Obsidian Local REST API Skill

Control any Obsidian vault from OpenClaw using the Local REST API plugin. Works on any OS where Obsidian Desktop runs (Windows, macOS, Linux). No extra CLI tools needed — just curl.

---

Critical: Known Pitfalls (Read First)

These issues were discovered in real-world use and will cause silent failures if ignored:

1. Trailing slashes are mandatory on directory paths

The API returns {"message":"Not Found","errorCode":40400} if you omit trailing slashes on directory endpoints.

Path	Result
$OBSIDIAN_URL/vault/	✅ Correct — lists vault root
$OBSIDIAN_URL/vault	❌ 40400 error
$OBSIDIAN_URL/vault/My%20Folder/	✅ Correct — lists subfolder
$OBSIDIAN_URL/vault/My%20Folder	❌ 40400 error

2. The root health check endpoint is / — nothing else

There is no /api/, /api/healthz, /healthz, /status, or /health endpoint.

Path	Result
$OBSIDIAN_URL/	✅ Returns plugin status JSON
$OBSIDIAN_URL/api/	❌ 40400 error
$OBSIDIAN_URL/api/healthz	❌ 40400 error

3. Shell variable expansion may fail in exec contexts

$OBSIDIAN_URL and $OBSIDIAN_API_KEY are available in the gateway process but child shells spawned by the exec tool may not inherit them depending on your OpenClaw configuration. Always test variable expansion before using them in curl:

echo "URL=$OBSIDIAN_URL KEY_LEN=${#OBSIDIAN_API_KEY}"

If either is empty, the exec shell isn't inheriting the gateway's environment. Fix the inheritance (confirm the Environment= lines are in the systemd unit and restart the service), or re-export the vars in the shell by sourcing them from the service config. Never paste the literal API key into commands — it lands in shell history and session logs.

4. Never dump raw JSON to the user

Always interpret API responses and reply in plain English. See the Output Formatting section.

---

Prerequisites

1. Obsidian Desktop installed and running with a vault open.
2. Local REST API plugin installed and enabled in Obsidian:
   • Open Obsidian → Settings → Community plugins → Browse → search "Local REST API" → Install → Enable.
3. API Key copied from: Settings → Local REST API → API Key.
4. Port noted (default: 27124). HTTPS is strongly recommended.
5. Env vars set in your OpenClaw service (see Setup below).

---

Setup

1. Add env vars to your OpenClaw systemd service

sudo nano /etc/systemd/system/openclaw.service

Add these two lines in the [Service] block:

Environment=OBSIDIAN_URL=https://YOUR_OBSIDIAN_HOST:27124
Environment=OBSIDIAN_API_KEY=your_api_key_here

Then reload and restart:

sudo systemctl daemon-reload
sudo systemctl restart openclaw.service

2. Verify the env vars are set (without printing the key)

echo "OBSIDIAN_URL set: ${OBSIDIAN_URL:+yes}  |  API key length: ${#OBSIDIAN_API_KEY}"

You should see the URL marked set and a non-zero key length. If the key length is 0, the service isn't passing the variables — re-check the Environment= lines in the unit and restart. (Avoid dumping /proc/<pid>/environ or otherwise printing the key — it ends up in shell history and logs.)

3. Test the connection

curl -sk \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  "$OBSIDIAN_URL/" \
  | python3 -c "import json,sys; d=json.load(sys.stdin); print('OK — Obsidian', d['versions']['obsidian'], '| Plugin', d['versions']['self'], '| Auth:', d['authenticated'])"

Expected: OK — Obsidian 1.x.x | Plugin 3.x.x | Auth: True

If $OBSIDIAN_URL is empty, fix the env inheritance (see Pitfall 3) rather than inlining secrets. Only as a last resort for a one-off test, you can substitute placeholders locally — never commit or log a real key:

curl -sk \
  -H "Authorization: Bearer YOUR_API_KEY_HERE" \
  "https://YOUR_OBSIDIAN_HOST:27124/" \
  | python3 -c "import json,sys; d=json.load(sys.stdin); print('OK — Obsidian', d['versions']['obsidian'], '| Plugin', d['versions']['self'], '| Auth:', d['authenticated'])"

4. Install the skill

# Via ClawHub (recommended — versioned + checksum-verified)
openclaw skills install obsidian-rest

# Or manually, pinned to a release tag (avoid tracking mutable main)
git clone --branch v1.2.0 --depth 1 https://github.com/nj070574-gif/openclaw-obsidian-vault-skill.git
cp -r openclaw-obsidian-vault-skill/skill ~/.openclaw/workspace/skills/obsidian-rest

