How to Generate an ElevenLabs Voiceover With Codex

To generate an ElevenLabs voiceover with Codex, give the agent final reviewed copy, discover the current text-to-speech model through Aident Loadout, inspect its live voice and pacing controls, preflight the exact request, and generate once after approving the quote. Review the returned audio against the script before it enters a video, podcast, demo, or support workflow.

This guide uses the current Fal-hosted ElevenLabs text-to-speech path in Aident Loadout. The provider model and cost can change, so the live model listing and preflight are part of every run. You do not need to place an ElevenLabs or Fal key in the prompt.

Start With a Voiceover Acceptance Contract

Text-to-speech is easy to call and surprisingly easy to get wrong. A valid audio file can still mispronounce a product name, rush a legal line, flatten an important phrase, or speak a date differently from the approved script.

Define the deliverable before choosing settings:

Keep the script in a reviewed file or manifest. Do not ask the speech model to improve the copy during generation. Copy editing and voice rendering are separate review steps.

Set Up Aident Loadout

Give Codex the canonical setup instruction exactly as written:

Follow https://aident.ai/SETUP.md

Then verify the installed public CLI and Vault state:

aident account auth status
aident vault vault --action status

Ask Codex to discover Actions by job instead of copying an identifier from an old run:

aident capabilities search \
  --targetEnv staging \
  --queries '["list current text-to-speech models","generate one text-to-speech audio asset"]' \
  --types '["action"]'

Use staging for discovery when the installed CLI supports it. Copy the exact names returned by search, then inspect each Action's description, schema, model list, price, and risk before execution. In this guide, the public agent-facing jobs are List Text to Speech Models and Text to Speech. Catalog names and versions can change, so the current result is the source of truth.

Step 1: Inspect the Current ElevenLabs Model

Run the read-only model-listing Action first. On August 11, 2026, the live Aident catalog returned one active text-to-speech model for the ElevenLabs query: ElevenLabs TTS Turbo v2.5 through Fal. The listing described it as the default model, required text, and priced provider usage at $0.05 per 1,000 characters.

The live model contract exposed these useful controls:

• voice, with Rachel as the dated default;

• speed, from 0.7 to 1.2, with 1.0 as the default;

• stability, similarity_boost, and style;

• language_code for an ISO 639-1 language choice;

• timestamps for word timing when supported by the result; and

• apply_text_normalization, with auto, on, and off choices.

ElevenLabs documents Turbo v2.5 as a balanced multilingual model. Its current model guide recommends Flash over Turbo for lower-latency applications, but the live Aident model listing did not expose Flash in this workflow on August 11. Do not substitute an unlisted endpoint. Discover again later and use only a model that the current Action actually supports.

Step 2: Prepare Speech-Ready Copy

Read the final script aloud before sending it to the model. Spoken copy needs different punctuation and rhythm from a web page.

Use short sentences. Expand ambiguous abbreviations. Decide how the voice should say dates, currencies, URLs, version numbers, and product names. For example, 2026-08-11 may need to become August eleventh, twenty twenty-six, and a path such as /SETUP.md may need a plain-language alternative.

For sensitive terms, keep a pronunciation review list beside the script:

{
  "scriptRevision": "voiceover-4-approved",
  "languageCode": "en",
  "voice": "Rachel",
  "speed": 1,
  "mustMatch": ["Aident", "Aident Loadout", "Codex"],
  "maxCredits": 2,
  "reviewer": "content-owner"
}

Do not place private customer data, credentials, unreleased financial information, or a voice-cloning sample in a routine voiceover prompt. This workflow uses a current stock voice. Consent and identity controls for cloning require a separate contract.

Step 3: Choose Conservative Voice Settings

Start near the defaults and change one dimension at a time. ElevenLabs describes lower stability as more expressive but less predictable, while higher stability can become monotonous. Similarity boost increases adherence to the source voice and can also amplify artifacts. Style adds exaggeration and may reduce stability.

For a first product voiceover, use:

{
  "text": "<exact approved script>",
  "voice": "Rachel",
  "speed": 1,
  "stability": 0.5,
  "similarity_boost": 0.75,
  "style": 0,
  "timestamps": true,
  "apply_text_normalization": "auto"
}

These are current defaults and a review starting point, not a universal quality recipe. If the first result fails, name one failed dimension such as pace, expressiveness, or pronunciation and revise only that field or the source text.

Step 4: Preflight the Exact Script

Preflight the final model and payload without dispatching the provider request:

aident capabilities preflight \
  --name "<exact Text to Speech Action from discovery>" \
  --input '{"model":"<model from the live listing>","model_input":{"text":"<exact approved script>","voice":"Rachel","speed":1,"timestamps":true}}'

Confirm that the input is valid, the model is still active, and the estimate is within the manifest ceiling. A 270-character sample preflighted at exactly 1.35 Aident credits on August 11, 2026. Treat that as a dated example, not a reusable price. The reviewed script length and current pricing resolver determine the quote.

