Semahash MCP Server

Content-addressed semantics for multi-agent coordination. Sema is a content-addressed reference system for reasoning and communication. Participants encode and hash information under an agreed representation, then reuse the content address as a verifiable reference, optionally paired with a human-readable handle. Matching full references establishes identity of the resolved hashed content; semantic equivalence…

People who work with agent communication, content addressing and coordination and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in Python.

VERIFIED ACTIVE

LAST COMMIT 2026-09-10 · ★ 13 · #195 OF 945 MAINTAINED OTHER · VERIFIED 2026-09-18

MIT · Python servers · how we verify → /methodology

01 · Install Semahash

before you install - you'll need

GOOGLE_API_KEY

Environment variables documented in the project's README - it lists which are required and which have defaults.

Claude Code

claude mcp add emergent-wisdom-sema -- uvx semahash

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "emergent-wisdom-sema": {
      "command": "uvx",
      "args": [
        "semahash"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license MIT - declared in the repository

pypi package semahash - check the name against the project README before installing (PyPI has no namespace ownership)

registry namespace io.github.emergent-wisdom is GitHub-verified and matches the repo owner

03 · What Semahash can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v0.5.5 · 2026-09-06

All 457 bootstrap pattern identities and both aggregate roots are unchanged. · Fixed · The MCP Registry launch command installs the required MCP extra and pins the · package version advertised by the registry. Release…

v0.5.4 · 2026-09-06

All 457 bootstrap pattern identities and both aggregate roots are unchanged. · Added · Published a reproducible v0.3.0 to v0.4.0 delta-reconstruction · experiment and a permanent CI contract covering additions…

v0.5.3 · 2026-08-21

Added · Published versioned canonicalization-v2 golden vectors with exact preimages, · digests, normalized values, and rejection cases for independent implementations. · Fixed · Canonical hashing now rejects non-finite…

04 · Who maintains Semahash

semahash is maintained by emergent-wisdom. We track 3 MCP servers from emergent-wisdom - 3 actively maintained, 14 combined GitHub stars, oldest repo from Mar 2026.

05 · Facts

repository: github.com/emergent-wisdom/sema
website: https://semahash.org/
category: other - ranked #195 of 945 actively-maintained other servers as of 2026-09-18.
release cadence: 8 releases in the last 90 days (latest 2026-09-06)
registry: io.github.emergent-wisdom/semahash (active, first published 2026-04-08 · 9 versions)
packages: pypi:semahash

06 · Semahash FAQ

What is Semahash?

Is Semahash still maintained?

Yes - as of 2026-09-18, its last commit was 2026-09-10 and it shipped 8 releases in the last 90 days. We re-verify nightly.

How do I install Semahash?

Run `uvx semahash`. The README documents one environment variable (GOOGLE_API_KEY) to set first. You can also paste the ready-made client config above.

Does Semahash run locally?

Yes - it's a stdio server: it runs on your machine (via uvx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Semahash

Alternatives to Semahash

Maintained other servers if Semahash isn't the fit.

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