forthling
MCPB · FORTHLING.MCPB
Run Forth-2012 in a sandbox: definitions stay between calls, each result shows the stacks.
Available components
Last scanned (10 hours ago)
Scores higher than 72% of MCPB servers
Category Developer Tools
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security0
- No malware scan is available for this kind of package: the supply-chain vendors we use do not cover it. This is a permanent gap in our coverage, not a finding about the package.Unverified
- Known CVEs could not be checked: we found no dependency list to check in this bundle: either it runs a compiled binary, whose bundled manifests we do not read, or none of the package.json, requirements.txt, pyproject.toml or uv.lock files it ships for its runtime declares a dependency we can read (a requirements.txt that only points at a setup.py project, a local path, or a nested requirements file we cannot follow counts as none).Unverified
- Install-script risk not yet assessed.Unverified
- Dependency health could not be checked: we found no dependency list to check in this bundle: either it runs a compiled binary, whose bundled manifests we do not read, or none of the package.json, requirements.txt, pyproject.toml or uv.lock files it ships for its runtime declares a dependency we can read (a requirements.txt that only points at a setup.py project, a local path, or a nested requirements file we cannot follow counts as none).Unverified
Provenance & Transparency45
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 2 days ago).Pass
- Security-disclosure policy not yet verified: we couldn't inspect the source repository.Unverified
Schema Quality & AI Usability59
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 1236 tokens (~309/item across 4 items; 4 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 Management13
- Stability observed for 4 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
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
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Unverified: 1 category
A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.
Checks we ran (11)
- Source repository
- Provenance
- License
- Maintenance
- Schema quality
- Stability
- Tool coverage
- Injection markers
- Destructive annotations
- Judged manipulation
- MCP protocol
Checks we could not complete (5)
These are gaps on our side, not findings about this package. We only credit what we can confirm, so a category made up entirely of them scores 0.
- Malware scan in Supply Chain Security (scores 0 for this)No malware scan is available for this kind of package: the supply-chain vendors we use do not cover it. This is a permanent gap in our coverage, not a finding about the package.
- Known CVEs in Supply Chain Security (scores 0 for this)Known CVEs could not be checked: we found no dependency list to check in this bundle: either it runs a compiled binary, whose bundled manifests we do not read, or none of the package.json, requirements.txt, pyproject.toml or uv.lock files it ships for its runtime declares a dependency we can read (a requirements.txt that only points at a setup.py project, a local path, or a nested requirements file we cannot follow counts as none).
- Install scripts in Supply Chain Security (scores 0 for this)Install-script risk not yet assessed.
- Dependency health in Supply Chain Security (scores 0 for this)Dependency health could not be checked: we found no dependency list to check in this bundle: either it runs a compiled binary, whose bundled manifests we do not read, or none of the package.json, requirements.txt, pyproject.toml or uv.lock files it ships for its runtime declares a dependency we can read (a requirements.txt that only points at a setup.py project, a local path, or a nested requirements file we cannot follow counts as none).
- Security disclosure in Provenance & TransparencySecurity-disclosure policy not yet verified: we couldn't inspect the source repository.
Does not apply to this package (2)
- Endpoint SecurityScored on hosted endpoints only. A package has no live endpoint of its own for us to probe.
- Transport & ReachabilityScored on hosted endpoints only. A package has no live endpoint of its own for us to probe.
The score does not measure everything. What the score does not measure →
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.
- 5 Nov 26 −1
- Security disclosure: pass → unverified ▼ functional
- 4 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.
- 2 Nov 26 +1
- Stability: 0.00 → unverified ▼ security
- Schema quality: 270 → 309 ▼ functional
- 1 Nov 26 38
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 5 Nov 2026 · Analysed mcpb/https://github.com/DeSchaker/forthling/releases/download/v0.2.1/forthling.mcpb
Provenance No attestation
The registry publishes no build provenance for this version, so there is nothing to verify.
| Result | No attestation |
|---|---|
| Ecosystem | mcpb |
| Reason | No attestation published |
Background: How many MCP packages publish verified provenance →
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 →
forth_eval Run Forth ~268
Runs Forth-2012 code in the session and returns what it printed, the data stack and the float stack, and the error if there was one. Definitions, variables, files and the stacks stay for the next call. Large input goes in data, which the code reads with DATA; source files to INCLUDE go in files.
| Name | Type | Req | Description |
|---|---|---|---|
| code | string | yes | Forth source; it may have several lines, each at most 1024 characters |
| data | string | – | Text for the word DATA ( -- c-addr u ), which gives a copy in ALLOCATEd memory (FREE it); without a line limit, for large input such as JSON. It stays for later calls until another call sends data. |
| files | object | – | Files to put in the session's file system before the code runs, as {"name": "text"}, replacing files of the same name; the code can INCLUDE them or open them with the FILE words. The files are in mem… |
| trace | boolean | – | If true, the result also gives a trace: each word that ran (not inside the built-in words), with how deep it was nested and the data stack when it started; at most 1000 words. For finding where code… |
| Name | Type | Req | Description |
|---|---|---|---|
| breaks | array | – | forth_eval only, when BREAK ran: what the program looked like at each BREAK (ALSO DEBUG), at most 100; BREAK does not stop the program |
| breaks_dropped | integer | – | the BREAKs past the first 100 |
| compiling | boolean | yes | whether a colon definition is still open |
| error | object|null | yes | – |
| fstack | array | yes | the float stack, the top last |
| max_depth | integer | – | forth_eval only: the deepest the data stack was during this call |
| output | string | yes | what the code printed |
| stack | array | yes | the data stack, the top last |
| steps | integer | – | forth_eval only: the steps this call took, of its limit |
| trace | array | – | forth_eval with trace only: a word per entry, in the order they ran |
| trace_dropped | integer | – | forth_eval with trace only: the words past the first 1000, which the trace leaves out |
No examples provided.
