Context Harness v0.9.0 is out. This release brings the local knowledge index and a durable agent runtime together: your tools can retrieve project context, and Context Harness can now use that context to carry out bounded work itself.

The practical difference is ownership. An external client can still use Context Harness for search and reusable prompt profiles. Or you can ask Context Harness to run the model-and-tool loop, enforce permissions, and retain an inspectable record of what happened.

Agents that work inside your project

Define an agent’s role, model, tools, permissions, and limits in a standalone TOML resource. Run it from the CLI with OpenAI or a local Ollama model, then inspect its model turns, tool calls, approvals, usage, and artifacts.

Tools can be restricted to particular sources and paths. Higher-risk operations can require approval. Static resource validation does not contact providers, resolve secrets, invoke tools, open run databases, or start processes.

Start with a project researcher or code reviewer and a small, read-only tool set. The Build Local Agents guide walks through the setup, and examples/local-agents contains complete starting configurations.

Durable work, explicit limits

Agent execution now includes durable task submission and foreground workers, typed outcomes, cumulative run budgets, structured working state, and explicit continuation of suspended runs. A task that needs input can stop with a recorded reason and continue within the same run when the host supplies that input.

Bounded context projection keeps the model request within configured limits without deleting durable history. Recoverable tool errors can become observations for the next model turn, with safeguards against repeating the same failed call.

Recovery remains conservative: changed definitions, uncertain side effects, or incompatible checkpoints can prevent continuation. This is not a promise to replay every interrupted operation automatically.

An execution foundation for your application

The public Rust APIs let a trusted host register compiled model and tool implementations, assemble an agent host, submit durable tasks, and run workers. Configuration selects registered implementations; it does not dynamically load provider code.

Applications can also refresh specific changed documents through the targeted refresh API, without rediscovering an entire connector source. The host keeps ownership of its events, files, publication rules, and user experience.

See Embed an Agent Host for the public contracts and integration fixture. Context Harness supplies generic execution and retrieval capabilities, not application-specific wiki or hook behavior.

Retrieval and profiles still have their place

This release also adds multi-workspace MCP routing, including bounded fan-out search, and improves natural-language keyword matching. SQLite remains the canonical store; the vector index remains a rebuildable accelerator.

Reusable prompt personas are now presented as profiles, distinct from executable agents. Existing legacy profile aliases remain supported. Use a profile when your editor or chat client owns the conversation; use an agent when Context Harness should own execution.

Download and upgrade

Get the archives and matching SHA256 files from the v0.9.0 release. Downloads cover Linux x86_64, Linux musl, Linux aarch64, Intel macOS, Apple Silicon macOS, and Windows x86_64.

For example, in a fresh directory on Apple Silicon:

curl -fLO https://github.com/parallax-labs/context-harness/releases/download/v0.9.0/ctx-macos-aarch64.tar.gz
curl -fLO https://github.com/parallax-labs/context-harness/releases/download/v0.9.0/ctx-macos-aarch64.tar.gz.sha256
shasum -a 256 -c ctx-macos-aarch64.tar.gz.sha256
tar xzf ctx-macos-aarch64.tar.gz
./ctx --version

Both Rust crates are versioned 0.9.0. To build from a clean source checkout at the release tag, use cargo install --path crates/context-harness --locked --force.

Finish active runs before upgrading. Some tool-binding implementation identities include the Cargo package version. Runs created with an older development build may therefore be refused by checkpoint compatibility checks after the upgrade. Retaining run history does not guarantee cross-version resume compatibility; those safety checks have not been weakened.

Release verification

The release passed main-branch CI and all six platform release builds. All six downloaded archives matched their published SHA256 checksums. The downloaded Apple Silicon binary reported ctx 0.9.0 and successfully displayed --help. The other platform binaries were built in CI but were not executed in this local smoke test.

For the complete change list, see the v0.8.0 to v0.9.0 comparison.

The best first step is small: index one project’s knowledge, configure a read-only agent, and ask one question whose answer you can verify.