Stop if the quote is unavailable, the model is absent, the voice is rejected, a required field changed, or the estimate exceeds the approved ceiling. Do not bypass the integration layer or call Fal or ElevenLabs directly to avoid the boundary.

Step 5: Generate Once and Save the Receipt

Execute only the exact payload that passed preflight, and only after the cost is approved. Ask Codex to return:

• the Action receipt and final credit cost;

• the model and normalized settings used;

• the returned audio asset or download URL;

• duration and format when available; and

• timestamps when requested and returned.

Download the result before any temporary delivery URL expires. Save it under a new revision rather than replacing a previously approved recording. The output is an external write because it creates a new media asset, even when it does not change a repository or SaaS record.

This article did not execute the paid generation. The model listing and 1.35-credit preflight are reproducible, but a human still needs to approve the exact quote before one audio asset is created.

Step 6: Review the Audio Against the Script

Listen from beginning to end while following the approved copy. Check:

1. every word appears once and in order;

2. names, acronyms, numbers, and dates are pronounced correctly;

3. pauses follow the meaning rather than only the punctuation;

4. volume and tone remain consistent;

5. the opening and ending are not clipped;

6. duration fits the target slot; and

7. the saved file matches the reviewed Action receipt.

If timestamps are present, use them to locate a failed phrase. Do not treat timestamps as proof that the phrase sounds right. If a name is wrong, revise the source text or an approved pronunciation control instead of repeatedly changing voice sliders.

Common Failure Modes

The voice sounds natural, but a product name is wrong

Change the speech-ready spelling or pronunciation instruction for that term, then preflight a new revision. Keep the approved written script and the speech-ready rendering linked so reviewers can explain the difference.

The voice is expressive but inconsistent

Raise stability in one controlled step or reduce style. Do not simultaneously change the voice, speed, stability, similarity, and script because you will not know which change fixed the result.

Numbers are spoken unexpectedly

Write the intended spoken form explicitly or review text normalization. The current Action exposes auto, on, and off; ElevenLabs notes that normalization can change latency and model behavior.

The output is too fast for the video

First remove unnecessary copy. If the approved words must remain, reduce speed within the live schema's supported range and preflight again. Do not time-stretch a final voiceover without reviewing pitch and quality.

Codex reports success without a usable file

Require a playable asset or download URL, the Action receipt, and the final cost. A successful request log without reviewed audio is not the deliverable.

Reusable Codex Prompt

Follow https://aident.ai/SETUP.md

Generate one reviewed ElevenLabs voiceover from my approved script.

1. Confirm Aident authentication and Vault status.
2. Discover the current Actions for listing text-to-speech models and generating
   one text-to-speech asset. Use staging for discovery when supported.
3. Inspect both live schemas, prices, and risk. Do not reuse an old Action ID.
4. List current ElevenLabs models and select only an active supported model.
5. Use my exact script revision and acceptance manifest. Do not rewrite it.
6. Preflight the exact model, text, voice, language, and settings. Show me the
   input validation and exact or bounded credit estimate.
7. Wait for approval if the request costs credits.
8. After approval, execute once and return the receipt, normalized settings,
   audio asset or download URL, duration and format when available, timestamps
   when returned, and final cost.
9. Do not clone a voice, expose credentials, publish the audio, retry unchanged
   failed input, or bypass Aident Loadout

Success means one playable audio asset matches the approved script, voice, pace, pronunciation, and cost ceiling, with a complete receipt. Measure first-pass acceptance, pronunciation corrections per minute, revision count, final duration, review time, and credits per approved minute.

For the account, Vault, discovery, and approval sequence, read How to Use Aident Loadout. For spend limits around media generation, use AI Agent Cost Guardrails. If the voiceover belongs in generated video, pair it with How to Generate AI Video With Codex and fal.

Set up Aident Loadout and preflight one reviewed voiceover.

Sources

• ElevenLabs TTS Turbo v2.5 on Fal, official model schema, accessed August 11, 2026

• Text to Speech, official ElevenLabs product guide, accessed August 11, 2026

• ElevenLabs models, official model comparison, accessed August 11, 2026

• Text to Speech with timestamps, official API reference, accessed August 11, 2026

• ElevenLabs text-to-speech skill, official agent workflow reference, accessed August 11, 2026

Refresh this guide when the Aident model list, Fal pricing, ElevenLabs voice controls, output contract, or approval flow changes, or when Search Console reveals a more specific owned query.