placebo
Make boto3 calls that look real but have no effect
Decision gist · record as of 2026-08-14
No. The package is abandoned (last commit 2021-09-28) with no maintenance or compatibility updates. While it works for basic mocking, you risk incompatibility with newer versions and lack of support for bugs or edge cases. Actively maintained alternatives exist for this use case.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires a boto3 Session object to attach to; placebo itself has no runtime dependencies but is tightly coupled to the botocore event system.
- Install friction is high due to source-only distribution.
- The package is abandoned—last commit was 2021-09-28, over 1781 days ago—so expect no maintenance, bug fixes, or compatibility updates.
License · maintenance · safety
Apache License 2.0 (permissive) — Licensed under Apache License 2.0 (permissive), so you can use it freely in commercial and open-source projects without restriction, though you must include a copy of the license.
last release 2021-09-28 (1781 days) · last repo commit 2021-09-28 · 393 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 227,507 downloads/mo, #9,176 on PyPI
Alternatives
Verify before relying
import placebo
session = boto3.Session()
pill = placebo.attach(session, data_path='/path/to/responses')
pill.record()
# Make calls; responses are recorded
# Later, to replay:
pill.playback()
# Calls return recorded responses- Whether placebo remains compatible with current boto3 versions given its abandoned status since 2021.
- Whether the package works with Python versions beyond 3.9 (classifiers list up to 3.9 only).
- Performance or behavioral differences when using pickle vs. JSON response format in large test suites.
What it is and what it does
Placebo is a mocking library that intercepts AWS API calls and replays recorded responses instead of hitting real endpoints. It works by attaching to a Session and using the event system to capture and store responses as JSON or pickle files, then replay them deterministically during test runs. This lets you write integration-style tests without incurring API costs or network latency, and without manually constructing mock responses.
The library supports recording all services or filtering by service and operation name, manual response injection, and a decorator-based test interface with environment variables for record/playback mode selection. It has no runtime dependencies, making it lightweight to add to existing projects.
Use it for
- Unit testing code that calls AWS services without making real API calls or incurring costs.
- Recording API interactions once in development, then replaying them consistently in CI/CD pipelines.
- Building deterministic test suites where response order and timing are predictable and reproducible.
- Mocking complex responses with nested structures that would be tedious to construct manually in test code.
- Testing legacy code that uses the default session without refactoring it to accept an injected session object.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
No.
The package is abandoned (last commit 2021-09-28) with no maintenance or compatibility updates. While it works for basic mocking, you risk incompatibility with newer versions and lack of support for bugs or edge cases. Actively maintained alternatives exist for this use case.
Install
placebo on PyPI
Before you install
Install friction is high due to source-only distribution. The package is abandoned—last commit was 2021-09-28, over 1781 days ago—so expect no maintenance, bug fixes, or compatibility updates.
Requires a boto3 Session object to attach to; placebo itself has no runtime dependencies but is tightly coupled to the botocore event system.
License in practice
Licensed under Apache License 2.0 (permissive), so you can use it freely in commercial and open-source projects without restriction, though you must include a copy of the license.
Quickstart
import placebo
session = boto3.Session()
pill = placebo.attach(session, data_path='/path/to/responses')
pill.record()
# Make calls; responses are recorded
# Later, to replay:
pill.playback()
# Calls return recorded responsesVerify before relying
- Whether placebo remains compatible with current boto3 versions given its abandoned status since 2021.
- Whether the package works with Python versions beyond 3.9 (classifiers list up to 3.9 only).
- Performance or behavioral differences when using pickle vs. JSON response format in large test suites.
Package facts
| License | Apache License 2.0 permissive |
| Python support | Not specified |
| Install friction | High. Source build required |
| Runtime dependencies | None |
| Maintenance | Abandoned 1,781 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 227,507 / month, #9,176 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 3 - AlphaIntended Audience :: DevelopersIntended Audience :: System AdministratorsLicense :: OSI Approved :: Apache Software LicenseNatural Language :: EnglishProgramming Language :: Python :: 3Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9 |
Evidence: placebo-0.10.0.tar.gz
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