Local REST API with MCP

Local REST API with MCP

Give your scripts, browser extensions, and AI agents a direct line into your Obsidian vault via a secure, authenticated REST API.

• Interactive API docs: https://coddingtonbear.github.io/obsidian-local-rest-api/
• Obsidian Community page: https://community.obsidian.md/plugins/obsidian-local-rest-api/

• What you can do
• Quick start
  • REST API
  • MCP clients
    • Claude Code
    • Claude Desktop
    • Cursor
    • Other clients
• API overview
  • Browser clients and response headers
• Patching notes
  • Raw-content mode
• Targeting specific sections
• Searching
• MCP (Model Context Protocol)
  • Protocol revisions
  • Connecting a client
  • Available tools
  • Binary files and attachments
  • Available resources
• API Extensions
  • Typed extension API
  • Known extensions
• Contributing
• Credits

What you can do

Access your vault through the REST API or the built-in MCP server — both interfaces expose the same core capabilities, so scripts, browser extensions, and AI agents all speak the same language.

• Read, create, update, or delete notes — full CRUD on any file in your vault, including binary files
• Surgically patch specific sections — target a heading, block reference, or frontmatter key and append, prepend, replace, delete, or move just that section without touching the rest of the file
• Search your vault — simple full-text search or structured JsonLogic queries against note metadata (frontmatter, tags, path, content)
• Access the active file — read or write whatever note is currently open in Obsidian
• List and execute commands — trigger any Obsidian command as if you'd used the command palette
• Query tags — list all tags across your vault with usage counts
• Open files in Obsidian — tell Obsidian to open a specific note in its UI
• Extend the API — other plugins can register their own routes via the API extension interface

All requests are served over HTTPS with a locally generated certificate and gated behind API key authentication.

Quick start

After installing and enabling the plugin, open Settings → Local REST API to find your API key and certificate.

REST API

# Check the server is running (no auth required)
curl -k https://127.0.0.1:27124/

# List files at the root of your vault
curl -k -H "Authorization: Bearer <your-api-key>" \
  https://127.0.0.1:27124/vault/

# Read a note
curl -k -H "Authorization: Bearer <your-api-key>" \
  https://127.0.0.1:27124/vault/path/to/note.md

# Read a specific heading (URL-embedded target)
curl -k -H "Authorization: Bearer <your-api-key>" \
  https://127.0.0.1:27124/vault/path/to/note.md/heading/My%20Section

# Append a line to a specific heading (PATCH with a JSON instruction)
curl -k -X PATCH \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/json" \
  --data '{"targetType":"heading","target":["My Section"],"operation":"append","content":"New line of content"}' \
  https://127.0.0.1:27124/vault/path/to/note.md

To avoid certificate warnings, you can download the plugin's certificate authority from https://127.0.0.1:27124/obsidian-local-rest-api.crt and trust it in your OS or browser, or point your HTTP client at it directly (for example curl --cacert obsidian-local-rest-api.crt ...). The plugin generates its own certificate authority on first run and serves a server certificate signed by it, so the download is a CA certificate rather than the server certificate itself. That CA is name-constrained: it can only vouch for 127.0.0.1, localhost, your configured binding host, and the hostnames you list under Subject alternative names, so trusting it does not let it (or anyone who obtains its key) impersonate other sites.

MCP clients

The MCP server runs at https://127.0.0.1:27124/mcp/ and requires that you provide your bearer token for authentication via an Authorization header (i.e. Authorization: Bearer <your-api-key>). Because the plugin uses a locally generated certificate authority, you may need to either trust that certificate in your OS/client, or use the plain HTTP endpoint at http://127.0.0.1:27123/mcp/ (enable it under Settings → Local REST API → Enable HTTP server).

Claude Code

Claude Code has native HTTP MCP support. The quickest way to add the server is via the CLI:

claude mcp add --transport http obsidian https://127.0.0.1:27124/mcp/ \
  --header "Authorization: Bearer <your-api-key>"

Or add it manually to .mcp.json in your project root (project-scoped) or configure it user-wide via claude mcp add --scope user:

{
  "mcpServers": {
    "obsidian": {
      "type": "http",
      "url": "https://127.0.0.1:27124/mcp/",
      "headers": {
        "Authorization": "Bearer <your-api-key>"
      }
    }
  }
}

Claude Desktop

Claude Desktop does not natively support remote HTTP MCP servers, but you can bridge it with mcp-remote (requires Node.js). Add the following to claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "obsidian": {
      "command": "npx",
      "args": [
        "mcp-remote@latest",
        "https://127.0.0.1:27124/mcp/",
        "--header",
        "Authorization: Bearer <your-api-key>"
      ]
    }
  }
}

Restart Claude Desktop after saving the file.

