent lost updates), needs a token in every client, and treats git as secondary. This gateway operates on the files directly, with git as the system of record - and adds the graph + convert tools the same way: one server, opt-in extras, no new servers to wire.

Architecture

flowchart LR
    subgraph clients [Agents]
        A1[Claude Code]
        A2[Codex]
        A3[Gemini]
        A4[Copilot - VS Code]
        A5[Cursor]
        A6[Antigravity]
    end
    A1 --- M(( MCP ))
    A2 --- M
    A3 --- M
    A4 --- M
    A5 --- M
    A6 --- M
    M -->|stdio, per repo, no auth| L[Local gateway]
    M -->|HTTP + bearer + ACL| S[Shared gateway]
    L --> V[/Vault: Markdown files/]
    S --> V
    V <-->|atomic write + scoped commit| G[(git)]

Both modes run the same tool implementation over the same path guards; they differ in transport, authentication/ACL, vault loading, and error masking.

Two ways to run

Most repos want Local mode. The shared server is only for a central, always-on team gateway.

Distribution - PyPI ("update once")

The gateway ships as a PyPI package, so a release reaches every consumer and server without re-pinning anything by hand.

flowchart LR
    PR[merge PR to main] --> CI[green ci on main]
    CI --> REL["release.yml<br/>publish PyPI + tag vX.Y.Z"]
    REL --> C["Consumers<br/>uvx --refresh knowledge-gateway<br/>(updates next session)"]
    REL --> S["Servers<br/>daily uv tool reinstall<br/>(restart if the version moved)"]

• Consumers run uvx --refresh --from 'knowledge-gateway[graph]' knowledge-gateway -> the latest release is resolved on every launch, so a new release auto-propagates the next time an agent starts. No per-repo re-pin.
• Servers (long-running) run uv tool install 'knowledge-gateway[graph,convert]' plus a daily job that reinstalls + restarts only when the published version actually moves.
• Every release is also an immutable vX.Y.Z git tag - pin ==X.Y.Z when you need a frozen, auditable version.

Earlier releases moved a stable git branch for this. PyPI does the same job with a real version number, so that branch is gone.

Quickstart - local mode (zero secrets)

Add this to the repo's .mcp.json at the repo root:

{
  "mcpServers": {
    "wiki": {
      "command": "uvx",
      "args": ["--refresh", "--from", "knowledge-gateway",
               "knowledge-gateway", "--local"]
    }
  }
}

• --local auto-detects the vault in the cwd, in order: the cwd itself if it has .obsidian/, then ./wiki, then a single *-obsidian-vault/, then a single child dir with .obsidian/ (ambiguous matches error). Pass --vault ./<dir> to be explicit.
• --refresh re-resolves the latest release each launch, so releases auto-apply (adds ~1-2s to start).
• Commits are scoped to the vault's git subdir and attributed to your own git config user.name/email. No token: the trust boundary is local filesystem access.

Open the repo in your agent, approve the wiki server once, done.

Tools

Note writes are atomic (temp file + rename) and use safe_note_path. Attachments, canvases, conversion inputs and graph files use their own type-specific containment guards. Together they block traversal, symlink escape and access outside the configured vault.

Agent skills

The repository includes a validated, provider-neutral Agent Skills pack under skills/. .agents/skills and .claude/skills point to the same canonical files for native discovery. Consumer repositories can instead own copies in their documented project-level directory.

The pack covers:

• gateway-setup and gateway-operations for configuration, verification, operation and release;
• code-graph-build, code-graph-explore and code-impact for architecture discovery and blast-radius analysis;
• wiki-query, wiki-curate, wiki-ingest, wiki-lint, and wiki-fold for durable knowledge;
• canvas and obsidian-markdown for Obsidian-native authoring;
• document-convert for reviewed PDF and Office conversion; and
• cordis-composability for reversible effects and declared dependencies.

Skills add repeatable procedures, not privileges. Server-side ACLs, path guards, hooks and CI remain the enforcement layer. The machine-readable inventory is skills/manifest.json; CI validates that every skill is registered and references only real gateway tools.

Copy selected skills into the destination listed in the sourced compatibility table:

mkdir -p ../consumer/.agents/skills
cp -R skills/wiki-query skills/wiki-curate ../consumer/.agents/skills/

Copy on a branch, do not overwrite an existing same-name skill blindly, and review the consumer diff. The copied files are then owned and versioned by the consumer repository.

See docs/agent-skills.md for the compatibility matrix, required extras, workflow harness, maintenance rules and security boundaries.

For the complete pack, run local mode with all optional capabilities:

{
  "mcpServers": {
    "wiki": {
      "command": "uvx",
      "args": [
        "--refresh",
        "--from",
        "knowledge-gateway[all]",
        "knowledge-gateway",
        "--local"
      ]
    }
  }
}

The dependency-free core quickstart above remains the preferred setup when only vault operations are needed.

Code graph and conversion (optional)

Two opt-in capabilities, gated behind extras so the core install stays dependency-free:

Build a graph (AST-only - local, no network, no LLM) where the code lives:

knowledge-gateway-graph /path/to/code-repo -o /path/to/vault/.graph/myrepo.json
# in a local-mode session the graph_build tool does the same, writing .graph/<name>.json

Hidden directories (.git, .next, .venv, caches, ...) and common build/vendor output (node_modules, dist, build, target, vendor, ...) are always skipped. --exclude <name> ... adds directory names to skip; --include <name> ... force-keeps names the rule would skip (e.g. .github, a first-party vendor/). Matching is by directory basename, not path or glob. Same exclude/include on the graph_build tool.