---

Environment Variables

Variable	Required	Description
OBSIDIAN_URL	✅ Yes	Full base URL including protocol and port, e.g. https://192.0.2.100:27124
OBSIDIAN_API_KEY	✅ Yes	API key from Obsidian → Settings → Local REST API

The plugin uses a self-signed certificate by default, so these examples use curl -sk. ⚠️ -k skips TLS certificate verification, so the API key and note contents travel over an unverified connection — only acceptable on a trusted LAN. When the traffic crosses any untrusted network, export the plugin's certificate (Obsidian → Settings → Local REST API → download the certificate) and use curl --cacert /path/to/obsidian-local-rest-api.crt instead of -k, or front the plugin with a reverse proxy holding a properly trusted cert.

---

API Reference

All requests require the auth header:

Authorization: Bearer $OBSIDIAN_API_KEY

Check API status (root endpoint only)

curl -sk -H "Authorization: Bearer $OBSIDIAN_API_KEY" "$OBSIDIAN_URL/"

Returns: {"status":"OK","authenticated":true,"versions":{"obsidian":"1.x.x","self":"3.x.x"}, ...}

---

List vault root (trailing slash required)

curl -sk -H "Authorization: Bearer $OBSIDIAN_API_KEY" "$OBSIDIAN_URL/vault/" \
  | python3 -c "import json,sys; [print(f) for f in sorted(json.load(sys.stdin)['files'])]"

List a subfolder (trailing slash required)

curl -sk -H "Authorization: Bearer $OBSIDIAN_API_KEY" "$OBSIDIAN_URL/vault/My%20Folder/" \
  | python3 -c "import json,sys; [print(f) for f in json.load(sys.stdin)['files']]"

URL encoding: spaces → %20 | forward slash within a path segment → %2F

Encode any path automatically:

python3 -c "import urllib.parse; print(urllib.parse.quote('My Folder/My Note.md', safe=''))"

---

Read a note

curl -sk -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  "$OBSIDIAN_URL/vault/PATH%2FTO%2FNOTE.md"

Returns raw Markdown content.

---

Create or overwrite a note (PUT)

curl -sk -X PUT \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  -H "Content-Type: text/markdown" \
  --data-binary "# My Note Title

Content goes here." \
  "$OBSIDIAN_URL/vault/PATH%2FTO%2FNOTE.md"

Returns HTTP 204 No Content on success. Warning: PUT replaces the entire file. Use POST to append safely.

---

Append to an existing note (POST)

curl -sk -X POST \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  -H "Content-Type: text/markdown" \
  --data-binary "

## New Section $(date +%Y-%m-%d)

Content to append." \
  "$OBSIDIAN_URL/vault/PATH%2FTO%2FNOTE.md"

Returns HTTP 204 No Content on success.

---

Patch / insert at a heading (PATCH)

curl -sk -X PATCH \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  -H "Content-Type: text/markdown" \
  -H "Operation: append" \
  -H "Target-Type: heading" \
  -H "Target: My Section Heading" \
  --data-binary "Content to insert under the heading." \
  "$OBSIDIAN_URL/vault/PATH%2FTO%2FNOTE.md"

Valid Operation: append | prepend | replace | delete. Valid Target-Type: heading | block | frontmatter. (Plugin 3.x headers; older <3.x used a single Heading header.)

---

Delete a note

curl -sk -X DELETE \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  "$OBSIDIAN_URL/vault/PATH%2FTO%2FNOTE.md"

Returns HTTP 204 No Content on success.

---

Search vault (full-text)

curl -sk -X POST \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  "$OBSIDIAN_URL/search/simple/?query=YOUR+SEARCH+TERM&contextLength=150" \
  | python3 -c "
import json, sys
results = json.load(sys.stdin)
if not results:
    print('No matches found.')
else:
    print(f'Found {len(results)} match(es):')
    for r in results[:5]:
        print(' -', r['filename'])
        for m in r.get('matches', [])[:1]:
            ctx = m.get('context', '').strip()
            if ctx: print('   ...', ctx[:100])
"

---

Get currently active file in Obsidian

curl -sk -H "Authorization: Bearer $OBSIDIAN_API_KEY" "$OBSIDIAN_URL/active/"

---

List available Obsidian commands

curl -sk -H "Authorization: Bearer $OBSIDIAN_API_KEY" "$OBSIDIAN_URL/commands/" \
  | python3 -c "import json,sys; [print(c['id'], '|', c['name']) for c in json.load(sys.stdin).get('commands',[])]"

Execute an Obsidian command

curl -sk -X POST \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"commandId": "editor:save-file"}' \
  "$OBSIDIAN_URL/commands/execute/"

---

Output Formatting Rules

Never dump raw JSON to the user. Always interpret results and reply in plain English.

