Goose

Goose is a first-class Observal harness integration. Observal can install Goose custom agents, configure MCP extensions, expose skills, install a Goose hook plugin, and collect Goose session telemetry.

Supported Goose versions: 1.10.0 and later (the release that moved session storage to SQLite), verified against goose 1.45.0. Goose CLI and Goose Desktop share the same configuration, skills, agents, plugins, and session database, so a single install covers both.

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Overview

Goose custom agents are Markdown files with YAML frontmatter. Project agents live in .agents/agents/, user agents in ~/.agents/agents/.

MCP servers are Goose extensions. Goose reads them from a single user-level config.yaml, so Observal merges its extensions into that file and leaves every other key — providers, models, global settings — untouched.

Session telemetry uses a Goose hook plugin. observal doctor patch --harness goose writes ~/.agents/plugins/observal/, containing a plugin.json manifest and a hooks/hooks.json file. The hooks run observal_cli.hooks.session_push --harness goose, which reads Goose's SQLite session store and pushes new records through Observal's shared acknowledged delivery pipeline.

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Supported capabilities

Capability	Support
Agent profiles	Project and user scope
Hook bridge	Goose plugin (hooks/hooks.json)
Hook events	SessionStart, UserPromptSubmit, Stop, SessionEnd
MCP servers	extensions in ~/.config/goose/config.yaml
MCP transports	stdio and streamable_http
Agent prompt	Registry prompts are written into the generated Goose agent file
Skills	.agents/skills/{name}/SKILL.md and ~/.agents/skills/{name}/SKILL.md
Session parsing	SQLite session store mirrored to JSONL
Telemetry	Hook push plus observal reconcile
Model selection	Registry-backed Goose model catalog

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Setup

1. Install the Observal CLI

uv tool install observal-cli
# or: pipx install observal-cli

2. Authenticate

observal auth login

3. Pull an agent into Goose

observal agent pull <agent-name> --harness goose

Goose's default scope is user scope, so the agent is written to ~/.agents/agents/{name}.md. To install into the current project:

observal agent pull <agent-name> --harness goose --scope project

MCP extensions are always written to ~/.config/goose/config.yaml, because that is the only file Goose reads extensions from.

4. Install or refresh the Goose hook plugin

observal doctor patch --harness goose

Restart your Goose session afterwards so the plugin is discovered.

5. Check what is installed

observal scan --harness goose
observal doctor

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Config paths

Purpose	Project scope	User scope
Agent profile	.agents/agents/{name}.md	~/.agents/agents/{name}.md
MCP extensions	—	~/.config/goose/config.yaml
Skill definition	.agents/skills/{name}/SKILL.md	~/.agents/skills/{name}/SKILL.md
Hook plugin	.agents/plugins/observal/	~/.agents/plugins/observal/
Session database	—	~/.local/share/goose/sessions/sessions.db
Observal credentials	~/.observal/config.json	~/.observal/config.json
Observal lockfile	~/.observal/lockfile.json	~/.observal/lockfile.json

User-scope locations follow Goose's own resolution order:

1. $GOOSE_PATH_ROOT when set to an absolute path — config becomes $GOOSE_PATH_ROOT/config, data $GOOSE_PATH_ROOT/data, and skills, agents and plugins move to $GOOSE_PATH_ROOT/.agents/.
2. $XDG_CONFIG_HOME / $XDG_DATA_HOME when set.
3. ~/.config/goose and ~/.local/share/goose.

On Windows, Goose reads %APPDATA%\Block\goose\config\config.yaml and %APPDATA%\Block\goose\data\sessions\sessions.db. Scanning, doctor, and session reading resolve those locations automatically. observal agent pull still writes the documented Unix paths, so Windows users should move the generated config.yaml extensions into the %APPDATA% config by hand.

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Agent profile format

---
name: my-agent
description: Reviews code for correctness and risk
model: gpt-5.5
---

You are a Goose agent with the following specialization...

Only name is required by Goose. model is emitted when the install resolves a model from the Goose model catalog.

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Extension format

Observal writes MCP servers as Goose extensions:

extensions:
  filesystem:
    type: stdio
    name: filesystem
    enabled: true
    cmd: npx
    args: ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"]
    envs: {}
    env_keys: []
    timeout: 300
  remote-tools:
    type: streamable_http
    name: remote-tools
    enabled: true
    uri: https://example.com/mcp
    headers: {}
    envs: {}
    env_keys: []
    timeout: 300

Observal writes MCP servers as stdio or streamable_http extensions and only ever touches the entries it owns. observal scan additionally reports legacy sse extensions. Goose's builtin, platform and frontend extensions run in-process and inline_python carries code rather than a command, so none of them are reported or rewritten.

