About AsDecided
AsDecided is an MCP server that gives agents read-only access to engineering decisions stored as typed Markdown in a repository. A native Rust engine validates the content and retrieves decisions deterministically, with no embeddings, model calls or hosted index. The same repository state always yields the same answer.
Key features
- 01Read-only access to repository decisions
- 02Validation of typed Markdown knowledge
- 03Deterministic retrieval without embeddings or model calls
- 04Installation via Homebrew, Cargo or Scoop
Use cases
- 01Having coding agents follow recorded engineering decisions
- 02Validating decision files and checking code changes in CI
MCP support
This project is an MCP server that provides repository decision content to MCP clients in read-only form.
Configuration
Local server config is the same for every client. Copy it into your client’s MCP config file.
docker run -i --rm ghcr.io/asdecided/core:mcp-v0.31.2Local servers need a runtime on your machine (e.g. Node.js 18+). Config file locations differ by client; see your client’s docs.
ghcr.io/asdecided/core:mcp-v0.31.2stdioTools
Local servers expose tools only once running on your machine, and the maintainer has not provided a tool list.
Details
From the project READMEAsDecided
Engineering decisions your agents can follow. Build, as decided.
AsDecided keeps requirements, decisions, designs, roadmaps, and prompts as typed Markdown in your repository. Its native Rust engine validates that knowledge, retrieves relevant decisions deterministically, and serves it read-only to agents over MCP.
No embeddings, model call, hosted index, or Python runtime is required. The same repository state produces the same answer.
Product site · Documentation · Canonical sources · Changelog
Install
Install the native engine and MCP server through Homebrew:
brew install asdecided/tap/asdecided-core
Rust users can install the decided CLI directly from crates.io:
cargo install decided
cargo install decided-mcp
cargo install compiles from source. To install the prebuilt release binaries
instead, use cargo binstall.
Crates published after v0.31.0 point it at the GitHub release archives:
cargo binstall decided decided-mcp
Windows users can install both native executables through Scoop:
scoop bucket add asdecided https://github.com/asdecided/scoop-bucket
scoop install asdecided
Native decided and decided-mcp archives are also published on
GitHub Releases.
The Linux archives (x86_64 and aarch64) need glibc 2.17 or newer, so they run
on RHEL/CentOS 7 and later, Amazon Linux 2 and 2023, and current Debian and
Ubuntu releases.
Python API consumers should use the
asdecided/sdk client SDK. It talks to the
native engine; this repository does not ship a second Python engine or a PyPI
package.
Start a repository
decided quickstart
decided validate decisions/
decided gate decisions/
decided gate decisions/ --code --base origin/main
New repositories use:
.decided/config.yaml
decisions/
Existing artifact IDs such as RAC-ABC123DEF456 are durable identities and do
not change with the product name.
Federate corpora
Manifest version 2 composes several pinned, materialised parent corpora into one source-aware DAG while preserving every source, diamond route, override, and read-only boundary:
decided corpus status decisions/
decided corpus explain organization/standards::ADR-01K000000001 decisions/
Federation is fully offline and forge-neutral: the engine consumes verified working-tree bytes, not GitHub APIs or a hosted index. See the federation guide and runnable multi-parent example.
Migrate an existing repository
Migration is explicit and never runs during an ordinary command:
decided migrate layout . --dry-run
decided migrate layout .
The migration moves .rac/ to .decided/ and rac/ to decisions/. It
refuses to overwrite either destination.
MCP
The official MCP Registry identity is io.github.asdecided/core.
Its Registry package is the versioned local MCP image under
ghcr.io/asdecided/core; Homebrew and Cargo remain direct native installation
paths for the same Rust server.
The OCI server still needs an explicit repository grant:
docker run --rm -i -v "$PWD:/work:ro" \
ghcr.io/asdecided/core:mcp-latest --root /work
{
"mcpServers": {
"asdecided": {
"command": "decided-mcp",
"args": ["--root", "."]
}
}
}
Architecture
Rust is the product engine and the only CLI/MCP runtime in this repository.
The authoritative language-neutral compatibility fixtures live in
asdecided-spec. Live-corpus validation is
based on validity, determinism, freshness, and cache/no-cache equality.
Document ingestion remains an ancillary Python connector rather than part of
the core engine. The retired Python engine is preserved for historical review
at the immutable
python-engine-final
tag; it is not maintained or run in normal CI.
License
Apache-2.0. See LICENSE and NOTICE.
Governance and continuity
AsDecided core is solo-maintained and supported on a best-effort basis. The project does not depend on a hosted service: adopters keep their Markdown corpus in their own git repository, while the Apache-2.0 implementation and language-neutral specification remain public. See GOVERNANCE.md for the maintainer, release, support, and continuity posture.
Comments
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