Cursor

Cursor supports the Streamable HTTP MCP transport. Add the following to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project-specific):

{
  "mcpServers": {
    "obsidian": {
      "url": "https://127.0.0.1:27124/mcp/",
      "headers": {
        "Authorization": "Bearer <your-api-key>"
      }
    }
  }
}

Other clients

Any MCP client that supports the Streamable HTTP transport can connect to https://127.0.0.1:27124/mcp/ with an Authorization: Bearer <your-api-key> header. Consult your client's documentation for the exact configuration format.

API overview

For full request/response details, see the interactive docs.

Browser clients and response headers

Several endpoints answer in a response header rather than in the body: Content-Location tells you where a write actually landed, Markdown-Patch-Warnings reports what a PATCH had to work around, Deprecation warns that a format is sunsetting, and Mcp-Session-Id carries the session for a sessionful MCP connection.

Browsers hide response headers from JavaScript unless the server opts them in, so the API sends Access-Control-Expose-Headers: * and all of them are readable with response.headers.get(...). Safari honours the wildcard from 15.4 onward; older browsers see only the CORS-safelisted headers. Requests made with credentials: "include" are not supported — the API authenticates with a bearer token and sends Access-Control-Allow-Origin: *, which browsers reject for credentialed requests.

Patching notes

The PATCH method is one of the most useful features of this API. It lets you make targeted edits without rewriting entire files.

Send a JSON instruction: an operation (replace, prepend, append, or delete) applied to a scope (content, marker, markerAndContent, or parent) of a target — a heading (addressed as an array of heading texts from the top level down), a block reference, or a frontmatter key. The payload rides in content (a string), value (JSON, for frontmatter values), or destination (a heading move):

# Replace the value of a frontmatter field
curl -k -X PATCH \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/json" \
  --data '{"targetType":"frontmatter","target":"status","operation":"replace","value":"done"}' \
  https://127.0.0.1:27124/vault/path/to/note.md

Heading levels inside a content string are relative to the target (a leading # becomes a direct child). Advisory warnings (e.g. a heading rebased past level 6) come back as percent-encoded JSON in the Markdown-Patch-Warnings response header — decode with decodeURIComponent before parsing. Pass ifMatch (the version from a document map) for optimistic concurrency.

Note: Whitespace is library-owned — your content is reduced to trimmed, canonical form (leading and trailing blank lines are meaningless), and the API itself supplies the blank line wherever inserted content faces body text, so an append or prepend always lands as its own block and never merges into an existing paragraph. Heading lines, existing blank lines, and each document's spacing style are preserved as-is. See the interactive docs for worked examples.

To continue an existing block instead of starting a new one — say, extending a list — add within to a heading instruction: an index selecting one of the section's top-level body blocks (0-based in document order, negative counting from the end, so -1 is the last block). A within edit splices literally, so you own the joint:

# Add an item to the last list under "Log" (the leading \n continues the block)
curl -k -X PATCH \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: application/json" \
  --data '{"targetType":"heading","target":["Log"],"within":-1,"operation":"append","content":"\n- new item"}' \
  https://127.0.0.1:27124/vault/path/to/note.md

With markerAndContent scope, prepend/append instead insert a new block beside the indexed one. Indices are positional, so read the document map first and pair the edit with ifMatch.

Raw-content mode

If your client templates markdown into the request body (Shortcuts, Tasker, curl from a template), JSON-escaping that content into an instruction is fragile. Raw-content mode moves the instruction's fields out of the body — target in the URL (or in Target-Type/Target headers with an explicit Markdown-Patch-Version: 2), operation and options in headers — and the body is the raw payload, no JSON escaping required:

# Append a templated line under a heading — no JSON escaping anywhere
curl -k -X PATCH \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Operation: append" \
  -H "Content-Type: text/markdown" \
  --data "- $TEMPLATED_CONTENT" \
  https://127.0.0.1:27124/vault/notes/daily.md/heading/Log

A text/* body is the content carrier, an application/json body the value carrier, and no body at all carries nothing (a delete, or a move via a Destination header). Target-Scope, Within (the instruction's within index as a plain integer, e.g. -1), Create-Target-If-Missing, Reject-If-Content-Preexists, and If-Match headers round out the instruction. See the interactive docs for the header encodings and the full details.