Situation	What to say
Status check returns "authenticated": true	"✅ Obsidian vault connected — Obsidian v1.x.x, plugin v3.x.x"
Status check fails / 40400 error	"❌ Cannot reach Obsidian vault: [exact error]. Check Obsidian is running."
Vault listed	"Your vault contains X items: [list files and folders]"
Subfolder listed	"Found X notes in [folder]: [list]"
Note read	Return the note content (or a summary if it's long)
Note created (HTTP 204)	"✅ Created [path]"
Note saved / overwritten (HTTP 204)	"✅ Saved to [path]"
Note appended (HTTP 204)	"✅ Appended to [path]"
Search returns results	"Found X notes matching '[query]': [list filenames]"
Search returns nothing	"No notes found matching '[query]'"
40400 error	"❌ API returned Not Found — check the path and trailing slashes"
401 error	"❌ Unauthorised — check OBSIDIAN_API_KEY is set correctly"

---

Workflow Guide

Saving content ("sv" / "save this")

1. Check env vars expand: echo "URL=$OBSIDIAN_URL LEN=${#OBSIDIAN_API_KEY}"
2. Pick the right folder from context (infrastructure → Infrastructure/, daily log → Daily/)
3. Choose a descriptive hyphenated filename, e.g. Setup-Guide-2026-04-12.md
4. Check if file exists: GET /vault/PATH.md — HTTP 404 means safe to create
5. Use PUT to create, POST to append to existing
6. Confirm with plain English: "✅ Saved to Infrastructure/Setup-Guide.md"

Finding a note

1. Search: POST /search/simple/?query=TERM
2. If multiple results, list filenames and ask which to open
3. GET the file and return its content or a summary

Updating a note

1. Read the file first to understand its structure
2. POST to append, or PATCH with Heading header for targeted insertion
3. Confirm what was added and where

Creating new folders

New folders are created automatically when you PUT a file into a path that doesn't exist yet.

---

Common Patterns

Save a runbook

NOTE_PATH="Infrastructure%2FRunbook-$(date +%Y-%m-%d).md"
curl -sk -X PUT \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  -H "Content-Type: text/markdown" \
  --data-binary "# Runbook — $(date +%Y-%m-%d)

## Steps

1. Step one
2. Step two
" \
  "$OBSIDIAN_URL/vault/$NOTE_PATH"
echo "Saved to vault/$NOTE_PATH"

Append a timestamped log entry

curl -sk -X POST \
  -H "Authorization: Bearer $OBSIDIAN_API_KEY" \
  -H "Content-Type: text/markdown" \
  --data-binary "
- $(date '+%Y-%m-%d %H:%M') — Log entry here" \
  "$OBSIDIAN_URL/vault/Daily%2FLog.md"

---

URL Encoding Quick Reference

Character	Encoded
Space	%20
/ (within a path segment)	%2F
#	%23
&	%26
+	%2B

---

Troubleshooting

Symptom	Likely cause	Fix
curl: (7) Failed to connect	Obsidian not running or wrong host/port	Check Obsidian is open; verify OBSIDIAN_URL
{"message":"Not Found","errorCode":40400}	Wrong path — missing trailing slash, or non-existent endpoint	Add / to end of directory paths; use only documented endpoints
HTTP 401 Unauthorized	Wrong or missing API key	Verify OBSIDIAN_API_KEY matches plugin settings
SSL certificate error	Self-signed cert	Always use curl -sk — never curl -s alone (or --cacert with the exported plugin certificate for verified TLS)
$OBSIDIAN_URL empty in curl	Env var not inherited by exec shell	Confirm the Environment= lines are in the unit and restart; re-source the env in the shell. Don't inline the literal key.
Skill shows △ needs setup	Env vars not set	Add Environment= lines to openclaw.service, reload, restart
Obsidian on Windows, agent on Linux	Firewall blocking port	Allow TCP 27124 inbound in Windows Defender Firewall

Windows Firewall (Obsidian on Windows, OpenClaw on Linux)

Windows Defender Firewall → Advanced Settings → Inbound Rules → New Rule
→ Port → TCP → 27124 → Allow → All profiles → Name: "Obsidian Local REST API"

---

Plugin Information

• Plugin: Obsidian Local REST API by Adam Coddington
• Default port: 27124
• Protocol: HTTPS (self-signed cert) or HTTP
• Obsidian minimum version: 0.12.0
• Plugin version tested: 3.2.0