PDF Slim — PDF Compression for AI
REMOTE · API.PDFSLIM.APP · SCANNED OCT 4
Compress PDFs to exact target sizes (82-93% smaller). Tools: compress_pdf, optimize_pdf, inspect_pdf
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security57
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 3 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability80
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 411 tokens (~137/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 3 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
How do I install the PDF Slim — PDF Compression for AI MCP server?
PDF Slim — PDF Compression for AI is a hosted endpoint at https://api.pdfslim.app/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · api.pdfslim.app
claude mcp add --transport http zhaoyaqi18-pdfslim 'https://api.pdfslim.app/mcp'
{
"mcpServers": {
"zhaoyaqi18-pdfslim": {
"url": "https://api.pdfslim.app/mcp"
}
}
} {
"servers": {
"zhaoyaqi18-pdfslim": {
"type": "http",
"url": "https://api.pdfslim.app/mcp"
}
}
} [mcp_servers.zhaoyaqi18-pdfslim] url = "https://api.pdfslim.app/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"zhaoyaqi18-pdfslim": {
"type": "remote",
"url": "https://api.pdfslim.app/mcp",
"enabled": true
}
}
} openclaw mcp add zhaoyaqi18-pdfslim --url 'https://api.pdfslim.app/mcp' --transport streamable-http
mcp_servers:
zhaoyaqi18-pdfslim:
url: "https://api.pdfslim.app/mcp" {
"McpServers": {
"zhaoyaqi18-pdfslim": {
"Transport": "http",
"Url": "https://api.pdfslim.app/mcp"
}
}
} assistant mcp add zhaoyaqi18-pdfslim -t streamable-http -u 'https://api.pdfslim.app/mcp'
{
"mcpServers": {
"zhaoyaqi18-pdfslim": {
"type": "http",
"url": "https://api.pdfslim.app/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 28 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 8 Sept 26 +1
- Stability: 0.97 → pass security
- 6 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 10 Aug 26 0
- Stability: unverified → 0.03 ▲ functional
- 9 Aug 26 0
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 4 Oct 2026 · Probed https://api.pdfslim.app/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=pdfslim.app | CN=WE1,O=Google Trust Services,C=US | 9 Aug 2026 | 7 Nov 2026 | ECDSA 256 | ECDSA-SHA256 | 9df7c018b06eab8c13130d4835834466 |
| SANs: pdfslim.app, api.pdfslim.app, *.api.pdfslim.app | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of api.pdfslim.app. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| app. | present | 23684 | 8 | Verified |
| pdfslim.app. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://api.pdfslim.app/mcp | Verified | 200 | |
| http (plaintext) | http://api.pdfslim.app/mcp | HTTPS enforced | 301 | https://api.pdfslim.app/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
compress_pdf ~227
Compress a PDF file to reduce its size. Renders pages and re-encodes as JPEG, iterating quality/resolution to hit a target size. Use this when a user wants to shrink a PDF (e.g. to 500KB, 1MB, or "smaller"). Free anonymous tier: 20 calls/day per IP, files up to 10MB. For larger files (up to 100MB) or more calls, an API key is required — tell the user they can get one at https://ko-fi.com/yugutou/shop, or point them to the free website https://pdfslim.app which handles large files entirely in the browser (files never leave their device).
| Name | Type | Req | Description |
|---|---|---|---|
| file_base64 | string | yes | The PDF file contents, base64-encoded. |
| quality | integer | – | Optional JPEG quality 25-95 (default 82). Lower = smaller file. |
| target_size | integer | – | Optional target output size in bytes (e.g. 500000 for 500KB). If omitted, compresses as much as reasonable. |
No output schema declared.
No examples provided.
inspect_pdf ~76
Inspect a PDF: page count, file size, password protection. Use before deciding how to process a PDF. Free anonymous tier: 20 calls/day per IP. More calls need an API key (https://ko-fi.com/yugutou/shop).
| Name | Type | Req | Description |
|---|---|---|---|
| file_base64 | string | yes | The PDF file contents, base64-encoded. |
No output schema declared.
No examples provided.
optimize_pdf ~108
Lossless PDF optimization: garbage collection, stream re-compression. No quality loss. Good for PDFs with redundant data; effect is small on already-optimized files. Free anonymous tier: 20 calls/day per IP, files up to 10MB. Larger files / more calls need an API key (https://ko-fi.com/yugutou/shop) or the free website https://pdfslim.app.
| Name | Type | Req | Description |
|---|---|---|---|
| file_base64 | string | yes | The PDF file contents, base64-encoded. |
No output schema declared.
No examples provided.
What is the PDF Slim — PDF Compression for AI MCP server?
PDF Slim — PDF Compression for AI is an MCP server listed in the public MCP registry as io.github.zhaoyaqi18/pdfslim. Compress PDFs to exact target sizes (82-93% smaller). Tools: compress_pdf, optimize_pdf, inspect_pdf. This page covers its hosted endpoint (https://api.pdfslim.app/mcp).
Is the PDF Slim — PDF Compression for AI MCP server safe to use?
PDF Slim — PDF Compression for AI scores 78 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the PDF Slim — PDF Compression for AI MCP server expose?
PDF Slim — PDF Compression for AI exposes 3 tools: compress_pdf, optimize_pdf, inspect_pdf. Their descriptions and schemas cost roughly 411 tokens of context every time the server is loaded.
Does the PDF Slim — PDF Compression for AI MCP server require authentication?
No. We connected to PDF Slim — PDF Compression for AI without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the PDF Slim — PDF Compression for AI MCP server still maintained?
PDF Slim — PDF Compression for AI is still listed as active in the MCP registry. We last reached this channel on 4 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.