ChainWeaver MCP server
io.github.dgenio/chainweaver·v0.12.1·6 starsExpose deterministic ChainWeaver flows as MCP tools without LLM calls between steps.
6 stars15 downloads/wk
Reviews
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If you have run it, two minutes of your experience saves the next person an afternoon.
ChainWeaver tools (1)
write = sends, deletes, buys or postsRead from the package source without running it. The installed server may list more.
doubleDoubles a number.
Public scan report
scanner v0.1.9 · 2026-09-27 · same rubric, same numbers if you re-run it
- Code scan60 source files scanned25/25
- –Live reliabilityno gateway calls yet and no remote to proben/a
- –Tool poisoningtools not inspected (local package is not executed); not countedn/a
- Auth qualitylocal package, no credentials required12/15
- Maintenancelast push 28 days ago15/15
- Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10
How ChainWeaver compares
Against every graded AI and agents MCP server, from our own scans and uptime checks. Updated after each scan run.
- Safety score
- 92/100
- higher than 90% of 4,461 AI and agents servers
- Tools
- 1
- the typical AI and agents server has 6
- Tools that change things
- 0%
- typical: 0%. Fewer write tools means less an agent can break
- GitHub stars
- 6
- more than 80% of 2,713 AI and agents servers
- Downloads a week
- 15
- more than 4% of 1,554 AI and agents servers with a package
What its tools let an agent do: 1 read
Install ChainWeaver in Claude Code, Cursor or VS Code
claude mcp add chainweaver -- uvx chainweaver
What the publisher says
From the ChainWeaver repository's README, as published. We do not edit it. Read it on GitHub
ChainWeaver
<!-- mcp-name: io.github.dgenio/chainweaver -->
Find where your agent no longer needs to reason. Review the evidence. Turn the accepted path into a governed deterministic capability.
Product thesis under validation — observe → prove → review → compile. ChainWeaver can inspect repeated tool behavior, surface candidates, and execute reviewed deterministic paths with typed contracts. Deterministic execution by itself is not the moat: if you already know the exact workflow, a normal Python function, LangGraph node, or provider-native tool may be simpler. The hypothesis being tested is that trace-derived evidence, useful rejection, governed promotion, security-boundary preservation, and drift detection make ChainWeaver worth adopting. See Product validation & adoption gates and #553.
Remove reasoning boundaries, never security boundaries. Compiling several tool calls into one capability must not silently aggregate privileges or erase child approval requirements. That invariant is tracked explicitly in #554.
Governance for deterministic tool paths. Typed I/O at every step, file-serializable flows, schema-drift detection, determinism attestation, property fuzzing, and structured audit traces provide a disciplined execution substrate for paths that have actually earned deterministic promotion.
Benchmarks are evidence about the executor, not proof of product-market fit.
The repo's benchmark report is reproducible —
regenerate it yourself with python benchmarks/report.py — and shows the
deterministic core avoiding model-mediated transitions in its synthetic
comparison. It does not establish that every repeated path should
be compiled, or that ChainWeaver beats the obvious plain-Python implementation.
The independent validation program requires that manual baseline explicitly.
from chainweaver import Tool, Flow, FlowStep, FlowRegistry, FlowExecutor
# (NumberInput, ValueOutput, double_fn defined in full example below)
# 1. Wrap any function as a schema-validated Tool
double = Tool(name="double", description="Doubles a number.",
input_schema=NumberInput, output_schema=ValueOutput, fn=double_fn)
# 2. Wire tools into a Flow
flow = Flow(name="calc", description="Double a number.",
steps=[FlowStep(tool_name="double", input_mapping={"number": "number"})])
# 3. Register and execute — zero LLM calls
registry = FlowRegistry()
registry.register_flow(flow)
executor = FlowExecutor(registry=registry)
executor.register_tool(double)
result = executor.execute_flow("calc", {"number": 5})
# result.final_output → {"number": 5, "value": 10}See the full example below or run python examples/simplelinearflow.py
Shortened. The full README is on GitHub.
Nothing above is checked by us. What we check is on the safety report.
ChainWeaver: common questions
- Is ChainWeaver MCP server safe?
- Yes, by our scan: it is graded A (92/100). Read the ChainWeaver safety report
- How do I install ChainWeaver?
- It runs on your machine. Copy the Claude Code, Cursor, VS Code or Claude Desktop config from the install section.
- Does ChainWeaver need an API key?
- Not as far as the registry entry and our scan can tell: no credentials are declared or required.
- Is ChainWeaver maintained?
- The last commit was 67 days ago (2026-08-30). The latest release is v0.12.1.
- What can I use instead of ChainWeaver?
- Servers from other publishers that do the same job: Ausca MCP server, AKShare MCP server and Claude Prompts MCP server.
- How does ChainWeaver compare with other AI and agents MCP servers?
- safety score 92/100 (higher than 90% of 4,461 AI and agents servers); tools 1 (the typical AI and agents server has 6); tools that change things 0% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.
Alternatives to ChainWeaver
Same job from other publishers: the closest match first, then the best rated.
- AuscaPay-per-call APIs and MCP services for agents, no accounts or keys, with verifiable receipts.not reviewedEstablishedA
- AKShareLet a model explore AKShare's 1000+ China market data functions on its own — search, inspect, callnot reviewedEstablishedA
- Claude PromptsReusable prompt templates, multi-step workflow chains, and quality gates for any MCP client.not reviewedEstablishedA