forth_reset Start over ~34
Starts a new Forth session: every definition, variable and stack value is gone, and so are the data and the files.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| breaks | array | – | forth_eval only, when BREAK ran: what the program looked like at each BREAK (ALSO DEBUG), at most 100; BREAK does not stop the program |
| breaks_dropped | integer | – | the BREAKs past the first 100 |
| compiling | boolean | yes | whether a colon definition is still open |
| error | object|null | yes | – |
| fstack | array | yes | the float stack, the top last |
| max_depth | integer | – | forth_eval only: the deepest the data stack was during this call |
| output | string | yes | what the code printed |
| stack | array | yes | the data stack, the top last |
| steps | integer | – | forth_eval only: the steps this call took, of its limit |
| trace | array | – | forth_eval with trace only: a word per entry, in the order they ran |
| trace_dropped | integer | – | forth_eval with trace only: the words past the first 1000, which the trace leaves out |
No examples provided.
forth_stack Show the stacks ~21
Shows the data stack and the float stack, without running anything.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| breaks | array | – | forth_eval only, when BREAK ran: what the program looked like at each BREAK (ALSO DEBUG), at most 100; BREAK does not stop the program |
| breaks_dropped | integer | – | the BREAKs past the first 100 |
| compiling | boolean | yes | whether a colon definition is still open |
| error | object|null | yes | – |
| fstack | array | yes | the float stack, the top last |
| max_depth | integer | – | forth_eval only: the deepest the data stack was during this call |
| output | string | yes | what the code printed |
| stack | array | yes | the data stack, the top last |
| steps | integer | – | forth_eval only: the steps this call took, of its limit |
| trace | array | – | forth_eval with trace only: a word per entry, in the order they ran |
| trace_dropped | integer | – | forth_eval with trace only: the words past the first 1000, which the trace leaves out |
No examples provided.
forth_words List my words ~26
Lists the words defined in this session, the latest first (not the built-in words).
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| words | array | yes | – |
No examples provided.
How do I install the forthling MCP server?
forthling ships as an MCPB bundle, a single file you download and open in an MCP host that supports MCPB bundles, such as Claude Desktop. The host reads the launch command from the bundle's own manifest, so there is no command to copy. Before opening it, check the file's SHA-256 matches the one the MCP registry declares for it, 91385c3334583fa2ab791c100d8d059c5cfe313ae294d3e5e315b915bafe17e0; the commands to do that are on this page. If it does not match, do not open it.
mcpb · forthling.mcpb
Download bundleCheck the download matches the SHA-256 the MCP registry declares before you open it. If it does not match, do not open the file.
SHA-256
91385c3334583fa2ab791c100d8d059c5cfe313ae294d3e5e315b915bafe17e0
macOS / Linux
echo "91385c3334583fa2ab791c100d8d059c5cfe313ae294d3e5e315b915bafe17e0 forthling.mcpb" | shasum -a 256 -c
Windows (PowerShell)
(Get-FileHash -Algorithm SHA256 .\forthling.mcpb).Hash -eq "91385c3334583fa2ab791c100d8d059c5cfe313ae294d3e5e315b915bafe17e0"
Run it in the folder you saved the bundle to, then open the file with an MCPB-capable host such as Claude Desktop.
What is the forthling MCP server?
forthling is an MCP server listed in the public MCP registry as io.github.DeSchaker/forthling. Run Forth-2012 in a sandbox: definitions stay between calls, each result shows the stacks. This page covers its MCPB bundle (https://github.com/DeSchaker/forthling/releases/download/v0.2.1/forthling.mcpb).
Is the forthling MCP server safe to use?
forthling scores 39 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 forthling MCP server expose?
forthling exposes 4 tools: forth_eval, forth_stack, forth_words, forth_reset. Their descriptions and schemas cost roughly 349 tokens of context every time the server is loaded.
What licence is the forthling MCP server under?
forthling declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.
What did VerifyMCP test on the forthling MCP server?
VerifyMCP ran 11 checks on forthling, covering Source repository, Provenance, License, Maintenance and 7 more. 5 items could not be completed, a gap on our side rather than a finding about forthling: Malware scan, Known CVEs, Install scripts, Dependency health and 1 more. One category scores 0 for that reason, because we only credit what we can confirm. Endpoint Security and Transport & Reachability do not apply to an MCPB bundle, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.