Already using the older header-driven PATCH format? It spread the instruction across request headers instead of a JSON body, and is deprecated and will be removed in 6.0. It still works — send Markdown-Patch-Version: 1 to opt back into it (the same header also selects the legacy ::-joined document map on GET), and responses served by it carry a Deprecation: true; sunset-version="6.0" header. To upgrade, drop that header and move each header into the JSON body; the interactive docs have the field-by-field mapping table.

See the interactive docs for the full instruction schema and options.

Targeting specific sections

You can read or write a specific part of a note — a heading, block reference, or frontmatter field — without fetching or replacing the whole file. This works on GET, PUT, POST, and PATCH requests (for PATCH this is raw-content mode — add an Operation header).

Append /<target-type>/<target> after the filename. Each nested heading level is its own path segment, so a heading whose text contains :: needs no escaping:

# Read the content under a specific heading
curl -k -H "Authorization: Bearer <your-api-key>" \
  https://127.0.0.1:27124/vault/path/to/note.md/heading/My%20Section

# Read a nested heading (one path segment per level)
curl -k -H "Authorization: Bearer <your-api-key>" \
  https://127.0.0.1:27124/vault/path/to/note.md/heading/Work/Meetings

# Read a frontmatter field
curl -k -H "Authorization: Bearer <your-api-key>" \
  https://127.0.0.1:27124/vault/path/to/note.md/frontmatter/status

# Replace the content of a heading via PUT (heading levels are normalized for you)
curl -k -X PUT \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: text/markdown" \
  --data "Updated content" \
  https://127.0.0.1:27124/vault/path/to/note.md/heading/My%20Section

# Append to a heading via POST
curl -k -X POST \
  -H "Authorization: Bearer <your-api-key>" \
  -H "Content-Type: text/markdown" \
  --data "Appended content" \
  https://127.0.0.1:27124/vault/path/to/note.md/heading/My%20Section

Supported target types: heading, block, frontmatter.

On a GET, a Target-Scope header selects which part of the target comes back, mirroring the PATCH scopes: content (the default), marker (the label — a heading's raw text, a block's bare id, a frontmatter key), or markerAndContent (the whole node, in exactly the shape a PATCH replace at that scope consumes — a heading subtree reads back with its own line as # Title, levels relative to its parent):

# Read a whole section — heading line included — ready to edit and write back
curl -k -H "Authorization: Bearer <your-api-key>" \
  -H "Target-Scope: markerAndContent" \
  https://127.0.0.1:27124/vault/path/to/note.md/heading/My%20Section

Deprecated: header-based targeting. Earlier releases targeted a section with Target-Type, Target, and Target-Delimiter headers (plus Target-Scope/Trim-Target-Whitespace). That form is deprecated and will be removed in 6.0; it is only processed when you also send Markdown-Patch-Version: 1 (responses then carry a Deprecation header). Without it, supplying those targeting headers is rejected with 400. Supplying both URL-path targeting and the header form on one request returns 422 Unprocessable Entity.

Searching

POST /search/simple/?query=your+terms runs Obsidian's built-in fuzzy search and returns matching filenames with scored context snippets.

POST /search/ accepts a JsonLogic expression (content type application/vnd.olrapi.jsonlogic+json) and evaluates it against each note's metadata (frontmatter, tags, path, content).

MCP (Model Context Protocol)

[!NOTE] Several third-party MCP servers for Obsidian exist, but they are no longer necessary — this plugin ships a built-in MCP server that runs inside Obsidian and has direct access to your vault's live metadata, active file, and command palette. If you are currently using a third-party server, switching to this one is likely to give you better results.

The plugin includes a built-in MCP server at /mcp/ so AI agents and MCP-compatible clients can interact with your vault without hand-crafting HTTP requests.

Transport: Streamable HTTP — API key authentication required.

Protocol revisions

The endpoint serves the 2026-07-28 revision plus the sessionful revisions from 2024-10-07 through 2025-11-25, choosing per request, so clients on either can share it.

