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Lifecycle hooks

You can now intercept tool calls at three points during agent execution: before a tool runs (PreToolUse), after it succeeds (PostToolUse), and after it fails (PostToolUseFailure). Each hook receives the tool name and arguments, and can modify, skip, or block the call. This makes it possible to enforce project conventions — like auto-formatting after file writes — or add guardrails without modifying agent prompts.
fabro.toml
[[hooks]]
event = "PostToolUse"
tool = "write"
command = "cargo fmt"

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Server mode for fabro exec

fabro exec can now run as a long-lived server that proxies requests through a /completions endpoint. Instead of running a single agent session and exiting, server mode keeps the agent process alive and accepts Anthropic-style streaming requests over HTTP. This enables integrating Fabro agents into applications that speak the standard completions API. 
fabro exec --server --port 8080

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Auto-PR on workflow completion

Workflows can now automatically open a GitHub pull request when a run completes successfully. Fabro creates the PR from the agent’s working branch with the run summary as the description. No extra scripting or post-run steps needed — just enable the option in your run configuration.
Breaking: CLI commands renamed. fabro run start is now fabro run, and fabro agent is now fabro exec. The old command names no longer work.To migrate, update any scripts or aliases:
  1. Replace fabro run start with fabro run
  2. Replace fabro agent with fabro exec

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More

  • Renamed /runs/{id}/compare to /runs/{id}/files with standard paginated response
  • Added POST /runs/{id}/pause and POST /runs/{id}/unpause endpoints
  • Added POST /completions endpoint with Anthropic-style SSE streaming
  • Removed List Projects and List Branches endpoints
  • Added --goal-file flag to fabro run for reading goal from a file instead of inline text
  • MCP servers can now be configured in TOML via cli.toml instead of JSON
  • verbose = true in cli.toml defaults to verbose output without needing -v
  • goal is now optional in run config TOML — precedence is CLI --goal > TOML goal > DOT graph attribute
  • Configurable git author identity for checkpoint commits via [git.author]
  • Added [log] config section to server.toml and cli.toml for log level and format control
  • Script nodes now execute inside the configured sandbox instead of on the host — fixes issues where agents edited files in the sandbox but lint/test commands ran on the host
  • Asset collection is now opt-in via [assets] config with custom include globs, eliminating ~30s file scans per stage when not needed
  • Workflow runs now fail immediately on git checkpoint commit failure instead of silently continuing
  • GitHub webhook listener via Tailscale funnel — auto-configures webhook URL on startup
  • [sandbox.env] support passes environment variables through to sandbox tool execution
  • Dockerfile path syntax (dockerfile = { path = "..." }) in snapshot config
  • fabro validate and the workflow validator now catch unresolved @file references before execution
  • Fixed @file references with ~ home directory and .. parent directory paths
  • Compaction progress now visible in non-verbose fabro run output
  • Run ID printed at start of fabro run and on resume for cross-referencing
  • Git checkpoint commit skipped for start node to reduce noise
  • Daytona sandboxes now named fabro-{run_id} for easy correlation with workflow runs
  • Logs directory naming changed from fabro-run-YYYYMMDD-HHMMSS to YYYYMMDD-{run_id}
  • Truncated stage failure error display to show only the last line in fabro run output
  • apply_patch error responses now include file contents for better debugging of failed edits
  • v4a patch parser/applier rewritten to match canonical OpenAI codex spec
  • Accept bare @@ hunk headers in v4a apply_patch parser
  • Added Sprites (Fly.io) VM sandbox provider
  • Fixed SSE streaming format mismatch in /completions endpoint
  • Exempted /tmp/ paths from sandbox read-before-write guard
  • Fixed sandbox file-write validation incorrectly blocking valid operations
  • Fixed stall watchdog killing agent during long LLM reasoning turns
  • Added 5-minute stream read timeout with 5-second retry backoff for sandbox connections
  • Increased default stall watchdog timeout from 10 to 30 minutes
  • Fixed subagent and system prompt handling when prompt text is empty
  • Fixed parallel stage compaction bars interfering with each other