Query it over MCP with graph_query / graph_neighbors / god_nodes / graph_shortest_path / graph_stats. The graph captures functions/classes/imports/calls and - uniquely for Ansible - roles, tasks, handlers, include_role/import_tasks/notify, and task -> filter plugin edges. Graph files live in the vault's .graph/ and are vault-contained (resolved + checked to stay inside the vault). Query tools are read-only; local graph_build deliberately creates or replaces the selected graph artifact. Vault note tools never depend on it.

Shared server mode

Run this only for a central, always-on gateway reachable over the network.

1. Map vaults - cp vaults.example.yaml vaults.yaml, then set name -> path / repo_root / subdir. repo_root + subdir pathspec-scope commits to a vault that lives inside a larger repo.

2. Mint a token per user (the admin does this):

cp tokens.example.yaml tokens.yaml
openssl rand -hex 32          # once PER user -> the key
chmod 0600 tokens.yaml        # refused at load if group/world-readable

tokens:
  "8f3c…hex…":
    sub: alice                # identity recorded on that user's commits
    vaults: [teamwiki]        # the ONLY vaults this token may see/touch
    write: true               # false = read-only

A token sees only the vaults in its vaults list; anything else returns an opaque vault_forbidden. vaults.yaml + tokens.yaml are gitignored.

3. Run - uv run knowledge-gateway (127.0.0.1:8765, path /mcp/). For a team box, run it as a service behind Tailscale Serve - see deploy/ and Operate below.

4. Connect - the admin shares the token over a password manager (not chat):

claude mcp add --transport http --scope project teamwiki \
  https://YOUR-HOST.<tailnet>.ts.net/mcp/ --header "Authorization: Bearer $GW_TOKEN"

Security model

• No secrets in the repo. vaults.yaml / tokens.yaml are gitignored; only *.example.yaml ship. tokens.yaml is refused at load if group/world-readable.
• Local mode has no credential surface - a local stdio subprocess; the trust boundary is filesystem access the user already has.
• Server mode is defense in depth, not a public endpoint - tailnet ACL + HTTPS + per-user StaticTokenVerifier bearer token + per-vault ACL. The bearer layer is a shared secret for use behind a trusted tailnet; do not expose the server publicly.
• Path guards on all note I/O via safe_note_path (traversal, symlink, hidden/dotfiles incl. .env, non-.md, .git/.obsidian). Search/backlinks/tags are bounded to *.md.
• Server-mode error masking - the HTTP server runs mask_error_details=True: only the gateway's own expected failures surface as ToolError; unexpected OS/git errors are hidden. Local mode keeps details visible.
• Commits are attributed to the requesting user (server) or the local git identity (local), and pathspec-scoped to the vault subdir.

Set it up with an AI

Paste this into an agent at a repo's root to wire in local mode:

Add the knowledge-gateway to this repo so agents can read/edit our vault over MCP with zero
tokens:
1. Create or merge `.mcp.json` at the repo root with an mcpServers."wiki" entry that runs:
   uvx --refresh --from knowledge-gateway knowledge-gateway --local
   (`--local` auto-detects the vault: ./wiki, a *-obsidian-vault dir, or a dir with .obsidian/.
   If detection is ambiguous, use `--vault ./<vault dir>` instead of `--local`.)
2. Verify: `uvx --refresh --from knowledge-gateway \
   knowledge-gateway --help` resolves; then in the agent, call list_vaults and read one note.
Branch + PR, no direct push, no AI attribution.

For the shared server, ask your gateway admin for a token, then run the claude mcp add … from Connect above.

Operate (servers)

A server runs the latest release as a uv tool, with a daily job that reinstalls and restarts only when stable moved. Reference units are in deploy/:

uv tool install knowledge-gateway
# the binary lives in the uv cache, so point config at the live files via env:
#   KNOWLEDGE_GATEWAY_VAULTS= <dir>/vaults.yaml   KNOWLEDGE_GATEWAY_TOKENS= <dir>/tokens.yaml

• deploy/knowledge-gateway.service - the service (systemd --user).
• deploy/knowledge-gateway-update.{service,timer} + deploy/auto-update.sh - the daily auto-update.

Update now instead of waiting for the timer: uv tool install --reinstall --from knowledge-gateway, then restart the service. Health: curl -s -o /dev/null -w '%{http_code}' http://127.0.0.1:8765/mcp/ -> 401.

Release (maintainers)

1. Start a release branch from current main.
2. Move Unreleased changelog entries into the new version section and update the version in pyproject.toml and server.json.
3. Run uv lock --check, the skill validator, the full test suite and uv build; open a PR and merge only after the Python 3.11-3.13 CI matrix is green.
4. Tag the green main commit as vX.Y.Z and push the tag (the release workflow builds and publishes it).
5. Verify the GitHub release and PyPI publication, then move stable to the same tag with --force-with-lease.

Consumers pick it up next session; servers within a day (or restart now).

Develop

uv venv && uv pip install -e ".[dev]"
uv run pytest                              # ACL + path guards + edit/frontmatter + detect + masking