OpenAI Completions → Responses Migration Pack

Developer toolkit to migrate applications from the legacy OpenAI Completions/Chat Completions APIs to the unified Responses API, guided by the Codex CLI (local coding agent).

What this does

• Detects legacy Completions usage across your repo
• Proposes and applies edits to adopt the Responses API
• Updates imports/initialization and request/response shapes
• Runs tests/lints (when present) and summarizes results
• Creates a clean git branch and optional PR

Why migrate now

• Responses is the consolidated path forward for text, tools, and streaming. Completions/Chat Completions are legacy. See the official guide: Migrate to Responses.
• GPT‑5 works best on Responses. Migrating unlocks better reasoning and modern features (tool calling, steerability, metaprompting) with lower latency and cost. GPT‑5 orchestrates tools as part of its reasoning; legacy endpoints don’t preserve this structure and can cause repeated tool calls and degraded behavior.

Key Responses benefits vs Chat Completions:

• Stateful conversations: optionally use store: true and previous_response_id to maintain context without resending the full history.
• Encrypted reasoning: keep apps stateless while benefiting from reasoning items.
• Built‑in tools: add web_search_preview, file_search, or custom functions directly.
• Flexible inputs: send a single string input or an items array; use instructions for system‑level guidance.
• Better reasoning and lower costs: improved reasoning quality and cache utilization when compared to Chat Completions.
• Event‑driven model: Responses emits semantic events (e.g., specific text deltas) instead of mutating a single content string—simplifying multi‑step logic and improving type‑safety.

Requirements

• macOS or Linux (Windows via WSL2)
• OpenAI API access (or codex login interactive flow)

Demo Video

responses-upgrader-demo.mp4

Quick start

GitHub‑only one‑liner (main):

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/openai/completions-responses-migration-pack/main/scripts/completions-to-responses-upgrade.sh)"

Interactive run (prompts for repo and model policy):

bash scripts/completions-to-responses-upgrade.sh

Non‑interactive (write mode by default):

bash scripts/completions-to-responses-upgrade.sh --repo /path/to/repo --no-interactive

Dry‑run (no edits, prints a unified diff plan):

bash scripts/completions-to-responses-upgrade.sh --repo /path/to/repo --no-interactive --dry-run

Full‑auto (no approvals, write‑enabled sandbox):

bash scripts/completions-to-responses-upgrade.sh --repo /path/to/repo --no-interactive --full-auto

Approval policy examples:

# Ask for approval heuristically
bash scripts/completions-to-responses-upgrade.sh --repo /path/to/repo -a on-request

# Headless CI style (ask only on failure)
bash scripts/completions-to-responses-upgrade.sh --repo /path/to/repo --no-interactive -a on-failure

Model selection (prompted interactively; default is GPT‑5):

• If you choose GPT‑5, the tool enforces the runtime rule that temperature is omitted or set to 1 to avoid errors.

State & retention policy:

• The migration always sets store: false on Responses requests, avoids using previous message IDs or server‑stored context, and keeps conversation state local with minimal logged metadata.

Flags

• -r, --repo <path>: target git repo
• -m, --model <name>: model override (default: gpt‑5)
• --full-auto: automation shortcut (workspace write + on‑failure approvals)
• -n, --dry-run: plan only; do not write
• -a, --approval <policy>: untrusted | on-failure | on-request | never
• --write: alias to disable dry‑run
• --no-interactive: no prompts (requires --repo)
• --open-pr: open PR via GitHub CLI if available
• --dangerous: bypass approvals and sandbox (not recommended)

What gets changed

• Endpoint /v1/completions → /v1/responses
• prompt → input; max_tokens → max_output_tokens
• Node/Python: switch to OpenAI client + client.responses.create(...)
• Streaming preserved only where originally used
• Tools/function‑calling migrated to tools with JSON Schema and tool_choice
• Multi‑turn: callers updated to pass prior turns explicitly as input items

How it works

1. Ensures Codex CLI is installed and authenticated
2. Creates branch migrate/openai-responses-<timestamp>
3. Drops a small docs pack and sets AGENTS.md guidance
4. Runs Codex in automation mode with a structured prompt
5. Shows a final summary; optionally opens a PR

Troubleshooting

• “unexpected argument” errors: ensure the Codex CLI is up to date
• Sandbox write issues: use --full-auto or -a on-request interactively
• Diffs but no writes: apply with codex apply <TASK_ID> (printed at run end)
• Test runner failures from other ecosystems (Go/Maven/Ruby) are ignored unless they belong to your app; the agent focuses on your repo

Security & data handling

• No API keys written to disk; honors environment configuration
• Unified policy: store:false by default, no previous message IDs, client‑managed state only; always include encrypted reasoning tokens.

License & version

• MIT. See LICENSE
• Current version: see assets/VERSION

Contributing

• See CONTRIBUTING.md for guidelines on issues and pull requests

Version‑pinned (recommended for CI):

TAG=v0.1.0
curl -fsSL -o upgrade.sh \
  https://raw.githubusercontent.com/openai/completions-responses-migration-pack/${TAG}/scripts/completions-to-responses-upgrade.sh
# Verify integrity (replace HASH with the expected value from assets/SHA256SUMS for the same tag)
shasum -a 256 upgrade.sh | grep HASH
bash upgrade.sh

Alternate version‑pinned using a specific commit:

COMMIT=<commit_sha>
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/openai/completions-responses-migration-pack/${COMMIT}/scripts/completions-to-responses-upgrade.sh)"

Integrity data:

# Fetch checksums for a tag
curl -fsSL -o SHA256SUMS \
  https://raw.githubusercontent.com/openai/completions-responses-migration-pack/${TAG}/assets/SHA256SUMS
shasum -a 256 upgrade.sh | grep "$(awk '{print $1}' SHA256SUMS)"

Optional GitHub Release asset approach:

TAG=v0.1.0
curl -fsSL -o upgrade.sh \
  https://github.com/openai/completions-responses-migration-pack/releases/download/${TAG}/completions-to-responses-upgrade.sh
curl -fsSL -o SHA256SUMS \
  https://github.com/openai/completions-responses-migration-pack/releases/download/${TAG}/SHA256SUMS
shasum -a 256 upgrade.sh | grep "$(awk '{print $1}' SHA256SUMS)"
bash upgrade.sh

Release steps (maintainers):

# Update version
sed -i.bak 's/^v.*/v0.1.0/' assets/VERSION && rm -f assets/VERSION.bak

# Commit & tag
git add -A && git commit -m "chore: release v0.1.0" && git tag v0.1.0 && git push && git push --tags

# (Optional) Create GitHub Release with assets
gh release create v0.1.0 \
  scripts/completions-to-responses-upgrade.sh \
  assets/SHA256SUMS \
  --title "v0.1.0" --notes "Initial release"