The 2026-07-28 revision is stateless: there is no initialize handshake and no session, so the plugin neither issues nor reads the Mcp-Session-Id header. Each request carries its own protocol version and client identity in params._meta, repeats them in the MCP-Protocol-Version, Mcp-Method, and Mcp-Name headers, and is answered on its own. Clients can call server/discover to learn the supported revisions and capabilities up front.

Clients that open with an initialize request are served the sessionful revision they negotiate: the handshake returns an Mcp-Session-Id, GET /mcp/ opens that session's notification stream, and DELETE /mcp/ ends it. Sessions exist only on this path, and they are what keeps the handshake's listChanged capabilities honest: when another plugin registers or removes an MCP tool, every live session is notified, while 2026-07-28 clients hear about it on a subscriptions/listen stream.

Connecting a client

Connect your MCP client to https://127.0.0.1:27124/mcp/. Authentication uses a bearer token — find your API key under Settings → Local REST API, then pass it as:

Authorization: Bearer <your-api-key>

The exact config syntax varies by client; see the Quick start examples above or consult your client's documentation for Streamable HTTP remote MCP servers.

[!WARNING] To connect to the MCP server securely, your client must trust the plugin's locally generated certificate authority. You can download and trust it from https://127.0.0.1:27124/obsidian-local-rest-api.crt, or configure your client to skip TLS verification for 127.0.0.1.

If trusting a locally generated certificate is not possible in your environment, you can connect insecurely using http://127.0.0.1:27123/mcp/ instead of https://127.0.0.1:27124/mcp/ if you have enabled the HTTP endpoint under Settings → Local REST API → Enable HTTP server.

Available tools

Binary files and attachments

The REST API has always handled binary content: GET /vault/<path> returns raw bytes with a Content-Type derived from the file extension, and PUT /vault/<path> accepts a body of any content type and stores it byte-for-byte. Neither has a practical size limit.

MCP tools are a different story, because a tool's arguments and results pass through the model. vault_read and vault_write are text tools — they decode and encode UTF-8, which is lossy for anything that is not text — so reading an attachment with vault_read and writing the result back destroys the file. vault_read_binary and vault_write_binary exist for those files, and carry the bytes base64-encoded.

vault_write_binary refuses a payload it cannot decode cleanly rather than writing the bytes it managed to salvage.

Because base64 costs roughly 0.35-0.45 tokens per byte of context, both binary tools refuse files over 1 MiB. That ceiling is a context guard, not a storage limit — move larger attachments over the REST endpoints above.

Available resources

API Extensions

Other plugins can register their own authenticated routes, public routes, and MCP tools against this plugin's server. See Adding your own API Routes via an Extension for a walkthrough.

Typed extension API

Install this package as a development dependency to get getAPI and the types for everything it returns:

npm install --save-dev obsidian-local-rest-api

This package declares obsidian, zod, and @types/express as peer dependencies, because its types refer to all three — addRoute returns express's IRoute, and addMcpTool takes zod schemas. npm installs peers for you; if you pin them yourself, keep them resolvable. Without them, TypeScript quietly widens those positions to any instead of reporting an error, so a project that suppresses the missing-types diagnostic gets no warning that it has lost type checking exactly where it matters most.

import { getAPI, type LocalRestApiPublicApi } from "obsidian-local-rest-api";

const api: LocalRestApiPublicApi | undefined = getAPI(this.app, this.manifest, 2);

The package entry point is a small standalone module — it resolves the running host plugin out of Obsidian's plugin registry rather than pulling the plugin bundle into your build. Passing an extension API version (2 above) makes getAPI throw ApiVersionUnsupportedError when the installed host is older than the surface you need; omit it to accept whatever is installed and feature-detect yourself. getAPI returns undefined when the plugin isn't installed or hasn't loaded yet.

publicApi.d.ts is generated from src/publicApi.ts, which the implementation is compile-time-checked against, so the published types cannot drift from what the plugin actually offers.

Known extensions

• Periodic Notes: Adds support for periodic notes

Contributing

See CONTRIBUTING.md. If you want to add functionality without modifying core, consider building an API extension instead — extensions can be developed and released independently.

Credits

Inspired by Vinzent03's advanced-uri plugin, with the goal of expanding automation options beyond the constraints of custom URL schemes.