manage-openapi-overlays
Overlays let you customize an OpenAPI spec for SDK generation without modifying the source. This skill covers creating overlay files, applying them to specs, and using them to fix validation errors.
Content Guides
| Topic | Guide |
|---|
| OpenAPI Validation | content/validation.md |
| Security Schemes | content/security-schemes.md |
These guides cover validating specs, fixing common issues, and configuring authentication methods.
Authentication
When to Use
Use this skill when you need to manually work with overlay files:
- Creating an overlay file from scratch with specific JSONPath targets
- Applying an existing overlay file to a spec
- Validating overlay syntax and structure
- Comparing two specs to generate an overlay
- Understanding overlay mechanics (actions, targets, update/remove)
- Fixing lint issues via manual overlay creation
- User says: "create overlay", "apply overlay", "overlay file", "manual overlay", "overlay syntax", "JSONPath targeting", "validate overlay"
NOT for: AI-powered naming suggestions (see
instead)
Inputs
| Input | Required | Description |
|---|
| Target spec | Yes | OpenAPI spec to customize or fix |
| Customizations | Depends | Changes to apply (groups, names, retries, descriptions) |
| Overlay file | Depends | Existing overlay to apply (for apply workflow) |
| Lint output | Helpful | Validation errors to fix (for fix workflow) |
Outputs
| Output | Description |
|---|
| Overlay file | YAML file with JSONPath-targeted changes |
| Modified spec | Transformed OpenAPI spec (when applying) |
Commands
Generate an Overlay by Comparing Specs
bash
speakeasy overlay compare -b <before-spec> -a <after-spec> -o <output-overlay>
Use this when you have a modified version of a spec and want to capture the differences as a reusable overlay.
Apply an Overlay to a Spec
bash
speakeasy overlay apply -s <spec-path> -o <overlay-path> --out <output-path>
Validate an Overlay
bash
speakeasy overlay validate -o <overlay-path>
Creating an Overlay Manually
Create an overlay file with this structure:
yaml
overlay: 1.0.0
info:
title: My Overlay
version: 1.0.0
actions:
- target: "$.paths['/example'].get"
update:
x-speakeasy-group: example
x-speakeasy-name-override: getExample
Each action has a
(JSONPath expression) and an
(object to merge) or
(boolean to delete the target).
Example: SDK Method Naming and Grouping
yaml
overlay: 1.0.0
info:
title: SDK Customizations
version: 1.0.0
actions:
- target: "$.paths['/users'].get"
update:
x-speakeasy-group: users
x-speakeasy-name-override: list
- target: "$.paths['/users'].post"
update:
x-speakeasy-group: users
x-speakeasy-name-override: create
- target: "$.paths['/users/{id}'].get"
update:
x-speakeasy-group: users
x-speakeasy-name-override: get
- target: "$.paths['/users/{id}'].delete"
update:
x-speakeasy-group: users
x-speakeasy-name-override: delete
deprecated: true
This produces SDK methods:
,
,
,
.
Example: Apply Overlay
bash
# Apply overlay and write merged spec
speakeasy overlay apply -s openapi.yaml -o sdk-overlay.yaml --out openapi-modified.yaml
# Compare two specs to generate an overlay
speakeasy overlay compare -b original.yaml -a modified.yaml -o changes-overlay.yaml
Using in Workflow (Recommended)
Instead of applying overlays manually, add them to
:
yaml
sources:
my-api:
inputs:
- location: ./openapi.yaml
overlays:
- location: ./naming-overlay.yaml
- location: ./grouping-overlay.yaml
Overlays are applied in order. Later overlays can override earlier ones. This approach ensures overlays are always applied during
.
Common Fix Patterns
Use overlays to fix validation issues when you cannot edit the source spec.
| Issue | Overlay Fix |
|---|
| Poor operation names | Add x-speakeasy-name-override
to the operation |
| Missing descriptions | Add or to the operation |
| Missing tags | Add array to the operation |
| Need operation grouping | Add to operations |
| Need retry config | Add to operations or globally |
| Deprecate an endpoint | Add to the operation |
| Add SDK-specific metadata | Add any extension |
Fix Workflow
bash
# 1. Validate the spec to identify issues
speakeasy lint openapi --non-interactive -s openapi.yaml
# 2. Create an overlay file targeting each issue (see patterns above)
# 3. Add overlay to workflow.yaml under sources.overlays
# 4. Regenerate the SDK
speakeasy run --output console
Speakeasy Extensions Reference
Extensions (
) customize SDK generation. Apply them via overlays.
