Chroma’s official MCP server: vector search and collection management for RAG workflows.
Nothing to run from here
Halfnine is installed from its publisher's own source and answers where it runs, so this marketplace is not in the path of a single call. There is no address here to send one to, and a panel that pretended otherwise would be showing you an answer we made up. Install it and call it from your own client — the Installation tab has the entry for each one.
93/100
trust score
7
tools declared
local
runs on your machine
79
downloads
What it does
PostgreSQL through Halfnine: describe, read-only queries, and changes you approve in the app.
Quickstart
Install it the way its author documents:
1. Download halfnine-0.3.0.mcpb and open it in Claude Desktop or another client that installs MCP bundles (.mcpb)
2. Its sha256 is 26c0fbeb11e7ccb81d5899123bbd0628466f7a94d9262ce49e8c045ed27799ea
The full guide: https://github.com/notinferred/halfnine/releases/download/v0.3.0/halfnine-0.3.0.mcpb
Publishernot claimed
NOAll 1 server
notinferred1 server
1 category
Collected from a public index. Nobody has claimed this account, so nothing here was written by its author — claim it if it is yours.
Installation
Where are you running it?
Every route below installs the same thing and ends at the same approval screen. This one runs on your machine: your client starts Halfnine as a process under your own user, with your files and your network, so the tool surface below is what it can do to your computer rather than to a server somewhere else. Its scan result is on the Security tab — read the surface before you approve it.
Install it the way its author documents:
1. Download halfnine-0.3.0.mcpb and open it in Claude Desktop or another client that installs MCP bundles (.mcpb)
2. Its sha256 is 26c0fbeb11e7ccb81d5899123bbd0628466f7a94d9262ce49e8c045ed27799ea
The full guide: https://github.com/notinferred/halfnine/releases/download/v0.3.0/halfnine-0.3.0.mcpb
Tool surface
What the model actually sees. Descriptions are diffed on every release — see version history.
Read from its source code. A server that builds its tool list when it starts can list more tools than this.
The person's saved PostgreSQL connections: each one's name, colour label, what agents may do on it, and whether it is read-only. Use a connection's name in the other tools.
No parameter schema on file.
What a connection's database holds. Without a table: its schemas, tables and views with their columns and types, row estimates, enums and every foreign key. With a table: that table in full.
No parameter schema on file.
Runs one statement that reads (SELECT, WITH, VALUES, TABLE, SHOW or EXPLAIN) in a read-only transaction, with a 15-second limit, and returns up to limit rows. It never changes anything, on any connection.
No parameter schema on file.
Inserts, updates or deletes rows of one table, each named by its primary key. Halfnine runs it at once or shows it to the person as staged rows to approve, depending on the connection, and answers when it is done. At most 500 rows; use run_sql for bulk changes.
No parameter schema on file.
Changes one table's structure, or creates, empties or drops a table, in one transaction: add, rename, retype or drop columns, set nullability and defaults, create and drop indexes. Halfnine runs it at once or stages it for the person to approve, depending on the connection.
No parameter schema on file.
Runs statements that write, such as a bulk UPDATE or a function, in order in one transaction: all of them or none. Prefer change_rows and change_structure, which the person sees in the table itself. Halfnine runs it at once or shows the SQL to the person to approve, depending on the connection.
No parameter schema on file.
Keeps waiting for the person's answer to a change that answered WAITING, and says how it ended.
No parameter schema on file.
Free
$0 forever
- Every tool, no call limit
- No card, and mcprush charges nothing for it
- Source is public; its licence metadata reads NOASSERTION rather than naming a licence
- Runs on your machine — nothing of it reaches our gateway
- Nothing to cap, because mcprush bills nothing
What counts against your monthly calls
| Tool | Unit | Calls used | Out of the allowance |
|---|
Nothing here is billable: mcprush charges nothing to install Halfnine or to call it, at any volume.
Call allowance · this installenforced at the gateway
Monthly allowance, in calls
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Alert at 80% · then the tool returns a normal MCP error
Used this month: —
ATrust score 93 / 100
Release 0.3.0 · scanned 1 Nov 2026
Two independent axes, because powerful and malicious are different questions. The grade is threat only. The capability level is blast radius, and it is never a penalty on the grade — it is priced as one subtract-only term in the score, where you can see it.
Threat score100
Client score93
Findings3 threat · 0 capability
Capabilityhigh
Coveragesource
Verificationrepo
Surface digest2dc22d3bf39daa3966da07121ef3ae7218597d0cc75600bd6ac9471b4c82a657
Score vectorthreat 100 → client 93
| Term | Level | What it prices | Points |
|---|---|---|---|
| capability-exposure | high | capability blast radius (high) — client exposure if the model is manipulated | −6 |
| verification-discount | repo | publisher verification (public source) — no provenance, but the source is public and inspectable | −1 |
| coverage-honesty | source | inspection depth (source) — how much of the target the scan could see | −0 |
score = clamp(round(threatScore − E_cap − E_ver − E_cov), 0, 100). No model, no opinion, no network call at scoring time: the same methodology version against the same bytes always produces this number, and every line above is a field of the report rather than a summary of it.
What the scan could actually read
A grade is only as meaningful as its coverage, so the scanner publishes its own depth before it publishes its result.
Tool surfacenot available
Implementation sourceread
Package metadataread
Live transportnot available
No tools were enumerated, so prompt-injection, capability and toxic-flow analysis had no tool surface to inspect. To grade a package’s real runtime tools, scan the running server: --command "npx -y <package>".
Capability — what it could do if the model were manipulated
Tags derived from each tool’s schema and the implementation, not from what the tool calls itself. high is the level these add up to.
| Tool | Capability tags | Why the tag was assigned |
|---|---|---|
| No per-tool rows for this release — see the note below. | ||
reads sensitive or local data
Toxic-flow graph
The lethal trifecta, checked as a graph rather than as a checklist: untrusted input, a sensitive source and an external sink have to meet before there is a path worth worrying about.
The public result for this release does not print the flow graph, so there is nothing to show here. That is not the same as "no paths were found": what the scan did read is above, under coverage.
Supply chain and provenance
Integrityfirst-seen
Surface digest2dc22d3bf39daa39
Scanned2026-11-01
This is the first scan of this surface here, so there is nothing yet to compare it against.
Every result on this tab comes from one deterministic pass over the published package — offline, rule by rule, and auditable line by line above. Same methodology version, same bytes, same score.
Release history
It installs from its repository rather than from a versioned package, so the command cannot be pinned to a release. The history below is for reading; the current release on file is 0.3.0.
0.3.0
undated
latestNo release note was published with this version.
—
no reviews yet
Who can review
One review per account, from a signed-in account that does not publish this listing. Nothing else is asked — you can say what you think before you install it. Publishers can reply once per review, and a review can be edited or deleted by whoever wrote it.
Sign in to write one
Any signed-in account that does not publish Halfnine can review it, once — before installing it or after. A review from an account that has installed it is marked as one.
No reviews yet
Nobody has reviewed this listing. The rating on the card is the mean of the reviews written here and nothing else, so there is no rating until somebody writes the first — which takes a signed-in account that does not publish it, and nothing else.