> ## Documentation Index
> Fetch the complete documentation index at: https://docs.equa.cc/llms.txt
> Use this file to discover all available pages before exploring further.

# Transcript hygiene

# Transcript Hygiene (Provider Fixups)

This document describes **provider-specific fixes** applied to transcripts before a run
(building model context). These are **in-memory** adjustments used to satisfy strict
provider requirements. They do **not** rewrite the stored JSONL transcript on disk.

Scope includes:

* Tool call id sanitization
* Tool result pairing repair
* Turn validation / ordering
* Thought signature cleanup
* Image payload sanitization

If you need transcript storage details, see:

* [/reference/session-management-compaction](/reference/session-management-compaction)

***

## Where this runs

All transcript hygiene is centralized in the embedded runner:

* Policy selection: `src/agents/transcript-policy.ts`
* Sanitization/repair application: `sanitizeSessionHistory` in `src/agents/pi-embedded-runner/google.ts`

The policy uses `provider`, `modelApi`, and `modelId` to decide what to apply.

***

## Global rule: image sanitization

Image payloads are always sanitized to prevent provider-side rejection due to size
limits (downscale/recompress oversized base64 images).

Implementation:

* `sanitizeSessionMessagesImages` in `src/agents/pi-embedded-helpers/images.ts`
* `sanitizeContentBlocksImages` in `src/agents/tool-images.ts`

***

## Provider matrix (current behavior)

**OpenAI / OpenAI Codex**

* Image sanitization only.
* On model switch into OpenAI Responses/Codex, drop orphaned reasoning signatures (standalone reasoning items without a following content block).
* No tool call id sanitization.
* No tool result pairing repair.
* No turn validation or reordering.
* No synthetic tool results.
* No thought signature stripping.

**Google (Generative AI / Gemini CLI / Antigravity)**

* Tool call id sanitization: strict alphanumeric.
* Tool result pairing repair and synthetic tool results.
* Turn validation (Gemini-style turn alternation).
* Google turn ordering fixup (prepend a tiny user bootstrap if history starts with assistant).
* Antigravity Claude: normalize thinking signatures; drop unsigned thinking blocks.

**Anthropic / Minimax (Anthropic-compatible)**

* Tool result pairing repair and synthetic tool results.
* Turn validation (merge consecutive user turns to satisfy strict alternation).

**Mistral (including model-id based detection)**

* Tool call id sanitization: strict9 (alphanumeric length 9).

**OpenRouter Gemini**

* Thought signature cleanup: strip non-base64 `thought_signature` values (keep base64).

**Everything else**

* Image sanitization only.

***

## Historical behavior (pre-2026.1.22)

Before the 2026.1.22 release, Equabot applied multiple layers of transcript hygiene:

* A **transcript-sanitize extension** ran on every context build and could:
  * Repair tool use/result pairing.
  * Sanitize tool call ids (including a non-strict mode that preserved `_`/`-`).
* The runner also performed provider-specific sanitization, which duplicated work.
* Additional mutations occurred outside the provider policy, including:
  * Stripping `<final>` tags from assistant text before persistence.
  * Dropping empty assistant error turns.
  * Trimming assistant content after tool calls.

This complexity caused cross-provider regressions (notably `openai-responses`
`call_id|fc_id` pairing). The 2026.1.22 cleanup removed the extension, centralized
logic in the runner, and made OpenAI **no-touch** beyond image sanitization.