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Hook plugin spec

~/.agents/plugins/observal/hooks/hooks.json:

{
  "hooks": {
    "SessionStart":     [{ "hooks": [{ "type": "command", "command": "...", "timeout": 30 }] }],
    "UserPromptSubmit": [{ "hooks": [{ "type": "command", "command": "...", "timeout": 30 }] }],
    "Stop":             [{ "hooks": [{ "type": "command", "command": "...", "timeout": 30 }] }],
    "SessionEnd":       [{ "hooks": [{ "type": "command", "command": "...", "timeout": 30 }] }]
  }
}

Rules deliberately omit matcher: Goose treats matcher as a regular expression, so a bare "*" would be invalid and the rule would be skipped.

Goose runs every hook through sh -c on all platforms, passes the event JSON on stdin, waits for the command, and enforces the rule's timeout. The Observal hook therefore only reads Goose's database and appends to the local outbox; the network upload is handed to a detached worker so a slow or unreachable Observal server can never stall a Goose turn.

The hook writes nothing to stdout and never exits 2, so it can never block a PreToolUse tool call or a Stop turn boundary. doctor patch preserves any non-Observal rules you add to the same plugin.

Goose records each discovered plugin under a plugins map in config.yaml keyed by its absolute path, so the plugin activates itself on the next session.

To disable the plugin without removing it, add it to disabledPlugins in ~/.config/goose/settings.json. To remove it entirely:

observal doctor cleanup --harness goose

Hook payload coverage

Verified against goose 1.45.0:

Event	working_dir	Notes
SessionStart	no	Fires once per session
UserPromptSubmit	no	Carries the prompt in message
Stop	yes	Fires at the end of every turn, not the session
SessionEnd	no	Emitted by the goose CLI only

Because most events omit working_dir, Observal reads the session's working directory from sessions.working_dir instead, which keeps agent attribution and layer hashing correct on every event.

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Session push behavior

Goose stores sessions in SQLite rather than JSONL, so the CLI projects each session onto an append-only JSONL mirror at ~/.observal/sessions/goose/<session_id>.jsonl. Everything downstream — the durable outbox, acknowledged delivery, checkpoint recovery, and the final SHA-256 audit — is the shared engine used by every other harness.

1. A hook event resolves the Goose session id from the payload.
2. sessions.db is opened through a file:...?mode=ro URI with a busy timeout, so Observal never writes to, migrates, or checkpoints Goose's database, and never blocks a Goose session that is writing concurrently.
3. Rows newer than the mirror's cursor are appended as JSONL records. The mirror only grows, which keeps previously acknowledged byte offsets valid.
4. The batch is spooled to the local outbox and a detached worker performs the upload, so the hook returns in milliseconds regardless of server health.
5. SessionEnd appends a session_end boundary carrying the session's token and cost totals, then finalizes delivery with an integrity hash.
6. Delegated (subagent) sessions linked by parent_session_id are mirrored and delivered alongside their parent.

Mirror records:

Record	Meaning
{"type": "session", ...}	Session metadata: name, working directory, provider, model, parent session
{"type": "message", ...}	One messages row: role, content blocks, per-message token usage
{"type": "session_end", ...}	Final boundary with accumulated token and cost totals

Goose content blocks are parsed into trace events: text, thinking, redactedThinking, toolRequest, toolResponse (including failures), toolConfirmationRequest, and error.

Backfilling existing sessions

observal reconcile --harness goose
observal reconcile --harness goose --since 720 --dry-run

Reconcile reads the same read-only database, mirrors any session updated within the window, and drains it through the outbox.

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Caveats

The hook plugin is shared per machine. It is installed by doctor patch, not by each agent pull.

MCP extensions are user scope only. Goose reads extensions from one config.yaml, so --scope project still writes extensions to the user config. Agents and skills honour the requested scope. Goose rewrites that same file when it registers plugins, and neither Goose nor Observal preserves YAML comments in it.

Goose Desktop sessions finalize later. Only the goose CLI emits SessionEnd. Desktop sessions are still captured turn by turn through Stop; their final integrity audit runs from background recovery or observal reconcile.

Legacy JSONL sessions are not imported. Goose imports pre-1.10 .jsonl files into sessions.db on upgrade, and Observal reads the database, so those sessions are covered. Leftover .jsonl files on disk are ignored.

Rewritten conversations replay. goose session --resume --edit rewrites a session's messages. The mirror is append-only, so the rewritten history is appended rather than replacing what was already delivered.

Late writes land on the next event. If Goose persists a message after the SessionEnd hook has read the database, that row is delivered by the next hook event or by observal reconcile.