| Extension | Applies To | Purpose |
|---|
| Operation or root | Configure retry behavior |
| Operation | Enable automatic pagination |
x-speakeasy-name-override
| Operation | Override SDK method name |
| Operation | Group methods under namespace |
x-speakeasy-unknown-values
| Schema with enum | Allow unknown enum values |
| Root | Define SDK-wide parameters |
x-speakeasy-custom-security-scheme
| Security scheme | Multi-part custom auth |
Retries
yaml
actions:
- target: "$.paths['/resources'].get" # Or "$" for global
update:
x-speakeasy-retries:
strategy: backoff
backoff:
initialInterval: 500 # ms
maxInterval: 60000 # ms
maxElapsedTime: 3600000 # ms
exponent: 1.5
statusCodes: ["5XX", "429"]
retryConnectionErrors: true
Pagination
Offset/Limit:
yaml
actions:
- target: "$.paths['/users'].get"
update:
x-speakeasy-pagination:
type: offsetLimit
inputs:
- name: offset
in: parameters
type: offset
- name: limit
in: parameters
type: limit
outputs:
results: $.data
numPages: $.meta.total_pages
Cursor:
yaml
actions:
- target: "$.paths['/events'].get"
update:
x-speakeasy-pagination:
type: cursor
inputs:
- name: cursor
in: parameters
type: cursor
outputs:
results: $.events
nextCursor: $.next_cursor
Open Enums (Anti-Fragility)
Prevent SDK breakage when APIs return new enum values:
yaml
actions:
- target: "$.components.schemas.Status"
update:
x-speakeasy-unknown-values: allow
For all enums (add
x-speakeasy-jsonpath: rfc9535
at overlay root):
yaml
actions:
- target: $..[?length(@.enum) > 1]
update:
x-speakeasy-unknown-values: allow
Global Headers
Add SDK-wide headers as constructor options:
yaml
actions:
- target: $
update:
x-speakeasy-globals:
parameters:
- $ref: "#/components/parameters/TenantId"
- target: $.components
update:
parameters:
TenantId:
name: X-Tenant-Id
in: header
schema:
type: string
Result:
client = SDK(api_key="...", tenant_id="tenant-123")
Custom Security Schemes
For complex auth (HMAC, multi-part credentials):
yaml
actions:
- target: $.components
update:
securitySchemes:
hmacAuth:
type: http
scheme: custom
x-speakeasy-custom-security-scheme:
schema:
type: object
properties:
keyId:
type: string
keySecret:
type: string
- target: $
update:
security:
- hmacAuth: []
With
in gen.yaml, generates env var support for
,
.
JSONPath Targeting Reference
| Target | Selects |
|---|
| GET /users operation |
| All operations on /users/{id} |
$.paths['/users'].get.parameters[0]
| First parameter of GET /users |
$.components.schemas.User
| User schema definition |
$.components.schemas.User.properties.name
| Name property of User schema |
| API info object |
| API title |
| First server entry |
What NOT to Do
- Do NOT use overlays for invalid YAML/JSON syntax errors -- fix the source file
- Do NOT try to fix broken paths with overlays -- fix the source spec
- Do NOT use overlays to fix wrong data types -- this is an API design issue
- Do NOT try to deduplicate schemas with overlays -- requires structural analysis
- Do NOT ignore errors that require source spec fixes -- overlays cannot solve everything
- Do NOT modify source OpenAPI specs directly if they are externally managed
- Do NOT use a command -- it does not exist
Troubleshooting
| Error | Cause | Solution |
|---|
| "target not found" | JSONPath does not match spec structure | Verify exact path and casing by inspecting the spec |
| Changes not applied | Overlay not in workflow | Add overlay to in |
| "invalid overlay" | Malformed YAML | Check overlay structure: needs , , |
| YAML parse error | Invalid overlay syntax | Check YAML indentation and quoting |
| No changes visible | Wrong target path | Use with exact casing |
| Errors persist after overlay | Issue not overlay-appropriate | Check if the issue requires a source spec fix instead |
| Overlay order conflict | Later overlay overrides earlier | Reorder overlays in or merge into one file |