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Preview a session's undo

GET
/v1/observe/sessions/{id}/undo_preview
curl --request GET \
  --url http://127.0.0.1:8080/v1/observe/sessions/example/undo_preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Deedglass-Version: 2026-10-01'

Free. Plans the undo of every included transaction, newest first, from the row images Postgres committed, and runs S23’s checks without a lock; it never executes. conflicts counts rows that changed again after the session (any conflict blocks the run). sql is the same plan as SQL you review and run yourself, in one transaction, each statement guarded by the values the session left; refusals say why there is no SQL (a TRUNCATE, images past the cap, sensitive columns, expired frames).

Authorizations

Section titled “Authorizations”

Parameters

Section titled “Parameters”

Path Parameters

Section titled “Path Parameters”
id
required
string

The session (obs_…).

Header Parameters

Section titled “Header Parameters”
Deedglass-Version
string
/^[0-9]{4}-[0-9]{2}-[0-9]{2}$/

The API version (YYYY-MM-DD). Leave it out to use your org’s pinned version (public routes use the latest). An unknown version is 400 api_version_invalid.

Query Parameters

Section titled “Query Parameters”
allow_triggers
boolean

Let triggers fire again (the triggers check is then a warning).

steps_limit
integer
>= 1 <= 1000

Steps to list

Responses

Section titled “Responses”

200

Section titled “200”

The preview.

Media typeapplication/json
object
object
required
string
Allowed value: observe_undo_preview
session
required
string
available
required
boolean
summary
required
string
headline
required
string
plan_digest
required
string | null
connector
required
object | null
counts
required
object
rows
required
integer
tables
required
Array<string>
steps
required
object
checks
required
Array<object>
object
conflicts
required

Rows that changed again after the session.

integer
excluded
required
Array<string>
notes
required
Array<string>
redacted
required
Array<string>
sql
required

The undo SQL to review and run yourself (free).

string | null
refusals
required
Array<string>
pro
required

Whether this server may run the undo in one step.

boolean
free_path
required
string
observed
required
string
Example
{
  "object": "observe_undo_preview"
}

Headers

Section titled “Headers”
Deedglass-Request-Id
string
/^req_[0-7][0-9a-hjkmnp-tv-z]{25}$/

This request’s id. Quote it to support; it matches error.request_id.

Deedglass-Version
string

The API version this response follows.

default

Section titled “default”

An error. Every error has this envelope; doc_url explains the code.

Media typeapplication/json
object
error
required
object
type
required
string
Allowed values: invalid_request_error authentication_error permission_error policy_error rate_limit_error api_error
code
required
string
Allowed values: invalid_api_key api_key_revoked api_key_expired agent_suspended agent_stopped org_stopped insufficient_scope policy_denied approval_required approval_expired budget_exceeded intent_required intent_invalid intent_replay tool_unknown connector_unavailable upstream_error timeout rate_limited idempotency_conflict validation_failed not_found conflict internal_error authentication_required method_not_allowed request_too_large unsupported_media_type invalid_json api_version_invalid idempotency_key_invalid idempotency_key_in_use service_unavailable session_expired csrf_failed insufficient_role login_link_invalid login_code_invalid last_owner policy_unavailable policy_invalid credentials_missing destination_blocked vault_unavailable upstream_auth_failed upstream_not_found upstream_rate_limited response_too_large statement_refused row_limit_exceeded database_role_unsafe database_not_ready witness_not_configured approval_decided already_countersigned approver_not_eligible self_approval approval_needs_person context_changed approval_unsatisfiable approval_link_invalid approval_link_review_only approver_unmapped stripe_live_key_refused stripe_livemode_detected upstream_approval_pending schedule_needs_approval action_executing from_denied undo_unavailable undo_plan_stale already_undone undo_conflict replay_too_large replay_window_invalid suggestion_stale shadow_slot_taken suggestion_decided observe_not_enabled pro_required
message
required

One or more calm sentences with the next step.

string
param
required

The request field, query parameter or header the error is about.

string | null
request_id
required
string
/^req_[0-7][0-9a-hjkmnp-tv-z]{25}$/
doc_url
required
string format: uri
diagnostics

On policy_invalid only. Each problem with its line, code and hint.

Array<object>

One finding about a policy file, with its position and the next step. Codes are stable and listed in docs/POLICY_ERRORS.md. In the policy_invalid error envelope each diagnostic also carries object: policy_diagnostic. The full PolicyDiagnostic schema is in openapi.yaml.

object
action

One agent action. Its sections mirror the deed’s. status is the one field an agent needs; state is the exact lifecycle state (docs/GATE.md). The Gate’s own responses (POST /v1/actions and its result report) add execution.result and witness.reasons; lists leave both out. The full Action schema is in openapi.yaml.

object
checks

On undo_unavailable only. Every check of the undo, each with its fix. Additive (S23).

Array<object>

One of the twelve safety checks (S23 §3.3). Available means no check failed. The full UndoCheck schema is in openapi.yaml.

object
Example
{
  "error": {
    "type": "invalid_request_error",
    "code": "not_found",
    "message": "There's no endpoint at GET /v1/helth. Did you mean /v1/health?",
    "param": null,
    "request_id": "req_01j9zr3m5k8q2w7x4t6v0b1c9d",
    "doc_url": "https://docs.deedglass.com/errors/not_found"
  }
}

Headers

Section titled “Headers”
Deedglass-Request-Id
string
/^req_[0-7][0-9a-hjkmnp-tv-z]{25}$/

This request’s id. Quote it to support; it matches error.request_id.

Deedglass-Version
string

The API version this response follows.